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00:00:00Welcome to the Huberman Lab Podcast,
00:00:02where we discuss science and science-based tools
00:00:04for everyday life.
00:00:09I'm Andrew Huberman,
00:00:10and I'm a professor of neurobiology and ophthalmology
00:00:13at Stanford School of Medicine.
00:00:15This podcast is separate from my teaching
00:00:17and research roles at Stanford.
00:00:19It is, however, part of my desire and effort
00:00:21to bring you zero-cost-to-consumer information
00:00:23about science and science-related tools
00:00:25to the general public.
00:00:27In keeping with that theme,
00:00:28I'd like to thank the sponsors of today's podcast.
00:00:31Our first sponsor is InsideTracker.
00:00:34InsideTracker is a personalized nutrition platform
00:00:36that analyzes data from your blood and DNA
00:00:39to help you better understand your body
00:00:41and help you reach your health goals.
00:00:43I've long been a believer in getting regular blood tests,
00:00:46and the simple reason for that
00:00:48is that so many of the factors
00:00:50that impact our immediate and long-term health
00:00:53and wellbeing can only be analyzed from blood.
00:00:56And now with the advent of modern DNA tests,
00:00:58you can get additional layers of information
00:01:00that can really support your understanding
00:01:02about what's going on deep under the hood,
00:01:05so to speak, inside your body and brain
00:01:08and what to do about it.
00:01:10And I think that's really where InsideTracker
00:01:12sets itself apart from other similar tests.
00:01:15What InsideTracker offers is,
00:01:17first of all, they make the tests very easy.
00:01:19They can come to your home to take your blood and DNA test,
00:01:22or you can go to a testing center nearby you.
00:01:24Then you get the information back,
00:01:26and rather than just getting information
00:01:28about whether or not the levels of various things
00:01:30are high or low,
00:01:31you also get to find out what to do about it.
00:01:35So it offers directives related to nutrition,
00:01:37to exercise, and so forth.
00:01:39It really allow you to be in control of your overall health,
00:01:44both where you are now and its long-term trajectory.
00:01:47With InsideTracker,
00:01:49they also have something which is,
00:01:51is it can give you a readout of your inner age.
00:01:53They have something called the inner age test
00:01:55that really compares your biological age
00:01:57to your chronological age,
00:01:58something that's of extreme importance and interest
00:02:00because it has to do with lifespan or predicted lifespan.
00:02:03If you'd like to try InsideTracker,
00:02:05you can visit insidetracker.com slash Huberman,
00:02:08and if you do that,
00:02:09you'll get 25% off any of InsideTracker's plans.
00:02:12Use the code Huberman at checkout.
00:02:14That's insidetracker.com slash Huberman
00:02:16to get 25% off any of InsideTracker's plans
00:02:19and use the code Huberman at checkout.
00:02:22Today's episode is also brought to us by Helix Sleep.
00:02:25Helix Sleep is a company that makes mattresses and pillows
00:02:28ideally suited to your sleep needs.
00:02:30I've been sleeping on a Helix mattress
00:02:32for the last six months,
00:02:33and I can honestly say it's the best sleep
00:02:35that I've ever gotten.
00:02:37Helix Sleep has a quiz that can match you
00:02:39to the ideal mattress and pillows for you.
00:02:42It's a quiz that takes just about two minutes,
00:02:45asks you questions like,
00:02:46do you tend to sleep on your side or your back,
00:02:48on your stomach,
00:02:49or maybe you don't know
00:02:50whether or not you tend to wake up
00:02:51feeling too warm or too cold,
00:02:53various questions about your sleep habits.
00:02:56At the end of that quiz,
00:02:57it matches you to a specific mattress
00:02:59that's perfect for your sleep needs.
00:03:01For me, it matched me to the Dusk, D-U-S-K,
00:03:03because I wanted a mattress
00:03:05that wasn't too firm nor too soft.
00:03:07And I really love the mattress.
00:03:09As I mentioned,
00:03:09I've been sleeping terrifically well
00:03:11ever since I got that mattress.
00:03:13If you're interested in upgrading your mattress,
00:03:14you can go to helixsleep.com slash Huberman,
00:03:17take their two-minute sleep quiz,
00:03:19and they'll match you to a customized mattress,
00:03:20and then you'll get up to $200 off all mattresses,
00:03:24and you'll get two free pillows.
00:03:26They have a 10-year warranty.
00:03:27You get to try it out for 100 nights risk-free.
00:03:30If you don't like it,
00:03:31they'll even pick it up for free,
00:03:32take it away.
00:03:33But I really think you will.
00:03:34I certainly love mine.
00:03:36Again, if you're interested,
00:03:37you can go to helixsleep.com slash Huberman
00:03:39for up to $200 off and two free pillows.
00:03:42Today's episode is also brought to us by Theragun.
00:03:45Theragun is a handheld percussive therapy device
00:03:48that releases deep muscle tension.
00:03:50I first learned about Theragun on a lab expedition.
00:03:53We were actually headed out to Ocean
00:03:55where we were doing diving with great white sharks,
00:03:58filming those for our VR fear experiments in the laboratory.
00:04:01And it was very long days of carrying pelican cases.
00:04:05Those are cases,
00:04:06these hard plastic cases with equipment.
00:04:08It was diving.
00:04:10We were all sore and tired all the time.
00:04:12And someone had brought along a Theragun.
00:04:15It was the first time I had seen one.
00:04:16And pretty soon that thing was getting passed along
00:04:18and became one of the more coveted devices on board.
00:04:21Everyone wanted time with this thing
00:04:22because it was great.
00:04:23You could give yourself a really terrific massage
00:04:25and get deep into the tissue and relieve soreness.
00:04:28When I got back, I got a Theragun.
00:04:30And so I'm delighted that they're sponsoring the podcast.
00:04:33Whether or not you want to treat your muscles
00:04:35because they're tense from working out
00:04:37or whether or not you just want to release stress,
00:04:39it's a terrific tool.
00:04:40Many of you are familiar probably with professional massages,
00:04:44but Theragun is interesting
00:04:45because you can basically give yourself
00:04:46a deep tissue massage anytime, anywhere.
00:04:49It's also very quiet.
00:04:50If you want to try Theragun,
00:04:52you can try it for 30 days.
00:04:54They start at only $199.
00:04:55You can go to theragun.com slash Huberman right now
00:04:59and you can get your Gen 4 Theragun today.
00:05:01That's the one that I use
00:05:02or another one of their models.
00:05:03That's theragun.com slash Huberman to try Theragun.
00:05:08This episode marks the beginning of a new topic
00:05:11for the Huberman Lab podcast.
00:05:13As many of you already know,
00:05:15we go deep into a particular topic over four,
00:05:18sometimes even five episodes.
00:05:19We just closed out the episodes on hormones.
00:05:22Now we are going to talk about how to optimize
00:05:25physical performance and skill learning.
00:05:28We're going to look deep at the science behind this
00:05:30as well as specific practices.
00:05:33In fact, today, you're going to hear about specific tools
00:05:36that you can use to improve endurance and strength
00:05:39by up to, I'm not making this up,
00:05:42three or four times your current capacity.
00:05:44This is based on studies that were done at Stanford
00:05:47and are currently in use by collegiate and professional teams.
00:05:52If you're not a professional athlete
00:05:54or a serious athlete, that's okay.
00:05:56The topics this month
00:05:57and all the information we are going to cover
00:05:58are going to make you
00:05:59a better recreational exerciser as well.
00:06:03If you're not an exerciser
00:06:04and you're thinking about getting into that,
00:06:06or if you live in the Northern Hemisphere
00:06:07and you're just thinking about the beach this summer,
00:06:10fat loss, muscle building, that sort of thing,
00:06:13this month, we're going to cover all of that as well.
00:06:16There's so much confusion out there
00:06:17about how to optimize fat loss, muscle building,
00:06:21improvements in flexibility, for instance,
00:06:23or skill learning.
00:06:24I know many of you aren't so focused
00:06:26on the cosmetic aspects of physical exercise,
00:06:29but are interested in actual skill learning.
00:06:31We're going to talk about that too.
00:06:33I want to just take a moment
00:06:35to reflect on something that came up last episode.
00:06:38If you didn't see that episode, that's quite all right.
00:06:41But last episode, we were talking about
00:06:42the hormones adrenaline and cortisol
00:06:44and how to leverage those towards attention and learning.
00:06:48And there was a little bit of confusion
00:06:50that I want to clarify.
00:06:51I mentioned an optimal protocol for learning
00:06:54that involved leveraging adrenaline,
00:06:56also called epinephrine.
00:06:57And it involved four steps.
00:07:00The four steps that I spelled out
00:07:02were to be calm and focused
00:07:04while one is trying to acquire or learn the new skill,
00:07:08cognitive skill or motor skill.
00:07:10Then to have a spike in adrenaline.
00:07:12I mentioned ways to do that using cold
00:07:15or breathing or other tools
00:07:17immediately after the learning episode.
00:07:20Then to incorporate what I call non-sleep deep rest,
00:07:24a 20-minute episode of a shallow nap
00:07:27or some other protocol like NSDR,
00:07:30non-sleep deep rest protocol,
00:07:31of which we always provide links in the captions.
00:07:34And then to try and optimize sleep later that night
00:07:38and the subsequent night.
00:07:39Some of you heard this and it sunk in right away
00:07:43and it was straightforward.
00:07:44Others said, wait, I thought from a previous episode,
00:07:47even before that,
00:07:48you said you're supposed to do non-sleep deep rest
00:07:49immediately after learning.
00:07:51No, we added another step.
00:07:54The logic still follows that you want to be calm
00:07:57and focused during learning.
00:07:58Then you want to spike adrenaline at the end.
00:08:01Most people get that backward.
00:08:02They're drinking too much coffee
00:08:03or even taking nootropics and things,
00:08:05trying to be really focused while learning.
00:08:06Some people are taking Adderall recreationally,
00:08:09something I don't recommend.
00:08:10That's actually getting the whole process backwards.
00:08:12If you look at the data and the physiology,
00:08:14you want to spike adrenaline at the end
00:08:17or immediately after a learning episode
00:08:19and then non-sleep deep rest and then sleep itself.
00:08:24Okay, four steps.
00:08:25Hope that clarifies things for you.
00:08:27If you have any additional questions,
00:08:28please put them in the comment section below.
00:08:31Okay, so let's talk about physical performance.
00:08:34There are so many variables to physical performance
00:08:37and we can manage physical performance
00:08:40and skill learning from a variety of contexts.
00:08:43I made just a short list of some of the things
00:08:45that come to mind that can powerfully impact
00:08:47physical performance and skill learning.
00:08:50Some of them are what I would consider foundational.
00:08:53They allow you to show up with your current ability.
00:08:56And if you were to disrupt those,
00:08:58you would perform less well.
00:09:00So things like getting a good night's sleep,
00:09:03things like being properly hydrated,
00:09:05things like being well-nourished,
00:09:08whatever that means to you.
00:09:09I know some of you like to exercise fasted.
00:09:11Some of you prefer to have food in your stomach
00:09:14or have eaten a couple hours before.
00:09:17There are supplements, there are drugs,
00:09:19there are different ways to breathe.
00:09:20There are so many tools related to mindset, visualization.
00:09:24There are machines and devices.
00:09:25It's just a vast space, but it's not infinite.
00:09:30And there are a few things in the list of things
00:09:33that can impact and even optimize physical performance
00:09:37and skill learning that have an outsized effect
00:09:40that any of you can use.
00:09:42Many of them, most of them are low to zero cost.
