Huberman Lab - Supercharge Exercise Performance & Recovery with Cooling
Episode Date: May 10, 2021This episode I explain the science of heating and cooling the body, a process called thermoregulation-- and how to apply that knowledge to significantly improve physical performance. I describe the th...ree areas of our body that can remove heat (or bring heat into the body) faster than anywhere else, why that is so, and how proper cooling of these areas with specific protocols can allow people to perform 200-600% more volume and repetitions of resistance exercises at the same weight loads, or to run, cycle or swim significantly further. I also describe how to use directed cooling of so-called glabrous skin: the bottoms of feet, palms and face, to significantly enhance recovery times from exercise. Also, why the common practices of trying to heat up or cool the body via the torso or whole-body submersion in cold can be inefficient and/or dangerous-- and the better alternatives. Finally, I discuss the temperature-effects of caffeine, alcohol and anti-inflammatory compounds. The information in this episode is focused on mechanisms and tools for increasing athletic or exercise performance. For the full show notes, visit hubermanlab.com. Thank you to our sponsors AG1 (Athletic Greens): https://athleticgreens.com/huberman LMNT: https://drinklmnt.com/huberman Supplements from Momentous https://www.livemomentous.com/huberman Timestamps (00:00:00) Introduction (00:00:31) Sponsors: AG1, LMNT (00:05:08) Physical Performance & Skill Learning (00:06:40) Optimal Learning Protocol (Recap): 4 Steps (00:08:31) Variables Impacting Physical Performance (00:10:00) Temperature Is the Dominant Variable (00:12:08) Understanding Mechanism Is Key (00:13:42) Heat: The Enemy of All Performance (& Why) (00:16:30) Blood Flow & Sweating & Piloerection (00:22:35) Heat Is What Limits Effort: Even If You Feel Fine/Motivated (00:25:29) Proper Cooling Can Double, Triple, Quadruple (Or More) Your Ability (00:26:42) Heat Induced Confusion & Death (00:30:02) The Three Body Parts Best For Heating & Cooling Your Whole Body (00:31:38) Face, Palms, Bottoms of Feet; Glabrous Skin (00:33:00) Arterio-Venous Anastamoses (AVAs) Are Super Cool(ing)! (00:37:15) Palmar Cooling Can Supercharge Your Athletic Performance (00:38:35) ATP, Pyruvate Kinase & Heat (00:40:55) Palmer Cooling Outperforms Anabolic Steroids Several-Fold (00:43:45) Increasing Endurance, Willpower & Persistence (00:46:33) Cardiac Drift, & Moving the ”I Quit” Point (00:50:44) Deliberate Heating: Myths and Better Protocols (00:53:20) Protocols For Self-Directed Cooling To Vastly Improve Performance (00:59:23) How To Use Cold To Recover Faster & More Thoroughly (01:02:05) Ice Baths & Cold Showers Can Prevent Training Progress: mTOR, etc. (01:06:29) Alcohol, Caffeine, NSAIDs: Their Temperature Effects Matter (01:09:44) Are Stimulants Counter Productive For Performance? It Depends. (01:12:00) The Caffeine Rule & “Caffeine Adaptation” (01:14:20) NSAIDs for Training: Performance Enhancements & Risks (01:17:00) The Best Way to Explore Your Own “Parameter Space” (01:18:35) Tools: How To Try (01:21:35) Cost-Free Support, & Additional Support & Resources Title Card Photo Credit: Mike Blabac Disclaimer
Transcript
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Welcome to the Huberman Lab podcast where we 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.
This podcast is separate from my teaching and research roles at Stanford.
It is, however, part of my desire and effort to bring you zero cost to consumer information about science and science-related tools to the general public.
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I've done a couple of episodes now on the so-called gut microbiome
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This episode marks the beginning of a new topic for the Huberman Lab podcast.
As many of you already know, we go deep into a particular topic over four, sometimes even
five episodes.
We just closed out the episodes on hormones.
Now we are going to talk about how to optimize physical performance and skill learning.
We're going to look deep at the science behind this as well as specific practices. In fact today you're going to
hear about specific tools that you can use to improve endurance and strength by
up to, I'm not making this up, three or four times your current capacity. This is
based on studies that were done at Stanford and are currently in use by
collegiate and professional teams.
If you're not a professional athlete or a serious athlete,
that's okay.
The topics this month and all the information
we are going to cover are going to make you
a better recreational exercise or as well.
If you're not an exercise,
you're thinking about getting into that
or if you live in the Northern Hemisphere
and you're just thinking about the beach this summer
or fat loss, muscle building, that sort of thing, this month we're going
to cover all of that as well.
There's so much confusion out there about how to optimize fat loss, muscle building, improvements
in flexibility, for instance, or skill learning.
I know many of you aren't so focused on the cosmetic aspects of physical exercise, but are
interested in actual skill
learning, we're going to talk about that too.
I want to just take a moment to reflect on something that came up last episode.
If you didn't see that episode, that's quite all right.
But last episode, we were talking about the hormones adrenaline in cortisol and how to leverage
those towards attention and learning.
And there was a little bit of confusion that I want to clarify.
I mentioned an optimal protocol for learning that involved leveraging adrenaline, also
called epinephrine.
And it involved four steps.
The four steps that I spelled out were to become and focused while one is trying to
acquire or learn the new skill, cognitive skill or motor skill, then to have a spike in adrenaline.
I mentioned ways to do that using cold or breathing
or other tools immediately after the learning episode,
then to incorporate what I call non-sleep deep rest,
a 20 minute episode of a shallow nap
or some other protocol like NSDR,
non-sleep, deep rest protocol,
of which we always provide links in the captions.
And then to try and optimize sleep later that night
and the subsequent night.
Some of you heard this and it sunk in right away
and it was straightforward.
Others said, wait, I thought from a previous episode,
even before that, you said you're supposed to do
non-sleep, deep rest immediately after learning.
No, we added another step.
The logic still follows that you want to be calm
and focused during learning.
Then you want to spike adrenaline at the end.
Most people get that backward.
They're drinking too much coffee or even taking
neutropics and things, trying to be really focused
while learning.
Some people are taking aterol recreationally
something I don't recommend.
That's actually getting the whole process backwards
if you look at the data and the physiology.
You want to spike adrenaline at the end
or immediately after a learning episode.
And then non-sleep deep rest and then sleep itself.
Okay, four steps.
Hope that clarifies things for you.
If you have any additional questions,
please put them in the comments section below.
Okay, so let's talk about physical performance.
There are so many variables to physical performance
and we can manage physical performance
and skill learning from a variety of contexts.
I made just a short list of some of the things
that come to mind that can powerfully impact
physical performance and skill learning.
Some of them are what I would consider foundational.
They allow you to show up with your current ability.
And if you were to disrupt those, you would perform less well.
So things like getting a good night's sleep, things like being properly hydrated, things
like being well nourished, whatever that means to you.
I know some of you like to exercise fasted,
some of you prefer to have food in your stomach
or have eaten a couple hours before.
There are supplements, there are drugs,
there are different ways to breathe.
There are so many tools related to mindset visualization,
there are machines and devices.
It's just a vast space, but it's not infinite.
And there are a few things in the list of things that can impact and even optimize physical
performance and skill learning that have an outsized effect that any of you can use.
Many of them, most of them are low to zero cost.
So today, we are going to focus on what I believe to be one of the most powerful tools to improve
physical performance and skill learning and recovery.
We'll talk about why that's important.
And that's temperature.
Now, many of you might think, oh, that's kind of boring.
I want to know about the magic pill that I can take that's going to allow me a Dunk of
Basketball if I currently can't or I want to know about
the thing that's going to let me run further and faster is
going to shed fat. Believe it or not, temperature is the most
powerful variable for improving physical performance and for
recovery. I would argue it's even more important than sleep
because temperature itself is going to dictate how well and when
you sleep and the depth of your total recovery.
There are two aspects to temperature, of course. There's heat and there's cold.
We are mainly going to focus on cold as a way to buffer heat.
