Huberman Lab - GUEST SERIES | Dr. Andy Galpin: How to Build Physical Endurance & Lose Fat

Welcome to the Huberman Lab guest series,

where I and an expert guest discuss science

and science-based tools for everyday life.

I’m Andrew Huberman,

and I’m a professor of neurobiology and ophthalmology

at Stanford School of Medicine.

Today’s episode is the third in the six episode series

on fitness, exercise, and performance.

Today’s episode is all about endurance and fat loss.

That is the specific protocols required

to achieve the four different kinds of endurance

and how to maximize fat loss.

Dr. Andy Galpin, great to be back.

Today, we’re gonna talk about endurance,

and I’m very interested in this conversation

because I, like many other people,

strive to get a certain amount

of cardiovascular work in each week,

maybe a longish jog, maybe a swim, ride the bike, et cetera.

But when I think about the word endurance,

the idea that almost immediately comes to mind

is about doing something for a long period of time,

repeatedly, but I have a feeling that there are other ways

to trigger this adaptation

that we call the endurance adaptation.

So I’m excited to learn about that.

I’m also excited to learn about the fuel systems

in the body that allow for endurance

and other modes of repeated activity.

So in order to kick things off,

I’d love for you to frame the conversation

by telling us what is endurance

and are there indeed a large variety of ways

to induce what we call this endurance adaptation?

Sure, the way I wanna start actually here

is calling back to some of the things we talked about

in our previous conversations,

which are really, people exercise for three reasons.

Number one, you wanna feel better.

Number two, you wanna look a certain way.

And then number three,

you wanna be able to do that for a long time, right?

So you need to, the way that we say it in sports

is look good, feel good, play good, right?

So I want some sort of functionality

to be able to perform a certain way,

whatever that is for you.

You wanna be able to look a certain way that,

whatever that matters for you,

and then you wanna be able to do that for a long time.

So when it comes to endurance,

we have a bunch of misnomers here,

which is the same thing with the strength training

or resistance exercise side,

where we wanted to dispel this myth that

I lift weights only because I wanna gain muscle

or play a sport.

And I wanna do cardio because I wanna either lose fat

or for long health sake.

And just like we smashed that myth

from the strength training side,

I wanna smash it from the endurance training side.

There are so many other reasons

that you wanna perform endurance training,

regardless of your goal, right?

Whether it is longevity, whether it is performance,

or whether it is aesthetics.

And so I wanna cover all those reasons,

exactly what to do, protocols of course,

and why those things are working that way.

In general though, the quick answer

is really endurance comes down to two independent factors.

Factor number one is fatigue management,

and then factor number two is fueling.

And that’s all it really comes down to.

So all the different types of training

are going to reach a limitation,

which are either again,

your ability to deal with some sort of fatigue,

and that’s generally a fatigue signal.

The other one is managing some sort of restriction

of energy input.

And a lot of the, the spoiler here is,

a lot of the times people think it’s a fueling issue

when really it’s a fatigue management issue,

or the opposite.

And to have a complete health spectrum,

regardless of whether you’re a high performance athlete,

like I typically deal with, or general public,

you need to be able to do both,

manage fatigue as well as understand fuel storage.

So that’s really what we’re going to get into today.

Fantastic, I can’t wait.

Before we dive in, I’m going to ask you

what I often ask people who are expert

in their respective fields,

which is, is there any non-obvious tool or mechanism

or tool and mechanism that can allow people

to access better endurance?

You know, when I think about training for endurance,

again, I think about trying to run longer

and longer each week or swim further and further and so on.

But I do wonder whether or not there are other forms

of training that can amplify the endurance adaptation

that I or most people perhaps don’t think of as endurance.

Sure, the way I want to answer this is,

if we look back and think about how we’ve answered

that question with power and strength and force production,

it is really about how much can you produce maximally once.

What you’re asking now is how can I repeat

that same quality of performance?

If that’s the case, endurance really comes down

to your ability to maintain proper mechanics.

That’s going to, like the biggest way

we can increase your endurance exponentially

very quickly is mechanical.

And this is starting with breathing.

And so we need to be breathing properly.

We need to have proper posture and positions,

and then we need to be moving well.

Efficiency is going to trump force always for endurance.

The other side of the equation is not that.

You can have a little bit of leaks in your mechanics

and still squat well or jump high and be fine

because you don’t have to suffer

those consequences repeatedly, right?

That’s going to drain you over time.

So the quickest way to improve endurance

is to improve mechanics.

And the mechanical thing I would go after first

is your breathing techniques, your pattern,

your entire approach, as well as your posture.

And then from there,

the third one would be your movement technique.

Is it possible to describe the best way to breathe

when doing endurance training,

or is it far more complex than that?

And if it is far more complex than that,

then certainly we can get into it during today’s episode.

Yeah, it is both of those.

I will give you a quick answer though.

A lot of the times you can kind of hit the cheat code,

which is nasal breathing.

There’s plenty of times when you don’t want

to nasal breathe or don’t need to nasal breathe,

but just, again, as like a one tool

that is a pretty general answer,

if you can do that,

a lot of the times that will fix breathing mechanics

just by default.

And we can maybe talk about why that is later,

but that would be my sort of one sentence

bullet point answer immediately

of how to get in the right position.

So second one would be simply looking at your posture,


So whether you’re on a bike or you’re doing a lift

or you’re running,

if you’re literally hunched over

and your ribs are touching your femur

and we’re getting closer and closer,

like tends to happen on a bike or an air assault thing

for somebody I’ve seen recently.

This morning I was on the assault bike doing a sprint

and I asked Andy, Dr. Galpin,

to critique my form and anything else he wanted to critique

so that I could improve.

And he did comment on my rather C-shaped posture.


Encouraged me to be more upright,

which I should probably do now as well.

And he also cued me to the fact

that during a one minute sprint,

there is something that is quote unquote magic

that happens right about the 40 second mark.

And I use that as a milestone to look for

and indeed something does happen at the 40 seconds

into a one minute sprint where all of a sudden

it does seem to get much easier

for reasons I don’t understand.

Maybe you can tell me that,

but it certainly had nothing to do with my posture.

My posture needs improvement.

Thank you.

Yeah, well, yeah.

So breathing mechanics and breathing strategies.

People tend to be over-breathing early on

and this is going to lead to problems later.

So having a more strategic breathing pattern

and approach is again, a very quick solution.

I know that we’re going to dive very deep

into the mechanisms of energy and metabolism

and endurance today.

But as long as we’re having a discussion

about these brief sort of tidbits

of how to improve endurance,

are there any other ways to improve endurance

that are of relatively short time investment,

even if they require a lot of energy?


The classic paradigm you’re going to find here

is steady state long duration

posed up against what a lot of folks

will now call higher intensity

interval training specifically.

And there’s a lot of misconceptions here.

The quick answer is you need to be doing both.

And there’s probably a bunch of stuff in between

that you should be practicing.

If you honestly want to maximize those three factors

we talked about at the beginning,

you need to be training across this full spectrum.

Just like I told you to train across the full spectrum

of your lifting,

we want to be doing the same thing here.

So are there independent special factors

that can happen with the shorter time length,

higher intensity stuff?


There’s also magic that happens

on the other end of that spectrum.

So it’s very important

that people don’t just choose one side

because what tends to happen is people either go with,

oh, I’m going to do 30 or 45 minutes of steady state stuff.

That’s it.

Or I’m going to do the opposite,

which I’m going to leave that stuff on the table,

not do it,

because I only want to do high intensity intervals

because I can get it done in five minutes.

So there’s magic on both sides of the equation.

We want to get into all of that.

But just to answer your question directly,

there’s a whole bunch of things you can do

in under one minute that are convenient to do.

And there’s a wonderful set of papers

out of a couple of laboratories in Canada

that championed this idea that’s called exercise snacks.

So there’s a bunch of,

there’s a series of studies that have been done here

that are really interesting.

And they’ve looked at a couple of things

that are noteworthy.

One of them is a 20 second bout of all out work.

And this is actually done in workers in an office.

And so what they had them do is run upstairs.

And I believe it was about 60 steps is what it took them.

Something along the order of 20 seconds, exactly.

And they repeated that about once every four hours.

So really it’s just, you go to work,

you get, you know,

put your coffee in your bag down, whatever.

You run up a flight of stairs,

20 seconds later,

then you go right back to work at lunch.

And before you go home,

you sort of repeat it there.

And if you repeat that,

that’s multiple times a week,

you’re going to do that.

I think they, in one of the interventions,

it was three times a week for six weeks,

18 total times you did that.

And what you’ll see is a noticeable improvement.

This is statistically significant improvements

in cardiorespiratory fitness,

specifically VO2 max,

as well as a number of cognitive benefits,

work productivity, et cetera,

that can happen in as little as 20 seconds.

You don’t have to go to the gym.

You don’t have to shower.

You don’t have to do anything like that.

Just find the stairs,

run up and down them a few times.

Now you may have noticed,

you actually sort of caught me yesterday.

I did that right here, right?

I was just, I,

and we had a little bit of a break.

I was feeling an energy lull.

I ran up the stairs three or four times,

felt a lot better.

So that can actually also help.

They ran another study where they looked at that

following a giant high glycemic index meal.

And what they saw,

and then they took insulin measures

and a whole bunch of other biological markers associated

that you want to pay attention to

with the high glycemic index meal.

And they looked at those immediately

an hour, three hours, six hours as opposed.

And it was very clear that same intervention

was able to improve postplandial glucose control,

insulin, and a whole bunch of other factors

in addition to that.

So if you are the sort of type who’s like,

wow, I’m in an office all day,

maybe also had a giant high glycemic index meal,

not the best approach,

but a little bit of mitigation there

can just be running up a flight of stairs

or doing something like that for as little as 20 seconds.

So there’s a lot of magic and power in maximal exertion.

If one does not have access to a flight of stairs at work,

could they do jumping jacks?


I mean, you could do anything you really wanted.

It’s not the mode of exercise that matters here.

It is simply the exertion.

You just get up as hard as you can.

You could do burpees, you could do any number of things.

You can sprint down your road,

down the hallway, back and forth.

The mode is just something that was easy

for the scientists to control.

And X number of steps, people could do it.

You’re not gonna fall, hurt yourself, things like that.

Just to remind me, it’s once every four hours,

one minute of all out.

20 seconds.

Oh, 20 seconds, excuse me.

20 seconds of essentially all out exertion

while remaining safe,

not going so fast up the stairs

or doing jumping jacks so fast.

And certainly not down the stairs.

Up the stairs, please.

Escalators don’t count.

Well, I suppose they count if you’re moving,

if you’re not remaining on the same steps.

In fact, in an airport recently,

I saw somebody walking against the conveyor

while talking on the phone

while waiting for their flight to take off.

And I thought, it’s genius, right?

It looked a little awkward.

Who cares?

Yeah, but it was-

I’ve looked awkward in every airport

I’ve been in for the last 15 years

for these exact reasons, doing wild stuff like that.

Yeah, well, nothing’s more awkward

than not being able to walk to the end of the terminal

simply because one isn’t familiar

with walking that far carrying a couple of suitcases.

There you go.

Yeah, that’s the other fit test.

The suitcase carrier in the airport.

I love this.

So once every four hours, 20 seconds.

So maybe once when arriving to work,

once four hours in and then four hours,

most people are probably at work somewhere,

plus or minus two hours.

Now, one thing I actually really want to make clear

because your audience is so incredible,

they tend to be really excited about these protocols

and they follow them exactly as written.

That’s not exactly how science works.

So it doesn’t necessarily have to be every four hours.

It doesn’t have to be three times a day.

It doesn’t have to be 20 seconds.

They literally built that protocol

because they’re trying to replicate a real life scenario.

Maybe you’re in an office building.

You’re generally there for eight hours.

Let’s see if you did one every sort of…

So if you want to do it four times a week, great.

If you can do it only 10 seconds, amazing.

You’re probably going to get the same benefits.

Those are not the details to pay attention to.

The detail to pay attention to is every so often,

multiple times a day,

try to get your heart rate up really quickly.

Doesn’t require sweating, doesn’t require anything else.

There’s no warmup associated with it.

Again, you need a minute break

in between meetings or whatever,

and you can sprint up them.

I do this all the time in my house.

When you have those days

when you’re on like seven straight hours of Zooms, et cetera,

you can get out of 20 seconds.

I run to my garage, which is over there.

I hop on the air bike and I will just smash out 30 seconds

as fast as I can and then walk right back in.

Love it.


I’m going to start.

Yeah, just also, you can just put one of those things,

which I do also, just put one in your office

and hop over out of there.

The whole entire thing now literally takes 23 seconds.

Before we begin,

I’d like to emphasize that this podcast

is separate from my teaching and research roles at Stanford.

It is also separate from Dr. Andy Galpin’s teaching

and research roles at Cal State Fullerton.

It is, however, part of our desire and effort

to bring zero cost to consumer information about science

and science related tools to the general public.

In keeping with that theme,

we’d like to thank the sponsors of today’s podcast.

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The Huberman Lab Podcast is proud to be partnering

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First of all, as I mentioned,

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If you’re going to develop a supplementation protocol,

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So tell me about endurance.

What is endurance?

How do I get more endurance?

And how does it work?

When we think about endurance,

I would like to open up the conversation

to include more things than people generally do

when they hear the word endurance.

So, if we just think about

what you typically ask your body to do,

or would like to ask your body to do,

and we just walk through them,

it’s gonna be things like this.

Number one, I wanna have energy throughout the day.

That’s actually a form of endurance.

Great, I don’t wanna have these lulls and fatigue,

and I wanna feel fantastic

as I move throughout my activities of daily living,

whatever those may be.

Work, exercise, enjoyment, paying attention,

focus, all that stuff.

Great, that’s one thing.

Another thing you wanna ask your body to do

is I wanna be able to repeat some small effort

in a muscle group and feel great about that.

This is what we generally call muscular endurance.

So this is something like,

I wanna be able to walk up those 10 flights of steps,

and my quads aren’t burning at the end of it, right?

Or it even gives me energy.

Another thing you’ll wanna ask your body to do

is to be able to perform a tremendous amount of work

for a longer period of time,

something in the realm of 20 to 80 seconds.

So this could be something like if you’re surfing

and you’ve gotta paddle extremely hard for a minute

to get on top of a wave,

or you’re out riding your bike

and you need to be able to get up a hill

and it’s a very steep hill.

These are gonna take maximal efforts

for some small amount of time

and then you’ll get back up there.

We tend to call that maximum anaerobic capacity.

So the max amount of work you can perform

at a high rate for some amount of seconds,

like maybe a minute.

Past that is your ability to repeat an effort

kind of like that for something like five to 15 minutes.

And this is the example would be run a mile, right?

Some interval like that, which is a longer distance, right?

That is gonna be your maximum aerobic capacity.

Another thing you’re gonna want your body to do

is what we call sustained position.

So this is, you wanna be able to sit in your chair at work

and have perfect posture for 20, 30, 40 minutes, right?

You wanna be able to stand in line at a grocery store

for 15 minutes and not have a breakdown in posture.

So you wanna be able to maintain position

when you’re riding your bike, you’re not collapsing,

you’re doing any of these activities

and you don’t get hurt or lose efficiency

simply because you couldn’t sustain basic positions.

All right, whatever those shapes and positions need to be.

And then the last one is a maximum distance.

So you wanna be able to go for a longer hike

or have just a long day at Disneyland

for whatever it needs to be

and feel great at the end of it, right?

So the goal with all of these things

is not can you just do them, but can you do them

and then you feel good afterwards?

So we’re back in a right position

where they give you energy, you feel good about it

and it’s not just something you had to do

and you regretted and you felt awful.

So those are the factors I think about

when someone says, I want better endurance

is I wanna walk backwards and say,

okay, when you say endurance, what do you mean?

And that’s generally the things I’ve come across

is if you can handle all of those things,

you’re gonna feel like you’re in fantastic shape.

You’re gonna feel your recovery is going to be excellent

and your physical performance in the gym

or in any of the sporting activities you do

will be enhanced.

Given what you told us a little bit earlier

that endurance really reflects fatigue management

and energy production,

how do each and both of those things

relate to endurance at a mechanistic level?

I mean, really what I’m asking is

what is fatigue management

and what is energy production?

In order to do that, it’s important that we understand

all of those functional capacities that I just talked about.

They all have different points of failure, okay?

So in order to then work backwards and say,

well, how do I optimize my performance

in all those categories?

We need to go through each one and figure out,

well, where am I failing?

Some of them are gonna be failing

because of fatigue management

and some of them will be failing

because of energy production issues.

So if we walk through a little bit of how we make energy

and how we handle fatigue,

then we’re gonna have a better understanding

of exactly what to do for each one of these categories

if you feel like one of them in particular

is worse for you or lagging behind,

or if in general you just wanna improve all of them.

All right, now I’m gonna make a little bit

of a 90 degree turn here.

I’m gonna do it with strategy though, I promise.

And I wanna ask you a very simple question.

How do you lose weight?

I was taught that the calories in, calories out,

thermodynamics of energy utilization

governs most everything.

That is if I’m ingesting less caloric energy than I burn,

then I’m going to lose weight.

And if I’m ingesting exactly as much as I burn,

I’ll maintain weight.

And if I ingest more than I burn, then I’ll gain weight.

Sure, that is the approach you would take.

What I’m asking really is

how are you actually physically losing the weight?

So my understanding is that we have

different fuel sources in the body.

Glycogen, which is stored in muscle and liver,

body fat, which is stored in mainly white adipose tissue,

and which is subcutaneous and around our organs,

intravisceral fat,

and that we can also use protein as a fuel.

And then as I recall,

there’s also a phosphocreatine system.

And I think you’re going to tell me

that each of these systems is tapped into

on different timescales,

and perhaps according to different levels of exertion.

And I’m certain that what I just said is not exhaustive,

but hopefully it is most or entirely correct.

Pretty correct.

What’s that got to do with fat loss?

At some point, body fat stores adipocytes, fat cells,

are going to start liberating fat as a fuel source.

And the stimulus for that,

I’m assuming is going to be that other fuel sources

are either depleted

or that the energy and metabolic systems of the body,

I don’t want to say decide

because they don’t have their own consciousness,

but are flipped-


Are signaling in a way that registers

that body fat would be the optimal fuel source

given how long and or intensely

a given activity has been performed.

Okay, we have some stuff to clean up there,

but we’re still not really answering the question.

How am I actually losing that body fat?

How is it actually leaving the body?


My understanding is that

it leaves the body through respiration.


So now we have some interesting things to talk about.

How am I actually losing fat via respiration?

What the hell does that even mean?

How is something that occupied this physical space

on the side of me, leaving my body through my mouth?

And there is a very clear answer there, right?

Which I’m sure you’re cued up to.

When you take a breath in,

you’re generally breathing in oxygen, O2.

There’s some other things, but we’ll just stick to oxygen.

When you exhale, you’re breathing out CO2.

The difference between those two is that carbon molecule.

Well, one of the things that’s important to understand here

is all of your carbohydrates,

which is that word itself is a carbon

that has been hydrated.

So it is a carbon molecule attached to a water molecule.

It is a simple chain of carbons.

Your fat molecules are also chains of carbon.

All of metabolism really, in terms of energy production,

is simply trying to figure out a way

to break those carbon bonds.

As a result, we get energy from that.

We use that energy to create a molecule called ATP,

which is the central source of energy for any living being.

That carbon is then floating around in free form,

which is bad news internally.

So we’ve got to figure out a way

to get that carbon out of our system.

So all of energy production, all of fatigue management

really comes down to this core issue

of how are we handling carbon

and how are we moving it around the body?

And so what we do is we do this sneaky thing.

So another question I like to ask people

is why do we breathe?

Well, for two reasons,

to bring oxygen into the system

and to offload carbon dioxide.

But the neural trigger for breathing

is when carbon dioxide hits a threshold level

in the set of neurons in the brainstem

and elsewhere activate the phrenic nerve

or the gas reflex or a combination of things

and we inhale or inhale.

Right, so a reduction of oxygen intake

generally doesn’t stimulate ventilation

unless you’re at altitude.

Then that sort of changes, right?

In general, it’s an elevation in CO2

that’s gonna stimulate breathing up.

The only reason you bring in O2 for the most part

is to get rid of the CO2.

Oxygen is not a fuel source.

It is not a way, it works the same with fire, by the way.

So you know you have to have oxygen present

for a fire to go and if you squelch oxygen,

the fire will go out, right?

That’s sort of half of how those fire extinguishers work.

But we think then that means oxygen is the fuel.

It is not the fuel.

It is something entirely different.

It is a product that is necessary

for the metabolism process to actually occur.

All right, so we’re kind of dancing around an idea here,

which is this carbon cycle of life.

So what happens in plants

is they generally will breathe in the opposite

and breathe out the opposite of humans.

So a plant will breathe in CO2 and exhale O2.

All right, this is why we have to have

a certain amount of these things

and algae and forests and trees and stuff

to maintain this O2, CO2 balance in our atmosphere.

We do the opposite.

And so we have this wonderful circle of life.

We breathe in O2, breathe out CO2, they do the opposite.

Well, what happens is because carbohydrates

are long chains of carbon and fats are as well.

Generally, when we think about fats, by the way,

it’s important to understand that structure a little bit.

So if we think about triglycerides,

it is a three carbon backbone chain of glycerol.

So it’s one, two, three,

and horizontally running off of each one of those

are fatty acid chains, right?

And so we form this structure that looks like an E, right?

Like the letter E, three in the back,

and then three chains coming off of it.

Each of those chains are called fatty acids

and each of those fatty acids are a length of carbon, right?

Or a number of carbons strung together.

However many carbons are there

determines which type of fatty acid it is, right?

So stearic acid, linoleic acid,

like any different number of things.

It’s also what determines whether or not

is a monounsaturated or polyunsaturated

is if carbon requires a special thing called a double bond.

So if there’s a double bond across every carbon and carbon,

then they’re all fully saturated and you’re great.

If there’s any of them that are not double bonded,

in fact, an example,

if there is one that doesn’t have a double bond,

that is now called mono and saturated.

And if there are many, it is called polyunsaturated.

So there’s pros and cons to all of these things, right?

In either case, we’re still talking long carbon chains.

So what a plant will do is bring in carbon.

And then it has this wonderful ability

to use energy from the sun called photosynthesis.

And it can take those carbons that it inhales

and use the energy from the sun to form a bond.

Now, in our prior discussion,

when we were going over hypertrophy,

we talked about the energy required

to go through protein synthesis.

That’s because forming a new atom

or a new bond between atoms oftentimes takes energy.

In this case, it does.

The same thing happens here.

So if a plant does not have oxygen

or does not have carbon dioxide in the air, it has no fuel.

Then basically think about it as that’s what it eats.

It needs to get nitrogen from the ground and the soil.

Just like we need to get nitrogen from our protein,

but fuel-wise, it needs to get carbon dioxide.

Then it needs sun to give it energy

so that it can actually form that bond.

That’s what it’s getting its fuel from.

So if we think about a classic plant

that produces either a starch or a fruit,

here’s what happens.

It inhales that carbon and then it starts packing it away.

Now, in a root vegetable,

what it does is it stores those things together.

And if we store that thing

and we grow a fruit at the bottom of it,

we tend to call those things starches.

It’s going to then take the carbon

that is packed away in its root and send it up the tree.