00:09:45So today we are going to focus on what I believe
00:09:48to be one of the most powerful tools
00:09:51to improve physical performance and skill learning
00:09:55and recovery.
00:09:57And we'll talk about why that's important.
00:10:00And that's temperature.
00:10:02Now, many of you might think,
00:10:03oh, well, that's kind of boring.
00:10:04I want to know about the magic pill that I can take
00:10:07that's going to allow me a dunk of basketball
00:10:08if I currently can't,
00:10:10or I want to know about the thing
00:10:11that's going to let me run further and faster
00:10:12is going to shed fat.
00:10:14Believe it or not,
00:10:15temperature is the most powerful variable
00:10:17for improving physical performance and for recovery.
00:10:22I would argue it's even more important than sleep
00:10:25because temperature itself is going to dictate
00:10:28how well and when you sleep
00:10:30and the depth of your total recovery.
00:10:33There are two aspects to temperature, of course.
00:10:35There's heat and there's cold.
00:10:38We are mainly going to focus on cold
00:10:41as a way to buffer heat.
00:10:43In a previous podcast episode,
00:10:45I talked all about growth hormone.
00:10:47You can find that episode
00:10:48about thyroid and growth hormone
00:10:50and how heat can be a powerful stimulus
00:10:52for increasing growth hormone,
00:10:54which is involved in tissue repair and et cetera,
00:10:56can burn fat and improve metabolism in various ways.
00:11:01However, cold, I would argue,
00:11:03is even more powerful than heat as a tool.
00:11:06And I'm not just talking about putting ice packs
00:11:08on sore muscles or slightly sprained limbs and ankles
00:11:13and things of that sort.
00:11:14We're going to talk about cold
00:11:16from the standpoint of thermal physiology.
00:11:19This is a literature that's rich in scientific information
00:11:23that goes back very deep into the last century
00:11:27where physiologists and neuroscientists figured out
00:11:30that there are different compartments in your body
00:11:32that heat and cool you differently
00:11:35and that you can leverage those in order to double,
00:11:38and as I mentioned before,
00:11:39or even triple or quadruple your work output,
00:11:41both strength, repetitions, and endurance.
00:11:44So this is not weak sauce, as they say.
00:11:47This is the stuff that can really shift the needle quite a bit.
00:11:51And it's not just about performing well once,
00:11:54it's about being able to perform well
00:11:56and recover from that performance
00:11:57so that you do even better
00:11:59when you're not incorporating these tools.
00:12:01on days where, for instance,
00:12:03you can't access cold or an ice pack
00:12:06or an ice bath or things of that sort.
00:12:08Okay?
00:12:09So we're going to cover cold.
00:12:10We're going to talk a little bit about
00:12:11the physiology of cold and heat and how they work,
00:12:15because as you've probably heard me say before,
00:12:18if you can understand some mechanism,
00:12:21if you can just push yourself
00:12:22through a little bit of new knowledge
00:12:23into understanding a little bit of mechanism
00:12:26about how you work,
00:12:27you will be in a far better position
00:12:29to implement the tools
00:12:31in the best and most flexible ways for your needs.
00:12:34This is why at the Huberman Lab Podcast,
00:12:37I never, ever do a just list of the things
00:12:40that you should do.
00:12:41I don't believe in the, just tell me what to do.
00:12:43First, I tell you why you should do something.
00:12:45What's the logical framework that it's grounded in?
00:12:48And then we distill that down to specific protocols.
00:12:51For those of you that are too impatient for that,
00:12:53there are millions, if not billions,
00:12:55of other resources out there
00:12:56that will take you into the cul-de-sac
00:12:58of one protocol that will work and then stop working
00:13:01or might work for you indefinitely.
00:13:03That's not how we work here.
00:13:04This is about really understanding the mechanism
00:13:07so that you can tweak things and modify things,
00:13:10adjust the timing and the dosage of things
00:13:12and really get the most out of these tools and protocols.
00:13:15Everything I'm going to talk about
00:13:18pertains to both endurance exercise
00:13:20and strength and speed type exercise.
00:13:24So sprints, weightlifting, endurance work,
00:13:27and to some extent flexibility,
00:13:29but we are going to cover flexibility in depth,
00:13:31as well as another feature that's not often talked about,
00:13:34which is suppleness or smoothness of movement
00:13:36over different ranges of movement in a subsequent episode.
00:13:41Let's start by talking about temperature.
00:13:43What is temperature?
00:13:44How does temperature impact the body
00:13:48and its ability to perform, including learn new skills?
00:13:51So everyone probably remembers
00:13:54or has at least heard of the word homeostasis, right?
00:13:57That the body wants to remain
00:13:59in a particular range of temperatures,
00:14:02that it doesn't like to be too hot or too cold.
00:14:05And I want to emphasize from the outset
00:14:07that there are many mechanisms that are installed into us
00:14:11by way of our evolutionary design and our genome,
00:14:15meaning we were just born with this stuff ready
00:14:18to keep our body temperature in a particular narrow range.
00:14:22Heating up too much is just plain bad.
00:14:26It's not just bad for physical performance,
00:14:28it's bad for all tissue health.
00:14:31If your brain heats up too much,
00:14:33neurons start dying and those neurons don't come back.
00:14:37Okay?
00:14:37You may have heard about neurogenesis,
00:14:39the ability for the brain to regenerate itself
00:14:41or generate new neurons in adulthood.
00:14:43There's very little neurogenesis, excuse me,
00:14:47in adulthood, even after, anytime after puberty really.
00:14:51And you don't want to lose neurons
00:14:53in the central nervous system.
00:14:54If you get too hot, that'll happen.
00:14:56It's called hyperthermia.
00:14:57You want to avoid hyperthermia.
00:14:59And you have many mechanisms that are built into you
00:15:02to avoid becoming hyperthermic.
00:15:05The other thing that happens when we get too warm
00:15:08is that we have in all of our cells what are called enzymes.
00:15:13You generally know if something's an enzyme
00:15:16because it ends in the letters A-S-E, right?
00:15:19So lipase is an enzyme that exists to digest fats.
00:15:24You have proteases that are there to digest proteins, right?
00:15:29So anytime you see A-S-E, chances are it's an enzyme.
00:15:35Enzymes are proteins and they have a particular structure
00:15:40and their structure becomes modified when heat increases.
00:15:46And that's not good.
00:15:47You want their structure to be of a particular type.
00:15:50Imagine a car with four wheels.
00:15:52Let's just say the car is the enzyme.
00:15:54If it gets too hot, it's like two of the wheels fall off
00:15:58and that thing can't function.
00:15:59So one of the reasons why the body and nature
00:16:02goes through so much effort to build in mechanisms
00:16:05to make sure that we don't become too warm
00:16:07is because when we get too warm,
00:16:10these enzymes don't function.
00:16:11Cells stop functioning.
00:16:13They stop being able to generate energy.
00:16:15They stop being able to digest things.
00:16:18You stop being able to think.
00:16:21and eventually those cells start dying off entirely.
00:16:24So keeping temperature in a particular range is really good.
00:16:27You don't want to get too hot.
00:16:29We have much more flexibility in terms of getting cold.
00:16:32Now, you don't want to become hypothermic either.
00:16:35You can die from hypothermia
00:16:36just like you can die from hyperthermia.
00:16:39However, that you have a lot more range to be cold
00:16:44than you do to be too warm, okay?
00:16:46And in general, the idea is to keep the body and brain
00:16:50in a particular range.
00:16:51But anytime we do anything, our body temperature can shift.
00:16:56So for instance, if you were to stand next to a campfire
00:17:00where you were outside on a hot day,
00:17:02various things would happen to dump heat from your body.
00:17:06If you were outside on a cold day
00:17:08or you would get into a cold shower or a cold lake,
00:17:11various things would happen to insulate heat within your body.
00:17:14This is all pretty straightforward and obvious, I realize.
00:17:16Now, what are those things?
00:17:18Well, there are a huge category of them.
00:17:20When you get into cold water, you secrete adrenaline.
00:17:23On a hot day, if it's really hot or in a very hot sauna
00:17:26or in the hot desert,
00:17:27you will generate what are called heat shock proteins,
00:17:30which will set off other sets of cascades,
00:17:33metabolic cascades, biological cascades.
00:17:37But the simplest way to think about this process
00:17:39is that when we get cold, we tend to vasoconstrict.
00:17:44We tend, our blood vessels tend to constrict
00:17:46and we tend to push energy toward the core of our body
00:17:51to preserve our core organs.
00:17:52Okay?
00:17:53So our periphery, our hands and our feet and our toes
00:17:55and our legs become colder
00:17:57and our core therefore can maintain blood to that area
00:18:01and we are insulating our core.
00:18:04Conversely, when we heat up,
00:18:06our blood vessels vasodilate.
00:18:08They expand a bit and more blood flows to our periphery
00:18:12and more blood can move throughout the body generally.
00:18:16And we will perspire, we will sweat.
00:18:19Water will actually get pulled out of the blood
00:18:21to some extent, moved up through sweat glands
00:18:24and will be brought to the skin surface
00:18:26so that it can be dumped.
00:18:28We are dumping heat.
00:18:30Animals, as you know, vary in their capacity to sweat.
00:18:34Some animals like camels won't start sweating at first.
00:18:38If they heat up, what they'll do is they'll spit.
00:18:40They'll dump heat by spitting.
00:18:42Okay?
00:18:43Dogs pant.
00:18:44Costello's off to my left here.
00:18:46He pants when he gets too warm.
00:18:48He can't sweat.
00:18:49Or if dogs can maybe sweat a little bit,
00:18:52but we can sweat.
00:18:54And you've probably noticed that on a humid, hot day,
00:18:59you'll feel much warmer just walking or running
00:19:02than you would with the equivalent exercise or movement
00:19:06that you would on a cold day.
00:19:08And some of you probably know this, but if you don't,
00:19:10the reason is you sweat on a cold day,
00:19:12but because the air is dry typically,
00:19:16you will bring that sweat to the surface
00:19:19and provided you're wearing clothes
00:19:21that allow some air to get out away from the body.
00:19:26So you're not wearing, you know, really tight,
00:19:28you know, spandex type clothing or something like that,
00:19:30or, you know, seal type, saran wrap type clothing,
00:19:33that sweat will evaporate off into the dry atmosphere.
00:19:37Whereas on a humid day,
00:19:38the reason you see people in, you know,
00:19:40New York and Florida on a humid summer day,
00:19:42and they're like moving their shirts off themselves.
00:19:44And you see people with, you know, big sweat stains
00:19:46and back sweat stains and all this kind of stuff
00:19:49is because they're sweating as they normally would,
00:19:52but it's humid.
00:19:53And so there is the humidity of the air
00:19:55doesn't allow transfer of that sweat
00:19:57into the atmosphere as readily.
00:20:00And so you're hot, okay?
00:20:02So without the evaporation, you're going to be warmer.
00:20:06So we evaporate off sweat, we sweat,
00:20:09and we vasodilate when we want to dump heat.
00:20:11When we want to maintain heat, we vasoconstrict,
00:20:14and we tend to not sweat.
00:20:16The other thing that happens is you'll get goose bumps,
00:20:19so-called goose pimples, they're sometimes called.
00:20:21Those are a throwback to the time where we had fur
00:20:25over most, not all of our body.
00:20:27All mammals in the cold have a process whereby adrenaline
00:20:33is released at low levels, typically, into the body.
00:20:36That adrenaline activates what are called sympathetic fibers.
00:20:40They have nothing to do with sympathy.
00:20:41Those little fibers, which are neurons, those fibers,
00:20:45what I'm saying are fibers are neurons,
00:20:46not clothing fibers, reach up into the skin.