In a previous podcast episode, I talked all about growth hormone.
You can find that episode about thyroid and growth hormone and how heat can be a powerful stimulus for about growth hormone, you can find that episode about thyroid and growth hormone, and how heat can be a powerful stimulus for increasing growth hormone, which is involved
in tissue repair and et cetera can burn fat and improve metabolism in various ways.
However, cold, I would argue, is even more powerful than heat as a tool, and I'm not just
talking about putting ice packs on sore muscles or slightly
sprained limbs and ankles and things of that sort. We're going to talk about cold from the
standpoint of thermal physiology. This is a literature that's rich in scientific information
that goes back very deep into the last century, where physiologists and neuroscientists figured out that there are different compartments in your body
that heat and cool you differently, and that you can leverage those
in order to double, and as I mentioned before, even triple or quadruple your work output,
both strength, repetitions, and endurance. So this is not weak sauces
they say, this is the stuff that can really shift the needle quite a bit.
And it's not just about performing well once, it's about being able to perform well and
recover from that performance so that you do even better when you're not incorporating
these tools.
On days where, for instance, you can't access cold or an ice pack or an ice bath or things
of that sort.
Okay, so we're going to cover cold.. We're gonna talk a little bit about the physiology
of cold and heat and how they work,
because as you've probably heard me say before,
if you can understand some mechanism,
if you can just push yourself through a little bit
of new knowledge into understanding a little bit
of mechanism about how you work,
you'll be in a far better position
to implement
the tools in the best and most flexible ways for your needs.
This is why at the Hubertman Lab podcast, I never, ever do a just list of the things that
you should do.
I don't believe in that.
Just tell me what to do.
First I tell you why you should do something.
What's the logical framework that it's grounded in?
And then we distill that down to specific protocols.
For those of you that are too impatient for that,
there are millions, if not billions,
of other resources out there that will take you
into the cul-de-sac of one protocol that will work
and then stop working, or might work for you indefinitely.
That's not how we work here.
This is about really understanding the mechanism
so that you can tweak things and modify things,
adjust the timing and the dosage of things, and really get the most out that you can tweak things and modify things, adjust the timing
and the dosage of things, and really get the most out of these tools and protocols. Everything I'm
going to talk about pertains to both endurance exercise and strength and speed type exercise. So
sprints, weightlifting, endurance work, and to some extent flexibility, but we are going to cover
flexibility in depth, as well as another feature that's not often talked about, which is suppleness, lifting, endurance work, and to some extent flexibility, but we are going to cover flexibility
in depth, as well as another feature that's not often talked about, which is suppleness
or smoothness of movement over different ranges of movement in a subsequent episode.
Let's start by talking about temperature.
What is temperature?
How does temperature impact the body and its ability to perform, including learn new skills?
So, everyone probably remembers, or as at least heard of, the word homeostasis, right?
That the body wants to remain in a particular range of temperatures, that it doesn't like to be too hot or too cold.
And I want to emphasize from the outset that there are many mechanisms that are installed into us
by way of our evolutionary design and our genome meaning we were just born with this stuff ready
to keep our body temperature in a particular narrow range. Heating up too much is just plain
bad. It's not just bad for physical performance, it's bad for all tissue health.
If your brain heats up too much, neurons start dying and those neurons don't come back.
Okay, you may have heard about neurogenesis, the ability for the brain to regenerate itself,
or generate new neurons in adulthood. There's very little neurogenesis, excuse me,
in adulthood, even after any time after puberty, really.
And you don't want to lose neurons in the central nervous system.
If you get too hot, that'll happen.
It's called hypothermia.
You want to avoid hypothermia.
And you have many mechanisms that are built into you to avoid becoming hypothermic.
The other thing that happens when we get too warm is that we have in all of our cells,
what are called enzymes. You generally know if something's an enzyme because it ends in the
letters ASE. So lipase is an enzyme that exists to digest fats. You have proteases that are there
to digest proteins. So anytime you see ASE, chances are it's an enzyme.
Enzymes are proteins, and they have a particular structure, and their structure becomes modified
when heat increases, and that's not good.
You want their structure to be of a particular type.
Imagine a car with four wheels.
Let's just say the car is the enzyme.
If it gets too hot, it's like two of the wheels fall off and that thing can't function.
So one of the reasons why the body and nature goes through so much effort to build in mechanisms
to make sure that we don't become too warm is because when we get to warm these enzymes don't function.
Cells stop functioning. They stop being able to generate energy. They stop being able to digest things.
You stop being able to think and eventually those cells start dying off entirely.
So keeping temperature in a particular range is really good. You don't want to get too hot.
We have much more flexibility in terms of getting cold.
Now, you don't want to become hypothermic either.
You can die from hypothermia,
just like you can die from hyperthermia.
However, that you have a lot more range
to be cold than you do to be too warm, okay?
And in general, the idea is to keep the body and brain in a particular range, but
anytime we do anything, our body temperature can shift. So, for instance, if you were
to stand next to a campfire, or you were outside on a hot day, various things would happen
to dump heat from your body. If you were outside on a cold day, or you would get into a cold
shower or a cold lake, various things would happen to insulate heat within your body. If you were outside on a cold day or you were to get into a cold shower or a cold
lake, various things would happen to insulate heat within your body. This is all pretty straightforward
and obvious I realize. Now what are those things? Well, there are a huge category of them.
When you get into cold water, you secrete adrenaline. On a hot day, if it's really hot or in a very
hot sauna or in the hot desert, you will generate what are called heat shock proteins, which will set off other sets of cascades,
metabolic cascades, biological cascades.
But the simplest way to think about this process
is that when we get cold, we tend to vasoconstrict.
We tend to, our blood vessels tend to constrict,
and we tend to push energy toward the core of our body
to preserve our core organs.
So our periphery, our hands and our feet and our toes and our legs become colder, and
our core, therefore, can maintain blood to that area and we are insulating our core.
Conversely, when we heat up, our blood vessels vasodilate. They expand a bit and more blood flows to our periphery and more blood can move throughout
the body generally and we will perspire.
We will sweat.
Water will actually get pulled out of the blood to some extent, moved up through sweat
glands and will be brought to the skin surface so that it can be dumped.
We are dumping heat. Animals, as you know, vary in their capacity to sweat.
Some animals like camels won't start sweating at first.
If they heat up, what they'll do is they'll spit.
They'll dump heat by spitting.
Okay, dogs pant.
Costillers off to my left here.
He pants.
When he gets to warm, he can't sweat.
Or dogs can maybe sweat a little bit.
But we can sweat.
And you've probably noticed that on a humid hot day, you'll feel much warmer, just walking
or running than you would with the equivalent exercise or movement that you would on a cold
day.
Some of you probably know this, but if you don't, the reason is you sweat on a cold day, but because the air is dry typically, you will bring that
sweat to the surface and provided you're wearing clothes that allow some air to get out
away from the body. So you're not wearing really tight, you know, spandex type clothing or something like that or or, you know, seal type serranorap type clothing.
That sweat will evaporate off into the dry atmosphere.
Resonant on a humid day, the reason you see people in, you know, New York and Florida on a humid summer day and they're like moving their shirts off themselves and you see people with, you know, big sweat stains and back sweat stains and all this kind of stuff.
and back sweat stains and all this kind of stuff is because they're sweating as they normally would,
but it's humid and so the humidity, the air,
doesn't allow transfer of that sweat
into the atmosphere as readily, and so you're hot, okay?
So, without the evaporation, you're going to be warmer.
So, we evaporate off sweat, we sweat,
and we vase a dilate when we want to dump heat. When we want to off sweat, we sweat, and we vase a dilate when we want
to dump heat. When we want to maintain heat, we vase a constrict, and we tend to not sweat.
The other thing that happens is you'll get goosebumps, so called goose pimples, they're
sometimes called. Those are a throwback to the time where we had fur over most, not all
of our body. All mammals in the cold have a process whereby adrenaline is released at low levels, typically,
into the body.
That adrenaline activates what are called sympathetic fibers.