And it’s gonna actually do that

by breaking it down into a smaller form of carbohydrate

that we tend to often call things like sucrose and glucose.

It’ll ship that up the tree.

It’ll go out to the leaves

and it’ll convert it into the fruit.

And it’s gonna eventually transform that stuff

into smaller carbon things called fructose.

And if we think about the fruit or the sugar in fruit,

it’s often in the form of fructose or sucrose

or a combination and sometimes glucose.

So we have these smaller carbon, six carbon chains,

generally in the form of glucose

that are being made from this larger storage

of carbohydrates that we call starch, right?

So it’s packed in together.

Your body does the exact same thing.

So if it’s a potato

and it has a whole bunch of glucose packed away,

we call that starch.

If it’s in your quadricep

and we pack about a whole bunch of glucose away,

we now call it glycogen.

If it’s in your blood as that six carbon chain,

we call it glucose.

If it’s in the tree and in the fruit,

we call it fructose, right?

Those are different molecules,

but that’s effectively the same thing happens.

So the biology or the chemistry is almost identical.

It just runs in the reverse order.

And that’s why again,

tubers and potatoes and stuff tend to be starches

and fruits tend to be glucose, fructose and sucrose.

So we have this wonderful circle of light.

The plants can survive on just breathing in the CO2

and then getting the energy from the sun.

We don’t have that ability, at least to my knowledge,

to run through photosynthesis.

So the only way we can get carbon into our system

is to actually ingest carbon,

which means we have to eat the starch, the fruit,

the animal, some other form of stored carbon

to get that into our system.

We then pack that away.

We put the carbohydrates, as you mentioned earlier,

either in our liver, our blood, or in our muscles.

We put the fat generally in adipose tissue.

We’ll put a little bit in muscle cells,

as intramuscular triglycerides,

and then the protein we’ll use as structure, right?

To do different things.

We don’t like to use protein as material or fuel.

It’s better to use as structure.

And what we have to do then is if all of a sudden

we realize that storage is getting too much in our body,

in other words, we’re gaining too much weight,

we have to figure out how to get the carbons

out of our body.

And that is metabolism, right?

Anytime we’re trying to break a carbon bonds

that we can get energy to make ATP,

that’s going to release the carbon out of our tissue

into the blood.

We have to bring in oxygen to bind that carbon molecule

to make CO2 so we can exhale it

and put it back into the atmosphere.

It’s a beautiful description of the circle of life

and energy utilization in the human body.

I have to ask the question that I’m sure

many people are wondering about,

which is if indeed we exhale these carbons

and as it relates to fat loss,

that is the way that we lose fat

if we’re in a subcaloric state, for instance.

Has it ever been explored as to whether

increasing the duration or intensity of exhales

can accelerate fat loss?

I mean, that’s sort of the logical extension

of what you described.

And here I’m actually interested equally

in whether or not the answer is yes,

as well as whether it could be no.

Because I could imagine if the answer is yes,

well, then there’s some interesting protocols

to emerge from that, but that if it’s no,

it will reveal to us some important bottlenecks

about metabolism and energy utilization.

You ever seen those magicians who like show up

and they can tell your mom’s name

or something like that before you

because they can sort of lead you down a path?

Yeah, I mean, not to take us down a deep dive tangent,

but I once went to the Magic Castle in Los Angeles

and I was one of the people called up front

and an incredible magician named,

I think his name was Ozzy Mind or something.

I think that’s right.

He had me write my name on a card in a Sharpie pen.

I ripped up the card, I ripped it up.

I put it in my pocket.

And at the end of the 10 or 15 minute bout

of him doing a bunch of other tricks,

he asked me to look in my right shoe

and under my foot in my right shoe was that card intact.

And it was no longer in my pocket.

And I swear on my life, I wasn’t a collaborator with him.

And to this day, it still gives me chills

because I don’t know how, magic.

Yeah, right, magic.

Well, the reason I say that is I’ve given that little spiel

that I just gave you countless times in my classes.

And I would say 99% of the time, as soon as I stop,

the very first question is,

so can I just like do a bunch of exhales and lose fat?

Which is wonderful,

because I was really hoping you would do that

and you rolled right into my trap.

You landed perfectly.

So I look like a magician over here.

I feel like I should look in my right shoe right now.

No, I asked the question because it’s the logical extension

of what you laid out,

but I know biology to be both diabolical and cryptic,

but also exquisite in the way that things are arranged

and you don’t get something for nothing.

There are no free passes in physiology.

That’s the saying, no free passes.

The answer to your question is yes.

A lot, 100%, yes.

In fact, that is the only way to go about it.

You have two options.

You can ingest less carbon or you can expel more carbon.

People always say calories in, calories out.

It’s really carbon in, carbon out.

That’s what a calorie is, right?

Calories is the amount of energy we get

per breaking a carbon bond.

So it’s really less in, more out.

Less in is fairly obvious, whether that comes in any form.

And by the way, this is exactly why the percentage

of your intake coming from fats or carbohydrate,

it doesn’t really matter that much.

If you look at fat loss, clinical trials,

you guys may have covered this when Lane was in here.

I’m sure like this is something he talks about a lot.

It doesn’t matter.

It’s irrelevant because it’s not about that.

There’s nothing magic in those things.

They are different.

They have different physiological responses.

Everything is different, right?

No doubt.

But in general, it’s just simply about carbon intake.

Turns out fat has a lot more carbons per mole

than carbohydrates do.

So there’s more calories per mole in there.

So if you, the physical amount of fat

needs to come in a smaller amount,

physical amount of carbohydrates

will come in as a larger amount,

but you can play any number of very high carb, low fat.

What matters?

Total calories, right?

Again, it’s not like the only thing that matters,

but you know what I’m saying?

Some percentages in the way can go.

Fat loss works fantastic.

High fat, low carbohydrate.


Why do all these things work?

Because it’s not about that.

It’s about total intake of carbon, total exhale.

So absolutely, can you lose fat by simply exhaling more?

In fact, that is exactly what you did this morning.

When I hopped on the Airdyne bike for-

When you did anything, right?

The question is, can you think of a scenario

in which you could have a bunch of

increased rates of exhalation that helps in fat loss?

Sure, I can think of a lot of things

that will stimulate increased rates of exhalation.

One thing could be simply going,

huh, huh, huh, huh, huh, huh, huh, huh, huh, huh, huh.

Right, and so the question is like,

can I literally do some breath protocols

where I force exhale and lose fat?

And the answer is yes.

But what happens?

What happens if you do hyperventilation training?

Well, my lab studies cyclic hyperventilation

as one of our many deliberate protocols.

And one of the most prominent things that one observes

is that levels of adrenaline increase very quickly.

Extremely quickly.

People feel jittery, anxious, stressed,

and unless they are consciously trying to anchor

their thinking about what that means

and the benefits set to persisting,

typically they abort the cyclic hyperventilation protocol

really quickly.

Within seconds, right?

You will feel tingling, sweating, all kinds of things.

You’re hyperventilating, right?

And we could talk ad nauseum about

how that changes everything from adrenaline

to focus to a whole bunch of things.

So unfortunately, a strategy of sitting around

and just exhaling more than you inhale

technically helps you lose more fat,

but it’s not going to last very long.

So then the question is,

well, how do I get into a situation or a scenario

in which I can increase my rate of expiration

where I’m not gonna pass out?

I’m not going and altering hypocapnia and hypercapnia issues.

Any idea of a situation in which you would have

an enhanced rate of exhalation

without worrying about passing out?

True, steady state exercise.

Or not steady state exercise, lifting weights,

intervals, moderate training, repeated.

Any of these things, they all work equally for fat loss

because all they’re doing is increasing respiration rate.

They’re saying increased demand for energy,

increased exhalation.

That’s the trick here.

And when you equate these things to that,

they have equal success in fat loss.

It doesn’t matter theoretically

where you’re getting it from.

And so when we get into this idea of,

well, what are the best training strategies for fat loss?

It doesn’t matter which one of these tactics you pick

as long as you maintain a consistent adherence over time

because of this exact fact.

It doesn’t matter if you’re burning quote unquote fat

in the exercise session

or if you’re burning carbohydrates in the exercise session.

It is totally irrelevant to your net fat loss over time.

Okay, now there’s some significant misconceptions there

about what I just talked and I would love to come back

and walk through that in more detail.

But that’s the main take home message here.

It won’t matter what’s coming in

and it won’t matter what’s coming out

because in either case,

it is the same rate of oxygen in and CO2 out.

That’s the key metric.

And hopefully this helps a lot of people have some relief

because they’re like, man, you’re so tied up

on what is the exact protocol for training

for optimizing fat loss.

What’s the exact nutritional intervention

I need for fat loss.

And then you wonder why all these different diets

can work effectively

and wonder why all these different training protocols

and surely you know somebody who lost a bunch of weight

and the only thing they did is they just started running.

There was no advanced protocol,

they just started running

and they ran five miles every day.

That works.

And then tons of people who tried that

and like didn’t lose anything.

And lots of people who went to,

I went to cardio kickboxing class, lost weight.

Oh, I just started doing intervals on my,

why mysteriously do all these things work?

Something has some spidey sense

has to be going off in your brain.

We’re like, there has to be something linking these things.

And what’s linking it is simply carbon exchange.

So put yourself in a position

in which you are exhaling more than you inhaling

without passing out.

The other problem is

if you were to simply do a breathing protocol

while the rate of exhalation would go up,

after that you would correct

and go in the opposite direction.

So that’s the problem is your net carbon output

over the course of the day is not gonna change

unless you increase the demand for energy.

And that’s how you get into that negative state.

Along these lines of exhaling carbons

as the route for fat loss,

it makes me wonder whether or not

increasing lung capacity is possible.

I’m guessing the answer is yes.

And whether or not increasing lung capacity

is a good goal in route to enhancing fat loss.

Essentially what I’m asking is

if you can offload more CO2,

okay, carbons per exhale,

are you a more efficient fat loss machine?

It’s a wonderful thought and the answer would be no.

Not something to worry about

because if you were to exhale more carbon

than actually needed,

now we’re in a state of inefficiency.

You’re burning way more energy

than needed to do your activity.

The heart has a metric called cardiac output.

This is in sciences, we abbreviate this as Q

for some odd reasons, it’s either CO or Q.

And cardiac output is heart rate

multiplied by stroke volume.

So it’s how many beats per minute you’re having

as well as how much blood’s coming out of it.

So cardiac output is actually

very specific to energy needs.

If you try to work around that,

it’s just going to adjust itself.

So what I mean by this is

if you were able to increase your stroke volumes,

the amount of blood coming out per pump,

you would automatically adjust to reduce your heart rate

so that you keep cardiac output

exact to energetic demands.

So you’re sort of pushing one end of the spectrum

but your body will pull the other one back

to keep you at that exact same neutral level.

So if you look at,

if you think about like cardiovascular adaptations

to endurance training,

any type of endurance training,

a common thing people will understand

is resting heart rate.

And so what that number is

how many beats per minute you’re having

when you’re sitting here doing nothing.

A very positive adaptation

is a lowering of that resting rate over time.

As general numbers,

what you will hear is people will say things like

a normal resting heart rate

is between 60 to 80 beats per minute.

And if any of the things I’ve talked about

with the individuals I work with,

I don’t work with anybody with disease,

just to clarify that.

I don’t do anything with disease,

management, treatment, anything.

It’s always about people who are in a good spot

who wanna optimize or get to the next level.

Whether this is professional athletes

trying to peak for physical performance

or the folks in our rapid health optimization program

that feel good.

Again, it’s not disease stuff

and they wanna feel incredible.

One of the metrics we’re gonna pay attention to

is this resting heart rate.

So here’s what happens.

As you improve your endurance,

your resting heart rate will go down.

If I see somebody over 70 beats per minute,

unless something’s going on,

you’re not physically fit.

Regardless of whether or not that is quote unquote

within the normative values,

I wanna see everybody sub 60 beats per minute or close.

And that is not a difficult thing

to really get to for most people.

So if you train a lot,

regardless of how you train,

intervals, steady state, doesn’t matter,

that resting heart rate will come down.

But since energy demands at rest haven’t really changed,

cardiac output stays the same.

So what happens is stroke volume goes up.

So literally like we trained your quadriceps

on the leg extension machine to get stronger

so you can produce more force per contraction,

the heart will do the exact same thing.

And so as you’re able to get more of the blood

out of your heart per pump,

the heart realizes I don’t need to pump as often.

So that’s the compensatory adaptation,

which is saying, hey, look,

I don’t need to beat 60 times a minute.

I now need to beat 55 times a minute

because I’m getting the same amount of blood out

per pump, chill.

And this is why your resting heart rate goes down,

your resting stroke volume goes up,

but your cardiac output is identical.

So that’s not a good metric of fitness.

It’s going to stay the same.

Cardiac output will only adjust per energetic changes,

energy requirements in the acute moment, right?

How much do I need?

Go, which is gonna be determined by ventilation, right?

How much air am I bringing in and putting out?

That’s gonna determine cardiac output

and that’s gonna determine where we’re at.

If you were to do like a sub-maximal exercise test,

when you were unfit to when you’re fit

or when you’re fit to where you’re super fit,

at sub-max, you’re gonna see the same thing.

Cardiac output will be identical

and you’re like, damn, nothing happened.

What you’re not realizing is your heart rate

at that same workload is now lower

and that’s efficiency because your stroke volume is higher.

Where it gets people tripped up is at max

because you may not see a much of a change at max

because you don’t really see an increase

in maximum heart rate with fitness.

That’s not a thing, right?

So maximum heart rate is not a good proxy

for fit or unfit or anything like that.

Stroke volume will get limited eventually

by filling capacity of your heart.

It has to have so much time to fill up with blood

before it can contract again and squeeze the blood out.

And when you have a heart rate of 200 beats per minute,

that just doesn’t leave much time to fill.

And so it won’t really push you past that.

So don’t worry about trying to increase

your maximum heart rate.

That’s not necessarily a good thing

and it won’t really change.

But your cardiac output will

because stroke volume will be higher.

But that doesn’t necessarily mean

that I should avoid training

that gets me up toward maximal heart rate, correct?

Oh, you should absolutely do it.

Right, that was my assumption.

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Getting back to energy production and metabolism.

So we’ve got these different modes of moving energy

but making and breaking energy bonds in the body,

moving energy into different tissues

and out of different tissues

and indeed out of the body through exhalation.

How do each of these different modes of energy utilization

relate to different modes of movement and exercise?

In my mind, I’m starting to draw a bridge between,

okay, when I walk for 60 minutes,

if I’m talking, I’m breathing a bit more,

maybe I’m burning a little more fat.

After all, speech is a modified exhale.

And if I’m sprinting, I’m breathing differently.

And if I’m doing a 30 minute moderate,

quote unquote, moderate jog, I’m breathing differently.

So you’ve beautifully illustrated this bridge

between energy production and utilization

and carbon dioxide offload through exhalation.

What are some of the specifics about energy utilization

according to different modes of exercise?

And if we could better define modes of exercise

or types of exercise that trigger specific adaptations,

I think this is where the bridge will move

from being a mere line to a real structure.

Yeah, absolutely.

I wanna lay one more foundational piece

and then it’s going to be much easier to understand

the limitations I put on some of these training protocols

as well as the lack of limitations.

Okay, so it’s really, really important.

The way I wanna start this is

we have this foundation now of carbon

and basic energy production.

That’s not to say there’s no difference.

There is, and that difference is important.

But maybe we can answer the question from earlier,

which is actually something you asked me this morning

when we were exercising.

You’re like, training fasted, right?

Does training fasted enhance fat loss?

And the logic is sound.

If I don’t have any fuel,

then I should be burning more fat,

therefore I shouldn’t be losing more fat, it’s sound.

It’s not true.

It’s a great idea.

It’s one of these classic things in science

and exercise physiology where you’re like, sounds good.

Turns out it’s not.

It’s actually a pretty gross misunderstanding

of metabolism.

So it’s not to pick on that topic.

I don’t really care about that topic,

but it’s a common question.

It also gives me an opportunity

to just tell you more about metabolism.

So here’s what happens.

You are breathing in O2 and breathing out CO2.

However, the ratio to that is what we call

the either RER, respiratory exchange ratio,

or RQ, respiratory quotient.

And I’m not gonna differentiate those two.

They’re not the same thing,

but we’re gonna skip past that for now.

As you begin to increase exercise intensity,

the percentage of O2 to CO2 rises in the favor of CO2.

So you start breathing out way more CO2

than you are breathing in O2, right?

And so if we were to look at that number,

what’s the relationship?

It goes up.

So at rest, most people have a value

that we would typically call something like 0.6, okay?

And that’s, again, the relationship between O2 and CO2.

Maybe 0.7.

If you were to go for a walk, that increases slightly

because you’re now expiring CO2 at a higher rate.

So now you’ve moved up to say 0.8 or something like that.

One of the ways that we mark somebody

of achieving an actual VO2 max on a test

is if that value exceeds 1.1.

Now, any of you who are paying attention

and thinking, well, wait a minute,

how the hell can a ratio between two things

ever get past one?

Well, that’s because you’re getting into a place

where you’re actually offloading more CO2

than is actually necessary.

And this is what actually causes and explains

a thing that people like to call EPOC,

which is excess exercise post-oxygen consumption.

This is another way to think about it.

The only reason you’re breathing

is to bring in oxygen when offload CO2, right?

If I’m no longer exercising, why am I still breathing?

In other words, once you stop the demand

or the need for energy, you should stop ventilating,

but you don’t, right?

And that’s because in the case of low intensity exercise,

the second you stop,

you’re right back down to respiring ventilation.

No problem, because you were able to match

the need for energy with the offload of waste

one-to-one during that exercise.

When you start creeping up the intensity, you can’t do that.

So you have to basically start stealing

a little bit of fuel here.

So even though you’re done exercising,

you’re still ventilating because you have to pay that back.

And pay that back by that,

I specifically mean you have to bring in oxygen

because you have a whole bunch of waste

that’s been accumulating in your tissue

that you’ve got to deal with.

And I’ll walk you through what that waste is.

It’s a particular molecule

that a lot of people have heard of,

but grossly misunderstand.

So you got to be able to handle that.

So the reason that you sit there and go,

and continue to ventilate

is because you’re now trying to pay back

that excess post-exercise oxygen debt.

That’s that oxygen debt we’re specifically talking about.

All right, so that being said,

as we start cruising up,

that RRQ starts going up, up, up, up, up, up, up.

And if we get to one, you’re 1.0,

you’re hurting, you’re in a pretty good spot.

All right.

I like that, you’re hurting, you’re in a pretty good spot.

A window into Dr. Andy Galpin’s mind.

Now you really want to be a subject in his laboratory study.

Masochists swarm to Andy’s lab.


All right.

So the idea that I will lose more fat

by being in an exercise situation that is burning more fat,

it seems to make sense,

but it’s a massive failure to understand the metabolism.

It’s the exact same explanation

as why exercising fasted doesn’t matter.

So the exercising fasted issue under normal circumstances

is irrelevant because you have plenty of fuel in the system

even when you haven’t eaten breakfast that morning.

Now, if you’re talking like extended fasting

over multiple days, this is a different scenario.

If muscle glycogen, liver glycogen,

and blood glucose are at sufficient levels,

then you absolutely have enough energy

to perform almost any type of exercise

that most people are doing.

Maybe if you’re Rob and you’re at mile 20 today,

it’s a different story,

but the vast majority of us have plenty of fuel

sitting around, so we’re not going to burn more into fat

just because we didn’t eat breakfast that morning.

So that just doesn’t make energetic sense.

We have a lot of backup supplies and you’re never out.

The trick here is this.

There’s a concept here we call crossover concept.

So as we are starting to move up exercise intensity,

we start burning a higher percentage of our fuel

from carbohydrates

and a lower percentage of our fuel coming from fat.

I’m sleeping.

That’s the highest percentage of your fuel

that will be coming from fat

of any activity you could ever do.

So if the theory that I’m going to stay at a lower intensity

to burn more fat was true,

the optimal fat burning strategy would then be to sleep.

Like that doesn’t make sense.

Of course it doesn’t.

So why would then going at a slightly elevated rate

somehow all of a sudden magically make you lose fat?

It doesn’t actually make sense.

When you think about that, we were like,

oh yeah, there’s no way.

So it’s a percentage trick.

It’s a difference between absolute and relative.

This is what this confusion is.

So yes, as you start doing lower intensity exercise,

whether you’re fast or not, it’s irrelevant.

But lower intensity exercise,

a greater percentage of your fuel is coming from fat.

However, your total fuel expenditure is very low.

So that whole total carbon balance

is not really being shifted much.

As you start exercising at a very high intensity,

you actually start getting a higher percentage

of your fuel from carbohydrate

and a lower percentage from fat.

In fact, at rest, about the highest you can get

in most people is about 60% of your fuel from fat.

As you’re sleeping, you might be 70%,

but you’ll never be in a position ever,

no matter what sort of thing you’ve heard on the internet,

you’ll never be in a situation

where fat is your only fuel source.

The highest I’ve probably ever seen is like 70%.

You should probably be at about,

that’s a kind of a good number to think, honestly.

But people who understand a little bit

about metabolism to be dangerous, but not enough,

will throw out these terms like fat adapted.

And fat adapted is a real thing,

but it is a massive misunderstanding oftentimes, right?

It is this idea of thinking like,

I can get to a spot where I’m maximizing fat burning.

Maximizing fat burning and maximizing fat for exercise

and maximizing fat loss over time

are not the same thing at all, right?

That’s the confusion.

So if you enhance fat oxidation in an exercise,

that does not enhance fat loss per se, right?

So this is a lot of the confusion that’s happening, right?

So as we start moving up,

we can never get in a position

where we’re using fat only as a fuel.

Again, at best you’re at 70% fat, 30% carbohydrate.

For a lot of reasons,

we probably just don’t have time to get into today.

However, the opposite is possible.

When you get into true high intensity exercise,

you’ll be basically 100% carbohydrate and 0% fat, right?

That is very possible.

That in fact is 1.0.

That’s what our cue, 1.1 is actually

because your ventilation got so high,

you actually exceeded that number,

even though you’re at 100% carbohydrate.

This is what people came up with the idea then.

It’s like, whoa, I don’t wanna burn carbs,

I wanna lose fat.

So my response to that is always like, okay, great.

So it makes sense, burning fat, losing fat,

burning carbs is losing what then?

Like you think your liver shrunk?

Like, wait a minute, what did you lose then?

Where did it come from?

It’s all coming as carbon.

Don’t worry about where it came from for your fuel.

It just has to come out as carbon, right?

There are differences in exercise efficiency for performance

with our professional athletes, of course,

but if the only goal here is fat loss,

it doesn’t matter where you get it from.

The last bridge we have to connect here is like,

well, wait a minute, if I only burned carbohydrate,

how did I actually lose that fat?

There was that love handle sitting on the side of me.

How did that come out of me?

If I never burned that for my fuel?

What you’re failing to understand

is there’s a balance game that happens here.

So if you were to do a bunch

of high intensity exercise training

and you burned only muscle glycogen and blood glucose,

and maybe even you did it for so long,

you burned some liver glycogen.

The body understands that it has expelled a lot of energy

from that side of the equation.

It’s going to do a couple of things.