00:20:49So your whole body is covered with these little tiny neurons
00:20:51that reach up into the skin.
00:20:52And when we are cold,
00:20:54they actually mechanically take the hair follicle
00:20:57and bend it up.
00:20:59It's a process called piloerection, P-I-L-O, erection.
00:21:04Okay?
00:21:05So on a hot day, you want to dump heat.
00:21:09Okay?
00:21:09So on a hot day, what would happen is you'd actually not see
00:21:13those goose pimples because you want the hairs lying down,
00:21:16which actually you would think that might insulate you more,
00:21:18but would actually let more heat dissipate out through the skin.
00:21:22On a cold day, you get these goose pimples or goose bumps,
00:21:25which are really just an ancient carryover from the body's attempt
00:21:29to make hair stand up on end.
00:21:31And when hair stand up on end and they're very close together,
00:21:35that traps air in between them
00:21:36and actually creates a sort of insulated blanket, a warm air.
00:21:40If you've ever seen an animal like a Malamute or a Husky,
00:21:45you might think, oh, that poor thing on a hot day,
00:21:48what does it do with all that hair?
00:21:50Well, it can be warm.
00:21:51So the animal will typically pant and its hair will lay down,
00:21:54which you might think would act as more of a blanket.
00:21:56But on a cold day, what'll happen is they'll become very puffy.
00:22:01Their hair will stand up on end
00:22:03and that's actually trapping heat between the hairs
00:22:05and they're actually quite well insulated.
00:22:07So it's very important that if you want to understand
00:22:11how you can leverage temperature for physical performance,
00:22:15you have to understand that you have vasoconstriction
00:22:18to conserve heat, vasodilation to dump heat,
00:22:20that you have sweating to dump heat
00:22:22and you have conservation of fluids in order to preserve heat.
00:22:27That's the most important thing
00:22:29in terms of understanding the mechanisms
00:22:31of maintaining and dumping heat.
00:22:33And now the most important thing to understand
00:22:35is that if you get too hot,
00:22:38not only do those enzymes stop working,
00:22:40but your ability to contract your muscles stops.
00:22:44Okay, I'm going to repeat this
00:22:45because it's vitally important.
00:22:49ATP is involved in the process
00:22:52of generating muscle contractions.
00:22:54It doesn't matter if you're running a marathon,
00:22:55doesn't matter if you're doing a yoga class,
00:22:57doesn't matter if you're going for a 700-pound squat.
00:23:00The range of temperatures within which ATP can function
00:23:04and muscles can contract is very narrow.
00:23:07Somewhere around 39 or 40 degrees Celsius,
00:23:11it drops off and you will not be able
00:23:13to generate more contractions.
00:23:15Now that's pretty hot,
00:23:17but that temperature can be generated locally really fast.
00:23:20Now, if you're too cold, it's true,
00:23:23it's hard to generate muscle contractions.
00:23:24I got into doing some cold water swimming a little while ago
00:23:28and we would joke that, you know,
00:23:29you come out of the water, we do no wetsuits.
00:23:32I'm not recommending people do this necessarily
00:23:33unless you're certainly with somebody else
00:23:35who's skilled at doing it, which I was.
00:23:37And you come out and you feel like you have claws for hands.
00:23:40You can, you know, you could never text on a phone
00:23:42for the first few minutes.
00:23:43I mean, the water was very, very cold
00:23:44and you can't even move your face.
00:23:46And so muscles will become rigid,
00:23:48but heating up muscles causes them to fail
00:23:52to be able to generate more contractions.
00:23:55Put simply, if you get too hot, you stop exercising.
00:23:58You may not even realize it,
00:24:00but your will to exercise further,
00:24:03your ability to push harder is entirely dependent
00:24:07on the heat of the muscle,
00:24:08both locally and your whole system.
00:24:11So let's talk about your whole system
00:24:14because I just described heat dumping and heat maintaining.
00:24:17I told you that increasing heat
00:24:20makes it hard for muscles to contract.
00:24:22It will stop you from being able to run further and faster.
00:24:26It will stop you from being able to lift more weights,
00:24:29more sets, more repetitions.
00:24:31If you can keep temperature in range, however,
00:24:34in a proper range, you will be able to do more work.
00:24:38You will be able to create greater output.
00:24:41You'll be able to lift more weight, more sets,
00:24:43more reps, and you'll be able to run further.
00:24:47Now, there are data that I'm going to talk about
00:24:49in a little bit that are absolutely striking
00:24:51that underscore that statement.
00:24:53There are data from my colleague, Craig Heller's lab
00:24:55in the Department of Biology at Stanford.
00:24:57And there are data that are now being implemented.
00:24:59They were first implemented in a grant funded by DARPA,
00:25:02but now in professional sports teams.
00:25:05Many, if not all the NFL teams are now using this technology
00:25:08as well as military uses it,
00:25:10and not just for sports performance,
00:25:12but also firefighters, construction workers,
00:25:15other professions where elevated heat
00:25:18becomes a barrier to performance.
00:25:20And you can leverage this to really improve your workouts.
00:25:23And when I say really improve, it is striking.
00:25:26I'm going to give away a little hint of this now,
00:25:27and then I'm going to tell you a little bit more
00:25:28of the data later after I tell you the protocols.
00:25:32Proper cooling of the body,
00:25:35which has to be done in a very specific way,
00:25:38has allowed recreational athletes,
00:25:41a college students and typical adults,
00:25:43as well as professional athletes
00:25:44to go from doing their usual output.
00:25:47In this case, what comes to mind best
00:25:50would be a particular professional athlete,
00:25:52a member of the 49ers at the time,
00:25:54was able to do 40 dips on his first set, 30, 20, 20.
00:25:58Basically did 10 sets of dips,
00:26:00unassisted with anything else.
00:26:01That's an impressive,
00:26:03especially since he's a really large guy.
00:26:0640 dips is a respectable.
00:26:08These are strict, full range dips.
00:26:11And then by the 10th set, there's a steep drop-off.
00:26:14Using proper cooling of particular body compartments,
00:26:18he was able to triple that within less than a week
00:26:22and maintain that performance
00:26:25even without the cooling approach.
00:26:26So it was actually a conditioning effect, all right?
00:26:29I'll get back to this in a little bit,
00:26:31but there are other fantastic leaps of effort
00:26:35and leaps of performance that were demonstrated,
00:26:38including endurance running.
00:26:41Before I continue any further,
00:26:43I just want to underscore again
00:26:45that overheating is terrible.
00:26:46There's a famous example of this.
00:26:50This was about 10, 15 years ago
00:26:52when a number of dietary supplements
00:26:54that included things like epinephrine,
00:26:56which is a stimulant.
00:26:57It's a beta-adrenergic stimulant.
00:27:00Drugs like glenbuterol,
00:27:02which were then banned from the Olympics,
00:27:04which are still out there a bit in recreational use,
00:27:06which were beta-adrenergic agonists.
00:27:08So these are drugs that sort of mimic
00:27:11epinephrine adrenaline to some extent.
00:27:13I know I'm oversimplifying this here.
00:27:15They improve fat loss
00:27:16because of the effects on metabolism,
00:27:18but they heat up the body.
00:27:20And what happened was,
00:27:21this hit the press very widely,
00:27:22is high school football players
00:27:24and various professional athletes were dropping dead
00:27:26because they were overheating during practice
00:27:28or in competition.
00:27:29So much so that glenbuterol was banned,
00:27:32although every once in a while,
00:27:33somebody gets in trouble for using this.
00:27:36There was an instance of this recently
00:27:37in professional boxing,
00:27:38which was attributed to a bad meat
00:27:40that contained the glenbuterol.
00:27:42I don't know what the source was.
00:27:45I don't have any commentary about that,
00:27:47but it still is in use.
00:27:48But these drugs increase body temperature,
00:27:51increase fat loss,
00:27:53but carry a severe danger.
00:27:55And that's the danger of hyperthermia.
00:27:58In fact, I would argue,
00:27:59and I think in talking to some folks
00:28:01at various professional fighting organizations,
00:28:03it's very clear that a lot of the deaths
00:28:05that one sees in professional combat sports
00:28:08may have to do as much with dehydration
00:28:11and overheating as it does with getting hit in the head,
00:28:15which is also bad,
00:28:16but that things can compound.
00:28:17They can have a synergistic effect.
00:28:19And just a note about that
00:28:21and hyperthermia and its dangers as well.
00:28:24My first project ever in science
00:28:26was to evaluate the thermogenic effects
00:28:28of MDMA, of ecstasy.
00:28:30That was my senior thesis in college, actually.
00:28:33And so what we found was that indeed drugs
00:28:37that remove your understanding of how warm you are,
00:28:41cause you to not take on the appropriate behaviors
00:28:45to cool yourself, right?
00:28:47So your vasoconstriction and your sweating,
00:28:50those are autonomic.
00:28:51Those are going to happen no matter what,
00:28:53unless you happen to take something
00:28:54that blocks that effect.
00:28:56However, there are a lot of things
00:28:57that we as humans do
00:28:58to prevent ourselves from overheating.
00:29:00and the main one is stop.
00:29:03When we are running in the desert
00:29:05or when we're running very hard
00:29:07and suddenly we stop,
00:29:09oftentimes that's because the muscles are overheating.
00:29:12It's a subconscious thing.
00:29:13We won't often think,
00:29:14oh, I'm really much too warm.
00:29:15It's just that we stop
00:29:17and it's a self-preservation mechanism.
00:29:19Sometimes it kicks in too early.
00:29:21Sometimes it kicks in too late.
00:29:23Kicks in too late, you can die.
00:29:25There's an instance in the 1984 Olympics
00:29:27where that was the first year I believe
00:29:30that there was a women's marathon.
00:29:32I think that's correct.
00:29:33And one of the front runners
00:29:35or top picks for winning
00:29:36was heading into the stadium.
00:29:38And all of a sudden,
00:29:39it seemed as if she was lost.
00:29:41She was kind of wandering around,
00:29:42not knowing where she should go.
00:29:44And in fact, she was in a position to win
00:29:45or at least take second place,
00:29:47at least take silver,
00:29:48got totally disoriented
00:29:49and did miserably in the race.
00:29:51And she was hyperthermic.
00:29:53She was running against that reflex to stop.
00:29:55So dumping heat is key.
00:29:58So how do you dump heat
00:30:00in order to perform longer safely?
00:30:04Well, in order to understand that,
00:30:06you have to understand
00:30:06that the body has three main compartments
00:30:09for regulating temperature, okay?
00:30:11We don't just have a center and a periphery.
00:30:13We have three main compartments.
00:30:15And there's one compartment in particular
00:30:17that all of you or most all of you,
00:30:20I have to assume have.
00:30:22And if you can understand how that works,
00:30:24you can do tremendous things for your performance
00:30:27and for your recovery.
00:30:29So what I'm about to tell you
00:30:30will allow you to perform better
00:30:32in all forms of exercise.
00:30:34And it is not commonly known, unfortunately.
00:30:37I'm here to try and change that.
00:30:39You have three compartments
00:30:40for increasing or dumping heat in your body.
00:30:44One is your core.
00:30:46We already talked about that.
00:30:47Your core organs, your heart, your lungs,
00:30:49your pancreas, your liver.
00:30:51This is the core of your body.
00:30:53The other is your periphery,
00:30:55which are obviously your arms and your legs
00:30:58and your feet and your hands.
00:30:59But then there's a third component,
00:31:02which is there are three locations on your body
00:31:05that are far better at passing heat out of the body
00:31:09and bringing cool into the body
00:31:12such that you can heat up
00:31:14or cool your body everywhere very quickly.