They have nothing to do with sympathy.
Those little fibers, which are neurons, those fibers that, what I'm saying are fibers are
neurons, not clothing fibers, reach up into the skin.
So your whole body is covered with these little tiny neurons that reach up into the skin.
And when we are cold, they actually mechanically take the hair follicle and bend it up.
It's a process called Piloirrection, P-I-L-O, erection.
So on a hot day, you want to dump heat.
So on a hot day, what would happen is you'd actually not see those goose pimples because
you want the hairs lying down, which actually you would think that might insulate you more,
but would actually let more heat dissipate out through the skin.
On a cold day, you get these goose pimples or goose bumps, which are really just an ancient
carryover from the body's attempt to make hair stand up on end.
And when hair step stand up on end
and they're very close together,
that traps air in between them
and actually creates a sort of insulated blanket,
a warm air.
If you've ever seen an animal like a malamute or a husky,
you might think, oh, that poor thing on a hot day,
what does it do with all that hair?
Well, it can be warm, so the animal will typically pant and its hair will lay down, which you
might think would act as more of a blanket, but on a cold day, what will happen is they'll
become very puffy.
Their hair will stand up on end, and that's actually trapping heat between the hairs
and they're actually quite well insulated.
So, it's very important that if you want to understand
how you can leverage temperature for physical performance,
you have to understand that you have vasoconstriction
to conserve heat, vasodilation to dump heat,
that you have sweating to dump heat,
and you have conservation of fluids
in order to preserve heat.
That's the most important thing in terms of understanding the mechanisms of maintaining and dumping heat. And now the most important thing in terms of understanding the mechanisms of
maintaining and dumping heat. And now the most important thing to understand is that if
you get too hot, not only do those enzymes stop working, but your ability to contract
your muscles stops. Okay, I'm going to repeat this because it's vitally important. ATP is involved in the process of generating muscle
contractions. It doesn't matter if you're running a marathon, it doesn't matter if you're
doing a yoga class, it doesn't matter if you're going for a 700 pound squat. The range of
temperatures within which ATP can function and muscles can contract is very narrow. Somewhere
around 39 or 40 degrees Celsius, it drops off
and you will not be able to generate more contractions.
Now, it's pretty hot, but that temperature
can be generated locally really fast.
Now, if you're too cold, it's true.
It's hard to generate muscle contractions.
I got into doing some cold water swimming a little while ago.
And we would joke that you come out of the water,
we do no wet suits.
I'm not recommending people do this necessarily unless you're certainly with somebody else
who skilled at doing it, which I was.
And you come out and you feel like you have claws for hands.
You could never text on a phone for the first few minutes.
I mean, the water was very, very cold and you can't even move your face.
And so muscles will become rigid, but heating up muscles causes them to fail
to be able to generate more contractions. Put simply if you get too hot you stop exercising.
You may not even realize it but your will to exercise further. Your ability to push harder
is entirely dependent on the heat of the muscle, both locally and your whole system.
So, let's talk about your whole system because I just described heat dumping and heat maintaining.
I told you that increasing heat makes it hard for muscles to contract.
It will stop you from being able to run further and faster.
It will stop you from being able to lift more weights, more sets, more repetitions.
If you can keep temperature in range, however, in a proper range, you will be able to do more work.
You will be able to create greater output. You'll be able to lift more weight, more sets, more reps,
and you'll be able to run further. Now, there are data that I'm going to talk about in a little bit
that are absolutely striking that underscore that statement, there are data that I'm going to talk about in a little bit that are absolutely striking
that underscore that statement.
There are data from my colleague Craig Heller's lab
in the department of biology at Stanford.
And there are data that are now being implemented.
They were first implemented in a grant funded by DARPA,
but now in professional sports teams.
Many, if not all, the NFL teams are now using this technology
as well as military uses it and not just for sports performance
But also firefighters
construction workers other
Professions where elevated heat becomes a barrier to performance and you can leverage this to really improve your workouts and when I say really improve
It is striking. I'm going to give away a little hint of this now and then I'm going to tell you a little bit more of the data later after I tell you the protocols.
Proper cooling of the body, which has to be done in a very specific way, has allowed
recreational athletes, college students and typical adults, as well as professional athletes,
to go from doing their usual output.
In this case, what comes to mind best would be
a particular professional athlete,
who's a member of the 49ers at the time,
was able to do 40 dips on his first set, 30, 2020.
Basically, 10 sets of dips,
unassisted with anything else.
That's an impressive, impressive,
especially since he's a really large guy.
40 dips is a respectable,
these are strict full range dips.
And then by the 10th set, there's a steep drop off using proper cooling of particular body
compartments.
He was able to triple that within less than a week and maintain that performance even without
the cooling approach.
So it was actually a conditioning effect.
All right.
I'll get back to this
in a little bit, but there are other fantastic leaps of effort and leaps of performance that were
demonstrated, including endurance running. Before I continue any further, I just want to underscore,
again, that overheating is terrible. There's a famous example of this. This was about 10, 15 years ago when
a number of dietary supplements that included things like epinephrine, which is a stimulant.
It's a beta adrenergic stimulant. Drugs like Climbuteral, which were then banned from
the Olympics, which are still out there, have been in recreational use, which were beta
adrenergic agonists. So these are drugs that sort of mimic
epinephrine adrenaline to some extent.
I know I'm oversimplifying this here.
They improve flat loss because they affect some metabolism,
but they heat up the body.
And what happened was this hit the press very widely
is high school football players
and various professional athletes were dropping dead
because they were overheating during practice
or in competition.
So much so that Climbutor always banned, although everyone's in a while, somebody gets in trouble
for using this.
There was an instance of this recently in professional boxing, which was attributed
to a bad meat that contained the clambuteral.
I don't know what the source was.
I don't have any commentary about that, but it still is in use, but these drugs increase
body temperature, increase fat loss, but it still is in use, but these drugs increase body temperature
increase fat loss
but carry a severe danger and that's the danger of hypothermia.
In fact, I would argue and I think in talking to some folks at various professional
fighting organizations, it's very clear that a lot of the deaths that one sees in professional combat
sports
may have to do as much with dehydration and
overheating as it does with getting hit in the head, which is also bad, but the things
can compound, they can have a synergistic effect.
And just a note about that and hypothermia and its dangers as well, my first project ever
in science was to evaluate the thermogenic effects of MDMA of ecstasy.
That was my senior
thesis in college actually. And so, thermo- what we found was that indeed drugs that remove
your understanding of how warm you are, cause you to not take on the appropriate behaviors
to cool yourself. Right? So, your vasoconstriction and your sweating,
those are autonomic, those are gonna happen no matter what,
unless you happen to take something that blocks that effect.
However, there are a lot of things that we as humans do
to prevent ourselves from overheating,
and the main one is stop.
When we are running in the desert,
or when we're running very hard,
and suddenly we stop, oftentimes that's because
the muscles are overheating.
It's a subconscious thing.
We won't often think,
oh, I'm really much too warm.
It's just that we stop,
and it's a self-preservation mechanism.
Sometimes it kicks into early,
sometimes it kicks into late.
Kicks into late, you can die.
There's an instance in the 1984 Olympics
where that was the first year I believe
that there was a women's marathon year I believe that there were there was a
women's marathon. I think that's correct. And one of the front runners or top picks for winning was
heading into the stadium. And all of a sudden it seemed as if she was lost. She was kind of
wandering around not knowing where she should go. And in fact, she was in a position to win or at
least take second place, at least take silver, got totally disoriented and did
miserably in the race.
And she was hyperthermic.
She was running against that reflex to stop.
So dumping heat is key.
So how do you dump heat in order to perform longer safely?
Well, in order to understand that, you have to understand that the body has three main
compartments for regulating temperature.
Okay, we don't just have a center and a periphery, we have three main compartments.
And there's one compartment in particular that all of you, or most all of you, I have to
assume have, and if you can understand how that works, you can do tremendous things for
your performance and for your recovery.