Now it’s very difficult to go through this fancy situation

where you convert carbohydrates into fat and back and forth.

Like that’s actually like fairly hard.

What’s easier to do is something you said earlier

is actually just bias energetics to a different fuel source.

In that scenario where you’re down really low

in your carbohydrate stores,

any carbohydrates you bring in are going to go to storage.

And since your net energy expenditure

is something that your body regulates a lot,

any fat that you then bring in

is going to be utilized as a fuel source

because it knows it doesn’t need it anymore.

That is in excess.

So that’s how you actually use fat as a fuel

because you’ve burned down carbohydrate storages.

As I’m hearing this, a couple of things come to mind.

First of all, thank you for that incredibly important

description of what is otherwise

a very confusing landscape for most people.

One of the key points I took away,

and I just want to say from the outset,

this is not exhaustive by any stretch,

is that burning fat does not equal

losing fat from the body.


And then burning fat has to be divided

into burning of body fat stores.

And we need to distinguish that

from burning of dietary fat that is brought in.

Oftentimes people don’t disambiguate those.


And I’m also understanding that reducing

one’s body carbohydrate stores,

muscle glycogen, liver glycogen, et cetera,

occurs during high-intensity exercise.

There’s other ways, but that is one very efficient way

to tap into those stores, which makes me wonder,

again, this is one of these things that,

does it lead to a protocol,

makes me wonder whether or not doing high-intensity,

let’s say weight training for 45 to 60 minutes,

75 minutes of strength training, power training,

hypertrophy training, which we’ve covered in an episode

about those topics,

and then doing some steady state cardiovascular exercise,

is there any benefit to that arrangement

that would quote-unquote enhance body fat loss

from the body, to be very specific now,

because unlike the idea that training fasted

would shift the bias towards fat loss,

which it doesn’t, you’ve told us,

under those conditions, muscle glycogen

and maybe even liver glycogen is going to be depleted.

Put simply, can I enhance body fat loss

by doing some cardio after a bout of weight training?

If you equate for total energy expenditure, it won’t matter.

Now, you did bring up a very important point

that I want to clarify.

If you look at the exercise modalities

that we laid out in our previous conversations,

we talked about nine different adaptations.

One was skill, and then speed, power, strength,

hypertrophy, muscular endurance, anaerobic capacity,

aerobic capacity, and long-duration endurance.

Now, speed, power, and skill development

have almost no benefit for fat loss,

because remember, those are low weight,

a lot of rest, and low volume.

They’re not really going to be helpful.

You can make a little bit of a case for strength,

a little bit, but the total energy expenditure

for strength training, even if it’s an hour,

if it’s truly strength training, it’s fairly low.

Because the repetitions are in the one to three range.

It’s not enough for total work.

So if you’re trying to develop a protocol

that sort of optimizes fat loss,

what you want to do, you were close.

In my opinion, is do a combination of something

in the hypertrophy slash muscular endurance

strength training realm.

Okay, so six to 30 repetitions.

Something like that.

Of resistance training.


Deplete muscle glycogen,

maybe even a little bit of liver glycogen.

Maybe a little bit, depending on if you’re doing it

for a long time, but probably not a noticeable amount.

Okay, so an hour of hypertrophy type training.

If you’re training hard with low rest intervals

and you really did an hour, you would for sure get there.

But most people don’t.

Is that the reason why I crave large bowls

of oatmeal and rice after I do weight training?

I want to replenish muscle glycogen.

Totally, right?

Then you maybe do a little bit of very high intensity,

maximum heart rate, well over VO2 max.

Hard as you can for 20, 30, 45, 60 seconds,

something like that with some recovery,

a lot of recovery and repeated.

And that’s going to do a great job

of depletion muscle glycogen, right?

If you do that long enough, you’ll get the liver.

But again, most people don’t

because it’s really, really hard to go that hard.

So liver is sort of last resort.

Yeah, basic mechanics here,

which we’ll actually get into as our third segment here

is energy production comes from the local exercising muscle

first and foremost from phosphocreatine

and carbohydrate stores, right?

And so again, and we store it in muscle,

we call it glycogen, right?

That’s just your first sign of light on defense.

If you need glucose outside of that,

you’re going to start pulling it from the blood.

But one of the things,

your body regulates a handful of things

over almost everything, blood pH, blood glucose,

blood pressure, and electrolyte concentrations.

Like it really does not want to mess

with those things at all.

It will change almost anything else in the body

to keep those things standardized, right?

You generally, because you need all those things

for your brain to work

and your brain will stop working, right?

If you lose blood pressure, it won’t go up there.

pH changes, you can’t run metabolism.

Electrolytes change, you can’t think.

And glucose is a primary fuel source for the brain.

It’s going to be a problem, right?

So if that number starts to come down

because you’re grabbing glucose out of the blood,

your liver is going to then kick in.

It’s going to break down its glycogen

to put glucose in the blood

to keep the blood number, the level.

In fact, one of the things you’ll see

is blood glucose concentrations rise during exercise.

They don’t fall.

In fact, they rise as an anticipatory state.

If you train a lot,

your blood glucose will start going up

before you start moving.

It knows it’s coming, right?

So you can play that game.

You can rob Peter to pay Paul for a long time

until your liver runs out.

And that’s what actually is a bonk

in terms of like long duration endurance stuff.

You’re talking many, many, many miles,

several hours typically.

We say, oh, it’s got to be over two hours

before your liver starts to become a real problem

or it has to be tremendously intense

because of those reasons.

You have to burn through just a lot of energy

before your liver starts to get into a problem.

You can continue to train

when your muscle glycogen levels are low.

In fact, people say glycogen depletion in muscle,

but it’s generally a misnomer.

And you are going to just have tremendous signals of fatigue

when that number gets lower than 75%.

So people think that like their muscles are getting heavy.

You’re probably still 75% full.

A lot of folks will quit around the 50%.

The highest I’ve ever seen is like 95% true depletion.

And that’s an extremely high level cross-country skiers

and like their deltoid gets very, very low.

Some very talented runners will get fairly low

in their quads, but the vast majority of folks,

by the time you’re 50% depleted, you’re going to quit.

It’s going to be really, really challenging.

So you’re never really going to get that low.

It’s like a bit of a protective mechanism, right?

But when your liver gets low, you’re going to be shut down.

And that’s the case of if you’ve ever been to like a marathon

and you’ve seen people run like 25 and a half miles

and then they just like bonk,

they go into like baby deer walking stance

and then they collapse and you’re like,

how are you mentally weak?

Like you ran 26 miles and you can’t run the last point.

It ain’t mentally weak.

It is if your liver is done, it’s going to stop you

because there’s no more backup reserves.

Muscle you can get away with, you can push through it.

Liver will not let you go any farther.

I find this fascinating because it makes me wonder

whether or not the liver being depleted

sends a neural signal to the brain

or the brain must register some signal.

I would like to be alive tomorrow, thank you.

Whatever is happening right now,

stopping is going to be safer than continuing.

And so that stop signal is one that I think a lot of people,

including myself, are intrigued by

because we always think that it’s related to willpower,

but the brain needs to preserve itself.

And as the master computer,

I mean, there are ways to go into kind of automaton type,

not thinking, just doing type of behavior.

You have override switches, right?

And you can play those cards

and you can get better at learning

and being less sensitive to that switch.

That’s exactly what happened when you first start training.

You start to realize like, oh my gosh, I’m super tired.

And then you realize really quick,

like, oh, I’m totally fine here.

And this is like the, pick your person

who’s made sayings like this,

but it’s like, you’re really only 10% depleted

or 30% or 40% or something.

We’re all operating at 40% of what we could do.

Of course, any of those things are true

because it is like a little bit of an override.

You’ve just gotten very sensitive

to being a small percentage depleted

and you’ve learned, okay, I’m tired.

And there is a long way to go past that.

But once you get past that

and you flip that override switch a lot,

you’re going to break quickly

because you basically learned to ignore that signal

and problems can happen really quickly after that.

And that’s even experienced endurance athletes.

If you hit that level,

it’s like you’re going to be hitting the concrete next.

And that’s potentially a problem.

I want to make sure I understand a concept

that you referred to earlier correctly

because I have a feeling that I don’t.

And that’s this issue of how the body accesses

body fat stores when in a sub caloric state

and I’m doing mainly glycogen burning exercise.

What I heard you say,

and please correct me where I’m undoubtedly wrong.

What I heard you say was that,

okay, I go into the gym and I start lifting weights.

I’m burning muscle glycogen,

mostly local to the muscles that I’m using.

And then I start pulling glycogen from the bloodstream.

Maybe there’s some body fat stores that are mobilized,

probably not dipping into my liver glycogen.

Okay, I complete the workout.

Maybe I even hop on the air dime bike

and do a little sprint.

I go for a jog.

Maybe I eat immediately afterward.

Maybe I don’t eat for a few hours afterwards,

but across the day, I ingest fewer calories than I burn.

Is it the case that body fat is mobilized

in order to replace the glycogen

that my sub caloric intake was insufficient to provide?

In other words, because I didn’t eat enough

to fill the glycogen stores,

am I using body fat converted into glycogen

to fill those stores?


And if so, is that a case

where I’m no longer exhaling carbons

in order to burn body fat,

but rather I’m repurposing body fat into muscle?

Have I turned fat into muscle in that case?

Yeah, I’m really glad you asked this

because I did a very poor job

on that last point talking about earlier.

I’m realizing, playing back in my head,

because that’s so many really good questions.

You cannot turn fat into muscle.

Can you turn muscle into fat?


I’m so glad you said that

because when I was in college,

I don’t want to out that person,

the physiology teacher seemed to think still at that point

that one could lift weights, get muscular,

but then it would eventually turn into body fat.

That myth has, I think, largely been dispelled.

I heard that so many times as a kid.

I heard it so many times in college.

I hear it so many times in our undergraduate students

from other faculty and such.

So no, they’re not the same structures.

They are very different.

Let me take a shot at answering this better.

You were really, really, really close.

So yeah, if you were to do that type of exercise

where you’ve burned a lot of muscle glycogen,

how is it I’m losing stored fat?

That’s really the crux of the question.

And it doesn’t even actually matter

if you then went ahead and ingested carbohydrates

or fat post-exercise.

That’s not really the thing.

You hit on a couple of key things.

Number one, this is all under the assumption

that total caloric intake is still low, right?

You have to have…

Below total need.

Below total need, right?


I also want to flag calories in, calories out

is not the only thing that matters.

This is a very complex thing.

Calories in is incredibly complicated.

Calories out is even more complicated, okay?

So we just…

Maybe another series we can spend on that alone.

So don’t go nuts about that.

You have to be hypo caloric one way or the other.

If you burn a bunch of muscle glycogen

and you are hyper caloric, you’re still going to add fat.

If you burn a bunch of muscle glycogen

and you’re hypo caloric, you’re going to lose fat, right?

Think about it this way.

You’re in a negative calorie state.

Where are those calories going to come from?

Are you going to reduce

your muscle glycogen storages permanently?


No, are you going to reduce

your glycogen storage in your liver?


You want to reduce blood glucose?


No way, right?

So where is that extra energy coming from?

It’s coming from your storage fat.

It is your backup reserve energy system.

The way that I want to flag this here is

people tend to think about it

as like carbohydrates versus fat.

It’s more like a chain, more like a bicycle

where there’s a front gear and a back gear.

You turn one gear, it turns the other one.

These are complementary systems.

They are not and or systems, right?

You’re turning one.

And when we go through carbohydrate metabolism,

maybe here in a second,

you’ll understand why you have to have

an anaerobic and an aerobic component to that.

There is absolutely no way

to complete carbohydrate metabolism without oxygen.

That has to happen.

The only way to engage in fat metabolism

is aerobic and oxygen.

There’s no anaerobic component to it.

There’s a fundamental difference there.

So your carbohydrates are meant to be incredibly flexible.

It is the primary fuel source for a reason.

Your fat is not meant to be flexible.

It is meant to be unlimited.

That’s the basic point.

So you want flexibility over here

and an unlimited capacity over there.

Now I’m safeguarded against any energetic need, okay?

I need to run up a hill for safety.

Cool, carbohydrates are there.

I need to then run for 17 hours.

Cool, fat is there.

We want both of these systems.

You wanna be able to have great energy throughout the day.

You want a slow drip coming from fat.

You don’t want up and down, up and down.

Feel great, up and down.


You wanna be able to think very quickly

and get hyper-focused.

Boom, carbohydrates ramp right up, right?

Get it into the brain, get thinking better,

get thinking clearly fast.

So we want all of these, not just for exercise purposes,

but for activities of daily living,

we want an optimal system here.

When people use the terms like fat adapted,

they’re generally hijacking that and they’re thinking,

it used to be a thing we said all the time

in like all of my undergraduate classes for years.

And that idea of metabolic flexibility

is using optimal fuel sources and optimal times,

not maximizing fat usage.

The people have co-opted that term

of metabolic flexibility to be like,

oh yeah, yeah, therefore learn how to maximize fat burning.

That’s not what that term means.

That term means maximizing your ability

to use whatever fuel is optimal in that time.

Now I’ll grant you,

most people aren’t fantastic at using fat as a fuel source

relative to the other direction,

but nonetheless the gold standard here

should be maximizing both.

All right, finally answering your question.

If I were to burn a bunch of muscle glycogen,

how am I losing that fat?

Well, the fuel you’re ingesting in that hypochloric state

is going to say, hey look,

we have a lot of muscle glycogen we have to replenish.

So any carbohydrate that comes in

needs to be biased towards storage.

It’s got to go into those tissue.

Any fat that comes in or doesn’t even come in,

but any fat that we’re using for fuel

needs to be utilized for activity.

And that’s where the caloric expenditure from fat comes in.

So you’re basically saying your general physiology,

the energy for that starts coming from fat.

And the energy that’s coming in from carbohydrate

needs to be simply stored.

And so what you see is your respiratory cushion changes.

Right, the RER is going off.

And so in the exercise moment,

it’s shot way up for carbohydrates

and shot way down for fat.

As a compensatory response, it goes the other direction

because your body is saying we are low on carbohydrates,

don’t use them for fuel,

unless we absolutely have to, right?

So use them for storage.

Get our fuel from the fat side of the equation.

And so what you’re generally going to say is like,

oh, I’m burning more fat just sitting around

after things like that.

And that’s not even taking into the equation,

the EPOC part, which is like,

it’s not actually as large as people think it is.

It’s fairly small, but it adds up sort of over time.

So does that explain a little bit better

about how you lose fat

when you actually only burn carbs for exercise?

Yeah, you explained it beautifully.

You talked about EPOC,

the post-exercise oxygen consumption,

not being that significant in terms of energy utilization.

Even though today we’re talking about endurance

and different forms of endurance,

I do have to ask whether or not people consider

the elevation in basal metabolism

that occurs when there’s more muscle around

because muscle is such a metabolically demanding tissue.

Is there a straightforward-ish equation?

If one adds one pound of lean muscle tissue to their body,

even if it’s distributed across multiple muscle groups,

does that equate to a caloric need

of X number of calories per day?

And is that because of the muscle protein synthesis needs

of that muscle or it’s glycogen storage needs or both?

If you don’t have enough muscle,

you start to have problems with fat loss.

It’s a difficult challenge.

If you have enough muscle

and you’re just trying to get extremely large,

if your FFMI is 24 and you’re 15% body fat,

adding more muscle is not really gonna play a lot

in the equation and here’s why.

Muscle is more metabolically active at rest than fat,

but fat is not inert.

So fat is still going to burn a small number of calories.

Muscle burns more,

but it’s not nearly what people think it is.

I’m a muscle guy, I’m a muscle physiologist.

I would love to get people to have more muscle

for any excuse I can.

It’s not honest to say that though.

You’re talking about when I was in undergraduate,

we would say numbers like 50 kcals per day per pound

is what you can look at, right?

So if you put on a pound of muscle spread across the body,

your basal metabolic rate would go up

by around 50 calories per day.

I think that number is grossly exaggerated.

It’s probably a 10th of that, six to 10 calories, maybe.

It’s hard to know exactly what that number is,

but the more recent estimates are something like that.

So now on one hand, you could say,

oh my gosh, that is not even meaningful.

The other hand, you could say that’s super meaningful.

It just depends on time domain

you want to put that out, right?

So if you were to put on five pounds of muscle

and your basal metabolic rate went up

30 or 40 calories a day,

well, over the course of a thousand days,

like that actually adds up.

So you can slice this any way you want.

Now, maybe that number is somewhere in between.

I don’t really know.

It’s not a field I pay that much attention to candidly

because it’s not a metric kind of like Epoch

where it’s like, we used to really harp on it

and now it’s sort of like,

well, maybe we exaggerated that like honestly just a bit.

But to me, it doesn’t change the equation much

because if you don’t have enough muscle, as I described,

there are other consequences

that are going to make fat loss hard.

And so you need to have sufficient muscle.

If the additional caloric expenditure is the carrot, great.

If it’s something else, I don’t really care.

There’s just enough evidence that you need to have it.

Or I should say, there’s enough evidence

that it will really help you in your path.

Maybe a few calories here, there is not really that thing.

Especially if you understand a normal food item,

anything you pick is going to be

probably a couple of hundred calories.

One bad food choice a day

will outkick almost any amount of coverage

you got on adding muscle mass to you.

So like you’re really stepping over a dollar

to pick up a dime.

If you’re worried about how many calories

you’re getting from adding muscle,

fat loss is going to be about regulating that carbon intake

above and beyond anything else.

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So I’ve heard about this concept of metabolic flexibility

mentioned a few times.

Frankly, you’re the first person who’s ever explained it

to me in a clear and concise way.

How do I know if I am metabolically flexible

and how do I increase my metabolic flexibility?

Sure, there’s no specific standard,

which is actually a good thing, right?

And so if you have a level of specificity

that you want or need metabolically,

then you don’t actually want to be in this middle ground.

An example would be if you are performing

in a type of exercise or an athlete who performs

in a sport that is glycolytically dominated,

you don’t want to be optimally metabolically flexible.

You don’t want to be super, quote unquote, fat adapted.

You want to be biased towards the energy you’re going to use.

The same could be true for the other end of the spectrum.

So in those particular cases,

it’s not optimal to be equally effective

because there are no free passes in physiology, right?

Your energy producing systems

will up-regulate or down-regulate accordingly.

So you will actually limit your ability

to say maximally utilize carbohydrates as a fuel

if you’re trying to up-regulate your ability

to use fat as a fuel.

And so this is like, there’s a saturation point.

Outside of that spectrum, most people would just say,

hey, like I want to feel great throughout the day

to be able to do a bunch of different things.

How do you know?

A couple of things.

There’s a lot of biological markers you can take.

There’s also just some practical takes.

Now, none of these markers by themselves are any sign.

What you want to do is probably a couple of them

and then say, okay, this is maybe a clue.

So again, it’s really important to emphasize

not a single one of these tests

that I’m about to walk you through

automatically means you can’t use fat as a fuel

or the other case, which is maybe you’re poor

at using carbohydrate as a fuel.

So disclaimers aside, we’ll get into a couple of them.

So should we think about these as informative and useful

but not diagnostic?


We would call this data inspired or data led

and not data driven, right?

Okay, cool.

So number one, you want to think about

just overall functionality.

Do you have a reasonable regulation

of your energy throughout the day?

Now, many things could be going into this

which is why these are not specific diagnostics

but as a basic measure, we talked about blood glucose levels.

You know, a lot of people will say,

again, you want that to be something like

between 80 and 90 milligrams per deciliter

is a blood glucose level.

And you can go look at the cutoff points

for what determines to be pre-diabetic

and type two diabetic, et cetera.

What I can actually recommend,

there’s a little bit of science here actually

that I’ll talk you through,

but a lot of this is my personal preference.

I generally want people to be at 85 or lower.

And that’s because of a couple of things.

Number one, there’s actually some papers that showed

every single point increase above 85

increases your likelihood of developing type two diabetes

by about 6%.

Okay, great.

So technically while maybe 90 or 95 or even up to 100

are in the quote unquote normative values,

that’s one clue.

Again, it’s not definitive by itself,

doesn’t mean anything.

You need to really pay attention to what increasing

by 6% actually means,

but it’s a data point where I’m looking at.

If I actually then see symptomology

and we run you through maybe some questionnaires,

ask how you’re feeling throughout the day

and we see uncontrolled energy bouts.

So you’re a lot of energy,

then you get really, really tired and swings.

Okay, another data point.

All right, and we may patch a few of these things together.

That may give me some clues.

That being said, again, a lot of this rhetoric is used

to then scare people off of carbohydrates.

And that is, I want to be as clear as possible.

That is not, not truly the only thing

people should care about, right?

It can be a thing that can also be unrelated.

There are reasons you could have blood glucose concentrations

at this level or energy swings

that are unrelated to carbohydrate ingestion at all.

All right, so one test you can either run.

In addition to that,

if you’re going to get blood glucose measured,

you can look at some markers we talked about earlier,

which are AST and ALT.

We talked about how you can kind of look at that

AST to ALT ratio before.

You can actually do the inverse,

which is look at ALT and AST.

The kind of normative value there

you’re going to look at is like 0.8.

I actually like to see it lower than that.

And that alone has been actually associated

with blood glucose dysregulation.

And so if you see multiple of these signs,

again, we’re looking for patterns and patterns and patterns

in both, in our case, biomarkers,

symptomology and performance.

And now you’re, if all three of those things are lining up,

you may have an issue.

So performance wise,

a couple of little tests you can run.

Ideally you have some sort of standard workout you do.

Oh, and hopefully it’s pretty objective.

So in other words, like I run the same 15 minute loop

every morning for my cardio.

Okay, great.

How long does it take you to run that loop?

Like you could pick whatever distance,

it doesn’t really matter.

What’s your heart rate during that thing?

And then what’s your perceived exertion?

Now you should be able to do that fasted

with very little drop in performance.

Okay, if you can do that,

then that tells me you’re fairly good

at using a fat as a fuel source.

If however, the one day you go to do your standard workout

and you feel awful fasting,

that may be another clue that perhaps

you’re not very good at dialing in that system.

If your recovery afterwards

in terms of heart rate recovery is very long,

it may be another clue that you have a poor utilization

of fat as a fuel source.

The inverse can also be true.

So if I give you something in the neighborhood

of like 50 or so grams of carbohydrate

and 30 minutes later, your face is falling off the table,

that’s a good sign that you’re in the opposite.

You’re actually very, very, very poor

utilizing carbohydrate as a fuel.

And the reason I bring that up is that is equally a problem.

We hear people a lot make comments like,

man, I have to stay away from carbs.

I crash really hard if I do them.

What that actually means is you’re very poor

at utilizing carbohydrates as fuel.

Your sensitivity is way off.

We should be able to have carbohydrate

at a reasonable dosage, 50 grams,

and not fall asleep 30 minutes later

or have to run to caffeine.

So that is a sign in our opinion.

This is, again, now just my practical brain telling you

is that’s a sign of dysfunction.

We should be able to have plenty of carbohydrates

through the day if we choose to,

if we want to for any reason.

Now, of course, if you were to throw 150 or 200 grams

of carbohydrate in your belly,

you’re probably going to take a little bit of an energy hit

after that, but we should be able to have a reasonable dosage

and not have to fall asleep afterwards.

What is one way that people can enhance

their utilization of carbohydrates for exercise?