00:31:18Those three areas are your face,
00:31:22the palms of your hands,
00:31:24and the bottoms of your feet.
00:31:26Now the skin on your hands
00:31:28and on the bottoms of your feet
00:31:29and to some extent on your face
00:31:30are called glabrous skin.
00:31:32That's G-L-A-B-O-R-O-U-S,
00:31:37glabrous skin.
00:31:38And what's special about those areas of your body
00:31:42and the glabrous skin
00:31:43is that the arrangement of vasculature,
00:31:47of blood vessels, capillaries,
00:31:49and arteries that serve those regions
00:31:51is very different than it is elsewhere in your body.
00:31:55Now this has ancient roots.
00:31:59Typically, if you were another mammal,
00:32:01like a bear or some sort of ape,
00:32:04you would have hair all over your body.
00:32:06Now we all know some pretty hairy people
00:32:08or presumably you've heard
00:32:09that there are these hairy people.
00:32:11I know a few excessively hairy people
00:32:13and Costello is excessively hairy,
00:32:15but he's not a person obviously.
00:32:17But all mammals have hair on their bodies.
00:32:21Just some people have very light hair
00:32:23or very fine hair.
00:32:26We don't have hair on these glabrous skin regions.
00:32:29Now, of course you can have beard
00:32:31or facial hair growth,
00:32:32but there are still regions like the cheeks
00:32:34and other areas that maintain this special vasculature.
00:32:38Okay, so technically the hands and feet
00:32:40are real glabrous skin
00:32:41and the face is not always quite classified as glabrous,
00:32:45but these three locations,
00:32:47face, palms of hands, not tops,
00:32:49and bottoms of feet
00:32:51are very good at dumping heat and bringing in cool.
00:32:55And the reason is there's a rule in vascular biology
00:33:01that blood moves from arteries to capillaries
00:33:04and then to veins and then back to the heart.
00:33:07Okay, so arteries, which are the big ones, obviously,
00:33:10capillaries, which are the little fine ones
00:33:12where oxygen and carbon dioxide are exchanged,
00:33:16and veins, which then bring blood back to the heart
00:33:20and other tissues, of course.
00:33:23In these three regions of your hands,
00:33:26your face, and the bottoms of your feet,
00:33:29we have what are called AVAs.
00:33:32AVAs are a very special pattern of vasculature.
00:33:36AVAs are described in the medical textbooks.
00:33:38You can find them in Grey's Anatomy,
00:33:40not the television show,
00:33:41but the actual Grey's Anatomy textbook,
00:33:44which is a real thing that exists,
00:33:45and in all medical textbooks.
00:33:48Okay, so let's talk about AVAs and what they are
00:33:51and why they allow these three regions of the body
00:33:54to heat or cool ourselves more readily.
00:33:59So what are AVAs?
00:34:01AVAs are arteriovenous astimoses.
00:34:05So if you want to look that up,
00:34:07you can just look up AVAs, veins, capillaries, arteries,
00:34:11if you like, but I'll spell it for you.
00:34:14A-R-T-E-R-I-O, arteriovenous, V-E-N-O-U-S,
00:34:23arteriovenous anastomoses, A-N-A-S-T-O-M-O-S-E-S.
00:34:30Arteriovenous astomoses, okay?
00:34:32You want to know about arteriovenous astomoses, trust me.
00:34:36And you want to remember that they are in your hands,
00:34:38the bottoms of your feet, and on your face,
00:34:41and in particular on the palms of your hands,
00:34:43not the tops of your hands.
00:34:44Now, before I said blood flows typically
00:34:47from arteries to capillaries to veins
00:34:49and then back to the heart.
00:34:51But AVAs are direct connections
00:34:53between the small arteries and the small veins.
00:34:56They bypass the capillaries to some extent.
00:34:59They're little short vessel segments.
00:35:02They have a big, large inner diameter
00:35:04and they have this very thick muscular wall.
00:35:07and they get input from what are called adrenergic neurons.
00:35:12They get input from neurons
00:35:13that release norepinephrine and epinephrine,
00:35:16which allows them to contract or dilate.
00:35:19Now, there's some rules of physics
00:35:21that talk about how the radius of a pipe
00:35:23and small changes in the radius of a pipe
00:35:27leads to massive increases in the rate
00:35:30and amount of stuff that can flow through that pipe, okay?
00:35:35That's a rule of physics that says essentially
00:35:37that the radius is proportional
00:35:39to the amount of stuff
00:35:41that can flow through something to the fourth power.
00:35:44We're not going to make this a physics class,
00:35:45but if you want to look that up, you can.
00:35:48You can just look up
00:35:48how does the radius of a tube or pipe
00:35:50relate to how quickly
00:35:52or how much stuff can flow through it.
00:35:54What you need to know,
00:35:56even if you don't want to know
00:35:57any of the underlying physics,
00:35:58is that these AVAs allow more heat
00:36:01to leave the body more quickly
00:36:03and more cool to enter the body more quickly
00:36:08than other venous arterial capillary beds
00:36:12throughout the body.
00:36:13In other words, you can heat up best
00:36:15at the face, the palms, and the bottoms of the feet,
00:36:18and you can cool down best at the face,
00:36:21the palms, and the bottoms of the feet
00:36:23than you can anywhere else on your body.
00:36:25And when I say heat up or cool down,
00:36:27I mean actually heat or cool the core and your brain, okay?
00:36:31So this is vitally important.
00:36:33I realize we're getting down
00:36:34into the mechanistic weeds here,
00:36:35but you need to know
00:36:36that these three compartments of your body,
00:36:39palms, bottoms of feet, and face,
00:36:41are your best leverage points
00:36:44for manipulating temperature
00:36:45to vastly improve physical performance, okay?
00:36:49I also want to point out
00:36:51that the work that I'm going to tell you about
00:36:54is not work from my laboratory.
00:36:55It's the work of, as I mentioned,
00:36:57my colleague Craig Heller's laboratory at Stanford.
00:37:00And we're going to have Craig on as a guest
00:37:02to talk more about these discoveries.
00:37:04They are his and his colleagues' discoveries
00:37:08and how you can leverage them.
00:37:09They're building out some amazing technology.
00:37:11I had a conversation with Craig yesterday
00:37:14as a prelude to this episode
00:37:16and to the future conversation with him.
00:37:18So you're getting the very latest on this topic.
00:37:21So what Craig and his colleagues did
00:37:24really illustrates perfectly
00:37:26what these body surfaces can do and why.
00:37:30They were studying overheating in athletes
00:37:34and in military and in construction workers
00:37:37and trying to prevent it.
00:37:39And they did a bunch of experiments.
00:37:41I won't go into all of them now,
00:37:42but what they essentially found
00:37:44was that cooling the palms,
00:37:47palmer cooling allowed people,
00:37:51athletes and recreational athletes
00:37:53to run much further,
00:37:55to lift more weight
00:37:57and to do more sets and reps
00:37:59to a absolutely staggering degree.
00:38:04Let's talk for a second,
00:38:05a bit more about why we stop,
00:38:08why we shut off effort when we get too hot.
00:38:13Because in doing so,
00:38:14you'll really understand how and why
00:38:17the best protocols exist
00:38:18for being able to do more work,
00:38:20to be able to exercise longer
00:38:23and actually to feel good doing it.
00:38:25You actually can make a doubling of your dips
00:38:27or believe it or not,
00:38:29a tripling or quadrupling or more
00:38:30of your pull-ups fairly straightforward.
00:38:34I mentioned before that when muscle heats up,
00:38:39enzymes start getting disrupted
00:38:41and ATP and muscles can't work so well
00:38:44and those muscles can't contract.
00:38:46Let's get a little more specific about that.
00:38:48The enzyme that's involved here
00:38:50is something called pyruvate kinase.
00:38:52You don't need to know about pyruvate kinase,
00:38:54but what you do need to know
00:38:55is that it ends ASE,
00:38:56which means it's an enzyme.
00:38:58And pyruvate kinase
00:39:01is essentially a rate limiting step.
00:39:04It's a critical step that you can't bypass
00:39:06if you want muscles to contract
00:39:08and it's very temperature sensitive.
00:39:12Therefore, if you can keep temperature lower,
00:39:16you can do more work per unit time.
00:39:18You can do more pull-ups
00:39:20and that actually was done
00:39:21by Craig and his colleagues.
00:39:24Excuse me.
00:39:24The pull-ups weren't actually done by Craig.
00:39:26I don't know how many pull-ups Craig can do.
00:39:27I'll ask him next time,
00:39:28both cooled and uncooled,
00:39:30how many pull-ups he can do.
00:39:31But what they essentially did
00:39:33is they brought someone into their laboratory
00:39:35who could do 10 pull-ups on the first set
00:39:39and they were able to get 10 rest two or three minutes,
00:39:42get another 10 rest two or three minutes.
00:39:44And if you've ever tried this,
00:39:45what you find is that you start dropping
00:39:46to eight, seven, six, et cetera.
00:39:49Now the person might not necessarily feel
00:39:51like they're overheating,
00:39:52but the muscle is heating up.
00:39:55Then with their knowledge that these AVAs,
00:39:59that these portals in the palms
00:40:02are a great way to both heat the body,
00:40:05but also to dump heat from the body,
00:40:07they used a device
00:40:09and I'll talk about what you can do at home,
00:40:12but a device where they had people hold on
00:40:14to what was essentially a cold tube.
00:40:18Now this is crucial.
00:40:20The tube can't be so cold
00:40:21that it causes vasoconstriction
00:40:23because then the cold won't pass from the tube
00:40:27to the hand and to the core.
00:40:29But if it's the right temperature,
00:40:32it's neither too hot nor too cold,
00:40:34that cool from the cold tube passes into the hand,
00:40:39these so-called palmar regions,
00:40:41and then cools the core.
00:40:43And in theory, by lowering body temperature
00:40:46would allow the person or the athlete to do more work.
00:40:50And indeed, that's what they saw.
00:40:52The actual data, the specific data showed
00:40:55that subjects could do,
00:40:57at least the subjects they worked with,
00:40:58on their first day with no cooling,
00:41:00about 100 pull-ups across the timeframe that they had.
00:41:06Okay?
00:41:06So it might've taken anywhere from 10 to 15
00:41:09or maybe more sets,
00:41:10depending on how skilled that person was,
00:41:13but in a fixed amount of time.
00:41:15And then they came back and did the cooling.
00:41:18They did it the very next day,
00:41:19which if you've ever trained a muscle the very next day,
00:41:22typically you wouldn't do as well in its training
00:41:25if it took any damage from the previous sessions,
00:41:27or you at least do as well,
00:41:29but you probably wouldn't do what they then observed,
00:41:31which was they started cooling after every other set.
00:41:34The person would just hold the cold tube,
00:41:36cool down the body after every other set rest,
00:41:40everything else was kept the same.
00:41:41And they found that they went to 180 pull-ups,
00:41:45which is incredible.
00:41:46It's a near doubling.
00:41:47And by doing this repeatedly over several sessions,
00:41:50over several weeks,
00:41:51they quickly went in the cooling group
00:41:54from a maximum of somewhere between 180 and 200,
00:41:58as I recall, I'm sort of estimating now,
00:41:59to 600 pull-ups in the equivalent amount of time,
00:42:03which is absolutely incredible.
00:42:05They then repeated this in a study on the bench press.
00:42:09And actually the bench press study was pretty interesting
00:42:11because they actually had a control group
00:42:13that was admittedly taking specific amounts
00:42:16of anabolic steroids.