So what I'm about to tell you will allow you to perform better in all forms of exercise,
and it is not commonly known, unfortunately.
I'm here to try and change that.
You have three compartments for increasing or dumping heat in your body.
One is your core.
We already talked about that.
Your core organs, your heart, your lungs, your pancreas,
your liver, the core of your body. The other is your periphery, which are obviously your
arms and your legs and your feet and your hands. But then there's a third component, which
is there are three locations on your body that are far better at passing heat out of the body and bringing cool into the body
such that you can heat up or cool your body everywhere very quickly. Those
three areas are your face, the palms of your hands, and the bottoms of your feet.
Now the skin on your hands and on the bottoms of your feet and to some extent on your face
are called glamorous skin.
That's G-L-A-B-O-R-O-U-S, glamorous skin.
And what's special about those areas of your body and the glamorous skin is that the arrangement
of vasculature, of blood vessels, capillaries, and arteries that serve those
regions is very different than it is elsewhere in your body.
Now this has ancient roots.
Typically, if you were another mammal, like a bear or some sort of ape, you would have
hair all over your body.
Now we all know some pretty hairy people, or presumably you've heard that there are these
hairy people, or presumably you've heard that there are these hairy people.
I know if you excessively hairy people,
and Costello is excessively hairy,
but he's not a person, obviously.
But all mammals have hair on their bodies.
Just some people have very light hair or very fine hair.
We don't have hair on these glamorous skin regions.
Now, of course, you can have beard or facial hair growth, but there are still regions like
the cheeks and other areas that maintain this special vascular.
So technically the hands and feet are real glamorous skin and the face is not always quite
classified as glamorous, but these three locations face, palms of of hands not tops and bottoms of feet are
Very good at dumping heat and bringing in cool and the reason is
There's a rule in vascular biology
That blood moves from arteries to capillaries and then to veins and then back to the heart, okay?
So arteries which are the big ones obviously
Capillaries which are the little fine ones where oxygen and carbon dioxide are exchanged and veins, which then bring blood
back to the heart and other tissues, of course.
In these three regions of your hands, your face, and the bottoms of your feet. We have what are called AVAs.
AVAs are a very special pattern of vascular.
AVAs are described in the medical textbooks.
You can find them in Gray's Anatomy, not the television show, but the actual Gray's Anatomy
textbook, which is a real thing that exists, and in all medical textbooks.
Okay?
So let's talk about AVAs and what they are
and why they allow these three regions of the body
to heat or cool ourselves more readily.
So what are AVAs?
AVAs are arterio-vanus-estimoses.
So if you want to look that up,
you can just look up AVAs, veins,
capillaries, arteries, if you like,
but I'll spell it for you.
ARTE, RIO, arterio,
veinus, V-E-N-O-U-S,
arterio-vanus,
anastomoses,
ANASTOM, OSES.
Arterio-vanus astimosis.
Okay, you want to know about arteriovanus astimosis.
Trust me.
And you want to remember that they are in your hands,
the bottoms of your feet, and on your face,
and in particular, on the palms of your hands,
not the tops of your hands.
Now, before I said, blood flows typically
from arteries to capillaries to veins,
and then back to the heart. But AVAs are direct connections between the small arteries and the
small veins. They bypass the capillaries to some extent. They are little short
vessel segments. They have a big large inner diameter and they have this very
thick muscular wall. And they get input from what are called adrenergic neurons.
They get input from neurons that release
noripinephrine and epinephrine,
which allows them to contract or dilate.
Now, there's some rules of physics
that talk about how the radius of a pipe
and small changes in the radius of a pipe
leads to massive increases in the rate and amount of stuff that
can flow through that pipe.
Okay, it's a rule of physics that says essentially that the radius is proportional to the amount
of stuff that can flow through something to the fourth power.
We're not going to make this a physics class, but if you want to look that up, you can,
you can just look up how does the radius of a tube or pipe relate to how quickly or how much it can, it stuff can flow through
it.
What you need to know, even if you don't want to know any of the underlying physics, is that
these AVAs allow more heat to leave the body more quickly and more cool to enter the body
more quickly, then other venous arterial capillary beds throughout the body.
In other words, you can heat up best at the face, the palms, and the bottoms of the feet,
and you can cool down best at the face, the palms, and the bottoms of the feet, then you
can anywhere else on your body.
When I say heat up or cool down, I mean actually heat or cool the core and your brain.
Okay?
So this is vitally important.
I realize we're getting down into the mechanistic weeds here, but you need to know that these
three compartments of your body, palms, bottoms of feet, and face are your best leverage points
for manipulating temperature to vastly improve physical performance.
Okay.
I also want to point out that the work that I'm going to tell you about is not work for
my laboratory.
It's the work of, as I mentioned, my colleague Craig Heller's laboratory at Stanford, and
we're going to have Craig on as a guest to talk more about these discoveries.
They are his and his colleagues' discoveries and how you can leverage them.
They're building out some amazing technology.
I had a conversation with Craig yesterday
as a prelude to this episode and to the future conversation
with him, so you're getting the very latest on this topic.
So what Craig and his colleagues did,
really illustrates perfectly what these body services can do
and why. They were studying overheating in athletes
and in military and in construction workers and trying to prevent it. And they did a bunch of
experiments. I won't go into all of them now, but what they essentially found was that cooling,
the palms, palm or cooling allowed people, athletes and recreational athletes to run much further,
to lift more weight and to do more sets and reps to a absolutely staggering degree.
Let's talk for a second a bit more about why we stop, why we shut off effort when we get too hot.
Because in doing so, you'll really understand how and why the best protocols exist for
being able to do more work, to be able to exercise longer and actually to feel good doing
it.
You actually can make a doubling of your dips, or believe it or not, a tripling or quadrupling
or more of your pull-ups,
fairly straightforward.
I mentioned before that when muscle heats up,
enzymes start getting disrupted,
and ATP and muscles can't work so well,
and those muscles can't contract.
Let's get a little more specific about that.
The enzyme that's involved here
is something
called pyruvate kinase. You don't need to know about pyruvate kinase, but what you do need to know
is that it ends ASC, which means it's an enzyme. And pyruvate kinase is essentially a rate limiting
step. It's a critical step that you can't bypass if you want muscles to contract and it's very temperature sensitive.
Therefore, if you can keep temperature lower, you can do more work per unit time.
You can do more pull-ups and that actually was done by Craig and his
colleagues. Excuse me. The pull-ups weren't actually done by Craig. I don't know
how many pull-ups Craig can do. I'll ask them next time, both cooled and uncooled.
How many pull-ups he can do. I'll ask them next time, both cooled and uncooled, how many pull-ups he can do.
But what they essentially did is they brought someone
into their laboratory who could do 10 pull-ups on the first set
and they were able to get 10 rest two or three minutes,
get another 10 rest two or three minutes.
And if you've ever tried this,
what you find is that you start dropping to 8, 7, 6, et cetera.
Now, the person might not necessarily feel like they're
overheating, but the muscle is heating up. Then, with their knowledge that these AVAs,
that these portals in the palms are a great way to both heat the body, but also to dump
heat from the body, they used a device, and I'll talk about what you can do at home,
but a device where they had people hold on to what was essentially a cold tube.
Now, this is crucial.
The tube can't be so cold that it causes vasoconstriction,
because then the cold won't pass from the tube to the hand and to the core.
But if it's the right temperature, it's neither too hot nor too cold, that cool from the
cold tube passes into the hand, these so-called polymer regions, and then cools the core
and in theory, by lowering body temperature, would allow the person or the athlete to do
more work.
And indeed, that's what they saw.
The actual data, the specific data showed
that subjects could do, at least the subjects
they worked with, on their first day
with no cooling, about a hundred pull-ups
across the time frame that they had.
Okay, so it might have taken anywhere from 10 to 15
or maybe more sets depending
on how skilled that person was, but in a fixed amount of time.
Then they came back and did the cooling. They did it the very next day, which if you've
ever trained a muscle the very next day, typically you wouldn't do as well in its training if
it took any damage from the previous session, or you at least do as well, but you probably
wouldn't do what they then observed,
which was they started cooling after every other set.