The reason I ask is I think I fall into that category.

I do consume some complex carbohydrates

and fruit post-resistance training.

And that tends to be when I’m hungriest for them.

But typically, unless I’ve just done some resistance training

I keep most of my daytime meals

relatively low carbohydrate.

And then in the evening, I prefer slightly less protein

and more carbohydrate because it has this effect

of sedating me a little bit and I sleep well.

And I know this runs against what everyone was taught,

which is to not eat carbohydrates late in the day.

But I like it because then I tend to wake up

in the morning with, at least as far as I can tell,

my glycogen stores, not necessarily topped off,

but certainly filled.

And I’m able to train fasted in the morning.

And my favorite pre-workout consists of water

and caffeine and electrolytes

and maybe some supplementation as well.

But I love training fasted.

So there’s actually a number of things.

One little sneaky thing you threw in there

is actually the use of caffeine.

So that’s another sign.

If you have to have caffeine to do your fasted training,

that’s generally another sign

you’re not very good at using fuel.

So I use caffeine prior to resistance training workouts.

Generally, I don’t need it

for any kind of cardiovascular training.


And when I say that, it doesn’t mean it’s bad.

It’s just like another clue that’s like,

okay, you should be able to do this

without having to have caffeine to execute it.

Now, using caffeine to get a better result

is sort of different as an ergogenic aid.

We actually use a lot of high carbohydrate meals

at the end of the day,

a lot of the times for our athletes who are cutting weight

or trying to reduce weight.

It is a fantastic way to handle a lot of things.

And that idea that if you eat carbs late at night,

that’ll increase fat.

So like that’s all is so old

and so well destroyed scientifically

that that’s not a concern.

There’s just so much data showing.

In fact, there’s so much data on like eating timing

is generally poorly understood

about when you can eat and what you can’t eat.

Eating in the morning versus eating at night.

Like a lot of what we’ve heard in there is tough.

And maybe we just save that for sort of another day

because we’re going to get really far down

in this water we can dive into it.

Yes, I think our plan is to cover that

in an episode on nutrition, which is in this series.

The only thing that I would add to it is,

you know, when you hear about

ingesting carbohydrate late at night,

I should just say that at least in my case,

I’m eating the majority of my carbohydrate

unless I trained, resistance trained early in the day,

in which case I post resistance training.

In the last meal of the day,

but for me, that’s not really late at night.

That last meal is somewhere between 6.30 and 7.30 PM.

So it’s three or so hours or something like that

before you go to sleep.

Yeah, I go to sleep around 10, 10.30 or so.

Yeah, yeah.

So it’s not, you know, midnight bowls of pasta.

I’ve done that too, but typically it’s not.

So I think that people will be very interested,

myself included, in how meal timing relates to all of this,

but yeah, let’s put that towards it.

So how do you improve fat utilization?

How do you improve carbohydrate utilization?

Let’s hammer both out really quickly.

Enhancing fat utilization is as simple

as doing a little bit of work

in a either pre-fat ingested state.

So anytime you ingest a nutrient prior to training,

you’re going to bias towards that nutrient, right?

Which is almost what we were talking about earlier.

So if you want to guarantee you burn more fat,

eat more fat prior to a workout.

Now you’re not going to lose fat,

but what you’re effectively signaling

is we have an overabundance of this fuel.

Preferentially target this fuel.

Now the downside is that may actually

hinder your performance.

That’s typically only a concern

for people at a very high level.

Fat is a slower fuel source.

So if you’re relying more upon that,

your top end is going to come down a little bit.

And so you wouldn’t want to use that strategy prior to race

if it is a carbohydrate dependent race, right?

And in fact, we actually see long-term adaptations

that would suggest that.

So the enzymes responsible for carbohydrate metabolism

will down regulate.

And so you get worse at that.

So not a great strategy there.

Carbohydrate would be the opposite, right?

So if you have carbohydrate prior to exercise,

you’re going to bias more towards that.

So a handful of things you can do.

If your total caloric intake is simply managed,

that’s going to take care of a lot of these problems.

An appropriate eating strategy.

So the types of food, the combinations of food,

all of those things are going to make

your post-carbohydrate ingestion bonk.

A lot of those things can go away.

So there’s a little bit of physiology

that has to be corrected for.

So it’s a little bit…

In one hand, you can go very deep here, right?

So the real answer of how we would do this

is if we see a scenario like that,

we’re going to do a whole set of analyses.

We’re going to go full labs, right?

Extensive blood panel, urine, saliva, stool even.

And we’re going to figure out

where is that glucose dysregulation coming from?

So a lot of people think like,

oh, it’s a metabolism issue.

It might be.

It also might just be a flag

that something else is happening in the body.

So we’re going to actually work backwards a lot

to try to figure out exactly why that’s occurring.

It may be as simple as,

oh, you’re eating a lot of your carbohydrates

without any fiber or protein.

And we know that that’s important

because those will actually blunt the glycemic index,

like the rise in blood glucose.

So it could be a simple thing of just like,

oh, your combination of food is doing it.

It’s not the total amount.

It may be something again,

more endogenous to the actual system.

It could be a heart rate issue.

It could be a breathing issue.

There could be a number of things.

So the way to get better at it is to simply train it.

And specificity is king here.

So if you want to get better

at managing your blood glucose throughout the day,

so that you’re not feeling those things,

it could be a fuel issue,

but it could be a number of other things.

And it’s just hard to go into all of them

within our time constraint.

So the practical tool that I would say here is,

if you want to get better at managing energy

throughout the day,

make sure that number one, your protein is stabilized.

Make sure number two,

you’re ingesting your food in the right combinations,

ideally with some fiber and or some protein or both.

That alone will help stabilize a lot of the problems.

Then you need to train at a high intensity.

You want to get better at using carbohydrates as a fuel,

train at a higher intensity

and have carbohydrates right before the workout.

We’ll do that a lot if we see folks who are,

I kind of walked you through the test of identifying

if you’re not very good at using fat as a fuel.

The test for not being good at using carbohydrate as a fuel

is both that eating test I talked about,

as well as performance.

If you’re a very, very, very slow starter,

it’s just like really hard to get going,

that generally indicates you might be in a situation

where you’re not very good at using carbohydrates as a fuel.

So we’re going to practice that.

We’re going to have a pre-carbohydrate,

pre-exercise carbohydrate meal,

and then we’re going to do higher intensity stuff.

Not to the point of making you sick

and digestive issues, all that stuff,

but we want to get better at using carbohydrates

as a fuel faster.

If you want to get better at doing the opposite,

then you do that opposite strategy.

Either again, using fat prior to the workout,

knowing your peak performance

is going to go down a little bit,

but you’re investing in adaptation, right?

So it’s not about that workout.

It’s about what’s going to happen six, eight, 10 weeks from now.

Investment is what you want to think about it.

Or you could bring in some fasted training.

And so I want to really make sure I clarify

when we were talking about earlier,

I’m not at all against fasted training.

It’s not, it works.

It just isn’t required for fat loss.

It isn’t required for fat adaptation.

It is a great option though, if you want.

What I was hoping to do with that conversation

and maybe I didn’t articulate that well

is to not restrict people, but is to open you up.

And at least you have a lot of options.

If you like to do fasted cardio, amazing, it is great.

If you hate it, you don’t have to.

You can reach the same performance goals,

the same physique goals without ever doing it.

If you love long duration steady state stuff, it is great.

If you hate it, there are other options,

higher intensity stuff.

Again, if we’re just talking about fat loss.

So I hope now that that’s a little clearer

in terms of the same thing in nutrition.

If you like higher carb, great.

If you like lower carb, these are all great.

You have options and you don’t have to fret so much over,

oh my gosh, I have to do this thing a certain way

and I absolutely hate it.

You don’t have to worry about it.

Hit those concepts and you’ll be fine.

A few minutes ago, you mentioned that

if we ingest a given macronutrient, like fat,

then the body will preferentially use that fuel source.

If you ingest carbohydrate, it will use that fuel source.

Is it always the case that the body uses

the ingested macronutrient prior to using glycogen?

I have to imagine it’s using both.

I mean, if I were to have some carbohydrate

before doing any kind of training,

the muscles still burn glycogen, right?

Or do they have some way to register the amount

of circulating carbohydrate that would allow

or available carbohydrate in the form of foodstuffs

that would allow them to not tap

into their own muscle fiber stores of glycogen?

All right, so the way that we derive energy

for exercise or basic maintenance,

a little bit about cellular physiology.

So you’ve got a couple of organelle and structures

that we need to pay attention to.

The first one is the nucleus.

That’s holds your DNA.

The second one is the mitochondria.

And then everything outside of that,

you’ve got all these other organelle

that do a bunch of things like ribosomes

or protein synthesis, et cetera, et cetera.

All right, now, when you wanna produce energy for exercise,

anytime you hear the word anaerobic,

you automatically understand

we are meaning without oxygen.

All right, great.

That all happens in the cytoplasm.

The cytoplasm is that space

that is not the mitochondria, not the nucleus.

So it’s the space in between everything else.

This is like jelly-like substance that stands there.

So anaerobic metabolism happens there.

Every single aerobic metabolic process

happens in the mitochondria.

All right, why is that important?

If I go to create cellular energy

and I need it the fastest possible,

I’m going to go for phosphocreatine

because it is stored directly in the cytoplasm.

The stoichiometry is one-to-one there,

which means for every mole of phosphocreatine I burn,

I can create one ATP.

It’s one-to-one.

It is incredibly fast, but it is very limited

because think about it,

how much of that could I possibly store

in the small size of the cell?

That’s it.

If I need energy past that point,

now I’ll start using muscle glycogen

because that is also stored in the cytoplasm.

So it is right there.

The stoichiometry is not one-to-one.

It’s a little bit higher, probably like four-to-one.

So for every molecule of glycogen you burn,

you’re going to get something like four-ish,

like some small number of ATP out of that,

which is great.

But again, you’re running into a storage problem.

How much can I possibly store inside a muscle cell?

It is very, very fast,

much more effective than phosphocreatine, but so there.

If I then want to metabolize any form of fat,

or if I want to complete the metabolization

of carbohydrates,

I have to start transferring into the mitochondria.

Now I start getting whole hosts of ATP.

If you were to fully run through this thing,

which I’ll talk about in a second,

called the TCA cycle or Krebs cycle,

you’ll get now something like 28 or 30 or 35,

kind of depending, ATP per.

So the energetic output is much higher.

Okay, so here’s exactly what happens.

And I’m going to walk you through this

in the form of carbohydrate,

and then I’ll come backwards and go through fat.

So remember, carbohydrate,

it is one carbon molecule that has been hydrated.

So it is one-to-one.

So the actual chemistry here,

it is CH2O, one carbon, 2H10.

Glucose is a six carbon chain.

So the chemistry here is C6H12O6,

six carbons, six waters.

Very simple, that’s a carbohydrate.

All right, so you can imagine

if you’re watching on the video here,

you’ll see my fingers going nuts.

I’ll try to make sure I explain it to you all

just listening in an easy fashion.

So you’ve got this chain of six carbons

that is in front of you.

And the very first step to metabolism

is you snap that thing in half.

Right, so you break into two separate three carbon chains.

All right, now in doing that,

you got a little bit of energy

because you broke that one bond,

but not a tremendous amount.

This is called glycolysis.

So lysis being the split and glycogen,

like you split glycogen up,

got a little bit of energy of that.

All right, you form this three carbon chain

called pyruvate or pyruvic acid.

Okay, there’s differences there,

but don’t kill me.

General audience, friends.

All right, I gotta give this,

communicate this to everybody.

So you got a little bit of that.

Now you can’t do much past that

besides rip one more carbon

off of each of those three carbon chains.

So I’ve got two, three carbon chains.

I gotta be careful how I do this with my fingers

so I don’t flip you off here in a second.

But I burn one more off of each.

I get a little bit of energy

and now that little two carbon chain,

I have two, two carbon chains,

those are called acetyl-CoA.

All right, amazing.

I have now completed anaerobic glycolysis.

I’ve got really nothing left I can do here.

I made a little bit of ATP.

Now, wait a minute.

I have now freed two carbons

because remember I started with six

and I split them apart,

but I didn’t, I had two, three carbon chains.

I burned one each.

I’ve got two free floating carbons.

I have to now do something with them.

My body will not let me go through that last process

unless I’ve got a plan for that free carbon

because I can’t break it in half.


Here’s what’s going to happen.

If I have those three carbon molecules

and I don’t have anywhere I can put that carbon,

you’re not going to go through that process.

It’s going to stop it.

You’re gonna start building up pyruvate.

Now, at the same time, you’re breaking ATP for fuel.

That’s called ATP hydrolysis, right?

You have water that comes in,

you have an adenosine and three phosphates.

That’s why it’s called ATP,

adenosine triphosphate, one, two, three.

You break one of those phosphates off.

There you go, there’s your energy.

So now you have a free floating inorganic phosphate

and an adenosine diphosphate, so two over there.


That actually results because you use water for it,

results in a free floating hydrogen ion.

Okay, you just have to trust me, hydrogen H2O.

Any idea what a free floating hydrogen is?

It’s gonna…

That’s acid.

Yeah, I was gonna say it’s gonna increase acidity.

That’s what acidity is.

For anyone that’s ever measured pH,

what you’re really measuring is the amount of hydrogen.

Potential hydrogen, that’s what pH is, right?

100%, there’s two definitions of pH,

but you get it, that’s one of the two.

So is this, are you gonna tell me

this is related to the burn?

We’re gonna get close, right?

So I’ve got a bunch of free floating.

You’ve got the phosphates, which are actually a problem,

two, probably more of a problem than people realize,

and that hydrogen.

What are you going to do with that hydrogen?

Well, one thing you can do is actually ship it over

to pyruvate and bond it there.

We have a special name for that little molecule

when you have pyruvate and you have hydrogen attached to it.

Do you know what it’s called?

Hydrogen peroxide?


Lactate, lactic acid, this is that whole system, right?

Again, I was skipping some steps,

making a little bit of mistakes here,

intentionally folks, just to make this assumed.

So what happens when you start running

a bunch of anaerobic glycolysis?

You start seeing massive rises in lactate.


Not lactic acid.

Right, right?

That’s why we see associations

between a lot of lactate and a lot of fatigue,

but the lactate is actually not causing the fatigue.

The lactate is actually sparing you

from having a bunch of free floating acid.

It’s also can be then used directly back in the muscle

because as soon as you bring in enough oxygen

and you can take that hydrogen back off of it,

you’ve now turned it right back into pyruvate

and you can run it through this whole cycle

as fuel that I’m about to do.

You can actually actually ship it

out of the exercising muscle

and ship it into a non-exercising muscle

and then go backwards and make glucose.

What actually liberates hydrogen from lactate?

You mean like chemically?

Yeah, so what liberates,

well, what are the stimuli that can take hydrogen

off the pyruvate?

Yeah, oh yeah.

And then in other words,

to reduce lactate and free up that hydrogen.

Oxygen availability.

So in fact, one of the major places

that you ship hydrogen to,

or one of the major places that you ship lactate to

is your heart,

because it’s what we call the ultimate slow touch fiber.

And it has a ton of freely available mitochondria,

which have a ton of access to oxygen

so it can actually then go to it, form water.

The H2O can be used to form water

and now we have a place to store the hydrogen.

Got it.



So as a result of anaerobic glycolysis,

we have made a little bit of ATP.

We’ve created a lot of waste

and we don’t have anywhere to go with these end products.

So when you do anything of a higher intensity

and it says, I need energy fast,

you’re gonna go to this system first, right?

Right past ATP,

because it is the fastest place to get energy,

but you’re not gonna get much of it

and you got to deal with the waste products.


Right back to the beginning of our conversation.

Endurance is about two things,

energy production and waste management.

And we’re right, we’re fatigue buffering.

This is it, right?

How well can you handle the elevations in hydrogen,


Drop in pH.

And then what are you gonna do with these products?

If you want to fully metabolize a carbohydrate,

you then have to do something with those pyruvates

or those acetyl-CoAs,

which are going to do,

if oxygen is available,

you will take those things

and ship them into the mitochondria.

They have to go through some cell walls

and some other things like that,

but they’re going to get inside there.

Once they’re in there,

that two carbon acetyl-CoA

runs through this entire cycle

that we call the Krebs cycle.

And that’s this really interesting place.

That’s where B6 and NMN,

people are like,

that’s where that whole stuff starts to kick in.

All your B vitamins basically run that entire circle

and you’re gonna start off at the top.

You have a bunch of fun stuff going on,

but as a part of that circle,

you’re gonna pull off some hydrogen ions.

You’re gonna send these

to what’s called the electron transport chain.

That’s where you’re gonna get a ton of ATP out of.

And as a result,

about halfway through the turn,

you’re gonna pull off one carbon

and about halfway through the other,

almost the other way to the finish,

you’re gonna pull off the second carbon.

So you’re gonna take the second acetyl-CoA,

run that entire thing,

same through as well.

And so what we did is we started off

with a six carbon glucose chain.

We split it in half.

We call those pyruvate.

We made a little bit of energy

because we broke that one bond

of those two carbons that are in the middle.


Those two, three carbon molecules,

we pulled one carbon off of each.

We brought in,

sorry, we moved those into the mitochondria.

We brought one off.

We took a breath,

brought in some oxygen,

bonded that,

took out two CO2 exhales.

We ran the acetyl-CoA through the Krebs cycle.

One, two carbons per turn coming out of CO2.

So we had six carbons total as we started

and we exited with zero carbons.

Now we have fully metabolized

a molecule of carbohydrate.

That required an anaerobic start

and an aerobic finish.

If you don’t have a lot of mitochondria,

large mitochondria,

high functioning mitochondria,

you’re going to limit your anaerobic performance

because you’re going to get,

they’re gonna run that door full very, very quickly.

You can’t go past it

because hydrogen will build up way too fast.

And one of the things that we know

is both temperature and pH run enzyme function.

So they’re going to stop.

You won’t even be able to run through,

in fact, that ATP hydrolysis phase.

Even if I gave you a whole infinite supply of ATP,

if I put enough acid in there,

it would stop working

because the ATPase enzyme needed to split.

It won’t be able to run

in a highly acidic environment or a hot environment.

Yeah, at some point,

perhaps today,

perhaps in the future discussion,

but still not too far from now,

we could talk about the role of temperature

in pyruvate in terms of its regulation

of muscle contraction.

But I want to make sure I understood something correctly.

You mentioned these two parallel fuel systems, right?

One is essentially anaerobic, right?

And the other is aerobic.

You said that if we can’t pull enough,

if we can’t break enough bonds,

then we limit our anaerobic capacity.


I would have thought,

given that the mitochondria are the site

for essentially for aerobic metabolism,

that we would be limiting our aerobic capacity as well.

Perhaps you could just clarify for me

how these two things are divided

or is there not a clean division?

Is it not an either or?

No, in fact, again,

I think it’s better to think of these things

rather as two separate parallel things as one big cycle.

They’re one gear turning the next.

Being compromised in one will compromise the other.

That, I should say,

reminds me of what you said earlier,

which is the bicycle gear analogy.

That works great.

So if you short circuit one,

basically the chain can’t move.

That’s fantastic.

Okay, so indeed they are running in parallel,

but they are interdependent.

Yeah, well, they’re actually not even running in parallel

because they’re actually funneling to the same endpoint,

right, which is like,

if you’re going to come from the anaerobic glycolysis route

or you’re going to come from the fat route,

which I’ll talk about in a second,

they’re both going to be limited in the mitochondria.

So when that thing’s full, it doesn’t matter.

You can’t run either system, right?

So it is more of like a,

again, if you’re running the bike gears,

it doesn’t really matter if the back one’s larger or smaller

because if either one is limited, you’re toast

because they’re running on the same system.

You can sneak a little bit here and there, but not much.

You also really nicely highlighted how lactate,

this thing that we think of as a limiting factor,

like the burn, it gets in the way

and it’s the thing where you need to stop

and buffer and all sorts of things.


It’s actually really a fuel.

It’s a tremendously effective fuel.

Yeah, it is a strongly preferred fuel, actually.

It’s interesting, this is a very classic case

of association, correlation versus causation, right?

So the original actually,

like there’s a really cool history on lactate,

but it was originally found, I think in Germany,

pardon my history there,

somewhere in Europe in hunted stags.

So one of the things is they sort of realized

is like if we harvested a stag in a rest state

when it didn’t know we were there

versus if we chased it and it was ran down,

that these lactate concentrations were significantly higher

in the latter situation.

Therefore, lactate started immediately getting

this association between high fatigue points.

It is easy to measure.

If you do any sort of lactate test,

any sort of metabolic test,

you will see as fatigue increases,

lactate will also increase.

The assumption there was then, oh my gosh, it’s the cause.

Now we know like, again, it’s not the thing,

it’s in large part trying to buffer

the negative consequences of ATP hydrolysis

and some other things.

So it is certainly playing a part in that role,

but it is not the core driver.

It’s also why you don’t need to worry

about doing things to, quote unquote,

reduce lactate in the muscle after exercise

or to clear lactate or any of those things.

You may still wanna do those activities,

but not for that reason.

Lactate’s fine, you’re actually gonna use it

in, again, the neighboring exercise muscle fibers

in the same muscle.

Another muscle, you can send it actually to the liver

and it can actually go through gluconeogenesis

and it can actually replenish liver glycogen

just as a fuel source,

or you can send it to the heart or any number of sources.

You can also just kind of put it in circulation,

put it back in the muscle,

and once enough oxygen is there,

you can just kick it right back

into either glucose or glycogen.

It’s totally fine.

So it is obviously clear though,

once that number gets very, very high,

other things are going to be happening

that are gonna be causing a lot of hurt.

And this is your managing waste, right?

It’s really an issue of managing

what am I gonna do with all this extra carbon?

What am I gonna do with all this extra inorganic phosphate

and some other nasty byproducts?

But that’s the thing you have to deal with.

I’d love for you to teach me

how different ratios of fuel sources are used

depending on how long I happen to be exercising.

For example, if I do a very short bout of exercise,

typically that’s correlated with a higher intensity output.

I mean, I suppose I could jog for one minute,

but here I’m thinking about sprinting for one minute or less.

Which fuels are used?

Is that mainly driven by fat,

by carbohydrate stores?

Is it driven by dietary fat preferentially

or carbohydrate that I’ve ingested

if indeed I’ve ingested those or protein for that matter.

And then as we transition to exercise

that goes a little bit longer,

anywhere from three to five minutes,

how do those ratios change?

And as we transition to longer duration,

what most people think of as endurance exercise,

but long duration output of 20 minutes or more

leading all the way up to a full marathon.

How does that change the ratio

of fuel sources that are used?

And I’d be particularly interested

in distinguishing between carbohydrate,

fat and protein that’s ingested.

So coming from food sources

or carbohydrate, fat and protein

that are coming from storage sites within the body.

Okay, great.

Let’s start at zero seconds

and run all the way through marathon.

And we’ll flag the distinctions where they start changing.

As soon as you want to create muscle contraction and power,

the very first source of energy is phosphocreatine.

That’s gonna power you for zero to maybe say eight

to 15, 20 seconds of maximal exertion.

And that’s coming from the muscle fibers themselves.

Yeah, that is actually stored

in what’s called the cytoplasm.

So this is a little area or space in the muscle fiber

that’s sort of like in this jelly-like substance.