00:42:17The anabolic steroid was testosterone cipionate,
00:42:20which is essentially testosterone.
00:42:23And indeed the testosterone cipionate,
00:42:25the steroid group improved
00:42:26at a rate of about 1% per week
00:42:29where it's different, there were differences.
00:42:32And the cooling group basically left
00:42:35all other groups in the dust.
00:42:37It was just remarkable.
00:42:38So cooling the core,
00:42:40I want to be very clear that it's not cooling the muscle.
00:42:42It wasn't about cooling the chest alone
00:42:44or just cooling the palms.
00:42:46It was about allowing cold to pass through the palms
00:42:49because of the unique vasculature that's there,
00:42:52these AVA's allowed these subjects
00:42:55to do far more work per unit time.
00:42:58And the important thing is that if they were to come back
00:43:02after doing 600 pull-ups or 500 pull-ups,
00:43:05you might say, well, wow,
00:43:06that's going to create a situation
00:43:08where recovery is going to be absolutely impossible.
00:43:11They could come back, not use the cooling,
00:43:13and they still saw a highly significant increase
00:43:16in the amount or the number of pull-ups or dips
00:43:18or bench press weight that they could do.
00:43:20Okay?
00:43:21So what that meant is that it was both
00:43:23an excellent performance
00:43:24and an excellent training stimulus
00:43:27that they were able to recover from.
00:43:29Okay?
00:43:29I don't know if all of you are following this,
00:43:31but these are the sorts of increases
00:43:33in exercise output that are absolutely staggering.
00:43:36And that's why professional teams
00:43:38and the military and others
00:43:41capitalized on them very quickly and use these.
00:43:44Okay?
00:43:44Now you may be asking,
00:43:47what about endurance, right?
00:43:49Not everyone wants to be able to bench press a lot
00:43:52for multiple reps and sets.
00:43:54And I should just mention for the bench pressing,
00:43:56it was, I believe they were,
00:43:58they found people that could bench press 225.
00:44:00So that's two 45 pound plates
00:44:01on the 45 pound standard Olympic bar
00:44:03for repetitions of anywhere from six to 10.
00:44:05And then they had them do the same thing.
00:44:07They did a set,
00:44:07they'd rest two or three minutes,
00:44:09sometimes up to four minutes,
00:44:10then do another set, repeat, repeat, repeat.
00:44:12And with cooling, they were able to increase
00:44:15the amount of work,
00:44:16the number of reps with the same weight.
00:44:18Sometimes they did have to increase sets
00:44:20to approximately double.
00:44:22So it's pretty fantastic.
00:44:25So with endurance,
00:44:27similar increases have been shown.
00:44:29And the way that they would do those tests
00:44:32are a little bit different.
00:44:33And they also point to a really important mechanism
00:44:35of why we stop doing work at all
00:44:38when we perceive that we are putting in too much effort.
00:44:42So it gets right to the heart of the relationship
00:44:44between temperature and muscles and your willpower.
00:44:47Those are directly related.
00:44:49Your body heat and your willpower
00:44:51are linked in a physiological way.
00:44:53So I'm not talking about the kind of stuff
00:44:55that you see is kind of like clickbait on the internet
00:44:57or like increase willpower now
00:44:58or become resilient now
00:45:00or never do this again
00:45:01if you want to be mentally strong.
00:45:03I'm talking about a physiological mechanism
00:45:05that exists in the body and brain
00:45:06that causes you to stop
00:45:08or that will allow you to continue
00:45:10to go harder and further than you normally would.
00:45:14Okay, so let's talk about willpower and heat
00:45:16and how heat shuts you down.
00:45:18In other words, if you are cool,
00:45:21if your body temperature is in a particular range,
00:45:24not only can you go further,
00:45:26but you will go further if you want to.
00:45:30Said differently,
00:45:32if you heat up too much,
00:45:33you will stop or you will die.
00:45:37Typically, people stop.
00:45:38There are individuals who will push to the point
00:45:40where they black out and die
00:45:41in the same way that,
00:45:42and please don't do this experiment.
00:45:45There are people who can sit down face-to-face
00:45:48and say, let's hold our breath
00:45:49and whoever breathes first loses.
00:45:53Some people will just go until it's painful
00:45:55and then they'll gasp and take a big breath.
00:45:57There are always those individuals
00:45:59who can override that reflex
00:46:00and they will go until they pass out, okay?
00:46:03And if you do that in water, you can very easily die.
00:46:06So please don't do that experiment.
00:46:08But there's a reflex that relates the body to the brain
00:46:14and the brain to the body
00:46:15that shuts off our effort when we get too hot.
00:46:18So what Craig and his colleagues
00:46:20and now others have done
00:46:21is to do a test in the laboratory
00:46:23where rather than ask people to run outside
00:46:26until they absolutely don't want to run anymore,
00:46:29you put them on a treadmill and you set the speed.
00:46:31Okay, so they have to keep up with the treadmill
00:46:34and at some point they quit.
00:46:37And you take groups and you do those
00:46:41in different temperature environments.
00:46:44So some people are running in a nice chilly laboratory,
00:46:47they get their heart rate up.
00:46:49So maybe their heart rate goes from,
00:46:51you know, 40 or 50 baseline heart rate,
00:46:54maybe it gets up to 80 or a hundred.
00:46:56And then they keep the rate of the treadmill going the same
00:46:59and they'll just plateau.
00:47:00So they're getting to a steady state cadence or rhythm
00:47:03and their heart is beating it more or less a steady state.
00:47:05Eventually they'll probably stop
00:47:07because they have something else to do,
00:47:08but people will continue at that temperature
00:47:13and at that heart rate
00:47:15unless you start turning up the temperature in the room.
00:47:18And at some point they will stop
00:47:20and they'll stop much earlier when it gets hot
00:47:23because of something called cardiac drift, okay?
00:47:27So let's say I'm running
00:47:28and I'm running at a steady cadence on this treadmill
00:47:30and my heart rate is 85 beats per minute
00:47:33or a hundred beats per minute, doesn't matter.
00:47:34Let's say a hundred just for sake of example.
00:47:37Well, just making the room hotter
00:47:39is going to increase my heart rate further
00:47:42even though I'm at the same output.
00:47:44And the brain does a computation.
00:47:47It somehow figures out that there's a heat component
00:47:51that's increasing heart rate
00:47:52and there's an effort component from running
00:47:54that's driving heart rate.
00:47:56And if the heat component
00:47:57and the heart rate output from the effort
00:48:00get to hit a certain threshold, I stop, okay?
00:48:04And some of you may think,
00:48:06well, there are people who just run and run and run
00:48:08and never stop.
00:48:09Eventually everyone stops.
00:48:11Maybe it's because the race ended.
00:48:12Maybe it's because everyone else quit.
00:48:15I actually saw some stuff online.
00:48:16There are these races
00:48:17where people just will continuously do the same loop
00:48:19until everyone else drops out.
00:48:21And then one guy or gal keeps going past everybody.
00:48:25But typically it stops because the race is over
00:48:27or because people quit.
00:48:29Increasing temperature increases the rate of quitting
00:48:33in part, not entirely,
00:48:35but in part because of this thing called cardiac drift,
00:48:38which you've probably experienced
00:48:39if you've been out on a hot day
00:48:41and you're walking uphill,
00:48:42you might stop to take a breath.
00:48:43If you sit in a sauna, your heart rate will increase.
00:48:46Heat increases heart rate.
00:48:48Effort increases heart rate.
00:48:50At a steady effort, you'll have a steady heart rate.
00:48:53If you increase the heat in the environment
00:48:55that you're engaging in that steady heart rate,
00:48:58your heart rate will now go up due to cardiac drift
00:49:01and you will quit, okay?
00:49:03So Heller and colleagues have done experiments
00:49:07where they do palmer cooling under these environments.
00:49:10And that's wonderful because not only does it enable people
00:49:15to go further and faster for much longer.
00:49:20That's been shown statistically significant every time,
00:49:23but it also protects the brain and body
00:49:25against hyperthermia, overheating, coma, nerve injury,
00:49:29nerve death, and actual death, okay?
00:49:32So you can see why this is such a valuable tool.
00:49:36So what are they doing?
00:49:37Well, in this case too,
00:49:38they're having them cool their hands
00:49:41and they're cooling the palms.
00:49:43Cooling the bottoms of the feet is a little trickier,
00:49:45but cooling the face could actually work as well.
00:49:48And we're going to talk about cooling the face
00:49:49and how to incorporate this.
00:49:50So at this point,
00:49:52I've just really wanted to impress upon you,
00:49:56not impress you, but impress upon you
00:49:58the fact that you have these three surfaces of your body
00:50:01that are very good at passing cold into the body
00:50:04such that it cools the core body temperature.
00:50:06and that's a good thing for health and safety
00:50:09and in order to maintain work output
00:50:13over longer periods of time
00:50:14or actually just do more work.
00:50:15I mean, to me, the result is just so staggering
00:50:18is the 100 to 180 pull-ups in the controls
00:50:21and then 600 pull-ups in the cooled individuals, right?
00:50:25They actually also feel mentally as if they can do more work.
00:50:30It's not just that they can,
00:50:31their willpower is adjusted somehow
00:50:34by these shifts in temperature.
00:50:36Now, before we continue and get to the exact ways
00:50:39that any number of us can start to use this information,
00:50:43I want to talk about the opposite thing,
00:50:45which is heating.
00:50:47And you have to remember that these surfaces,
00:50:50the palms and the bottoms of the feet and the face,
00:50:52were not just arranged with these AVAs,
00:50:55these special ways to pass blood from arteries to veins
00:51:00in order to cool us for better athletic performance
00:51:03or to heat us on cold days, but for both of those things.
00:51:09Now, Heller and colleagues and others have also explored
00:51:12how these can be used to heat up the core.
00:51:16There are times when we want to heat up our core.
00:51:19Typically, we hear that most of the heat escapes
00:51:22through our head, so we'll put on a hat when we go outside.
00:51:25That's actually not true.
00:51:27Most of your heat escapes through your face,
00:51:30the palms of your hands, and the bottoms of your feet.
00:51:33Now you should know why that's the case.
00:51:36What this means is that for post-surgery patients
00:51:40or for people that are hypothermic,
00:51:42indeed, you want to heat the core, right?
00:51:45But actually, I was out on a swim recently
00:51:47where a friend became hypothermic.
00:51:49He was kind of slurring his words
00:51:51and kind of staggering around
00:51:53when we got him back on the beach.
00:51:54We brought him over to the lifeguard station.
00:51:56He turned out to be fine.
00:51:57Again, this is why cold water swims
00:51:59are something that you really need to do in groups,
00:52:01not alone, and you really have to know what you're doing.
00:52:03There were reasons why this happened that day.
00:52:08But basically, people thought we were a little strange
00:52:10until they realized what was happening.
00:52:12We were walking down the beach,
00:52:13basically sandwiching him at our chest
00:52:16because we were still warmer
00:52:17than the ambient environment, the environment around us.
00:52:20and we were pushing our chests against him
00:52:22to try and warm him up, to warm up his core.
00:52:25In retrospect, that was the wrong thing to do.
00:52:27In talking with Craig and talking to other colleagues
00:52:30that work on thermogenesis,
00:52:33what we should have done was warm the palms of his hands,
00:52:36the bottoms of his feet and his face
00:52:38because that would insulate the heat loss.
00:52:41Now, he was very cold.
00:52:42So presumably there was vasoconstriction
00:52:45of the veins at these locations.
00:52:48And so it's not clear
00:52:49that that would have been the only strategy to use,
00:52:51but they have explored
00:52:54how to heat up post-surgery patients.