The person would just hold the cold tube,
cool down the body after every other set,
rest, everything else was kept the same,
and they found that they went to 180 pull-ups,
which is incredible.
It's a near doubling.
And by doing this repeatedly over several sessions, over several weeks, they quickly went
in the cooling group from a maximum of somewhere between 180 and 200, as I recall, I'm estimating
now, to 600 pull-ups in the equivalent amount of time, which is absolutely incredible.
They then repeated this in a study on the bench press.
And actually, the bench press study was pretty interesting because they actually had a control
group that was admittedly taking specific amounts of anabolic steroids.
The anabolic steroid was testosterone-cipionate, which is essentially testosterone.
And indeed, the testosterone-cipionate, the steroid group, improved at a rate of about
1% per week.
In other words, there were differences.
And the cooling group basically left all other groups in the dust.
It was just remarkable.
So cooling the core, I want to be very clear that it's not cooling the muscle, it wasn't
about cooling the chest alone or just cooling the palms.
It was about allowing cold to pass through the palms because of the unique vascular vascular
that's there, these AVAs, allowed these subjects to do far more work per unit time.
And the important thing is that if they were to come back after doing 600 pull-ups or
500 pull-ups, you might say, well, wow, that's going to create a situation where recovery
is going to be absolutely impossible. They could come back, not use the cooling, and they still saw a highly
significant increase in the amount or the number of pull-ups or dips or bench press weight that
they could do. So what that meant is that it was both an excellent performance and an excellent
training stimulus that they were able to recover from. I don't know if all of you are following this, but these are the sorts of increases in
exercise output that are absolutely staggering.
And that's why professional teams and the military and others capitalize on them very
quickly and use these.
Now you may be asking what about endurance, right?
Not everyone wants to be able to bench press a lot
for multiple reps and sets.
And I should just mention for the bench pressing,
it was, I believe they were,
they found people that could bench press 225.
So that's 245 pound plates on the 45 pound standard Olympic bar
for repetitions of anywhere from six to 10.
And then they had them do the same thing.
They did a set, they'd rest two or three minutes.
Sometimes up to four minutes,
then do another set, repeat, repeat, repeat.
And with cooling, they were able to increase the amount
of work, the number of reps with the same weight.
Sometimes they did have to increase sets
to approximately double.
So it was pretty fantastic.
So with endurance, similar increases have been shown.
And the way that they would do those tests are a little bit different.
And they also point to a really important mechanism of why we stop doing work at all, when
we perceive that we are putting in too much effort.
So it gets right to the heart of the relationship between temperature and muscle and your willpower.
Those are directly related.
Your body heat and your willpower are Those are directly related. Your body heat and your will power
are linked in a physiological way. So I'm not talking about the kind of stuff that you
see as kind of like clickbait on the internet or like increase will power now or become
resilient now or never do this again if you want to be mentally strong. I'm talking
about a physiological mechanism that exists in the body and brain that causes you to stop
or that will allow you to continue
to go harder and further than you normally would.
Okay, so let's talk about willpower and heat and how heat shuts you down.
In other words, if you are cool, if your body temperature is in a particular range, not
only can you go further, but you will go further if you want to. Said differently, if you heat up too
much, you will stop or you will die. Typically people stop. There are individuals who will
push to the point where they black out and die in the same way that and please don't do
this experiment. There are people who can sit down face to face and say, let's hold our breath and whoever breathes
first loses. Some people will just go until it's painful and then they'll gasp and take a big breath.
There are always those individuals who can override that reflex and they will go until they pass out.
And if you do that in water, you can very easily die. So please don't do that experiment.
very easily die. So please don't do that experiment. But there's a reflex that relates the body to the brain and the brain to the body that shuts off our effort when we get too hot.
So what Craig and his colleagues and now others have done is to do a test in the laboratory
where rather than ask people to run outside until they absolutely don't want to run anymore,
you put them on a treadmill
and you set the speed. Okay, so they have to keep up with the treadmill and at some point
they quit. And you take groups and you do those in different temperature environments.
So some people are running in a nice chilly laboratory. They get their heart rate up so maybe
their heart rate goes from, you know, 40 or 50
baseline heart rate, maybe it gets up to 80 or 100.
And then they keep the rate of the treadmill going the same, and they'll just plateau.
So they're getting to a steady state cadence or rhythm, and their heart is beating it
more or less a steady state.
Eventually, they'll probably stop because they have something else to do, but people will continue at that temperature and at that heart rate,
unless you start turning up the temperature in the room.
And at some point, they will stop and they'll stop much earlier
when it gets hot because of something called cardiac drift.
Okay, so let's say I'm running and I'm running at a steady cadence on this treadmill
and my heart rate is 85 beats per minute or 100 beats per minute, doesn't matter. Let's
say 100 just for sake of example. Well, just making the room hotter is going to increase
my heart rate further, even though I'm at the same output. And the brain does a computation.
It somehow figures out that there's a heat component that's
increasing heart rate and there's an effort component from running that's driving
heart rate and if the heat component and the heart rate output from the effort
get to hit a certain threshold, I stop. And some of you may think, well, there are
people who just run and run and run and never stop. Eventually, everyone stops.
Maybe it's because the race ended, maybe it's because everyone else quit.
I actually saw some stuff online.
There are these races where people just will continuously do the same loop until everyone
else drops out and then one guy or gal keeps going and past everybody.
But typically, it stops because the race is over or because people quit. Increasing temperature increases the rate of quitting in part, not entirely, but in part
because of this thing called cardiac drift, which you've probably experienced if you've
been out on a hot day and you're walking uphill, you might stop to take a breath.
If you sit in the sauna, your heart rate will increase.
Heat increases heart rate.
Effort increases heart rate, effort increases heart rate. At a steady effort, you'll
have a steady heart rate if you increase the heat in the environment that you're engaging
in that steady heart rate, your heart rate will now go up due to cardiac drift and you
will quit. Okay? So, heller and colleagues have done experiments where they do palm or
cooling under these environments.
And that's wonderful because not only does it enable people to go further and faster for
much longer that's been shown statistically significant every time, but it also protects
the brain in body against hypothermia over heating, coma, nerve injury, nerve death, and actual death.
Okay, so you can see why this is such a valuable tool.
So what are they doing?
Well, in this case, too, they're having them cool their hands and they're cooling the palms.
Cooling the palms of the feet is a little trickier, but cooling the face could actually work
as well.
We're going to talk about cooling the face and how to incorporate this.
So at this point, I've just really wanted to impress upon you,
not impress you, but impress upon you,
the fact that you have these three surfaces of your body
that are very good at passing cold into the body
such that it cools the core body temperature.
And that's a good thing for health and safety
and in order to maintain
work output over longer periods of time or actually just do more work.
I mean, to me, the result is just so staggering is the 100 to 180 pull-ups in the controls
and then 600 pull-ups in the cooled individuals, right?
They actually also feel mentally as if they can do more work.
It's not just that they can.
Their willpower is adjusted somehow by these shifts in temperature.
Now, before we continue and get to the exact ways that any number of us can start to use this
information, I want to talk about the opposite thing, which is heating. And you have to remember
that these surfaces, the palms and the
bottoms of the feet and the face, were not just arranged with these AVAs, these
special ways to pass blood from arteries to veins in order to cool us for better
athletic performance or to heat us for on cold days, but for both of those things.
Now, heller and colleagues and others have also explored
how these can be used to heat up the core.
There are times when we want to heat up our core.
Typically, we hear that most of the heat escapes
through our heads, so we'll put on a hat
when we go outside.
That's actually not true.
Most of your heat escapes through your face,
the palms of your hands,
and the bottoms of your feet. Now you should know why that's the case.
What this means is that for post-surgery patients, or for people that are hypothermic,
indeed, you want to heat the core, right? But actually, I was on a swim recently where a friend
became hypothermicmic who was kind of
slurring his words and kind of staggering around when we got him back on the beach.