And it’s nice because one molecule of phosphocreatine

gives you one molecule of ATP.

So it’s not a big energy output,

but it’s very fast because it is stored right there

in the local exercising muscle, right?

Now, if you need energy past that point,

say 10 or 15 seconds up to maybe a couple of minutes,

this is now you’re gonna have to transition

because you’re gonna burn through that phosphocreatine

and it’s gonna be out.

You’re gonna have to move to now carbohydrate metabolism.

This is what we call anaerobic glycolysis.

So there’s two phases of glycolysis.

Glycolysis itself means glucose burning, all right?

So it just means we’re using carbohydrate as a fuel source.

So initially, when we start off this cascade,

which is gonna take us again for a couple of minutes,

carbohydrate utilization comes first

from the exercising muscle.

So it’s very similar to phosphocreatine that way.

If you start running low on it,

you can actually start pulling blood glucose.

And if blood glucose gets low,

you’ll have to start getting glycogen from the liver

to keep that up.

So we’ve sort of covered that conversation.

All right, so a little bit of chemistry here,

just give me a little bit of room here.

So now remember a carbohydrate is a carbon molecule

that has been hydrated.

So one carbon attached to one water,

and remember water is H2O.

Most of the time when we’re talking about glucose,

it is in a six carbon chain.

So six carbons attached to six water molecules.

All right, great.

When I go to split this up through anaerobic glycolysis,

it works a little bit like this.

So you’ve got this six carbon chain.

The first step is to snap that thing in half.

You’re gonna make two, three carbon chains.

Now we broke one bond right there,

so we got a little bit of energy,

but not a tremendous amount.

At the end of anaerobic glycolysis,

you’re gonna net something like three or four ATP.

So more than you get from the phosphocreatine.

Triple or quadruple, but still not very much.

There’s another major downside that’s coming in a second

to this system.

The upside is it’s fast.

Actually, one adaptation we get to training in this style

is you’ll increase your ability

to store glycogen in your muscle.

Which is great, right?

We can actually biopsy you and measure the amount

that you store, and a training adaptation is awesome.

So you’re able to sustain this system longer.

So perhaps 90 seconds into your interval training,

you hit a fatigue point,

and now you maybe can extend that to 100 or 115 seconds

simply because you’re storing more glycogen in the muscle.

Before we have to then go into the blood

and get it in the form of glucose.

So that’s great.

So we’ve got this six carbon molecule,

and we split this in half.

We got that little bit of ATP.

And now we’re in this little tricky position

because this three carbon molecule

is what we call pyruvate, pyruvic acid.

And again, chemistry folks, I’m skipping some steps.

I’m gonna intentionally make some mistakes here.

I’m making sure the entire world listening,

regardless of where they come in, can follow me here, okay?

So don’t burn me on the details.

Right, you’ve got this pyruvate.

The problem is you can no longer do anything

with that glycolysis is over.

You’ve gotta make a choice, right?

In order to make something

out of those three carbon molecules,

you’ve got to ship them to the mitochondria.

As we’ve said, that is the only place of aerobic metabolism.

Right, we cannot do aerobic metabolism anywhere else

until we enter the mitochondria.

So anytime we cross that barrier,

we know we’ve automatically switched

from anaerobic to aerobic.

Well, here’s the problem.

If you were to take one more carbon

off that three carbon pyruvate,

you have to now do something with that carbon waste, okay?

So before when we split the six carbon chain,

we didn’t actually leave any carbons free-floating.

We just split a two molecule in half.

When we go to split from pyruvate

and make it into this two carbon molecule

called acetyl-CoA or acyl-CoA,

now we’ve got a free-floating carbon.

We have to have a strategy for that

because that’s going to increase the acidity level.

Any enzyme in our body that works to create fuel

is very pH sensitive, right?

So if this thing, if pH gets off either high or low,

these enzymes can’t work.

And that’s really, really important

because even if I were to give you a direct injection

of ATP, remember that’s that energy currency,

that’s the only way we can actually form energy.

I guess remember to clarify,

anytime we’re using phosphocreatine or glucose or fat,

which we’ll get to a second,

we’re not actually getting energy for exercise

by breaking those down.

We’re getting energy that we can use to then make ATP.

We break that ATP down.

That’s what’s actually powering muscle contraction.

You can go back to our previous episode

where we walked you through the detail

of the muscle contraction.

But that’s what we’re after, okay?

So in the case of pyruvate,

if we split that off, we have got to deal with that.

And the only way and the best way

we can deal with that is oxygen.

Remember, we’re going to breathe in O2.

That O2 is going to combine with that free-floating carbon,

make CO2, we’re going to exhale that thing out.

That’s our waste management strategy.

But that has to happen in the mitochondria.

Remember, if we’re using oxygen,

it has to be in the mitochondria.

So if we have the ability to ship pyruvate

into the mitochondria, we’re golden.

But what happens if we don’t?

Why do we not?

Well, if we don’t have enough mitochondria

or our mitochondria are too small or they’re too far away,

or we don’t have sufficient oxygen availability.

Why don’t we have sufficient oxygen availability?

Because we created the pyruvate too fast.

And the demand in the mitochondria is exceeded

by the buildup of pyruvate.

And so now we’re having this giant backlog

and this thing fills up fast.

We have a couple of strategies here.

Well, when you’re going through ATP and you’re splitting,

it’s called ATP hydrolysis.

Of doing that, remember ATP is an adenosine molecule

and then the T part is triphosphate, one, two, three,

which means you have three phosphates attached at the end.

When you break that phosphate off,

that’s where you get your energy.

So now you have an inorganic phosphate

and an ADP, adenosine diphosphate, two.

That process requires water, it’s called hydrolysis.

As a result of that, you then have a free floating hydrogen.

And as you well know, that is acid, right?

That’s potential hydrogen, that’s what that means.

And so you’ve increased the acidity in the muscle

by breaking up all this ATP.

And so, uh-oh, we’re building up acid,

we are building up pyruvate,

we have nowhere to go with it,

and we can’t cleave off a carbon

because now we’re just gonna exacerbate the acid increase.

So what we can do is we can take those hydrogens

that we’re building up and store them on the pyruvate.

A pyruvate that’s holding an extra acid

has a special name and we call that lactate, all right?

So that’s why we see this buildup of lactate.

So one of the downsides of anaerobic glycolysis

is an incredibly high rate of waste production.

Now, lactate is not the cause of fatigue.

In fact, if you think a little bit more carefully

about what I just said, it’s actually stopping you.

It’s what we call a acid buffer.

You can actually use it for a bunch of other things.

You can ship it to a neighboring muscle fiber

in the same muscle that’s not working,

you can ship it to the liver,

you can ship it to the heart and a bunch of other places,

and then you can actually just work backwards.

So if you ship it to, for example, the heart

and it’s got a bunch of mitochondria that are free,

you can bring in the oxygen,

attach it to that hydrogen, make water,

and now you’re right back to pyruvate.

You put two pyruvate back together

and now you just make glucose.

So you can actually store it in the liver.

This is a process called gluconeogenesis

through this fancy thing called the Cori cycle,

which is what the proper cycle here is.

So you can use it as a very potent fuel source.

In fact, lactate is a tremendously valuable fuel source,

not only for exercise, but for cognition

and a bunch of other things.

So lactate, in fact, this is why,

if you’ve seen any of the research

about pre-exam testing exercise,

you’ll see a noticeable increase in exam scores

if you do a 20-metabyte of exercise prior to taking the exam.

And it’s largely in part probably

because of things like elevations in lactate.

How intense of exercise would be most beneficial?

I don’t know that exact answer.

I just know that generally any form of exercise is good,

but if you were to reach a reasonably high heart rate,

you’re probably going to see…

In fact, there’s an acute and chronic adaptation here.

So folks that exercise have better memory retention,

scores in exams, et cetera,

but then also doing it prior to that exam,

make sure you recovered and rested back down to straight,

but you’ll generally perform better.

I had a previous guest on the Huberman Lab podcast

who’s a psychology professor and neuroscientist

and also Dean of College of Arts and Sciences

at New York University, NYU.

Wendy Suzuki is religious about daily morning exercise

specifically for this purpose

of enhancing learning and memory

and has a lot of really beautiful data.

I consider her one of the real pioneers in this space.

So if people want to learn more,

they can look to that episode or Wendy’s work.

We can provide a link to a couple of the papers,

but this is fantastic in that it’s incredibly clear.

I think for the first time,

I’m understanding what lactate is really doing.

And it’s dispelling a lot of myths

that I think I and a lot of other people

arrived to the discussion about lactate with.

What happens when the bout of exercise extends longer?


So if we want to continue past that point,

we have to have some sort of strategy

to get through it, right?

We’re stuck, we’re out of gas.

We have to then ship it to the mitochondria.

And now we’re going to enter

what’s called aerobic glycolysis.

And this is going to take us anywhere from,

again, say that 90 seconds of all that work

up to really 20, 30 minutes.

In fact, it really will take us to unlimited.

If you look at a highly competitive marathon runner,

even those that are running, say your two-hour marathon,

those folks are burning up to 80% carbohydrate.

It is not a fat burning thing.

And the reason is fat metabolism is way too slow.

It provides a lot of energy, but it is incredibly slow.

If you’re trying to run a four and a half

or so minute mile repeated 26 times,

you have to be moving fast.

Are they ingesting carbohydrate

as a fuel source during the race?

Unless you’re on the team, you don’t know.

They won’t really tell you.

These are sort of trade secrets.

It would be, I would say, fairly rare to not have something.

There’s a bunch of different strategies.

If you’re going to go really long,

like some of these, like cycling,

where the races will be several hours,

then you actually might go to some fat as fuel sources.

I know a lot of cyclists are using ketones

and things like that now.

But traditionally, most endurance folks

are going to bias heavily towards carbohydrate.

Now, in one respect,

you’re not going to run out of carbohydrates

until you’re many hours in.

These folks are a unique case,

but the average individual who’s doing an hour,

hour and a half cardio even,

you’re not going to be limited by your carbohydrate stores.

You’re going to be just fine.

You’re going to be limited by some other things,

which we’ll maybe sort of break down here in a second,

but you’re going to be fine there.

A lot of those folks will take carbohydrate,

they’ll have very specific intervals.

You do want to be careful though

of ingesting too many fast carbohydrates

prior to your exercise spout.

We actually have this little thing

that’s called the insulin glucose double whammy.

And what that means is when you ingest carbohydrates,

immediately your blood glucose goes up

and that’s depending on the type of carbohydrate

and things like that.

Well, the same thing happens with exercise.

And so what happens is insulin wants to start

pulling glucose out of the blood.

At the same time, muscle wants to start pulling glucose

out of the blood.

And so we have this giant bolus of carbohydrate come in

and then all of a sudden our blood sugar crashes.

And so if you’re going to be doing so

your first half marathon or something like that,

and you’re in those giant corrals

where there’s like a hundred people waiting to go

and you’re standing there for 45 minutes,

you may or may not want to slug down

like three or four bananas and a bagel and honey.

And you probably don’t need that.

Now, not everyone experiences this double whammy,

but it has been shown in the literature

to happen to some people.

So you want to just be a little bit careful.

An easy way to combat that is just practice

exactly what you’re going to do in your race

in your training.

That’s like the simplest advice ever,

but you’d be stunned how many people do things

during the race that they’ve actually never done in training.

I suggest people do exactly what you described

also for any kind of cognitive testing.

Before a big exam is not the time to discover

whether or not you can handle twice as much espresso

or take a nootropic for the first time or change anything.

I mean, if indeed the score on that exam

is meaningful to you, keep things regular.

So to recap, what we’ve done here

is we started off in the cytoplasm

with this glucose molecule that has six carbons.

We took that thing, we split it in half.

We call that thing anaerobic glycolysis.

We made a little bit of energy, but not much.

We take those three carbon molecules,

we ship them into the mitochondria.

We take each one of those, we clear off one carbon each.

Those carbons, we take a breath in,

we attach them to oxygen, we exhale them,

get rid of that energy.

We are now fully into aerobic glycolysis.

Each one of those two carbon molecules,

we run through the Krebs cycle.

Each round of the Krebs cycle burns one, two carbons.

So we go one, two, one, two.

And now we’ve gone from six carbon molecule

all the way down to zero.

We used the hydrogens that we pulled off of that

Krebs cycle run to go to the electron transport chain.

From there, we made a whole bunch of ATP.

And so we have now fully metabolized

one molecule of carbohydrate.

And the end product of all of it is simply ATP,

water, and CO2.


And leads me to the conclusion that

most everything is really about utilization of carbons

and exhaling CO2.

Is that how I should think about bookending

what you just described?

This is why we started off the conversation

with the circle of life.

This is really a carbon game.

This is why we call chemistry with carbon,

organic chemistry.

That’s what this whole thing is about.

Any living being has to run through metabolism.

It’s all a carbon game.

Any living being has to use ATP.

This is all just a big fancy game

of how do I make ATP and handle the waste?

Remember, endurance is all about waste management,

fatigue resistance, the same thing,

and energy production.

We’re playing a game here.

The whole game, bring in energy, use it,

mitigate waste products.

So when thinking about aerobic exercise

or long duration exercise,

in this case, anything longer than five minutes

for that matter, five minutes all the way up

to an ultramarathon,

the breathing associated with endurance exercise,

the heart beating, which of course is associated

with the breathing and vice versa,

it’s really all about bringing oxygen into the system

that then allows those carbons to be used

within the mitochondria specifically

and then carbon dioxide to be exhaled

as we work through the carbons

of the sort of beads on a string.

Is that right?

Unless you’re moving incredibly fast

for a very long time,

and we’re talking probably north of 90 minutes,

endurance is really not a game

of making sure I have enough fuel.

It is simply managing the waste production.

And that’s exactly what you described.

You need to bring in the oxygen

so you can handle the carbon that’s building up

as a result of both the anaerobic glycolysis.

That’s our game here.

If we start talking about endurance events longer than that,

now we do have to start worrying

about running out of muscle glycogen,

running out of liver glycogen, et cetera,

or if we are at that two hour mark or so

and we’re moving very, very, very fast.

But anything south of that is just managing carbon buildup

and we do that best through oxygen utilization

or getting more efficient

and having a higher capacity for our anaerobic side.

So we can do that by having either more glycogen

in our muscle so that lasts longer

or building better acid buffering systems.

And there’s a whole line of supplementation

that are specifically acid buffers.

There’s a whole line of training.

There’s a whole line of breathing to manage this step.

So we have a lot of strategies

where we can maximize endurance.

All we have to do is go back

to the earlier part of our talk,

which is figure out what’s the actual limiting step

and then train according to that

or do your strategy, your nutrition, your supplementation

that defeats that limiting factor.

For an example, if you are trying

to maximize your performance in this 22nd maximal burst

and your strategy for that was to make sure

that your muscle glycogen is saturated,

it’s probably not going to help a ton

because you’re not going to be limited by total fuel.

You’re going to be limited by your ability to buffer acid.

However, storing more glycogen in your muscle

in preparation for a marathon

is a tremendously effective strategy

because that will become a limiting factor.

So what we can do actually next if you’d like

is we can just walk through these

and look at the individual limitations

where the failure point happens

and then that effectively will outline your strategy

for improving them.

So you taught us about carbohydrate utilization

as a fuel source.

What about fat and what about protein?

Great, I’ll start with protein because it’s easy.

It is generally at best going to represent 10%

of your energy output.

Now that will grow over time

in terms of if you did a several hour amount of exercise.

When you started doing it,

you might be using 5% of your energy from protein

and then that might grow to 10 or so.

And that happens

because you start running low on muscle glycogen.

You start running low on liver glycogen.

You start then having to pull in energy from another place.

So like as those numbers go down,

you’ll see an increased uptick of energy from fat

as well as protein.

Having said that, it’s not a tremendous fuel source.

It is only aerobic.

So it has to be oxidized.

Those are the same thing.

When I say oxidized,

you use oxygen to burn something to make a fuel.

So it’s not a significant contributor

to energy in that regard.

And unless you’re talking ultramarathons or longer

and it is also not something that can enhance performance.

And so we don’t really need to talk much more

about it than that.

In terms of fat as a fuel source,

now here’s the fundamental difference.

While carbohydrate starts anaerobically

and finishes aerobically in the mitochondria,

you’re using mostly the carbohydrate

in the exercising muscle tissue.

Eventually you can pull from blood

and then you can pull from the liver.

With fat, you have a tiny amount stored in the muscle,

intramuscular triglycerides.

But the overwhelming majority of fuel you get from fat

comes systemically.

And so now we have a fundamental difference.

We actually literally have a time problem.

I can get energy from carbohydrates faster

because it is directly there.

If I go to pull it from fat,

I’ve got to pull it from the rest of the body.

Which is why somebody who loses fat

loses it from their entire body.

Despite the fact that they may be only exercising

a couple of parts.

So think about a runner.

Someone who lost a lot of fat running.

You don’t see them just lose fat in their legs.

It comes from their face and their neck and everywhere.


Because what you’re going to do is pull fat

from the entire system.

You’re going to break it down

through a process called lipolysis.

Which just means you break it down from the stored form.

You put it in the blood as that glycerol backbone,

which is that three carbon backbone

in the individual fatty acids.

It’s going to float through the blood.

There’s a seven step system here,

but we’ll skip it for now.

It’s going to have to get then uptaken into the muscle.

In the muscle then it has to get taken up

and run into the mitochondria.

Now that backbone, that three carbon glycerol backbone

is actually going to function almost exactly

like the three carbon pyruvate.

Just get it into the mitochondria,

cleave off one carbon, run it as that’s took away.

Bada bing, bada boom.

Exact same thing.

Super easy to metabolize.

Small enough to go through the mitochondria membrane.

The fatty acid chains become a problem.

So if you have a chain that’s longer

than our eight or so carbons,

it has to actually go through a special transporter

on the cell wall to get in.

And that’s going to be limited by a thing called carnitine.

And you’re probably familiar with that as a supplement.

You may have talked about it.

There’s a lot of places that make it.

That’s going to be a limiting factor.

If it is a smaller, what we call a short chain

or even a medium chain,

triglyceride which a lot of folks have heard of MCT.

That’s what we’re talking about.

That can actually go directly through

because it’s small enough to pass through

and you can use it immediately as an energy source.

In either case, the way that you finally metabolize

a fatty acid is a process where you would go through

and cut off two carbons at a time.

Why would you cut off two?

Because you’re trying to make that two carbon acetyl-CoA

so you can run through that Krebs cycle again.

Because you’re cutting off two carbons at a time,

we have a special name for that oxidation process.

It’s called beta-oxidation.

That’s exactly why we call it beta-oxidation.

Two carbons in, you cut it off to make that acetyl-CoA.

So you can notice the oxidation pathway,

the electron transport pathway is identical

whether you’re talking about the carbohydrates or the fat.

In fact, it doesn’t even matter.

More to our point, if we’re talking about simply fat loss,

it really just is about running

that electron transport chain.

Whether it came from a carbohydrate original source

or a fat original source,

it ends up in the mitochondria

as basically the exact same thing.

It then ends, the end of metabolism as the same thing.

Remember the final endpoint of carbohydrate metabolism

is water, ATP and CO2.

Do you want to guess the final endpoint of fat metabolism?

It’s water, ATP and CO2.

So practical applications here.

If you want to maximize fat loss,

what type of training is best?

It really doesn’t matter.

If you enjoy longer steady state stuff, fantastic.

If you enjoy intervals, amazing.

If you would like to do a combination,

that’s my personal preference, that’s great too.

You have a ton of options.

Pick what you think is a combination of challenging.

Not all exercise should be easy,

but you will actually enjoy somewhat

or you’re willing to accept.

And anything that you absolutely hate, don’t do it.

Sometimes it’s very, very, very difficult

to do high intensity training.

You have to really be interested in doing it.

If not, it ends up turning into like

moderate intensity training.

You sort of just check the box

and it doesn’t work that well

if you’re just checking the box.

So if you’re like, man, mentally,

I don’t have it in me today

to get to a high heart rate and throw up

and all that stuff, cool.

But you can just do some moderate steady state stuff,

well, that’s a win.


If you’re like, oh my gosh,

more than 10 straight minutes and I’m so bored.

And you’re all, maybe you’re also like,

I don’t have 45 minutes,

I gotta get this done in eight minutes.

Great, go do some high intensity intervals.

Either option will be equally effective.

As you mentioned earlier,

exercise is useful for aesthetic changes,

functionality and for longevity.

But when thinking about exercise specifically for fat loss,

I do have to ask this question.

I often hear from people

that they prefer one type of exercise versus another

for sake of fat loss

because certain forms of exercise make them very hungry.

I’m wondering whether or not there’s any relationship

between the intensity or type of exercise

and the hunger stimulus.

Now, I don’t have this problem

because basically everything makes me hungry.

And yet I’m also okay fasting for part of the day.

I’m one of those pseudo intermittent fasters.

Talk about what I mean by that.

I just happen to eat between 11 a.m. and 8 p.m. naturally.

I’m not religious about it,

but I don’t do it for any other reason

except that that tends to be when I’m hungry

and I exercise outside of that in the morning typically.

In any case, is there a way that people can determine

what type of exercise might be better or worse for them

based on its appetite stimulating or inhibiting effects?

Because I also hear that some people will go for a long run

and then they are quote unquote not hungry

for several hours afterwards.

Does that have anything to do

with which fuels are being utilized

during different forms of exercise?

That’s actually a really good question.

I don’t know the mechanisms that could explain that answer.

What I can tell you is you hear the same comment

for physical activity.

In other words, people say,

man, if I do this type of training then I just am exhausted

and I lay around the rest of the day.

So my total caloric expenditure

is actually compromised as an aggregate because I’m down.

The data would suggest in general that doesn’t happen.

So most of the time we don’t see a reduction

in physical activity with either high intensity

or steady state training.

In fact, you generally see equal if not increased,

what’s called NEAT.

So it’s the non-exercising part of your day

in addition to the basal metabolic rate.

So physical activity wise you don’t seem to be propped.

Now hunger is a little bit of a different thing.

The answer here is I don’t think we have time

to actually do justice on this.

So perhaps best to not get into this one.

Yeah, why don’t we punt this down the road

to our discussion about nutrition specifically

and weave back to it.

So we’ll earmark it for that.

Meanwhile, it sounds like if one is thinking purely

in terms of burning calories

and getting the health benefits of exercise

to create a caloric deficit, to create fat loss,

it doesn’t matter whether or not they burn those calories

using a form of exercise that relies predominantly

on carbohydrate, fat or protein, correct?

It’s not that it doesn’t matter.

It’s that either one will work.

Because when we say things like that,

it doesn’t mean they’re actually identical.

There are some slight differences

and maybe those differences are important for some people

and not others.

I’d say it’s either one is a viable strategy.


What about protein as a fuel?

As an actual fuel.

So let me give you an analogy.

Imagine that you were with me a few weeks ago

in Southern Montana and we were out

in the wilderness for a week, okay?

And it’s cold out there and you needed to make a fire.

And if I said, look, you can pick any of these things.

There’s some wood over there, we brought some newspaper

and then we brought a match and we need to create a fire.

We’re gonna use that fire to energy and heat up.

Okay, I said, great.

The very first place you would probably start

to make that fire is the match.