00:52:56And one of the best ways to do that
00:52:57is to get warm socks on the bottoms of the feet,
00:53:00get gloves on the hands,
00:53:01and if it can be done safely to warm the face.
00:53:03Now, of course, you don't want to obstruct respiration
00:53:05and things of that sort.
00:53:06But again, the ability to pass heat into the body
00:53:10or to remove heat to the body
00:53:12is best done through these three surfaces.
00:53:15I can't emphasize that enough.
00:53:17So I mentioned before that you want to cool the palms
00:53:20or the bottoms of the feet,
00:53:21although that's a little harder to do,
00:53:23or the face,
00:53:23but not so much that the blood vessels constrict
00:53:27because then you won't be able to pass cool into the body
00:53:30because those pipes got smaller
00:53:31and therefore you can't pass cool into the body.
00:53:35So how can you start to incorporate this?
00:53:37Well, Craig and colleagues have a company
00:53:40that they've spun out through Stanford.
00:53:42We'll talk about that when we sit down with Craig
00:53:44that has made engineered devices
00:53:47that are optimal for this,
00:53:49that are going to keep those passages open,
00:53:52keep the size of those veins correct
00:53:54to pass cool into the body quickly
00:53:56for sake of elite sports performance
00:53:58and even recreational sports performance.
00:53:59But you can actually start to incorporate this.
00:54:02First of all, I always get asked,
00:54:05how cold should the water be?
00:54:07Should it be ice water?
00:54:08Should it be very cold water?
00:54:10The answer is no.
00:54:13If you want to experience some of this effect
00:54:15without a device,
00:54:16one thing you could do would be for instance to do,
00:54:19I don't know,
00:54:20I'll use the gym or the treadmill as an example.
00:54:22You could do your maximum number of pull-ups, stop,
00:54:26and then you could actually put your hands into
00:54:29or on the surface of a sink
00:54:32that is presumably stopped up with cool water.
00:54:37So not ice water,
00:54:39not freezing cold,
00:54:40but cool water.
00:54:42Slightly cooler than body temperature
00:54:45before you started training
00:54:47would be a good place to start.
00:54:48You do that for 10 to 30 seconds,
00:54:51then you could go back and do your next set.
00:54:54You would repeat the cooling.
00:54:55You would want to extend the amount of cooling somewhat,
00:54:57so you might want to do that for 30 seconds to a minute.
00:55:00This is not going to be perfect.
00:55:01You're going to have to play with how cold to make it
00:55:04in order to get the optimal effect,
00:55:06but you ought to see an effect nonetheless.
00:55:09The same is true if you're running and you're fatiguing.
00:55:12Obviously you don't want to become hyperthermic.
00:55:15Cooling the hands or the bottoms of your feet
00:55:17or the face would be the ideal way to dump heat
00:55:20in order to be able to generate more output.
00:55:23Now, the face is something
00:55:25that we haven't talked a lot about.
00:55:27Everything I've told you up until now
00:55:28also says that if you are somebody who tends to get cold
00:55:31when you are outside, say in the winter
00:55:33or even in the fall, you tend to run cold,
00:55:37warming your face is going to be
00:55:38the most important thing that you can do.
00:55:40Now, it's kind of hard to do that without looking strange,
00:55:43like wearing a ski mask or something like that,
00:55:45but that is going to be more effective
00:55:46than covering and warming any other part of your body.
00:55:50Although it would be quite strange
00:55:51if you only had a ski mask on
00:55:52and you weren't wearing clothes anywhere else on your body.
00:55:54I don't recommend doing that outside.
00:55:56That will get you into all sorts of other kinds of trouble.
00:55:59It wouldn't be good for anybody.
00:56:01But now you understand the principle
00:56:03and the locations at which to deliver heat and cold.
00:56:06So let's say that you are out for a run
00:56:09and you want to incorporate this cooling mechanism.
00:56:12I talked to Craig about this.
00:56:13I said, what would be the kind of poor person's approach
00:56:16to this before this device is commercially available?
00:56:19And he said, well, you could take a frozen juice can,
00:56:24and if you have one of those or a very cold can of soda,
00:56:27and you would want to pass it back and forth
00:56:30between your two hands.
00:56:31The reason the passing back and forth is really important
00:56:33is because you, again, you don't want it to be so cold
00:56:36that you constrict those venous portals
00:56:39that will allow cold to go into the body.
00:56:43Now, there are certainly people
00:56:45that are working on bike handles
00:56:47and that can actually cool the hands.
00:56:49You can expect with the Olympics coming up,
00:56:51people are aware of these data
00:56:52and are starting to incorporate it into a number of things.
00:56:55Here's what you don't want to do.
00:56:57And there are sports teams that I won't mention
00:56:59by name or brand that have made this mistake
00:57:01and it costs them dearly.
00:57:03You don't want to cool the core
00:57:06if you want to cool the body, right?
00:57:09If it's a very hot day and you're going to train,
00:57:11getting into an ice bath first,
00:57:13sure, it will cool you down,
00:57:15but that's not going to be as effective
00:57:18as cooling the palms, the bottoms of the feet and the face.
00:57:22I have a friend who does some important work in this space
00:57:26with people in various, let's just say cultures
00:57:29where heat is generated quite a lot
00:57:30and they need to dump heat.
00:57:32Ice packs delivered to the face
00:57:33are something that they actually use
00:57:36in order to dump heat quickly.
00:57:37Now, again, you don't want to keep the ice pack on your face.
00:57:40These are people that are very high work output, right?
00:57:44Firefighters and similar,
00:57:45at very high work output and then they'll put this,
00:57:48essentially it's like a cool face mask on their face.
00:57:52It'll allow their core body temperature to come down
00:57:54and then they remove it.
00:57:55They're not keeping it on there so long
00:57:57that they're getting the vasoconstriction, okay?
00:57:59So there are a number of ways that you could do this.
00:58:01And again, I'm not giving specific temperatures
00:58:04because it depends on how hot that day
00:58:06and how hot your body temperature is.
00:58:07So you can see why there's a need
00:58:08to create more devices for this,
00:58:10but you can see a considerable improvement
00:58:15in endurance, in strength,
00:58:17and in all kinds of explosive
00:58:19and sort of explosive power type output in athletics
00:58:24by using these surfaces of the hands
00:58:27and bottoms of the feet and face.
00:58:29The one that I've tried
00:58:31because in anticipation of this episode
00:58:33was the dips where then I would cool my hands.
00:58:37I actually decided to cool the bottoms of my feet as well
00:58:39because it just feels good
00:58:40and it's particularly hot out lately.
00:58:41So no shoes or socks on,
00:58:43put my feet into the bottoms of my feet,
00:58:46just kind of hovering about a centimeter or two
00:58:48below the surface of a bucket of water
00:58:51that was just slightly, it felt cool,
00:58:53slightly cooler than body temperature or so.
00:58:56It just basically what came out of the spigot
00:58:58after I let it run for a little bit.
00:59:00And indeed, I saw a 60% increase
00:59:03in the number of dips I can do in a single session.
00:59:05So it's actually a quite significant effect
00:59:08and you don't have to be perfectly precise
00:59:10in order to do it.
00:59:11And of course, if you want to heat up for whatever reason,
00:59:14like you're in your camping
00:59:15or you're lost in the environment,
00:59:17remember these three surfaces
00:59:18are going to be the best way to heat your core as well.
00:59:22So up until now,
00:59:23we've been talking about how to use cold during a workout
00:59:26in order to improve performance.
00:59:28And indeed, cold applied to the appropriate parts
00:59:31of the body, the appropriate times
00:59:33can vastly improve our performance
00:59:36in endurance and strength.
00:59:38Now I want to talk about the use of temperature
00:59:41in particular cold to improve the speed
00:59:44and the depth of recovery.
00:59:47Recovery is obviously vital, right?
00:59:50During a weight training session
00:59:51or during an endurance session,
00:59:53that's just the stimulus for getting better the next time.
00:59:56And if you don't recover,
00:59:57you not only won't get better, but you'll get worse.
01:00:01There's a lot of interest in the use of cold
01:00:03in order to improve recovery in the short term.
01:00:08We see this and probably the best example of this
01:00:10would be fighters in combat sports between rounds
01:00:14or athletes during, in between quarters or halftime.
01:00:19That's one form of recovery.
01:00:20The ability to go back into the sport very soon
01:00:23on an order of minutes, anywhere from like one minute
01:00:26in between rounds in typical combat sports
01:00:28or several minutes at a halftime, et cetera.
01:00:33Typically, what we see is people cooling their core,
01:00:37cooling the back of their neck,
01:00:39cooling the top of their head.
01:00:39So it might be, you know, a sponge with cold water
01:00:42over the top of the head
01:00:43or an ice pack on the back of the neck,
01:00:45or in some case, even wearing cold ice vests.
01:00:49This has actually been done.
01:00:51And that's going to be a very inefficient way
01:00:53to improve recovery of that kind.
01:00:56Far better would be to cool the face,
01:00:58the palms of the hands or the bottoms of the feet
01:01:00for the reasons that I described up until now.
01:01:04Submerging the body in an ice bath
01:01:05or taking a cold shower,
01:01:08say up to the neck or up to the chest
01:01:10or getting under cold water
01:01:12or jumping in a cold lake or something of that sort,
01:01:15or in the locker room, getting under the cold shower,
01:01:17also would be a terrible way to cool off the body quickly
01:01:21compared to the ways that I described
01:01:24through the palms of the hands,
01:01:25the bottoms of the feet or the face
01:01:27for the following reason.
01:01:29First of all, it's not optimizing those portals
01:01:31of the face, palms, the hands, and the feet.
01:01:33And in addition, if it's very cold
01:01:36and you submerge or you cover a lot of the body
01:01:40with that cold,
01:01:41you're going to cause constriction
01:01:43of the very vessels and pathways
01:01:45that allow the body to efficiently dump heat.
01:01:48So again, the key thing is to cool these one or two
01:01:54or three of these surfaces,
01:01:55but not so cold that you cause the vasoconstriction.
01:01:59So what does this mean for you?
01:02:02It means that getting in an ice bath or a cold shower
01:02:04or putting an ice pack on the back of your neck
01:02:06in most cases is not going to be as good
01:02:09as splashing cold water on your face
01:02:11or even just holding your face
01:02:12with a damp, cool cloth or something of that sort.
01:02:17It's sort of kind of counterintuitive.
01:02:19You would think, oh, if I just jump into an ice bath,
01:02:21I'm going to cool down much faster
01:02:23than if I just cooled these one or two
01:02:26or three of these select regions of the body,
01:02:28but that's actually not the case.
01:02:29And then of course, there's recovery
01:02:31that occurs from session to session.
01:02:33So outside of the game or the match
01:02:35or the exercise session.
01:02:39And many people are now relying on things like cryotherapy,
01:02:43which requires a lot of expensive equipment,
01:02:45big liquid nitrogen driven machine.
01:02:49Those aren't so common for most people
01:02:51or accessible for most people,
01:02:52but a lot of people are using cold baths
01:02:54or ice baths or cold showers.
01:02:56And again, that's not going to optimize recovery.
01:02:59In fact, it's going to have an additional effect
01:03:01that is going to potentially block the training stimulus.
01:03:05When you get into an ice bath,
01:03:07indeed, there are, provided it's not very, very cold.
01:03:11If you get into a cold shower,
01:03:12provided it's not very, very cold,
01:03:14you are indeed blocking some of the inflammation
01:03:17that occurs because of the training session.