We brought him over to the lifeguard station.
He turned out to be fine.
Again, this is why cold water swims are something that you really need to do in groups, not
alone, and you really have to know what you're doing.
There were reasons for why this happened that day.
But we were basically people thought we were a little strange until they realized what was happening. We were walking down the beach
basically sandwiching him between at our chest because we were still warmer than
than the ambient environment, the environment around us. And we're pushing our
our chest against him to try and warm him up to warm up his core. In retrospect,
that was the wrong thing to do. In talking with Craig and talking to other
colleagues that work on thermogenesis, what we
should have done was warm the palms of his hands, the bottoms of his feet, and his face,
because that would insulate the heat loss.
Now he was very cold, so presumably there was vasoconstriction of the veins at these locations.
And so it's not clear that that would have been the only strategy to use, but they have
explored how to heat up post-surgery patients.
And one of the best ways to do that is to get warm socks on the bottoms of the feet, get
gloves on the hands, and if it can be done safely to warm the face.
Now of course you don't want to obstruct respiration in things of that sort.
But again, the ability to pass heat into the body or to remove heat to the body is best
done through these three surfaces.
I can't emphasize that enough.
So I mentioned before that you want to cool the palms or the bottoms of the feet, although
that's a little harder to do, or the face, but not so much that the blood vessels constrict
because then you won't be able to pass cool into the body because
those pipes got smaller and therefore you can't pass cool into the body.
So how can you start to incorporate this?
Well, Craig and colleagues have a company that they've spun out through Stanford.
We'll talk about that when we sit down with Craig that has made engineered devices that
are optimal for this, that are going to keep those passages open,
keep the size of those veins correct
to pass cool into the body quickly
for sake of elite sports performance
and even recreational sports performance.
But you can actually start to incorporate this.
First of all, I always get asked,
how cold should the water be?
Should it be ice water?
Should it be very cold water? The answer is no. If you want to experience some of this effect without a device,
one thing you could do would be for instance to do, I don't know, I'll use the the gym or the
treadmill as an example, you could do your maximum number of pull-ups, stop, and then you could
actually put your hands into or on the surface of
a sink that is presumably stopped up with
cool water. So not ice water, not freezing cold, but cool water.
Slightly cooler than body temperature before you started training.
Would be a good place to start. You do that for 10 to 30 seconds.
Then you could go back and do your to start. You do that for 10 to 30 seconds,
then you could go back and do your next set. You would repeat the cooling.
You would want to extend the amount of cooling somewhat,
so you might want to do that for 30 seconds to a minute.
This is not going to be perfect.
You're going to have to play with how cold to make it
in order to get the optimal effect,
but you ought to see an effect nonetheless.
The same is true if you're running and you're fatiguing, obviously you don't want to become
hyperthermic, cooling the hands or the bottoms of your feet or the face would be the ideal
way to dump heat in order to be able to generate more output.
Now the face is something that we haven't talked a lot about.
Everything I've told you up until now also says that if you are somebody who tends to get
cold when you are outside, say in the winter or even in the fall, you tend to run cold,
warming your face is going to be the most important thing that you can do.
Now it's kind of hard to do that without looking strange, like wearing a ski mask or something
like that, but that is going to be more effective than covering and warming any other part
of your body. Although it would be quite strange if you only had a ski mask on and you weren't wearing
clothes anywhere else on your body, I don't recommend doing that outside.
That would get you into all sorts of other kinds of trouble.
It wouldn't be good for anybody.
But now you understand the principle and the locations at which to deliver heat and cold.
So let's say that you are out for a run and you want to incorporate this cooling
mechanism, I talked to Craig about this, I said, what would be the kind of poor person's
approach to this before this device is commercially available? And he said, well, you could take
a frozen juice can, if you have one of those or a very cold can of soda, and you would
want to pass it back and forth between your two hands.
The reason the passing back and forth is really important is because you again, you don't
want to be so cold that you constrict those vanus portals that will allow cold to go into
the body.
Now, there are certainly people that are working on bike handles and that can actually cool
the hands.
You can expect with the Olympics coming up,
people are aware of these data
and are starting to incorporate it into a number of things.
Here's what you don't want to do.
And there are sports teams that I won't mention
by name or brand that have made this mistake
and it costs them dearly.
You don't want to cool the core if you want to cool the body,
right? If it's a very hot day and you're going to train,
getting into an ice bath first, sure,
it will cool you down,
but that's not gonna be as effective
as cooling the palms, the bottoms of the feet and the face.
I have a friend who does some important work in this space
with people in various, let's just say cultures
where heat is generated quite
a lot and they need to dump heat, ice packs delivered to the face are something that they actually
use in order to dump heat quickly. Now, again, you don't want to keep the ice pack on your
face. These are people that are very high work output, right? Firefighters and similar
and very high work output. And then they'll put this essentially, it's like a cool face mask
on their face. It'll allow their core body temperature to come down and then they remove it.
They're not keeping it on there so long that they're getting the vasoconstriction.
Okay, so there are a number of ways that you could do this. And again, I'm not giving specific
temperatures because it depends on how hot that day and how hot your body temperature is. So you
can see why there's a need to create more devices for this. But you can see a considerable improvement in endurance, in strength, and
in all kinds of explosive and sort of explosive power type output in athletics by using these
surfaces of the hands and bottoms of the feet and face. The one that I've tried, because in anticipation of this episode, was the dips where then
I would cool my hands.
I actually decided to cool the bottoms of my feet as well because it just feels good and
it's particularly hot out lately.
So, no shoes or socks on, put my feet into the bottoms of my feet just kind of hovering
about a centimeter or two below the surface of a bucket of water that was just slightly, it felt cool, slightly cooler than body temperature.
Or so, just basically what came out of the spigot after I let it run for a little bit.
And indeed, I saw a 60% increase in the number of dips that I can do in a single session.
So it's actually quite significant effect and you don't have to be perfectly precise
in order to do it.
And of course, if you want to heat up for whatever reason like you're in your camping or you're lost in the environment,
remember these three surfaces are going to be the best way to heat your core as well.
So up until now, we've been talking about how to use cold during a workout in order to improve performance. And indeed, cold applied to the appropriate
parts of the body, the appropriate times can vastly improve our performance and endurance
and strength. Now I want to talk about the use of temperature in particular cold to improve
the speed and the depth of recovery. Recovery is obviously vital, right? During a weight training session or
during an endurance session, that's just the stimulus for getting better the next time. And if you
don't recover, you not only won't get better, but you'll get worse. There's a lot of interest
in the use of cold in order to improve recovery in the short term. We see this and probably the best example of this
would be fighters in combat sports between rounds
or athletes during in between quarters or half time.
That's one form of recovery.
The ability to go back into the sport very soon
on an order of minutes anywhere from like one minute
in between rounds in typical combat sports
or several minutes at a half time, et cetera.
Typically, what we see is people cooling their core,
cooling the back of their neck,
cooling the top of their head.
So it might be a sponge with cold water
over the top of the head or an ice pack
on the back of the neck,
or in some case even wearing cold ice vests,
that's actually been done.
That's going to be a very inefficient way
to improve recovery of that kind.
Far better would be to cool the face,
the palms of the hands, or the palms of the feet
for the reasons that I described up until now.
Submerging the body in an ice bath
or taking a cold shower, say up to the neck
or up to the chest, or getting under cold water or jumping in a cold lake or something a cold shower, say up to the neck or up to the chest or getting under cold
water or jumping in a cold lake or something in that sort or in the locker room getting
it under the cold shower.
Also it would be a terrible way to cool off the body quickly compared to the ways that
I described through the palms of the hands, the bottoms of the feet or the face for the
following reason.
First of all, it's not optimizing those portals of the face, palms of the hands of the feet or the face. For the following reason. First of all, it's not optimizing those portals of the face palms of the hands and the feet. And in addition,
if it's very cold and you submerge or you cover a lot of the body with that cold, you're
going to cause constriction of the very vessels and pathways that allow the body to efficiently
dump heat. So again, the key thing is to cool these one or two
or three of these surfaces, but not so cold
that you cause the vasoconstriction.