You light the match and any match,

hey, it’s gonna light immediately

but it’s probably gonna last five to 20 seconds,

I don’t know, before it burns out.

That’s fossil creatine.

Real fast, real burns out.

If you were smart, you would take that match

and then light the newspaper on fire, right?

Now, if you were to burn a whole newspaper,

it is more energy than you get to the match,

but you still, I don’t know,

what’s it gonna take, a few minutes?

Some number of minutes before an entire newspaper

burns up?

Yeah, five, I don’t know, right?

Depends on which type of newspaper it is, I guess, right?


That’s carbohydrate, right?

If you were really smart, you would use that

to then light a piece of wood on fire.

And a wood, if you’ve been in the wilderness,

it could last hours, days, it’s really quite unlimited.

Your fossil creatine storage is very limited, small.

Glycogen is a lot higher,

because you can store it in muscle,

you can store it in other places,

so you have more, but not a lot.

Fat is unlimited.

The average person, if you’re around, say, 70 kilos,

up 170 pounds or so, and you’re moderately lean,

maybe 15% body fat, nothing crazy.

You probably have enough stored fat

to create enough energy to survive

for more than 30 days, right?

This would literally be, if you ingested zero calories,

you have enough fuel in your stored fat

to keep you alive for certainly 30 days.

You wouldn’t feel good and all those things.

But energetically, basically, fat will never,

ever be your limiting factor to performance.

So when we start talking about,

well, what limits my performance in these areas,

you can just wipe fat off the list.

It will never be your limiting factor

to any type of endurance performance.

You simply have way too much.

The only problem with fat is it’s just too slow.

I’ve gotta mobilize it, I’ve gotta get it in the blood,

move it, that whole thing.

Too slow.

So if I wanna go faster,

I will never be able to fully utilize fat,

which is why we talked about earlier.

You’ll never see a situation in which somebody

is 100% burning fat as a fuel and no percent carbohydrate.

It’s always going to be too slow.

Highest you’ll get, maybe 70 so percent.

Protein in this equation is none of that.

Now you may notice, how do you make paper?

What’s fibrous, you combine it with water,

it gets pressed, it gets compressed, yep.

Yeah, it’s made from wood.

How do you make a match?

It’s made from wood.

What’s carbohydrate?

A chain of carbon.

What’s fat?

A chain of carbon.

These are similar molecules, right?

They’re meant to give you pros and cons.

It’s very difficult to just light a log on fire

without a lot of work.

You’d have to burn, burn, burn, burn, burn.

So these are complimentary systems

that are really close to the same thing.

Protein is none of those things.

Protein is more like a piece of metal.

So if you were out in the woods with me

and we were trying to make a fire and you’re like,

hey look, I found some old railroad over there,

let’s throw that on there.

I would probably look at you like crazy.

Now technically, can you melt metal?

Sure, but you’re gonna burn a lot of energy

to try to get a little bit back out of the metal

and now you’ve also cost yourself

a very, very valuable structure.

So protein is a fuel source for exercise or metabolism.

It’s just an incredibly poor choice.

Your body will do it.

Again, maybe five to 10%,

but now you’re burning a very valuable supply

in a situation in which you don’t know

where there’s ever gonna be any more.

Remember, protein is fairly transient.

It’s not very good at storing it.

You can store a ton of carbohydrate

in an unlimited, literally, amount of fat.

So you just really need to disregard

thinking about protein as a fuel source.

Your body does not wanna do it.

You are not good at it.

You can go through a process of gluconeogenesis from protein,

make glucose from it, it’s just very poor.

You’re not gonna get much out of the exchange

and you’ve burned your supply of metal,

which is gonna be very difficult.

It’s a very high commodity in the woods

or the wilderness to have something like metal.

For people that consume very low carbohydrate

or zero carbohydrate diets,

are they pulling more energy from muscle?

Which I imagine is a conversion of amino acids

into ready carbon chains.

Yeah, I mean, in this particular case,

once you’ve reached a certain level of adaptation,

you’ve just gotten extremely good at generating glucose

from other fashions, right?

So you can bias heavily towards fat adaptation.

The downside is, and we’ve seen this born in the literature,

you’re going to perform slower.

So if you don’t care about maximizing performance,

especially over something where it is a maximal effort

for a few minutes or something,

then maybe you’re not concerned.

And that’s absolutely great,

especially for people just don’t exercise.

Then hey, geez, very little concern here.

But if you’re interested in your performance

and you’re wondering why you’re just like slugging it down,

well, what you’ve done is you’ve down-regulated the ability,

literally the enzymes responsible

for that entire anaerobic glycolysis portion,

they get down-regulated,

which means there’s not as much around anymore.

And so you get really bad and slow

at using carbohydrates as a fuel source.

So it’s a very poor strategy

for people in an anaerobic-based sport

or who like that type of activity.

Again, if you don’t care, no problem.

If you don’t exercise at all,

then you really have no problem there,

which is actually why a high-fat,

low-carbohydrate nutrition strategy

for people who don’t do much physical activity

is probably like, well, it’s very effective.

It is a really good strategy for weight management,

for energy stabilization throughout the day,

and the research would very much support that.

In my observation, I would agree.

I’ve tried low-carbohydrate diets

of severely limiting or completely limiting carbohydrate.

And after about two or three days, I feel pretty lousy,

but mostly because I want to train very intensely in the gym.

In addition to doing longer runs,

I tend to do all of those things across the week.

But I’ve also observed and in fact know several people

that love the very low-carbohydrate,

aka ketogenic-type diet.

They’re not doing ketogenic diets

for mental health reasons per se,

but indeed those people tend to do very limited exercise

or they tend to do a lot of long endurance,

but low-intensity long endurance.

These are the I-walk-to-get-my-exercise types,

and they do indeed walk a lot.

And some of them manage to control their weight very readily

and like that diet for that reason.

When we had Lane Norton on the podcast,

he pointed out quite aptly that in order to lose weight,

you have to restrict something,

either time or macronutrients, et cetera,

to arrive at that subcaloric threshold,

get below the sub-maintenance threshold.

I guess one of the things I want to point out

is this should be received as, again,

not a this is better or worse.

This is just, you now have a ton of options.

So whatever personal preference, other factors,

you get to craft this strategy of performance,

aesthetics, and health based on your personal preferences.

At this point, I’d like to go back to our classic list

of nine adaptations that exercise can induce.

The first four, of course, being largely,

largely unrelated to today’s conversation,

but that were covered in the episode

that we did on strength, speed, and hypertrophy.

So just to remind people,

the nine adaptations are number one, skill and technique,

two, speed, three, power, which is speed times force,

four, strength, and five, hypertrophy.

Today, we’re talking about the remaining adaptations

on that list, starting with muscular endurance,

followed by anaerobic capacity,

followed by maximal aerobic output,

and finishing at number nine with long duration exercise.

So if we could start with muscular endurance,

this would be number six on the list of nine adaptations.

Muscular endurance, how do I build muscular endurance?

Why should I build muscular endurance?

And just to remind me what fuel sources are predominating

when I’m training for muscular endurance.

Great, so remember muscular endurance

is something that’s going to be generally in a local muscle.

It is not a cardiovascular or systemic issue,

and it tends to be something in the neighborhood

of say five to maybe even up to 50 repetitions.

So this is the classic example we’ll give here

is how many pushups can you do in a row?

Most people are gonna land somewhere in that range,

I just said.

How many sit-ups can you do in a minute?

How many pull-ups?

How long can you hang on a bar as a dead hang?

Things like that, that’s muscular endurance.

Muscular endurance is not a mile run

or a marathon or anything like that.

So how long can I stand without breaking posture?

This is muscular endurance.

A plank, a wall sit.

Great, yes.

Love all these things, okay?

Now, the reason I took you on that big long metabolism

journey is so I could help you understand exactly

how to train this factor or any of these factors

with a more comprehensive understanding of what’s happening.

Meaning, thinking back to the metabolism,

if I’m gonna ask my triceps to do 50 pushups in a row,

what’s going to be my limiting factor?

Am I gonna run out of fat?

No chance.

Am I going to run out of glycogen?

No chance.

That’s way too few of repetitions.

You have a lot left there.

So what’s gonna be the thing that stops me

from getting 51 repetitions?

Either you’re gonna have too high of a pH rise,

so too much acid buildup,

or you’re gonna have a problem clearing the waste.

So really, this is two factors.

Dealing with acid buildup and getting acid out

of the muscle tissue and into circulation

because you have plenty of ability to handle

that small amount of acid buildup in your entire body.

It’s just you can’t handle it in that tiny spot.

Now, I picked the tricep for a very specific reason.

You’re gonna deal with more pain

when you use a large muscle group

like your quads or your glutes

than you are with a small muscle group.

For example, nobody ever threw up after arm day,

but a lot of people throw up after leg day.

Why is that?

Look at the total amount of waste

that you’re dumping into your system

when you have quadrupled or 10x the muscle size.

Small muscle groups are only really going to be challenged

in that local area.

Large ones will dump so much waste into the system

that you’ll wanna avoid that as quickly as possible,

and that’s one of the reasons why you throw up

after hard exercise.


So, the reason-

I’m laughing because I don’t think I’ve ever thrown up

from a weight training session,

and so it’s making me wonder if I’ve ever trained that hard.

I’ve received or obtained the progress

that I’ve wanted to generally over time,

not every week, every workout, every month,

but certainly over the 30 plus years

that I’ve been weight training,

I’ve achieved the results I’ve wanted.

I have, however, vomited after a long run

when I didn’t hydrate well.

Oh, sure.

Or if I drank too much water.


Oh, sure, too much water.

Yeah, you’ll get that out quick.

Right, I just wanna be clear

because I think some people are getting the picture

that if they’re not vomiting after their leg workout,

that they’re not training according to your standards.

Again, by the way, Dr. Andy Galpin runs experiments

in his lab, he’s recruiting subjects all the time.

Also known as my graduate students.

That’s right.

In any event, sorry to interrupt,

but I felt it was a necessary interruption.

So muscular endurance, there’s plenty of fuel.

Plenty of fuel, you manage acid buildup,

and you also need to get that fuel out of you.

That’s gonna be a capillarization issue.

So the way that we can think about this

is capillaries surround your muscle,

and the whole point of them

is so that blood can come into them,

they hit this capillarization,

that actually slows the diffusion rate of blood down,

and so you can exchange nutrients in

and get waste products out,

and then we get things back into circulation.

So the more of those you have,

the better you are at dispersing

any of these waste products buildup,

whether it’s CO2 or the acid.

So the adaptation you’re looking for here

is an increase in capillarization,

potentially a slight increase in mitochondria,

but the time is too fast, right?

So we’re gonna be able to need to do these 50 repetitions

in say under a minute or something like that.

So getting the mobilization into the mitochondria,

getting fuel that way, too slow.

It’s not really gonna get our performance here.

So what are strategies to increase acid buffering ability

and then capillarization?

So on the capillarization side,

you simply need to train at that ability.

So you go close to failure and practice that often.

That alone will increase blood flow to that local area,

which will take you through your process

of increasing capillarization.

Easy peasy, specificity.

Just to briefly interrupt, I find it remarkable,

although not surprising,

given how amazing the human body is,

that simply by doing some movement repeat,

like a wall sit or pushups or dips for that matter,

repeatedly over and over and over

until you reach that failure point

or that quaking point in the case of a wall sit,

that provides a stimulus for more capillaries

to be built into the system.

Literally the production or the trafficking

of endothelial cells, which make up the capillaries

and allow basically more little pipes

to feed the system with oxygen and remove waste products.

It’s like irrigation, right?

Imagine you had a giant field

and you had two big pipes running down the outside.

Well, in fact, if you wanna make sure water

gets evenly dispersed across the entire field,

you’ll have a bunch of offshooting little pipes.

And the more of those you have, the more coverage you get.

Do we know what the specific signal is that says,

hey, I failed at this, we need more capillaries.

I actually don’t know what that is.

I would speculate it’s a combination of acidity

as well as carbon dioxide

and probably some nitric oxide stuff happening there,

but I actually don’t know.

I’m guessing nobody knows for sure

because we still don’t know, for instance,

what the exact signal is for hypertrophy.

It’s kind of an amazing situation.

We know the requirements for getting the result we want,

but we still don’t know what the specific signal is.

In any event, what I’m hearing is building more capillaries

is great for enhancing muscular endurance.

And the way to get more capillaries into those muscles

is to train for muscular endurance

by getting close to failure or to some point

where you simply can’t continue for whatever reason.

Could you give us an example

of what a reasonable training protocol might be

in terms of the classic Galpin list now,

exercise choice, maybe a few options,

order, volume, and frequency.

What should we be doing?

How often should we be doing it?

And for instance, should I do wall sits to failure,

then pushups to failure?

Given that this is a local process,

I’m guessing that if I do pushups to failure,

I’m not gonna increase the number of capillaries

in my legs very much.


So you nailed it.

Exercise choice is high precision here.

So pick the muscle group and the exact sequencing

and movement pattern you want.

High precision, this is the thing.

If you wanna get better at a plank, hold a plank.

You wanna do more pushups, do more pushups.

You can do some other stuff that’s complimentary,

but really this is a high precision game.

Do the exact same thing for exercise choice.

Very simple there.

Okay, in terms of exercise order,

I suppose this dovetails with volume.

Can I combine training, let’s say wall sits for my quads

and nearby muscle groups and then do pushups to failure

and then also do some sort of pulling exercise to failure?

Yeah, absolutely.

Again, pick the exercises you want,

the movement patterns you wanna do and do them.

The order almost doesn’t matter with the one caveat.

With larger muscle groups,

particularly again, multiple leg activities,

that will induce a small amount of systemic fatigue.

I guess theoretically wanting to maximize

your pushup number and you did a whole bunch

of say split squats and you just did those

and you did lunges for a mile or something like that,

you might actually slightly compromise.

You might not, but you might slightly compromise

your ability to do as many pull-ups in a row

or hold a bent over row or something like that.

So if you really cared about that level,

then you maybe wanna do the one thing

that’s most important first.

In general, my recommendation though

is to do the bigger muscle group first.

How many sets and how often should one perform training

for muscular endurance and when?

Now, the lovely part here is we’ve moved down the spectrum

past hypertrophy.

You don’t need a lot of load here.

In fact, the load only needs to be at

or slightly above what you wanna move.

So if you wanna get better at moving 50%

of your 100 max, you don’t really need to train

much more than 50, maybe 55 or 60% of your 100 max

because if you go higher than that,

the repetition count’s going to fall

and you’re no longer going to be training

muscular endurance.

So you just need to stay right around that number

that you wanna work on.

So again, if the target is doing more pull-ups

and assuming that you have the strength to do it,

you check that box, you simply need to practice

the repetition range that you wanna be in.

That’s all it takes.

You can repeat that a number of times,

but because remember, the volume is fairly low.

The load is very, very low.

You can actually repeat these quite frequently.

So you won’t get extremely sore from muscular endurance

relative to traditional hypertrophy training

because the load is very, very light.

So you can do these more frequently if you would like.

More frequently such as?

You could do it three or four times a week easy

if you would like.

You don’t necessarily need to.

Three days a week per muscle group is probably fine here.

If you wanted to do more sets on a given day

and do less days, that would be fine.

So if you wanted to do two days a week

and you say you wanted to do,

let’s say you could do 25 push-ups

and the goal is to get to 30 push-ups just as an example.

You might say, okay, I’m gonna do sets of 17

and I’m gonna do three sets of that.

I’m gonna do that three days a week.

That’s gonna build up quite a bit.

Or you could say, look, I’m gonna do a set

basically to failure.

And I’m gonna recover and do one or two sets

that say 80% and I’ll do that twice a week.

That’s gonna push the pace pretty well.

You’re gonna have a lot of gains from that.

And again, this is not about hypertrophy.

This is about muscular endurance.

So I do wanna emphasize,

and again, please correct me if I’m talking out of line here.

Do you wanna emphasize that because we mentioned pull-ups,

if you can’t get 25 pull-ups and you’re doing 10,

you’re training for hypertrophy.

You’re not training for muscular endurance per se.

Remember, there’s a big crossover here.

So anytime we’re talking past like 15 reps,

we’re technically in hypertrophy and muscular endurance.

Got it.

So here’s a common mistake.

I don’t wanna get bulky.

So I’m gonna go lighter and do more reps.

And then people grow.

And then you landed still right in the middle

of hypertrophy range.

So like for people who are like, oh my gosh,

like every time I lift weights, I blow up, I go lighter,

I do more reps and I,

you’re still right in the hypertrophy zone.

They’d actually be much better off training

very, very heavy in the one to three rep range.

They’d get really strong and they wouldn’t grow much.


So tell me if this is a reasonable protocol

for what I’m gonna call the typical person.

In my mind, the typical person is somebody

who hopefully is doing resistance training,

hitting that 10 sets per muscle group per week minimum

to maintain or build strength and hypertrophy,

but is also doing some long duration training

that we’ll talk about in a little bit.

Maybe throwing in a high intensity workout here or there,

some sprints, maybe some plyometrics,

some skill-based training

and doing a bunch of different things

to be what I would call all around fit.

They’re not training for any specific event

or trying to maximize any one of the nine adaptations

to the exclusion of the others.

That person decide, okay, after they do their longer run,

they’re gonna do a plank to max duration.

They’re gonna do a wall sit to max duration

and they’re gonna do pushups to max duration.

And then also do that same workout

before they do their high intensity interval training,

some other point during the week,

and then maybe even do it again on their so-called rest day.

Just a real quick five minutes.

And in doing so, build more capillaries

into the relevant muscle groups

and build their muscular endurance

without eating into their overall recovery too much.

Too much, yeah.

So again, the nice part about this

is they don’t hammer you too much.

You’re not gonna get tremendously sore

if you keep the load light.

The only switch I’d make there

is I would probably do them after your interval

rather than before.

So you can make sure you keep quality there

and you’re not compromised by a local muscular endurance

when you’re actually trying to get a more systemic fatigue

with something like a higher intensity interval training.

So that would work fantastic.

The only other variable we haven’t hit on here

is progression.

And this is very simple.

Try to add a rep or two per week.

That’s really all you have to go after.

So if you’re up to 22 this week, try to hit 23 next week.

For wall sits and planks, that would mean add time.

Time, yep.

And if you run into a wall there,

just like the same concepts we talked about with strength,

back it down to more like in the 80 or 85% range

and accumulate a lot more practice.

That’s gonna help a lot with capitalization

as well as acid buffering.

So you’re gonna continue to give yourself signals

for upregulation of the processes needed for that.

And it’s not always pushing you to the end failure,

just like we don’t wanna always go to failure with strength.

We don’t wanna always go to failure

with high intensity intervals either.

Same thing would be happening here.

What about anaerobic capacity?

How should people train for anaerobic capacity?

What exactly are they training for?

Meaning what is the structural or cellar adaptation

or adaptations that are occurring

that allow for increases in anaerobic capacity?

And why are increases in anaerobic capacity good for us

even if we’re a quote unquote endurance athlete

or we are a recreational exerciser

who is not interested in building more muscle speed

or things that I typically associate

with anaerobic capacity.

So this is really, really fun.

Remember anaerobic capacity is the total amount of work

you can do for something like seconds to a few minutes.

And this is extremely high levels of fatigue,

the highest you’re really going to see.

And by fatigue here, I mean acid buildup byproducts,

not fatigue as in like mentally,

I don’t wanna do this anymore.

So if we just think about the energetics for a second,

I’m gonna do say, let’s take a really easy example

of people have done that thing where you go to the track

and you sprint the straightaways and you walk the corners.

You remember that sort of thing?


Tabatas, 30 on 30 off, things like this.

Like this is what we’re talking about

in this kind of anaerobic capacity area.

Now, here’s what’s gonna happen.

Is fat going to be your limiting?

No, we’ve already made that clear, right?

What about carbohydrates?

Well, if it’s a single bout or two or three bouts,

probably not.

But if you’re doing this for a long time,

say you’re gonna go 30 on 30 off for 20 rounds,

you may actually start reaching a point

of running out of muscle glycogen.

In any of those cases though,

you’re going to be running into an acid problem.

If you were to continue to do this multiple repetitions

in addition to running low on muscle glycogen,

you’re also gonna start running

into oxygen transportation problems

because you’re building up a lot of byproducts.

You gotta continue.

You will actually cruise into aerobic glycolysis.

This is exactly why the community

that I have worked a lot with, professional fighters,

very high level boxers, world champions, UFC fighters.

It is a five minute round

that you’re going to do five times.

This is for world championship fights.

You get one minute break in between.

So imagine going like 30 on 30 off for five minutes,

getting a one minute break and doing that five times.

Even though the individual bouts are 30 seconds long,

the entire thing lasts so long.

It is primarily aerobic.

You have to have both capacities.

You gotta get really high anaerobic.

You also have to have a lot of aerobic going on.

You’re going to start running into limitations

because of heart rate, stroke volume,

and then even potentially ventilation.

The need for oxygen to be able to come in

and clear the carbon dioxide totally out of the system

becomes a problem

because not only are you having so much buildup

for such a long time,

you’re also using multiple muscle groups.

So now this is a very important distinction.

Muscle endurance tends to be localized.

Now, this is not.

If you’re doing these intervals,

you’re on an assault bike, you’re sprinting up a hill,

you’re grappling with somebody,

you have a lot of muscles being involved,

which means all of that waste

is being dumped into the central part.

You have to clear it.

And by clear it, I now mean not out of the muscle,

I mean out of the body.

So your ability to bring in and utilize oxygen

is going to be a major limitation

to your ability to handle this stuff.

So what do you do?

Well, specificity wins.

Practice the exact thing you’re talking about.

So if you want to get better at sprinting the straightaways

and walking the corners, do that.

You can’t always do it though.

You’re going to run into limitations.

So this is when backing off to a lower intensity

is going to give you a lot of benefits.

We know very clearly

if you want to improve cardiovascular fitness,

high intensity, moderate intensity,

and low intensity are effective.

And you actually probably want to do

a little bit of all of them.

This is why none of our fighters

would ever just do high intensity training.

There’s going to be some moderate,

we tend to call this like cardiac output training.

You can think of this as like

anywhere between zone two to zone four.

If you like zones, I don’t use them personally.

So I’m just going to intentionally interrupt you

because this issue of zones has come up a few times.

I want to make sure everybody’s on the same page.

You also mentioned that you don’t necessarily favor

the zone nomenclature, but for those not familiar,

zone one, two, three, four, all the way up to five

is a kind of back of the envelope type verbiage

for some people and is more precisely followed

by for other people.

Meaning for me, zone one is simply walking, easy walking.

Zone two would be for anybody,

the pace or intensity of exercise that one could perform

while still maintaining a conversation, but just barely.

Meaning if you were to push any harder,

then it would be difficult to hold that conversation.

Then you’d be in zone three.

And then zone three, four, five, as I understand them

are a little bit vague, but maybe you could give us

a sense of the breathing patterns associated

with each of the zones so that people could map to those

when we discuss zone one through five.

And as I say all this, I certainly tip my hat

to all of those people out there who like to measure

percent of maximum heart rate.

They like to use heart rate monitors.

They’re using any number of different devices.

I sometimes use those devices, but in general,

I tend not to, and I use my breathing as a rough guide

of which zone I’m in.