01:03:19But in doing so, you also are blocking pathways
01:03:23such as mTOR, mammalian target or rapamycin,
01:03:27which are involved in the adaptation
01:03:29for a muscle to become stronger or bigger.
01:03:31Put simply, covering the body in cold
01:03:35or immersing the body in cold after training
01:03:38can short circuit or prevent the hypertrophy
01:03:41or muscle growth response.
01:03:42It has other effects that can be positive, right?
01:03:45It can induce thermogenesis, et cetera.
01:03:47It can reduce inflammation,
01:03:49but it can prevent some of the positive effects of exercise.
01:03:53Now, it hasn't been examined so much for endurance work,
01:03:56but let's say you come back from a round of endurance work,
01:04:00a run or a bike or a swim,
01:04:02getting into a cool bath or cooling the palms,
01:04:07the bottoms of the feet or the face,
01:04:08in my opinion, based on the science,
01:04:10would be better than completely immersing the body
01:04:13in the ice bath or the cold shower.
01:04:16There is a time and a place for the use of the ice bath
01:04:19or the cold shower or the cold plunge.
01:04:22Those tend to be when you want to deliberately increase
01:04:25brown fat thermogenesis
01:04:26or when you want to deliberately work on mental resilience.
01:04:31And in a subsequent episode on fat loss,
01:04:33I'm going to talk about how to optimize the use of cold
01:04:35specifically for increasing metabolism and fat loss.
01:04:39But for now, since we're talking about the use of cold
01:04:42for improving performance and recovery,
01:04:45the suggestion that I'm going to provide
01:04:47is based on the work of Craig Heller and colleagues
01:04:50that I've been talking about,
01:04:51as well as a excellent book.
01:04:53I mainly rely on textbooks and special volume books,
01:04:57which are collections of papers from experts
01:04:59in a particular area that go beyond standard
01:05:02kind of college level textbooks.
01:05:03The one that I've been relying on
01:05:04is called Thermal Regulation in Human Performance,
01:05:07Physiological and Biological Aspects by F.E. Marino.
01:05:11I don't know the publisher.
01:05:12I don't know the author.
01:05:13I do recognize some of the names
01:05:15of the particular papers there,
01:05:16but I just want to be clear.
01:05:17There's no sort of business relationship
01:05:19or deal with them, but it's an excellent text.
01:05:21It's called Thermal Regulation in Human Performance.
01:05:23You can find it online
01:05:24if you want to go really deep into this.
01:05:26But basically what they show is that
01:05:28if you can cool the body back
01:05:30to its resting temperature for a...
01:05:33And by resting temperature,
01:05:35I mean within the range that you would see
01:05:36at any time of waking day, but not in exercise.
01:05:40So just bringing the body temperature down to baseline.
01:05:44If you can do that,
01:05:45the sooner you can do that after a workout,
01:05:47the sooner that the muscle will recover,
01:05:50that the tendons will recover,
01:05:51and that the person, you,
01:05:53can get back into more endurance training,
01:05:55more weight training, et cetera.
01:05:56So cold actually can be a very powerful tool for recovery,
01:06:00but to maximize return to baseline levels of temperature,
01:06:05it's my belief based on the studies
01:06:08that are published in this book,
01:06:09as well as my discussions with my colleague, Craig Heller,
01:06:12and in reviewing the literature overall,
01:06:14that just simply cooling the entire body
01:06:16by jumping into an ice bath or a cold shower
01:06:18is not the best way to go.
01:06:20You really want to rely
01:06:21on one of these three glabrous skin portals
01:06:24of the palms, the bottoms of the feet, or the face.
01:06:26So now you probably know more
01:06:28than you ever wanted to know
01:06:29about how we regulate body temperature
01:06:32and how it can be applied to exercise,
01:06:34both during the exercise session
01:06:37and afterward to optimize recovery.
01:06:40Many of us, all of us presumably,
01:06:43are also eating and drinking things
01:06:45and taking things at various times
01:06:47that can impact this process.
01:06:49And so because of that,
01:06:51we should ask whether or not those things
01:06:54are impacting body temperature.
01:06:56And when we do that,
01:06:57we find that there are certain things
01:06:59that many of us are doing
01:07:00that are actually impairing our performance.
01:07:03So for instance,
01:07:04if you are taking a pre-workout drink
01:07:06or you're ingesting a lot of caffeine
01:07:08or other substance
01:07:09to bring your body temperature up
01:07:12before exercise,
01:07:13you are limiting the amount of exercise
01:07:15that you can do.
01:07:17I can recall a time in college
01:07:19when I would drink a lot of espresso.
01:07:22Back then, ephedrine was sold over the counter.
01:07:25I remember taking it.
01:07:26It will really energize you for workouts.
01:07:30You can generate a lot of energy
01:07:32and get extremely focused taking those things.
01:07:35They do increase heart rate.
01:07:36They can be quite dangerous.
01:07:37I don't recommend people take them.
01:07:39In fact, I think ephedrine is now off the shelves
01:07:41as a non-prescription compound
01:07:44because various people died from taking it
01:07:46who were sensitive to it
01:07:47or exercised in heat.
01:07:49But looking back at that,
01:07:50I realized it was a foolish approach.
01:07:52It was increasing core thermogenesis.
01:07:55Sure, I might've burned a few more calories,
01:07:57but actually when I look at the data
01:07:59that are coming from specific cooling
01:08:02and how that can so increase in performance
01:08:06if done properly,
01:08:07and then I compare that to the effects
01:08:09of taking some sort of thermogenic compound,
01:08:12whatever it is,
01:08:13some pre-workout or some pill
01:08:14or high levels of caffeine,
01:08:16it's very clear that increasing body temperature
01:08:20prior to working out
01:08:21is the exact wrong thing that one would want to do.
01:08:24You don't want to stay so cold
01:08:25that you can't generate good muscle contractions.
01:08:27You don't want to be like I am coming out of the cold ocean
01:08:31with claws for hands,
01:08:32but one wants to have your body temperature
01:08:35in a range that still allows you
01:08:37to work hard and perform well.
01:08:41Now, in terms of recovery,
01:08:43things like alcohol,
01:08:44we know are vasodilators.
01:08:47So those are going to cause people
01:08:48to drop body temperature.
01:08:50So you might think,
01:08:51oh, well, that sounds great for recovery.
01:08:52And I don't think people should be drinking
01:08:54who have problems with alcohol intake,
01:08:57alcoholics or they're not of drinking age, et cetera.
01:09:00I'm not a drinker,
01:09:01but I do have a good friend
01:09:02who's a quite accomplished athlete
01:09:03who basically drinks a beer or two
01:09:06after his long runs or cycling.
01:09:09And his argument is,
01:09:11well, I'm dumping body heat and I like a beer.
01:09:13And he's probably right.
01:09:14It's probably a really good tool
01:09:16provided you don't have issues with alcohol
01:09:18that would preclude that as a tool
01:09:20or you're not of drinking age.
01:09:22But anything that you ingest after exercise
01:09:25that would increase body temperature
01:09:27is going to impede recovery.
01:09:29Anything that you do that lowers body temperature
01:09:32provided it's in safe ranges
01:09:34is going to accelerate recovery.
01:09:36And that brings us to the whole host of compounds
01:09:39that people take
01:09:40that can increase body temperature.
01:09:43And many people are taking these things
01:09:45in order to increase fat burning
01:09:47and increase metabolism.
01:09:48But in my opinion,
01:09:50it's impeding their ability to perform well.
01:09:53And especially if the performance
01:09:55is something that you're focused on
01:09:56aside from body recomposition,
01:09:59losing fat, building muscle.
01:10:01But even if you're focused
01:10:02on losing fat, building muscle,
01:10:04you have to ask yourself,
01:10:05is the body temperature increase
01:10:07that I'm getting from these compounds
01:10:08really worth it
01:10:09given that it can block
01:10:11or prevent my performance
01:10:13from being as good as it could?
01:10:16In other words,
01:10:17is it worth taking something
01:10:18that makes you feel very energized
01:10:19to go work out,
01:10:20but then you now know
01:10:21that you are stopping earlier
01:10:23and you're performing less well,
01:10:25fewer reps, fewer steps overall,
01:10:27is it worth it?
01:10:28If you had not taken that thing,
01:10:30then you could perform much longer
01:10:33and at much higher capacity.
01:10:36Some of you are probably saying,
01:10:38well, that's ridiculous
01:10:39because when I drink a quadruple espresso
01:10:41and I pop a whatever pre-workout
01:10:43or drink a pre-workout,
01:10:45then I know I can go much further.
01:10:47Ah, that might be true,
01:10:49but the increase in temperature
01:10:51is also costing you
01:10:52on the recovery side.
01:10:53And unless you're doing other things
01:10:55to improve your recovery,
01:10:57and I know many people that are,
01:10:58I don't judge,
01:10:59but many people who are doing those things
01:11:00are also augmenting their recovery
01:11:02through hormone augmentation
01:11:03and other performance enhancing tools,
01:11:07then for the typical person
01:11:08who's not doing that,
01:11:09it's probably shooting yourself in the foot.
01:11:11So let's take a look
01:11:12at what some of those compounds are
01:11:13and what they do
01:11:14and just briefly review
01:11:16whether or not they would be a good
01:11:17or a bad idea to include
01:11:19if your main goals are performance
01:11:21or your main goals
01:11:22are body recomposition or both.
01:11:24So let's just briefly discuss stimulants.
01:11:26This could be caffeine.
01:11:27This could be any other kind of stimulant
01:11:29that are typically in a pre-workout drink
01:11:33or anything that might get you revved up
01:11:35before exercising.
01:11:36This could even be very strong tea.
01:11:38I've mentioned I'm a big consumer of mate.
01:11:40I like yerba mate.
01:11:41I love that stuff.
01:11:43And I also drink caffeine.
01:11:45I drink, I love coffee of various kinds,
01:11:47mushroom coffee, black coffee, espresso, et cetera.
01:11:50I'm a chronic caffeine user.
01:11:52I don't think I'm an addict,
01:11:54but I'm a chronic caffeine user,
01:11:57meaning when I drink caffeine,
01:11:58my heart rate doesn't increase so much
01:12:00that it feels like a shock to my system.
01:12:03Some people are not caffeine adapted
01:12:05or they're very caffeine sensitive.
01:12:07Here's the straightforward rule.
01:12:10Caffeine for somebody
01:12:12who doesn't drink caffeine very much
01:12:14will constrict the blood vessels
01:12:15and will increase retention of body heat.
01:12:18And it's probably a bad idea before exercise.
01:12:21For somebody who's caffeine adapted
01:12:23and is used to drinking caffeine,
01:12:26it won't have that vasoconstriction effect.
01:12:28That's what the data point to
01:12:29because I'm adapted to it.
01:12:31And, but it will cause vasodilation
01:12:34and will allow me to dump body heat.
01:12:36So for me, I use it before I train
01:12:37or do any kind of exercise
01:12:39because I tend to do that early in the day.
01:12:41It won't prevent me from sleeping
01:12:42and it causes vasodilation.
01:12:44And then afterwards,
01:12:45I'm aware that it causes vasoconstriction
01:12:48after the caffeine wears off.
01:12:49So for somebody who drinks
01:12:51two or three or more cups of coffee a day
01:12:54or mate a day,
01:12:55so we're talking intake of anywhere
01:12:56from 100 to 400 milligrams of caffeine.
01:12:59What you want to do is you want to make sure
01:13:02that you would do that before exercise
01:13:05and probably not after exercise.
01:13:08That just makes logical sense
01:13:09given what we know about thermal regulation.