So what does this mean for you?
It means that getting in an ice bath or a cold shower
or putting an ice pack on the back of your neck,
in most cases, is not going to be as good
as splashing cold water on your face or even just holding your face with a damp cool cloth or something
of that sort. It's kind of counterintuitive. You think, oh, if I just jump into an ice
bath, I'm going to cool down much faster than if I just cooled these, you know, one or
two or three of these select regions of the body, but that's actually not the case.
And then of course, there's recovery that occurs
from session to session.
So outside of the game or the match or the exercise session.
And many people are now relying on things like cryotherapy,
which requires a lot of expensive equipment,
big liquid nitrogen-driven machine.
Those aren't so common for most people or accessible for
most people, but a lot of people are using cold baths or ice baths or cold showers.
And again, that's not going to optimize recovery.
In fact, it's going to have an additional effect that is going to potentially block the
training stimulus.
When you get into an ice bath, indeed, there are, provide it's not very, very cold.
If you get into a cold shower, provide it's not very, very cold.
You are indeed blocking some of the inflammation that occurs because of the training session.
But in doing so, you also are blocking pathways, such as MTOR, mammalian target or rapomycin,
which are involved in the adaptation for a muscle to become stronger
or bigger.
Put simply covering the body in cold or immersing the body in cold after training can short
circuit or prevent the hypertrophy or muscle growth response.
It has other effects that can be positive, right?
It can induce thermogenesis, et cetera.
It can reduce inflammation, but it can prevent some of the positive effects of exercise.
It hasn't been examined so much for endurance work, but let's say you come back from a round of endurance work, the face, in my opinion, based on the science, would be better than completely immersing the body
in the ice bath or the cold shower.
There is a time and a place for the use of the ice bath
or the cold shower or the cold plunge.
Those tend to be when you want to deliberately
increase brown fat thermogenesis
or when you want to deliberately work on mental resilience.
And in a subsequent episode on fat loss, I'm going to talk about how to optimize the use
of cold specifically for increasing metabolism and fat loss.
But for now, since we're talking about the use of cold for improving performance and recovery,
the suggestion that I'm going to provide is based on the work of Craig, heller and colleagues that I've been talking about, as well as a excellent book.
I mainly rely on textbooks and special volume books, which are collections of papers
from experts in a particular area that go beyond standard kind of college level textbooks.
The one that I've been relying on is called Thermal Regulation in Human Performance,
Physiological and Biological Aspects, by F.E. Marino. I don't know the publisher, I and biological aspects by F.E.
Marino. I don't know the publisher. I don't know the author. I do recognize
some of the names of the particular papers there, but I just want to be clear
there's no sort of business relationship or deal with them. But it's an
excellent text. It's called Thermoregulation in Human Performance. You can find
it online if you want to go really deep into this. But basically what they show
is that if you can cool the body back to its resting temperature and by resting temperature, I mean within the range that you would
see at any time of waking day, but not in exercise. So just bringing the body temperature down
to baseline. If you can do that, the sooner you can do that after a workout, the sooner
that the muscle will recover, that the tendons will recover and that the person you can do that after a workout, the sooner that the muscle will recover, that the tendons will recover,
and that the person you can get back
into more endurance training, more weight training, et cetera.
So cold actually can be a very powerful tool for recovery,
but to maximize return to baseline levels of temperature,
it's my belief based on the studies that are published
in this book, as well as my discussions
with my colleague Craig Heller, and in reviewing the literature overall, that just simply
cooling the entire body by jumping into an ice bath or a cold shower is not the best way to go.
You really want to rely on one of these three glamorous skin portals of the palms, the bottoms of
the feet, or the face. So now you probably know more than you ever wanted to know about how we regulate body
temperature and how it can be applied to exercise both during the exercise session and afterward to
optimize recovery. Many of us, all of us presumably, are also eating and drinking things and taking
things at various times that can impact this process. And so because of that, we should ask whether or not those things are impacting body temperature.
And when we do that, we find that there are certain things that many of us are doing
that are actually impairing our performance.
So for instance, if you are taking a pre-workout drink or you're ingesting a lot of caffeine
or other substance to bring your body temperature up before exercise, you are limiting the amount of exercise that you
can do.
I can recall a time in college when I would drink a lot of espresso back then.
A fedron was sold over the counter.
I remember taking it.
It will really energize you for workouts.
You can generate a lot of energy and get extremely focused taking those things.
They do increase heart rate.
They can be quite dangerous.
I don't recommend people take them.
In fact, I think if Fedron is now off the shelves as a non-prescription compound because various
people died from taking it who were sensitive to it or exercised in heat.
But looking back at that, I realized it was a foolish approach.
It was increasing core thermogenesis.
Sure, I might have burned a few more calories, but actually when I look at the data that
are coming from specific cooling and how that can so increase in performance, if done properly,
and then I compare that to the effects of taking some sort of thermogenic
compound, whatever it is, some pre-workout or some pill, or high levels of caffeine, it's very clear
that increasing body temperature prior to working out is the exact wrong thing that one would want to do.
You don't want to stay so cold that you can't generate good muscle contractions. You don't want to,
you know, be like, like I am coming out of the cold ocean,
you know, with claws for hands.
But one wants to have your body temperature in a range
that still allows you to work hard and perform well.
Now, in terms of recovery,
things like alcohol,
we know our vasodilators.
So those are gonna cause people to drop body temperature.
So you
might think, oh, well, that sounds great for recovery. And I don't think people should
be drinking who are, you know, have problems with alcohol intake, you know, alcoholics
or they're not of drinking age, et cetera. I'm not a drinker. But I do have a good friend
who's a quite accomplished athlete who basically drinks a beer or two after his long runs or
cycling. And, you know, his argument is, well, I'm dumping
body heat and I like a beer. And he's probably right. It's probably a really good tool provided.
You don't have issues with alcohol that would preclude that as a tool or you're not of drinking
age. But anything that you ingest after exercise that would increase body temperature is going
to impede recovery. Anything that you do that lowers body temperature provided in safe ranges is going to accelerate
recovery.
And that brings us to the whole host of compounds that people take that can increase body
temperature.
And many people are taking these things in order to increase fat burning and increase
metabolism, but in my opinion, it's impeding their ability to perform well.
And especially if the performance is something that you're focused on, aside from body
recomposition, losing fat building muscle.
But even if you're focused on losing fat building muscle, you have to ask yourself, is the
body temperature increase that I'm getting from these compounds really worth it, given that it can block or prevent my performance
from being as good as it could.
In other words, is it worth taking something
that makes you feel very energized to go work out?
But then you now know that you are stopping earlier
and you're performing less well, fewer reps,
fewer steps overall, is it worth it?
If you had not taken that thing then you could perform
much longer and at much higher capacity.
Some of you are probably saying, well that's ridiculous because when I drink a quadruple
espresso and I pop a whatever pre-workout or drink a pre-workout, then I know I can go
much further.
That might be true, but the increase in temperature
is also costing you on the recovery side.
And unless you're doing other things
to improve your recovery,
and I know many people that are, I don't judge,
but many people who are doing those things
are also augmenting the recovery
through hormone augmentation
and other performance enhancing tools.
Then for the typical person who's not doing that,
it's probably shooting yourself in the foot.
So let's take a look at what some of those compounds are and what they do.
And just briefly review whether or not they would be a good or a bad idea to include
if your main goals are performance or your main goals are body recomposition or both.
So let's just briefly discuss stimulants.
This could be caffeine, this could be any other kind of stimulant that are typically in a pre-workout drink or
anything that might get you revved up before exercising.
This could even be very strong tea.
I've mentioned I'm a big consumer of mate.
I like yerba mate.
I love that stuff.
And I also drink caffeine.
I love coffee of various kinds, mushroom coffee, black coffee espresso, etc.
I'm a chronic caffeine user.