So before we go back to specific protocols

for anaerobic capacity, tell me how you think about

zone one through five and how people might be able

to assess whether or not they are in zone one,

two, three, or four or five.


So zone five is that absolute top thing

and we can flag ourselves there.

I liked how you flagged one and two.

The distinction between three, four, and five,

I’m less concerned with either.

We will do some heart rate stuff,

but not to identify what zone we’re in.

The fact is the distinction between those zones

is basically just made up, right?

Not that it’s fake, but there’s no like rationale there.

It’s a little bit like perceived effort in weightlifting.

Are you at a hundred percent output or 70%?

You know when you’re at zero and you know when you’re

at a hundred in that moment,

but the difference between 60 and 70 is anybody’s guess.

So we use, or the relevance, right?

So why does it matter if I’m at 60 or 70?

Is there actually a difference?

There’s not, right?

So it doesn’t really matter in that regard.

If you’re a very highly trained, particularly cyclist,

things like that, then,

and you can control a lot of circumstances,

those things start to make a lot more sense.

But when you’re in an open environment

like the athletes I deal with,

it’s just not gonna matter that much.

So the way that I approach this is,

and I will use this word intentionally,

stolen directly from Brian McKenzie

and his company Shift Adapt.

They use what’s called a gear system,

and I absolutely love it.

It’s what we’ve been using for a long time.

So with Brian, with your permission,

I’m gonna take it right now.

Thank you, Brian.

He gave me the permission.

Thank you, Brian.

Brian’s a good friend of ours.

And I do think the breathing gear system is a terrific way

to think about the zones and to get a good sense

of what zone one happens to be in.

Yeah, great.

The first gear is your ability to simply breathe in

and out through your nose at a set cadence.

So basically, regardless of how hard you’re working,

can you restrict your breathing

to like a two to three second inhale,

and then a two to three second exhale?

And this is really clever actually,

because a lot of folks will jump immediately

into an over-breathing strategy,

which means you’ll be ventilating more than you need,

which actually sends that RER up higher than it needs to be,

which kicks you higher into carbohydrate utilization.

If you’re supposed to be in quote-unquote zone one,

you’re trying to be efficient, not fast.

So using more carbohydrates than you need

is not beneficial here.

You’re walking for the day.

You’re out on a longer hike.

You’re enjoying the day.

You shouldn’t be trying to ramp up carbohydrate metabolism.

It should be efficient.

Ah, and so this would be getting into an argument

with somebody while on a long walk.

You feel exhausted afterwards.

You’ve been over-breathing.

Yeah, totally, right?

So you should be able to breathe at a specific cadence,

and generally people are doing that more frequently

than they need, right?

Zone two, rather gear two, is inhaling and exhaling

at whatever rate you need it to be, but still nasal only.

So it is a forced, right?

Whatever you need to do,

but your mouth is closed the entire time.

You shifted higher up.

You’re burning more and more carbohydrate as a fuel source,

but you’re still able to control that

and restrict it through nasal breathing.

Now, gear three and four, which is our final ones.

There’s no gear five.

Gear three and four is like a subtle distinction.

I actually don’t even care about the difference there.

I basically use gear one, two, and then that’s four,

but you’re basically talking about

either a nose-to-mouth strategy

or a straight-up mouth-to-mouth, right?

So breathing in through the nose, out through the mouth.

If you can control it that way.

You can do the opposite, actually, right?

Can you breathe in and out through your nose?

But the classic one people will do

is in through the nose, out through the mouth.

Again, I really don’t even care about distinction.

I basically jump from two to four.

Brian may do it differently.

I don’t actually know.

Four is just mouth-to-mouth, right?

And this is the case in most sporting applications.

You’re gonna be breathing

because the nose is restricted, right?

There’s only so much space.

And as we talked about earlier,

the consequences of not having enough oxygen in

or CO2 exhalation, if you’re restricting that,

this is gonna be problematic.

So in your actual competition,

please go to the mouth if you need to, right?

We practice a lot trying to stay nasal only

for as long as possible.

But that’s going to eventually happen.

When you’re doing your high intensity intervals

and you’re really going as hard as you can,

you’re gonna have to go to your mouth

unless you’re an absolute freakazoid.

And you can stay in your nose,

but that’s not gonna happen, right?

Most people can’t get past, say, 70 or 80%

while breathing through your nose.

I know some people can get higher,

but that’s the general distinction.

So we pay much more attention to those particular gears

than we do heart rate zones.

And zone five would be just pure mouth breathing all out,

running for your life.

The gear system is just one to four.

There’s no fifth gear.

Got it.

So the gear four would again be mouth-to-mouth,

breathing as much in as you can,

breathing as much as you can out.

Got it.

And I appreciate your description of the gear system

and how it roughly relates to the zones

we’ve been talking about.

I also am reminded,

if anyone wants to experience the relationship

between breathing and the offloading of carbon dioxide

and your ability to exert effort in anything,

a game that a friend of mine sometimes likes to play

when we walk or jog and talk is he’ll say,

let’s just hold our breath now until we hit that piling

or that lifeguard stand on the beach.

And within seconds, you actually can start to panic.


It becomes very hard to coordinate your action

after a little while.

Again, be really careful with this,

but it will teach you in a moment in a very real world way

how important it is to be able to offload carbon dioxide

because you’re probably not running out of oxygen

at those lower intensities.

No question.

You’re simply building up carbon dioxide

and that gas reflex is screaming to go off

and you’re actively suppressing it.


So the interesting test here is your CO2 tolerance.

On Brian’s website, you can go directly there.

There’s a video to how to run this test

and then you can put in your numbers

and it’ll tell you sort of exactly what to do

as a result of it.

But the CO2 tolerance test

is a test of exactly what you just mentioned.

So you should be fairly tolerant.

In other words, non-reactive.

You can be responsive, but non-reactive

to elevations in CO2.

So you should see them and feel them,

but you should be choosing how you respond

rather than an inert reaction.

There are interesting data looking at things

like out of the blue panic attacks.

You can actually notice those in blood

via rises in CO2 up to 45 minutes

prior to the event happening.

So there are signals happening in your body

that you may be sensitive or not sensitive to.

The more in tune you can get with that,

the better your life is gonna be.

And even if we’re specifically

just talking about exercise performance.

So it’s okay for CO2 to rise.

It’s going to rise.

It’s a byproduct of anaerobic metabolism.

It’s a byproduct of carbohydrate and fat metabolism

as we’ve established.

It’s going to get there.

You’re going to feel that.

However, if you immediately go into a panic

because of a small increase in CO2, this is a problem.

So we’re turning to anaerobic capacity.

This morning we were training, not together.

I couldn’t keep up with your workout,

but in the same general space.

And I did my once a week maximum heart rate

one minute sprint on the assault bike.

Sometimes I’ll do more minutes,

meaning I will do one minute,

then take some rest and do another minute after some rest.

But I decided to do that one minute with you there

so I could learn from you.

And indeed, I have to assume that

that was largely within the anaerobic capacity realm.

The first 30 seconds or so were manageable.

We’re getting more and more painful.

There was a quit signal going off in my head.

You said there’s real magic that occurs around second 40

and indeed somewhere around second 40,

for whatever reason, it seemed easier.

But at the one minute mark, I was happy to stop

because I was really at, at least what felt to me,

100% output.

Is that a good protocol for building up anaerobic capacity?

Keeping in mind what you said before,

which is that specificity or precision,

as you phrased it, is important.

That is, if I want to train anaerobic capacity for sprinting,

I probably should have been sprinting.

Cycling, I was on the assault bike and so on.

How many of those one minute all out sprints

or 30 second all out sprints on the bike

could and should one perform per workout and per week?

So marching through exercise choice.

Yep, let’s do it.

Order, volume, frequency, and progression.


Choice of exercises,

train for what you want to improve, is that right?

Not necessarily.

So in this particular case,

if you have a specific goal, yes, of course, do it.

Exercise choice, a couple of things you want to look for.

You want to pick something that you feel

extremely confident in the movement with,

because you’re going to forget your brain very quickly here

because you’re going to go into our pain cave.

So if you’re not comfortable running, don’t go run here.

You’re never going to get to the spot

when you need to get to it.

If you’re not comfortable,

or if every time you go on a rower,

your low back hurts the next day, don’t do it.

If you’re not comfortable using kettlebell swing,

you get the point.

If you do an exercise you’re not comfortable with,

you also secondarily want to be careful

or cautious of heavy eccentric loads,

because you’re going to be doing a lot of repetitions

at a high intensity.

So this is where I love an assault bike.

This is why a rower is great.

Swimming is amazing.

Running uphill, generally more favorable

than running on normal ground,

especially if you’re not a runner.

Don’t run downhill.

That’s a lot of eccentric load.

I don’t love things like box jumps here, right?

Because again, a lot of eccentric loading,

suppose you can jump up, land on the box, step down,

but now you’re, again,

too many things are going through your mind.

I don’t want to slip and fall.

I don’t want to smash my shin on the box.

What happens if I, too many variables.

Pick something that is safer

where you can really focus on your breathing

and your posture and the performance.

All right, so that’s exercise choice.

And then within that,

if there’s some specific thing you want to get better at,

go ahead and do it.


How many different movements?

Meaning, should I do the assault bike

and then some form of safe executable overhead pressing?

It’s a little harder to imagine anaerobic capacity

for the upper body unless you have access to a skier

or one of these, what are those things called?

The climber machines?

Yeah, the VersaClimber.

The VersaClimber.

That’s the one, the VersaClimber.

You can tell how often I do that one.

It’s a great piece of exercise equipment.

Yeah, so we’re thinking how many exercises

and in what order?

Is it going to be two or three exercises

since you’re involving a lot of muscle groups typically?

That’s a really distinction.

Generally, these are going to be total body movements.

So you can do something like a skier

if you want to really isolate your upper body.

Great, love that.

You can do lower body isolation like cycling,

right, where your upper body’s not involved.

You can use weights here.

You can do some barbell movements and stuff like that.

They’re just not my favorite choices for most people.

Too many complexity things going on.

So I generally am going to pick total body movements,

pushing a sled, dragging a sled, sprinting uphill,

swamming, these things like that are going to be good.

I’m seeing now why the assault bike is such a powerful tool

because you’re using your arms

with some degree of resistance

but not a lot of eccentric load, plus legs,

some resistance, not a lot of eccentric load,

and yet one can go quote unquote all out

for 30 to 60 seconds.

And the consequences of a technical breakdown are minimal.

It’s more like you’re going to actually

have a worse performance rather than an injury rate.

So there’s just a wonderful invention because of that

where other things, the consequences,

like say if you’re going to be doing a barbell

or kettlebell activity,

the consequences of making a technical mistake,

you might actually get an acute injury right there.

So they’re just a little bit higher in the risk scale.

How many sets or sometimes referred to as repeats.

So how many 30 to 60 second all out sprints,

again, doesn’t have to be running, sprinting,

but all out effort would be the better way to phrase it.

Should I perform, let’s say per week,

and then decide whether or not we can divide those up

across multiple workouts or whether or not

it’s better to do them in the same workout.

If you’re staying with the same exercise

for all of your workouts,

that’s a little bit different answer

than if you’re modifying them.

So say you’re going to do this three times a week

and you’re going to do an air bike one day,

you’re going to do some hill sprints another day,

and then you’re going to do some swimming another day.

For sake of example, I’m going to say same movement

because I think most people are going to be most comfortable

with one or two types of movements

unless they are really coordinated or an excellent athlete.

I think most people can probably find a hill

that they could run up and an air diner assault bike,

a rower, things of that sort.

You’re going to have a pro and a con here.

So the pro of doing less sets

is you can actually train much closer to truly 100%.

The downside is volume’s low.

So a major mistake people make here

is they’ll do something like,

I’ll do 20 seconds on, 10 seconds off,

and I’ll do that for 40 rounds.

You’re not really actually going that hard

in those 20 seconds.

So a key, in fact, if you look at the literature

and all the positive benefits

of high intensity interval training,

that assumes you are actually hitting very close to 100%.

If you’re sliding down into, again, moderate training stuff,

you start to actually be in a spot

where you’re not getting the total high-end stuff,

but you’re not doing it long enough

to get the low-end stuff either.

And so you end up in this, you burned some calories.

You probably still enhanced mitochondrial biogenesis

and a little bit of capitalization,

but you didn’t really justify only doing three rounds.

That’s where the problem comes in.

So in terms of a couple of protocols I’ll give you,

how many sets per week?

It’s really hard to give a number

unlike the strength training stuff

where it was easy to kind of land some stuff on.

A typical thing you’ll see is a minimum build

tends to be something like four rounds per day,

three times per week.

Wow, that’s a lot.

So my once a week all-out effort

of sprinting on the assault bike,

the so-called Airdyne bike,

for 60 seconds, one to three rounds of that,

might be doing something useful for me,

but I should probably be doing that

two or three times a week.

If you’re gonna get to a max heart rate,

I generally like to say,

give me a minimum of one day a week, two’s better.

Days per week, how many rounds?

Whatever it takes you to get to that maximum heart rate.

Right, so in your case, you did one minute.

Okay, good.

If you’re gonna extend past a minute or two,

one round might be enough.

So for example, if you wanna just do something

where I’m gonna run a mile as fast as I can,

that’s all you need to do for the day.

You don’t need to do multiple,

you can do mile repeats if you’d like,

but that is really, really challenging.

I know we’ve extended the time duration here,

but I wanted to go there to show you

the time domain matters here.

If you’re doing something like a 20 second burst,

you’re going to need more rounds.

If you’re doing something longer

like multiple minutes,

you don’t need as many rounds to get there.

So in addition, if you’re really reaching past

this 90 seconds of hell window,

it’s just gonna do a lot more damage to the system.

Not damaging than bad,

but as in there’s a lot to recover here.

So we need more recovery time from that.

A 20 second burst doesn’t really challenge you.

It challenges you in that 20 seconds,

but you’ll be recovered and fine.

The three minute thing is gonna hurt

and it’s gonna hurt for many, many, many minutes after that.

And you’re going to still see

maybe some performance decrements the next day,

depending on what your recovery stuff looks like.

So a couple of things to play with

would be something like this.

If you wanna try like a classic 30 seconds on,

30 seconds off protocol,

the literature will show like a minimum of four rounds

of that probably three days a week.

So 30 seconds all out, 30 seconds rest is one round.

Repeat that four times, at least once a week.

At least, two would be better.



If you wanna go something a lot longer than that,

you might be able to get away with one.

But generally two days a week of this is better.

If you start actually pushing past

like three to four days a week, up to five or six,

you may actually be causing some problems.

There’s just a little bit of excess fatigue

that’s gonna happen there

that you maybe wanna stay away from.

In fact, you can see a lot of endocrinological problems

and some other sleep issues and some other things kick in.

And we’ll talk about more of those things later.

But that’s the number to get with.

If you wanna try something more like a 20 second burst,

I actually would recommend giving yourself more rest.

So you can actually do a higher rest than work ratio.

Most people tend to think of this as doing like one to one,

20 seconds on, 20 seconds off or lower.

I love doing like 20 seconds on, 40 seconds off.

The quality of that 20 seconds becomes extraordinarily high.

And it’s also possible to now get like six to eight rounds.

So as I’m hearing this, I’m going to wager an offer to you.

And if you say okay, then to those listening.

Based on what you’re telling me about the relationship

between intensity and quality

and the need for sufficient duration of this anaerobic work,

how is five to six minutes per week of all out work?

That’s pretty good.

So what that means for me is I would do three

all out one minute sprints on one workout

separated by a minute or two, maybe more.

And I would do that two or three times per week,

just trying to hit that five or six minute

per week threshold.


Actually, I think one of the…

Marty Gabala is a scientist, a Canadian guy, amazing work.

He’s done a lot of the research

on high intensity interval stuff, right?

And I think the number he actually threw out there

in some of his original research

was comparing six total minutes of work

to upwards of like 180 minutes of work

throughout the entire week.

And then one of the classic studies

was looking at VO2 max improvements

and he saw equal if not greater improvements

of VO2 max with that.

So I think actually the name of his book

might be like the six minute workout or something.

And so you’d like may have nailed that directly on the head.

Purely by luck, but actually by-

I also may be wrong on that number

so we should probably fact check that.

Yeah, well, and also by inference from what you were saying,

if you’re gonna do this 20 seconds on 40 seconds off

and you’re doing more rounds or one minute all out.

So the way I’m going to think about this,

if it’s okay with you is for five to six minutes a week,

I am sprinting for my life.


But I’m sprinting for my life with good form

in whatever movement I happen to be doing.

And I can do all of that in one workout,

but I’m separating out bouts of 20 seconds

all the way up to one minute by the necessary rest

in order to recover my breathing,

get back to pure nasal breathing,

maybe zone one, zone two.


And then hit it again.

If you’re gonna do the one minute thing like you do,

I actually generally encourage one to three minutes of rest

before you do the next round

and probably up to four to six rounds.

That would be your six minute number there.

Now, the caveat there is

we don’t worry about heart rate recovery.

We worry about exactly what you mentioned,

which is nasal only recovery.

Once you can get back to that,

give yourself another 30 seconds or so

and then you’re ready to go for round two.

This is where it gets fun

because I can imagine challenging myself

to get on the assault bike for one minute

of kind of warmup, very low intensity each morning,

and then sprint for a minute

and then head off into my daily routine.



That, if you’re going to do that though,

you need to give me three minutes of nasal only breathing

before you go back to work.

We need to down regulate after that.

I can certainly do that.

And there are people in my life

that would love for me to engage in more nasal breathing

because it’ll have me speaking less.

So, no problem.

Chances are I’m going to use

the two or three workouts per week of one minute all out.

Maybe I’ll try the shorter protocol.

Can I give you one fun protocol to try here?


So, if you have a, you can use this on any equipment,

but I learned this from another mutual friend, Kenny Kane.

This is a great little, it’s a little test,

a little game you can play with yourself.

And the only way to play this game is you’re going to lose,

which is really, really lovely.

So, you can do this for any duration of time,

but two minutes is a good number.


So, you have to do this in somewhere

where you can know distance.

So, this could be running, cycling.

The air bike is what I use.

The first two minutes,

you’re going to cover as much distance

as you can possibly cover in two minutes.

And you’re going to note that.

So, let’s say you covered 400 meters, right?

Okay, great.

You’re going to rest for two minutes.


That next round, you’re now going to go for distance.

So, you’re going to cover the exact same amount of distance

you covered in round one,

which in this example was 400 meters.

And it doesn’t matter how long it takes you.

It may take you two minutes and five seconds,

two minutes and 10 seconds,

because you’re a little bit fatigued from round one.

Round three, you’re going to now come back

and do that exact same time domain

that you did in round two.

So, if it took you two minutes and five seconds

in round two,

now round three is going to last two minutes

and five seconds.

And you want to see if you can cover a greater distance,

405 meters, 410 meters,

than you did in round one.

And the beauty of this little protocol,

six minutes total of work, right?

But if you slack in one of the rounds,

you just make the next round harder.

Is there any rest between rounds?

Yeah, two minutes.

Always two minutes rest.

You don’t have to, but this would be my recommendation.

Kenny Kane came up with this.

I don’t know if he came up with it.

He taught me this thing.

We both know Kenny

and he’s an incredibly nice and incredibly skilled trainer.

I’m going to call it the sugar cane.

Yeah, it’s so great because it sounds really painful.

And if you go out too hard in round one,

you’re in such big trouble round two.

But if you go too easy in round one,

you’re going to get absolutely obliterated in round three.

So, it’s like a wonderful thing.

And you can pick that number as a standardization

and then just try to improve that a little bit per week.

So, progression is the last part of this whole thing

that we haven’t gotten to yet before we move on.

And the way you want to progress all of these things

is you can timestamp, again, how much work you can do

and then just try to do a slightly higher amount of work,

5% or so every week.

Or you can add a round, which is a really nice way.

So, in the research studies that have been done,

they’re going to do things like week one,

you’ll do three rounds.

Week two, you’ll do four rounds.

Week three, you’ll go five rounds.

So, you’ll like add a round until you get up to say six

or seven or eight rounds at the end of the protocol.

So, that’s a really nice way to go about it.

Or you can cap the rounds

and just try to get more work done

in that same amount of time.

Meaning go more intensely.

Correct, get further distance in your 30 seconds

or your 45 seconds or whatever.

I want to encourage people to go as low as 20 seconds.

That’s going to allow you to go very, very, very fast.

That’s going to actually challenge

that phosphocreatine piece a little bit.

I want to encourage people to also go as high as 90 seconds.

So, the honest way, the way that I will do it,

not that it’s about me,

but just as an example of something you could do,

I do something in the 15 to 20 second burst range.

And I will generally hedge towards a two to one

rest to work ratio.

So, I’m probably going to rest 40 to 60 seconds.

That’s to make sure that 20 second burst

is extremely high quality.


I’m also going to do something in the 30 to 50 second range.

I might go one to one work rest ratio.

The quality of those 30 seconds is going to come down,

but the acid buffering

is going to be extraordinarily challenged.

I also will do that with a triple or quadruple rest range.

So again, 30 seconds on, maybe two minutes off.

Now, I won’t be able to be,

I won’t be working on my ability to handle

the waste product build up there,

but I’ll be working on my ability

to produce more force over that time,

which is another skill set.

And then all the way up to say what you do,

a minute, 70 seconds, and you can go one to one there,

or up to three to one.

You’re going to be working on

a little bit of this different thing,

but that’s exactly how we hit both sides of this equation.

Working on dealing with waste,

as well as actually working on bringing in nutrients

and getting that system a little bit more effective.

So, you could set that up across your week.

And just, it could be something like,

day one is that 20 second burst window,

day two is that maybe 60 second window,

and then day three is maybe one all out effort,

and we’re done there.

Let’s talk about the specific protocols

and adaptations related to maximum aerobic output,

or maximum aerobic capacity as it’s sometimes called.


Now we’re moving past like that couple of minute range

into like the, you know, five to 15 minute range,

but at a maximum intensity.

So, what’s the highest you can go from there?

We’re not talking about our last category

of long duration here.

Well, the beautiful part is,

we’ve already explained a lot of it,

because it’s very similar to what we just talked about

with anaerobic capacity.

It is primarily going to be a problem

of dealing with waste products, especially at the end.

It’s not enough total distance

to be running out of muscle glycogen,

though it may start to creep down a little bit.

Fat’s not going to be an issue,

but certainly more oxygen transportation

is going to be an issue.

So, we’re just hedging a little bit more

towards that side of the equation.

Towards the end of that workout,

no doubt about it, clearing out waste products

is going to be a huge issue.

But really, oxygen demand delivery

is starting to take more of a prominent role,

because we have had more time to clear the waste.

And if we’re not good at that,

we’re going to be failing earlier than we need.

So, the training for that needs to be a little bit

at that exact same.

So, a classic thing here is a one mile test, right?

This is going to last for most people

somewhere between five and 10 minutes.

You’re sort of right in this window.

If you just want to practice that once a week,

we’re done here, right?

Exercise choice, same thing we talked about, right?

Pick an exercise you’re comfortable with

that you can actually do,

and you can progressively increase

in terms of the intensity.

You’re not going to have to stop and change your exercise.

You’re not going to have to move around.

It’s like a circuit isn’t great here,

because you got to put one implement down,

pick up another one.

You want to be doing something

where there is literally not a second of off switch.