01:13:11And if you're somebody who doesn't drink caffeine,
01:13:14drinking caffeine before a workout
01:13:16is going to be about the worst thing
01:13:18that you could possibly do
01:13:18because it's going to increase core body temperature
01:13:20through its thermogenic effects.
01:13:22And it's going to constrict your blood vessels
01:13:25and make it even harder to dump heat.
01:13:27So I don't suggest that people drink caffeine or not.
01:13:31I just suggest that you think about
01:13:33whether or not your caffeine adapted or not
01:13:35and decide whether or not you want to drink caffeine.
01:13:37In general, you're going to be better
01:13:39not drinking any caffeine
01:13:40than you are drinking caffeine
01:13:42unless you're a heavy caffeine user or abuser,
01:13:45in which case not drinking caffeine
01:13:47is going to give you vicious headaches
01:13:49and it's going to make it very hard to get motivated
01:13:51because you're just not used to it.
01:13:53It takes about three weeks to get used to no caffeine.
01:13:57It's brutal.
01:13:57I've done it before.
01:13:58I've done caffeine fast.
01:13:59I don't know that I ever want to do it again.
01:14:01That's how painful it was.
01:14:03But you get headaches because of the effects
01:14:05on vasodilation and constriction.
01:14:07If you like caffeine, use in moderate amounts
01:14:09and use it before your workouts, not after.
01:14:11If you don't like caffeine
01:14:12or you don't use it very often,
01:14:14stay away from it anywhere close to exercise
01:14:16before or after for that matter.
01:14:18One of the more commonly used compounds
01:14:21that's sold over the counter
01:14:23are non-steroid anti-inflammatories.
01:14:26So things like Tylenol and Advil
01:14:28and other trade names and naproxen sodium,
01:14:30things of that sort.
01:14:30Almost all of those drop body temperature to some extent.
01:14:35And that's why it's often recommended
01:14:38that people take them when they have a fever.
01:14:40Although the whole business
01:14:42of dropping body temperature artificially
01:14:44when you have a fever
01:14:45is itself an interesting discussion
01:14:47whether or not that's the most adaptive
01:14:49or best thing to do.
01:14:50Certainly you don't want fever to go too high.
01:14:52It can be very dangerous, can kill you.
01:14:53But artificially dropping body temperature
01:14:56with these compounds can be tricky.
01:14:59Now, a number of athletes,
01:15:01especially endurance athletes,
01:15:02will rely on these non-steroid anti-inflammatory drugs
01:15:06specifically to keep body temperature lower
01:15:08during long bouts of exertion.
01:15:11This is a little bit of a pharmacologic version
01:15:14of dumping heat instead of using Palmer cooling
01:15:19or face ice pack cooling.
01:15:22They're relying on pharmacology
01:15:24to drop their core body temperature.
01:15:26That has certain obvious advantages.
01:15:29Those advantages should be obvious
01:15:31and the reasons for them should be obvious
01:15:33based on everything we've talked about up until now.
01:15:35Lower temperature allows you to go further harder
01:15:37with more intensity.
01:15:39However, they do have effects on the liver
01:15:42and they can also have effects on the kidneys.
01:15:45And during long bouts of exercise
01:15:46or even short bouts of exercise,
01:15:48water balance and salt balance
01:15:49are also going to be vital to maintain
01:15:52in order to perform well,
01:15:55generate the best muscle contraction,
01:15:57stay mentally alert, and also to stay alive.
01:15:59We will do an episode on salt, electrolytes,
01:16:02and water and water balance.
01:16:04But you probably want to think carefully
01:16:06about whether or not you want to use
01:16:08non-steroid anti-inflammatories
01:16:10before any training session
01:16:12just for the performance augmentation effect,
01:16:15unless you're working carefully with a coach,
01:16:18whether or not you've done that in practices,
01:16:19and of course, whether or not you are in a situation
01:16:24where monitoring your body temperature carefully
01:16:26is going to be important.
01:16:27You might ask, well, when would that be?
01:16:29Well, desert races, summer training in races, winter rides,
01:16:33you certainly don't want to get too cool either.
01:16:36So alcohol, caffeine,
01:16:38and non-steroid anti-inflammatory drugs
01:16:41because of their effects on temperature
01:16:42will impact performance and recovery,
01:16:44but you want to be cautious about how you approach them.
01:16:47I personally am more a fan of using caffeine
01:16:51in moderate doses for the reasons I described before,
01:16:53as well to use the cooling of the palms,
01:16:56cooling of the bottoms of my feet, right?
01:16:59By placing them into a bucket
01:17:01or into a cool bath after training
01:17:04or cooling the face after training
01:17:07or sometimes even during training.
01:17:08It just seems like there's more of a margin
01:17:10to play with the variables,
01:17:11to heat up the water,
01:17:12cool it down a little bit,
01:17:14to include one palm or the other palm.
01:17:17There's just all sorts of good parameter space
01:17:21as we call it in science that you can play with
01:17:23and work with to find what works for you.
01:17:25Whereas when you pop a pill,
01:17:27sure, you can adjust the dose
01:17:29and you can adjust it next time,
01:17:30but once it's in you, it's in you
01:17:32and there's going to be some period of time
01:17:33before you can modulate it.
01:17:35What I've offered today
01:17:37are ways in which you can use temperature
01:17:39to powerfully improve performance.
01:17:42And if you think about it,
01:17:43you can vary that from set to set.
01:17:45You could do your pull-ups or your sprints
01:17:47and then cool your palms
01:17:49and then try and go with colder water the next round
01:17:52or warmer water the next round
01:17:54or do both feet and palms and face.
01:17:56I mean, you can do all sorts of things moment to moment
01:17:58and see what works for you.
01:18:00Again, essentially zero cost or no cost.
01:18:02Whereas when you pop something, you take a pill,
01:18:06you're basically in that regimen
01:18:08for the next hour or two or more.
01:18:10You can always take more,
01:18:11but you can't really take less.
01:18:13You can't really extract it from your body in real time.
01:18:15So it doesn't give you a lot of opportunity
01:18:16to play scientist, which is what I like to do
01:18:19because what I'm always trying to do
01:18:21is trying to dial in the best protocols possible
01:18:23based on the mechanisms and data.
01:18:25And if you can do that moment to moment,
01:18:26that places you in a position of power.
01:18:29Once again, we've covered a lot of material.
01:18:31By now, after seeing this episode
01:18:33or listening to this episode,
01:18:35you should understand a lot
01:18:37about how your body heats and cools itself
01:18:39and the value of that for physical performance.
01:18:42I hope you'll also appreciate
01:18:44that you have tools at your disposal
01:18:45to vastly improve your physical performance.
01:18:49And should you try those,
01:18:51please let us know how it goes.
01:18:52If you decide to do Palmer cooling during your runs
01:18:55or after your runs, during your weight workouts,
01:18:58during your yoga sessions, whatever it is,
01:19:00let us know.
01:19:01Please place that in the comments.
01:19:03I've given you specific protocols and some direction,
01:19:06but I've also left it slightly vague
01:19:08because as I mentioned earlier,
01:19:11I don't know all the environmental conditions.
01:19:12I don't know how hot your yoga studio is
01:19:14or how cool your gym happens to be
01:19:16or your body temperature or time of day.
01:19:19Remember, your temperature will vary
01:19:20according to time of day.
01:19:22We did a whole episode about that related to sleep.
01:19:24Typically, your body temperature is rising early in the day
01:19:27and is coming down as you approach the late evening
01:19:30and late night hours for sleep.
01:19:32In the middle of the night,
01:19:33your temperature is very low at its absolute lowest,
01:19:35something we call the temperature minimum.
01:19:37So we don't know exactly where you're at.
01:19:39You need to take the information that you received today
01:19:42and should you try and incorporate it,
01:19:44try and do it intelligently.
01:19:46Don't cool yourself off so much that you become cryogenic
01:19:50and please don't warm yourself up.
01:19:52In fact, we didn't talk at all about warming yourself up
01:19:55because warming yourself up too much can be quite dangerous.
01:19:59You never, ever, ever want to be hypothermic.
01:20:01That's what your body and your brain are trying to avoid.
01:20:04We talked a little bit about supplements,
01:20:07but not the standard sorts of supplements
01:20:09I usually list off on these episodes.
01:20:11Rather, we talked about caffeine,
01:20:13non-steroid and anti-inflammatories
01:20:15and how those can impact temperature,
01:20:17how alcohol can impact temperature.
01:20:19And I should just mention in closing
01:20:20that every time we eat, we also increase temperature.
01:20:23There's a eating-induced thermogenic effect,
01:20:26but that's a minor one.
01:20:27That's a small one.
01:20:27So you wouldn't worry about eating before training
01:20:30because of its effects on temperature,
01:20:33because it tends to be really minor.
01:20:35Going forward, we're going to talk more about temperature
01:20:38and other ways to improve physical performance
01:20:41and skill learning.
01:20:42We're going to talk about specific ways
01:20:44to accelerate fat loss, to improve muscle growth,
01:20:48to improve suppleness and flexibility.
01:20:52These approaches and mechanisms are anchored deeply
01:20:56in neuroscience and physiology
01:20:58and the relationship between our peripheral organs,
01:21:00which include our skin and our brain
01:21:03and all the organs in between.
01:21:05So it's really a pleasure for me
01:21:07because I'm able to look to the textbook literature
01:21:10that exists and really came out
01:21:12over the last 50 to a hundred years.
01:21:14And unlike a lot of areas of neuroscience,
01:21:16which are still sort of mystical,
01:21:18like consciousness and dreaming,
01:21:19of which we understand a little bit about,
01:21:21these core mechanisms of temperature and physiology,
01:21:24which are so powerful,
01:21:26involve very concrete studies
01:21:28that as you learned today are very actionable.
01:21:32If you're enjoying this podcast
01:21:33and you like the information that you're receiving,
01:21:36if you're incorporating it into your life in useful ways,
01:21:39please recommend the podcast to other people
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01:22:23That's a terrific way to support us.
01:22:25We also have a Patreon.
01:22:26You can find it at patreon.com slash Andrew Huberman.
01:22:30That allows you to support the podcast
01:22:32at any level that you like.
01:22:34Today, we didn't focus so heavily on supplements,
01:22:36but in other episodes I have,
01:22:38and there are certainly supplements
01:22:39that are beneficial for sleep,
01:22:41for performance, for learning,
01:22:44immunity, and so forth.
01:22:45We've partnered with Thorne,
01:22:47T-H-O-R-N-E.com,
01:22:50because Thorne supplements,
01:22:52we believe to be the most stringent
01:22:54in terms of what they put on the bottle
01:22:57is actually what's in the bottle.
01:22:59So the amounts are precise
01:23:00and the quality of the ingredients is very precise.
01:23:02They partner with the Mayo Clinic,
01:23:04all the major sports teams.
01:23:05So we're delighted that we're partnered with Thorne.
01:23:06If you want to see the supplements that I take,
01:23:08you can go to thorne.com slash the letter U slash Huberman,
01:23:13and you can see the supplements that I take.
01:23:15You could get 20% off any of those supplements
01:23:17should you choose to order them,
01:23:19as well as 20% off any other supplements
01:23:21that Thorne happens to make.
01:23:23That's thorne, T-H-O-R-N-E.com
01:23:26slash the letter U slash Huberman
01:23:28to get 20% off any of the supplements that Thorne makes.
01:23:32And last but not least,
01:23:34I want to thank you for your time and attention.
01:23:36I realize this is a lot of information.
01:23:38I hope you'll find some of it to be actionable
01:23:40and useful for you and for people that you know.
01:23:42And as always, thank you for your interest in science.
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