I don't think I'm an addict, but I'm a chronic caffeine user,
meaning when I drink caffeine, my heart rate
doesn't increase so much that it feels like a shock
to my system.
Some people are not caffeine adapted
or they're very caffeine sensitive.
Here's the straightforward rule.
Caffeine for somebody who doesn't drink caffeine very much
will constrict the blood vessels
and will increase retention of body heat
and is probably a bad idea before exercise.
For somebody who's caffeine adapted
and is used to drinking caffeine,
it won't have that vasoconstriction effect.
That's what the data point to,
because I'm adapted to it. But it will cause vasodilation and will
allow me to dump body heat. So for me, I use it before I train or do any kind of
exercise because I tend to do that early in the day, it won't prevent me from
sleeping. And it causes vasodilation. And then afterwards, I'm aware that it
causes vasoconstriction after the caffeine wears off. So for somebody who drinks two or three or more cups of coffee a day or matayaday, so
we're talking intake of anywhere from 100 to 400 milligrams of caffeine, what you want
to do is you want to make sure that you would do that before exercise and probably not
after exercise.
That just makes logical sense, given what we know about thermal regulation,
and if you're somebody who doesn't drink caffeine,
drinking caffeine before a workout
is going to be about the worst thing
that you could possibly do
because it's going to increase
core body temperature through its thermogenic effects,
and it's going to constrict your blood vessels
and make it even harder to dump heat.
So I don't suggest that people drink caffeine or not.
I just suggest that you think about whether or not your caffeine adapted or not and decide
whether or not you want to drink caffeine.
In general, you're going to be better not drinking any caffeine than you are drinking caffeine
unless you're a heavy caffeine user or a user in which case, not drinking caffeine is going
to give you vicious headaches and is going to make it very hard to get motivated
because you're just not used to it. It takes about three weeks to get used to no caffeine. It's brutal.
I've done it before. I've done caffeine fast. I don't know that I ever want to do it again. That's how painful it was.
But you get headaches because of the effects on vasodilation and constriction.
If you like caffeine, use in moderate amounts and use it before your workout's not after.
If you don't like caffeine or you don't use it very often,
stay away from it anywhere close to exercise
before or after for that matter.
One of the more commonly used compounds
that's sold over the counter are non-steroid
anti-inflammatories, so things like Tylenol
and Advil and other trade names and approximate sodium,
things of that sort.
Almost all of those drop body temperature to some extent.
And that's why it's often recommended that people take them when they have a fever.
Although the whole business of dropping body temperature artificially when you have a fever
is itself an interesting discussion, whether or not that's the most adaptive or best thing to do.
Certainly you don't want fever to go too high, it can be very dangerous, can kill you. itself an interesting discussion whether or not that's the most adaptive or best thing to do.
Certainly you don't want fever to go too high, it can be very dangerous, it can kill you.
But artificially dropping body temperature with these compounds can be tricky.
Now a number of athletes, especially endurance athletes, will rely on these non-steroid
anti-inflammatory drugs specifically to keep body temperature lower during long bouts of
exertion.
This is a little bit of a pharmacologic version of dumping heat instead of using pulmonary
cooling or face ice pack cooling.
They're relying on pharmacology to drop their core body temperature.
That has certain obvious advantages.
Those advantages should be obvious and the reasons for them should be obvious based on everything
we've talked about up until now.
Lower temperature allows you to go further harder with more intensity.
However, they do have effects on the liver and they can also have effects on the kidneys
and during long bouts of exercise or even short bouts of exercise, water balance and salt balance are also going to be vital to maintain in order to perform well, generate the best muscle
contractions, stay mentally alert and also to stay alive.
We will do an episode on salt electrolytes and water and water balance, but you probably
want to think carefully about whether or not you want to use non-starred anti-inflammatories before any training session just for the performance augmentation effect.
Unless you're working carefully with a coach, whether or not you've done that in practices,
and of course, whether or not you are in a situation where monitoring your body temperature
carefully is going to be important.
You might ask, well, when would that be?
Well, desert races, summer training and races, winter rides. You certainly don't want
to get too cool either. So alcohol, caffeine, and non-starred anti-inflammatory drugs, because
of their effects on temperature, will impact performance and recovery, but you want
to be cautious about how you approach them. I personally am more a fan of using caffeine and moderate
doses for the reason that I described before, as well to use the cooling of the palms,
cooling of the of the bombs on my feet, right, by placing them into a bucket or into a cool
bath after after training or cooling the face after training or sometimes even during
training. It just seems like there's more of a margin to play with the variables, to heat up the
water, cool it down a little bit to include one palm or the other palm.
There's just all sorts of good parameter space, as we call it, in science that you can
play with and work with to find what works for you.
Whereas, when you pop a pill, sure, you can adjust the dose and you can adjust it next time,
but once it's in you, it's in you, and there's going to be some period of time before
you can modulate it.
What I've offered today are ways in which you can use temperature to powerfully improve
performance.
If you think about it, you can vary that from set to set.
You could do your pull ups or your sprints and then cool your palms and then try and go with colder
water the next round or warmer water the next round or do both feet and palms and face.
I mean, you can do all sorts of things moment to moment and see what works for you.
Again, essentially zero cost or no cost.
Whereas when you pop something, you take a pill, you're basically in that regimen for
the next hour or two or more.
You can always take more,
but you can't really take less. You can't really extract it from your body in real time. So it
doesn't give you a lot of opportunity to play scientist, which is what I like to do, because what I've
always trying to do is trying to dial in the best protocols possible based on the mechanisms and
data. And if you can do that moment to moment, that places you in a position of power. Once again,
we've covered a lot of material by now, after seeing this episode or listening
to this episode, you should understand a lot about how your body heats and cools itself
and the value of that for physical performance.
I hope you'll also appreciate that you have tools at your disposal to vastly improve your
physical performance.
And should you try those, please let us know how it goes.
If you decide to do Palmer cooling during your runs
or after your runs, during your weight workouts,
during your yoga sessions, whatever it is,
let us know, please place that in the comments.
I've given you specific protocols and some direction,
but I've also left it slightly vague
because as I mentioned earlier, I don't
know all the environmental conditions.
I don't know how hot your yoga studio is or how cool your gym happens to be or your body
temperature or time of day.
Remember, your temperature will vary according to time of day.
We did a whole episode about that related to sleep.
Typically, your body temperature is rising early in the day and is coming down as you approach
the late evening and late night hours for sleep.
The middle of the night your temperature is very low at its absolute low is something we
call the temperature minimum.
So we don't know exactly where you're at.
You need to take the information that you received today and should you try and incorporate
it.
Try and do it intelligently.
Don't cool yourself off so much that you, you know, become cryogenic and
please don't warm yourself up. In fact, we didn't talk at all about warming yourself up
because warming yourself up too much can be quite dangerous. You never ever ever want
to be hypothermic. That's what your body and your brain are trying to avoid. We talked
a little bit about supplements, but not the standard sorts of supplements. I usually list off on these episodes.
Rather, we talked about caffeine, non-steroid anti-inflammatories, and how those can impact
temperature, how alcohol can impact temperature.
And I should just mention in closing that every time we eat, we also increase temperature.
There's a eating-induced thermogenic effect, but that's a minor one.
That's a small one.
So you wouldn't worry about eating before training because of its effects on temperature, because it tends to be really minor. Going forward,
we're going to talk more about temperature and other ways to improve physical performance and skill
learning. We're going to talk about specific ways to accelerate fat loss, to improve muscle growth, to improve suppleness and flexibility.
These approaches and mechanisms are anchored deeply in neuroscience and physiology and
the relationship between our peripheral organs, which include our skin and our brain and
all the organs in between.
So, it's really a pleasure for me because I'm able to look to the textbook literature
that exists and really came out over the last 50 to 100 years.
And unlike a lot of areas of neuroscience, which are still sort of mystical, like consciousness
and dreaming, of which we understand a little bit about, these core mechanisms of temperature
and physiology, which are so powerful, involve very concrete studies that, as you learn today,
are very actionable.
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