So, similar exercise choice principles we just covered.

If you’re going to become a real savage,

and you want to do repeats here, you can.

Endurance folks will do that a lot.

One mile repeats, 800 meter repeats, things like that.

I’m not sure what the swimming distance equivalents would be,

but swimmers, we do this constantly, but you don’t need to.

This is really hard.

It’s pretty hard in the system.

It’s very good for you.

One to twice a week of hitting this,

I think you’d be in a really, really good spot.

Frequency, we sort of just covered.

We covered exercise choice.

Volume, we just sort of nailed.

And intensity is basically running you up to the top there.

Now, because you can only do that so often,

you want to add in another 40 or so percent of your time

being lower intensity support work for that.

So, this is something probably less than 85%

of your heart rate,

but higher than quote unquote zone two.

You got to be working here.

This is not, I could have a conversation pace.

This is higher than that.

It’s in between conversation pace

and the pace I need to be at

to run my fastest mile I’ve ever done.

That’s that middle ground.

And you need to train that

so that you can continue to work on capitalization,

oxygen transportation,

but you’re not burning down the house,

getting all the way up to 100 plus percent of your VO2 max.

Could I use a crude version of this

where I say, okay, I’m going to exercise for 10 minutes.

I’m going to go as fast as I safely can.

And every week I’m going to measure how far I travel.

Yep, easy.

In that 10 minutes.

Love it.

Probably not on the same day

that I’m doing the anaerobic capacity work.

Probably not.

Probably okay to do after a strength training

or hypertrophy workout,

as long as I didn’t train legs.

You could.

It’s probably going to compromise recovery is the way.

So I would, if you’re going to do a session like this,

I would probably do it on its own day.

Unless you wanted to do something like speed or power,

then you could roll right into this and have no problem.

Maybe a strength day, a hypertrophy day.

I’m not sure you would do there because, again,

especially if you did any sort of lower body exercise,

you’re going to be compromised here.

But remember, these tend to be full body movements.

So even if you did arms that day,

your arms are going to be compromised.

And you don’t want to fail this

because of local muscular failure.

All right, so now I’ve got my work cut out for me.

I’m going to be doing five to six minutes per week

of all-out work divided into 20 to 60 second bouts

with sufficient rest.

And I’m going to give myself 10 minutes a week of,

in my case, it’ll probably be running as fast as I can

because I do enjoy running and I can do it safely.

Maybe uphill and see how far I go.


If you want to combine the two.

So if you’re just saying, hey, I’m bought in, Andy.

I want to do both of these things.

They are similar, but they have independent benefits.

I’m convinced.

How would I build these into the same week?

Maybe do one of each.

That still gets you at quote unquote, two days per week

where you’re going to hit a high maximum heart rate.

So we already checked that box off.

So one day can be a shorter length interval repeat one.

And the other one can simply be a five to 15 minute

maximum work and you’re done.

Long duration endurance exercise,

the stereotypical endurance exercise.


How far, how long, how fast or how slow rather should I go?

And here I’m going to venture that exercise choice

is one that we could click off even at this point

in the discussion, because obviously it’s got to be

something that I can do for a long while

without getting injured, overuse injuries.

There’s a little bit of novelty

we can actually throw in here.

So one of the things I love to do for long duration

and endurance for people who don’t love running,

cycling or swimming is you can do the really cool workout,

any number of things where you can put a little circuit

together, as long as there’s not a lot of downtime

between one circuit to the next time,

you can actually do something as simple as like,

maybe you’re going to do farmer’s carries

and you’ll do that for say three minutes

and you’ll set those down and you’ll go straight

into a plank for a minute.

And you’ll pick that up and you go straight

into maybe body weight squats for two minutes.

Then you go straight into another exercise

and you can sort of rotate things around.

Maybe you can do even some like shadow boxing stuff

or some jump rope.

You can do different gymnastics movements

and body weight movements.

And you can run that thing through

and you can basically get the exact same thing accomplished

and not feel like you’re doing,

oh my gosh, this mind numbing type of training

if it feels like that to you.

Another way you can do that to actually even simplify it

even more, we’ve done this at Kenny Kane’s gym

plenty of times where you just maybe even pick

three machines.

So you’re going to go, I’m going to go 10 minutes

on the rower and I’m going to go 10 minutes

on the treadmill and I’m going to go 10 minutes on the bike.

You can actually knock a 30 minute quote unquote

steady state session out in and not feel those problems

if those things happen.

So you can actually have a lot of fun there.

We will do a lot of times with our fighters,

we’ll do things like put a very low load.

I’m talking sub 50% of your max on a barbell

and you’re going to squat and you’re going to do,

you know, maybe a minute.

You’re going to put that down and then you’re going to go

over and do 50% of a bench press.

You’re going to put that down.

You’re going to go over and do 50% of a crab walk.

And then you’re going to go over and do another one.

And you can actually run through this entire thing.

You don’t hit that many reps in any individual movement.

The load is very, very light and you can keep heart rate

basically a steady state and do 15 or 20

or 30 different exercises.

And it’s actually like fairly fun and engaging to do.

And it’s a little bit more specific than trying to get

a 275 pound NFL player to run for 30 minutes,

which is not going to be good.

I’m just chuckling because I love to run outdoors

and I’ve enjoyed runs on all my travels.

And I find it to be a great way to see different places.

I like moving through space,

but there are weather conditions

and times when that’s not an option.

So what you described is a terrific alternative.

I have to assume that the specific adaptation

that’s occurring here is related to the fat burning system.

And again, that doesn’t necessarily mean fat loss overall,

but fat burning system.

And yet I do have a question, which is,

can you build enhanced micro capillary systems

into the muscles by doing this long duration cardio?

Yeah, absolutely you can.

In fact, depending on which paper you like more

than the other papers,

you may even find evidence that this is a superior method

than anything else.

So steady state endurance is very important.

I used to not like it as much.

There’s just so much evidence now that suggests

it’s probably a really good thing for basically everybody.

Maybe for some individuals,

it’s not in all year of their training,

but if you’re not a high level athlete

or have a very specific goal that’s right in front of you,

it’s probably best to do at least 20 minutes as a minimum,

maybe 30 minutes of some steady state exercise once a week

for basically any training goal outside of again,

a couple of really specific scenarios that are happening.

The other thing that kind of kicks in here

that we haven’t really talked about

is now we’re actually reaching a position

where fatigue of the intercostal starts to play.

So diaphragmic fatigue starts to run in an occasion.

So we forget generally breathing

is a contraction to open up the lungs to change pressure

so the air will flow in.

And then the exhalation is passive, right?

It’s just a muscle has been stretched,

it goes back to its resting.

When you get to a maximum heart rate,

inhalation and exhalation become active.

So you’re squeezing as hard as you can to open up

and you’re squeezing to contract to blow air out.

You’re going to get fatigued, that system, right?

Over time, you have contracted, contracted to open up.

If that system starts to get fatigued,

you start running into failure here.

So you need to practice that.

And this is when all kinds of things like breathing drills

to just simply training in this fashion.

There’s all kinds of exercise devices for your lungs.

And when we say that,

that’s what we’re really talking about.

The musculature around the lungs needs to not fatigue.

So that’s the only other little component

I wanted to throw in here.

If we’re not talking about acid buffering,

which in this particular case is not a problem anymore,

the time domain is long and slower.

So we have plenty of time to use fat as a fuel.

We also have plenty of time to use anaerobic

and aerobic glycolysis and clear out waste products.

So we don’t really see pH being a problem

with this type of exercise.

You may start running low on liver glycogen

if you’re going a very long time.

Muscle glycogen may start getting low,

but not really.

These are huge issues.

You’re going to run into maybe a little bit

of a stroke volume issue,

but an intensity is not high enough to become a problem.

You’re more likely to break down posturally

or breathing mechanics than really anything else.

Unless again, that duration really gets

generally past two hours for most people.

So those are the things that are going to limit us.

So how do we improve it?

What do we train?

We went through the exercise choices.

You also need to make sure you’re training

your intercostals.

We need to be training our diaphragm in some fashion.

Again, it can be the exercise itself,

can be your normal training.

The thing you need to be careful of here,

and this is actually true for all the things

we just talked about.

When we think about fatigue

and we think about failure and endurance,

we really need to pay attention to technical breakdown.

That is always the marker we look for.

So when we go through our stuff with our athletes

and they quote unquote fail, or they finish,

that’s generally because we saw

a massive technical breakdown.

You’re done.

Like you’re over there.

Not always the case during all your round of training,

but this is something to really pay attention to.

So if you’re on that bike and you’re 40 seconds in

and all of a sudden posture starts crunching over,

I may stop the test.

I may stop the training.

It’s like, no.

What we decided failure was

is when you lost your technique to some sufficient level.

So you want to pay attention to that too,

because that’s going to determine your ability

to perform well as well as maintain efficiency,

which is a really big problem here.

Tell me if the protocol I’m about to describe

would be a reasonable one for people to incorporate.

60 to 120 minutes

of long duration work per week.

So one way to accomplish that that I often use

is to head out for a weight vested hike.

It’s not a heavy weight vest.

It’s maybe, I think it’s eight or 10 pounds.

It’s one of these thinner ones.

And if people don’t have access to that,

you can bring a backpack with some items in it.

I mean, it can be as simple as that.

You don’t even need external load.

It can just be your body.

Okay, great.

And do some hiking at a fast enough clip

that I’m breathing harder than I would be

if I just kind of shuffled along.

I might stop here or there, drink some water, no big deal.

But I can carry on a conversation if I need to.

So it’s zone two-ish,

but probably pushing a little bit harder than that

for that duration.

Not a lot of deep soreness occurring after this,

maybe a little bit of achiness

and some stabilization muscles that were used

that may not be used too much,

especially if I’ve been sitting a lot during the week.

Kind of reminds me of how much I’ve been sitting.

But doing that all in one long afternoon,

typically on a weekend,

or doing two shorter sessions throughout the week,

maybe 45 minutes and 45 minutes,

and then working up the progression to longer duration.

Seems like that would be something

that most people should be able to do

and that it would weave in well

with any resistance training

or the anaerobic and aerobic output capacity work

that we talked about just a moment ago.

Great, that’s a fine version to do it.

If you wanna go shorter

and bring up the intensity a little bit,

so you wanna keep it more to the 30 to 60 minute range

and go closer into the,

I can’t have a conversation right now,

but again, I’m not at a blistering heart rate,

then you could probably get that same thing done

in a smaller time window if that was a consideration.

So if you wanted to blend all three of these together,

you have a lot of wiggle room, right?

So you could do something like order.

If we’re talking about this type of training,

you could do this first

and then finish with either one

of the higher intensity stuff we talked about.

So it could be roped into the same thing.

It could be its own independent day.

Could be your sort of active recovery day.

It tends to be fairly restorative

as you alluded to a little bit there.

So it’s not that big a deal

to do this on your quote unquote off day.

If you’re that type of person

who like even on your off day,

you have to do something physical,

this is fine, right?

If you wanted to do it on a lifting day,

especially if it’s a power or strength day,

it’s probably fine.

If you wanted to do it before the workout or after,

either way, you’re probably okay.

Probably best to do it after

if the primary goal

is one of the strength training adaptations.

If it’s not, if this is a primary goal, do it first.


If you wanted to do it in the combination

with the other interval stuff,

you could do it fine there.

You could do it before or you could do it afterwards.

I actually have no problem doing it afterwards

because that in effect,

especially if you say nasal only during this training

will help the downregulation go.

And so you could finish that

fairly well downregulated actually.

So it’s kind of like a nice way to get thoroughly warmed up,

go really, really hard

and then give it a nice 20 to 30 minute slow back down.

And by the time you finish,

maybe even on a three minute walk.

Nice, slow nasal breathing.

Four second inhale,

four second inhale, maybe five.

So you can play with the numbers a little bit.

Then maybe you don’t even need to do

the downregulation breathing afterwards.

You’ll be in a good spot.

Well, you wouldn’t want to do this before,

do your intervals, finish your intervals,

throw up, lay on the ground,

sweat all over the gym floor,

get up and go back to work.

That’s probably not our best strategy.

As people are hearing this all,

they may be thinking,

wow, this is a lot of work to do,

but I’ve been keeping track of the math here.

So I’m sure some of you out there are as well.

And we’re really talking about 10 minutes

of running or sprinting on the bike or rower once a week.

We’re talking about six minutes or so

of the much higher intensity,

but short bouts divided into rounds of 20 to 20 seconds

to a minute with rest in between.

And then some longer duration workout of 30 minutes minimum,

but maybe as much as an hour, even two hours,

which in total doesn’t really equate to that much time,

especially if one can access these things

right out their front door or at home.

And as we pointed out,

you don’t need any specialized equipment to do that.

Oh, and I forgot the muscular endurance.

I wasn’t trying to cheat there.

Some muscular endurance thrown in as well.

So that brings me to a question,

which is if I’m doing my training

for muscular endurance each week,

for anaerobic capacity and for maximum aerobic output

and long duration,

and given that all of that is gonna take roughly two hours

for the typical person total for the entire week,

which I would argue is going to give you back

so much life literally in terms of longevity,

you’re literally gonna earn back years of your life.

Productivity, you name it.

Offsetting all sorts of metabolic issues

and enhancing your sleep and improving mood.

I mean, there’s so much data,

so much data pointing to all those positive benefits.

If I do all of these things

and I’m fairly consistent about them,

am I going to be metabolically flexible?

Am I going to have a well-developed fat burning,

carbohydrate burning system?

And will I be essentially fit?

I mean, this is not leaving aside issues of strength

and hypertrophy,

which were covered in the previous episode.

I mean, to my mind, the ability to sprint very fast

if one needs to,

the ability to go longer duration if one needs to,

and the ability to do something in between

as well as hold a box overhead if necessary

while installing a shelf or something like that.

These are the realities of life.

And to me represent real functional world fitness.

If that’s the case,

is there anything that we would want to add to this program

or would you consider that a fairly comprehensive

and complete endurance training system?

If we remember the target,

which is I want to have energy,

I want to look a certain way,

and you want to be able to do that

for the duration of your life,

for a very long life.

This style of training

where you incorporate all of those areas of endurance

gives you all of the necessary adaptations

one would need to execute all of those things.

Remember, fat loss or weight management

is not best done with any individual style of protocol.

So if you do a little bit of all three of these,

you’ve checked that fat loss box.

You don’t need to go out and do anything separate for it.

You’ve done all the things then to cover aesthetics

from that side of the equation, right?

You’ve done the things to both enhance mitochondria,

to enhance blood flow,

increase oxygenation,

and manage fatigue and waste development.

Boom, energy’s there.

Fatigue is there.

I’m not going to get tired

or have to quit or stop or sit down

doing any of these activities I want.

At the same time,

if you look at the literature on mortality,

one of the strongest predictors

of how long you’re going to live is your VO2 max.

So we’ve set up a scenario

in which you’re going to hit all three

of those primary goals

by doing a combination of this training.

You’re not going to miss any plausible adaptation

from endurance training,

and you should be set for regardless of your goal.


And as I understand,

totally compatible with strength and hypertrophy training,

provided that your goal is to also be strong

and also selectively hypertrophy

or generally hypertrophy your muscles

or maintain your muscles.

For many people that are listening to this,

I’m guessing that they have an interest

in building more endurance,

but not just the ability to go further,

but the ability to go a given distance

at a higher speed and to do it with better form

and to breathe better

and to feel better before, during and after.

For those folks,

maybe you could spell out a program

that combines these different elements of endurance

and does so in a way that informs how,

for instance, the higher intensity,

short duration sprints

would be expected to improve their longer duration work

and how perhaps their longer duration work

can progress if they are careful

to include some planks and some wall sits

and things of that sort.

I asked this question specifically

because I have to believe that

while there probably are some folks out there

that are looking to just maximize their plank

from week to week to week,

typically it seems that people fall into these categories

of either wanting to get stronger and get bigger muscles

to varying degrees or to get better at endurance

or to get better at everything overall.

Right now, I’d really like to just focus on

what you think is a nice contour of a program

for the person that wants to get better at endurance

but do it with more speed, more stability

and just feel like a strong endurance runner,

cycler, swimmer,

or whatever happens to be their endurance event.

Okay, great.

So let’s just give an example.

Maybe you wanna run your first half marathon,

something like that, okay?

Maybe you’ve done it a couple of times before,

but you just wanna get better at that time.

I would probably put somewhere in the neighborhood

of 60 to 70% of your mileage

in the moderate intensity zone.

Okay, so you need to accumulate mileage

and you need to be able to handle

what we call the tissue tolerance.

So in this case,

your feet need to be able to handle 13 miles of pounding.

It doesn’t matter how much high heart rate training you do

or your fat deliverability,

none of that matters if your feet are blown up by mile eight.

Okay, so in addition,

we talked about how even training

in that 70 to 85% heart rate zone

is quite effective at oxygen delivery,

fat utilization, capitalization, et cetera.

So you’re going to get a lot

of direct endurance benefits from that work.

You’re also going to be working on

what’s honestly going to be one of your limiting factors,

which is that tissue tolerance and that pounding, okay?

In addition, you need to be efficient with your technique

and you need a lot of repetitions

for motor skill development.

So you wanna spend most of your time there.

It’s easy to recover from,

it’s not extremely demanding and challenging.


That leaves you with another 30 or 40% of training.

I would spend 10% of that in that like 22nd burst area.

You’re gonna drive up fatigue extremely high

and you’re gonna really maximize your ability

to recover from waste production.

All right, great.

I would spend the remaining amount of time

either on a little bit of actually maximum speed stuff

that could actually be in the 22nd burst

if you’re really trying to go as fast as you can

at the beginning of that exercise.

And then the rest of it, I would spend in that other zone,

which is more of like the five to 15 minutes,

but you’re probably gonna wanna repeat those.

And this is when things like 800 meter run,

rest for double the time,

and then repeat that two or three times.

You actually need that in this scenario

because you’re gonna need to be able to be running for two,

most people are gonna do a half marathon

for maybe around two hours or so, something like that.

And so you want a little bit

of what we call repeated endurance, right?

So be able to handle that higher heart rate,

come back down, do it again.

At the same time,

that’s actually how you bump your mileage up.

So instead of having this do more

of these long duration distance runs,

you can still get maybe five or six miles done in a day

if you’re gonna do a one mile repeat

or whatever number you’re looking at.

So for a lot of people,

that’s kind of how I would structure it.

Honestly, it’s very similar to what we laid out

in the previous conversation,

which is getting this idea

that more than 50% should be basically practice.

A little bit of work at the very top end of the spectrum,

but not too much.

And then a little bit of work at the other end,

and you should be in a good spot.

A major mistake one would make here

is only doing the long duration steady state stuff

and just sort of saying,

I’m gonna run five miles this week

and then do six miles next week and seven.

That might work for you.

I think we have enough evidence at this point,

both in the scientific realm,

as well as most of the coaches,

I think in this space would agree with me,

is that’s a suboptimal strategy.

So it could work, but we can do better.

And in terms of the structure of a program like this,

I realize that those structures vary tremendously.

Different coaches and different books

and different programs are gonna say,

oh, you should run Monday through Friday

with weekends off or every other day.

But in terms of this 70%, 30% divide,

where 70% is going toward the specific event,

doing the kind of work that you’re going to do

during the specific event

that you’re most interested in cultivating or improving,

and the remaining 30% coming from other sorts

of supporting work,

how should one think about distributing that other 30%?

Should it be all geared towards maximizing recovery

for the 70%?

Or in other words,

could I do all that 30% work on one day?

I probably would split it into two days.

That’s the reality of it.

So if you’re thinking,

man, coach wants me to train six days a week.

My schedule is tight.

I can pull off four to five.

Okay, great.

What I might say is two of those days

are just your tempo, right?

This is what like a runner would call it.

It’s like tempo training kind of in that space.

Remind us what tempo training is just for the uninformed.

It would be this like 60 to 80% effort range

where you’re like running at probably the same stride length

and rate that you’re going to run your race at,

maybe a little bit lower, but something similar.

You’re practicing skill,

you’re accruing mileage,

and you’re getting a little,

you’re getting work in for sure work,

but it’s not absolutely the fastest you can sprint.

And it’s also not conversation.

So this would be the,

what before we referred to as the 10 minutes

of fast running or 10 minutes of fast rowing.

This is lower intensity than that.

Got it.

This is work accumulation.

Got it.

This is the work that you practice stuff.

Then one of the days a week,

I would probably enter in that 20 second,

30 second burst for a little bit of speed there.

And then one of the other days is when I would do that

true high intensity as hard as I can

for hitting a VO2 max, something like that.

So that’s probably how I’d break it up.

If I had like four days a week,

if you had five,

you can maybe add in another day

where you do more of that volume accumulation practice work.

But that’s a pretty good split.

So this is the point in the episode where I say,

thank you ever so much.

You provided an enormous amount of incredibly interesting,

clear information that’s also actionable.

I do feel as if I far better understand endurance

in its many forms

and even the seller underpinnings of that.

And even subseller underpinnings

of what endurance adaptations are

and how to foster those through specific protocols,

things that not only I can do tomorrow,

but that I will do tomorrow.

And where I hit my pain points,

I’ll understand what’s happening

and the adaptation that I’m triggering.

When my legs are burning

or I’m sucking for air through my mouth,

or I can calmly move along just through nasal breathing,

I will now know what’s happening in my body

and the specific adaptations that I’m triggering.

I think you also highlight something

that is vitally important

and I’ve never heard it phrased as clearly as you did today,

which is that it really doesn’t matter

how one seeks out to achieve fat loss,

provided certain criteria are met.

Even while certain forms of exercise

tap into fat stores more than others.

And you beautifully illustrated

the relationship between energy utilization and breathing

and the fact that we literally exhale fat to some extent.

Of course.

So once again, thank you, thank you, and thank you.

I know I’m not alone in recognizing this information

as incredibly interesting and actionable.

And indeed, I do plan to put it into action

as I hope many of our listeners will as well.

Yet again, the pleasure is actually all mine.

And I actually really appreciate the fact

that you let me go so far into metabolism.

My PhD is in human bioenergetics.

So anytime I can go many hours into metabolism,

I get very excited

and I don’t typically get that leash in this format.

So I appreciate that.

I know you understand your audience will love that,


Oh, they’ll love it.

And I think that they’ll especially love it

because they understand that if one can wrap their head

around even just a small fraction of the mechanisms

that underlie a given protocol,

it gives both tremendous depth and meaning to that protocol

and makes it so much more flexible for people

that can really think about what’s happening

as they’re engaging in a given protocol

and know exactly what they can expect in terms of results.


We’ve been on a bit of a journey here.

We’ve covered a lot of ground

with speed development and strength and hypertrophy.

And now we walk through,

probably several hours here of endurance.

What I would love to do next

is to just give you a more straightforward,

not as much background, not as much metabolism,

none of the mechanisms,

right into protocols for someone who says,

look, I wanna hit those marks you keep talking about.

I wanna look good.

I wanna feel good.

And I wanna do that across my lifespan.

How would I build all these things into a protocol

that actually covers maybe the entire year?

And how would I be able to repeat that year after year?

So I almost have this evergreen, sustainable,

year-long periodization structure

that covers all the nodes I need to

if I want everything we’ve talked about

in these nine adaptations in this short series.

So I would love to do that in our next conversation.

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