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Welcome to Huberman Lab Essentials, where we revisit past episodes for the where we revisit past episodes for the most potent and actionable science-based most potent and actionable science-based tools for mental health, physical tools for mental health, physical health, and health, and performance. I'm Andrew Huberman, and performance. I'm Andrew Huberman, and I'm a professor of neurobiology and I'm a professor of neurobiology and opthalmology at Stanford School of opthalmology at Stanford School of Medicine. This podcast is separate from Medicine. This podcast is separate from my teaching and research roles at my teaching and research roles at Stamford. It is however part of my Stamford. It is however part of my desire and effort to bring you zero cost desire and effort to bring you zero cost to consumer information about science to consumer information about science and science related tools to the general and science related tools to the general public. We just closed out the episodes public. We just closed out the episodes on hormones. Now we are going to talk on hormones. Now we are going to talk about how to optimize physical about how to optimize physical performance and skill learning. There performance and skill learning. There are so many variables to physical are so many variables to physical performance and we can manage physical performance and we can manage physical performance and skill learning from a performance and skill learning from a variety of contexts. I made just a short variety of contexts. I made just a short list of some of the things that come to list of some of the things that come to mind that can powerfully impact physical mind that can powerfully impact physical performance and skill learning. Some of performance and skill learning. Some of them are what I would consider them are what I would consider foundational. They allow you to show up foundational. They allow you to show up with your current ability. And if you with your current ability. And if you were to disrupt those, you would perform were to disrupt those, you would perform less well. So things like getting a good less well. So things like getting a good night's sleep, things like being night's sleep, things like being properly hydrated, things like being properly hydrated, things like being wellnourished. There are supplements, wellnourished. There are supplements, there are drugs, there are different there are drugs, there are different ways to breathe, there are so many tools ways to breathe, there are so many tools related to mindset, visualization. It's related to mindset, visualization. It's just a vast space, but it's not just a vast space, but it's not infinite. And there are a few things in infinite. And there are a few things in the list of things that can impact and the list of things that can impact and even optimize physical performance and even optimize physical performance and skill learning that have an outsized skill learning that have an outsized effect that any of you can use. So today effect that any of you can use. So today we are going to focus on what I believe we are going to focus on what I believe to be one of the most powerful tools to to be one of the most powerful tools to improve physical performance and skill improve physical performance and skill learning and recovery. We'll talk about learning and recovery. We'll talk about about why that's important and that's about why that's important and that's temperature. Believe it or not, temperature. Believe it or not, temperature is the most powerful temperature is the most powerful variable for improving physical variable for improving physical performance and for recovery. There are
performance and for recovery. There are two aspects to temperature. Of course, two aspects to temperature. Of course, there's heat and there's cold. We are there's heat and there's cold. We are mainly going to focus on cold as a way mainly going to focus on cold as a way to buffer heat. We're going to talk to buffer heat. We're going to talk about cold from the standpoint of about cold from the standpoint of thermal physiology. This is a literature thermal physiology. This is a literature that's rich in scientific information that's rich in scientific information that goes back very deep into the last that goes back very deep into the last century where physiologists and century where physiologists and neuroscientists figured out that there neuroscientists figured out that there are different compartments in your body are different compartments in your body that heat and cool you differently and that heat and cool you differently and that you can leverage those in order to that you can leverage those in order to double even triple or quadruple your double even triple or quadruple your work output both strength repetitions work output both strength repetitions and endurance. So this is not weak sauce and endurance. So this is not weak sauce as they say. This is the stuff that can as they say. This is the stuff that can really shift the needle quite a bit. And really shift the needle quite a bit. And it's not just about performing well it's not just about performing well once. It's about being able to perform once. It's about being able to perform well and recover from that performance well and recover from that performance so that you do even better when you're so that you do even better when you're not incorporating these tools on days not incorporating these tools on days where, for instance, you can't access where, for instance, you can't access cold or an ice pack or an ice bath or cold or an ice pack or an ice bath or things of that sort. Let's start by things of that sort. Let's start by talking about temperature. How does talking about temperature. How does temperature impact the body and its temperature impact the body and its ability to perform, including learn new ability to perform, including learn new skills? So, everyone probably remembers skills? So, everyone probably remembers or has at least heard of the word or has at least heard of the word homeostasis, right? That the body wants homeostasis, right? That the body wants to remain in a particular range of to remain in a particular range of temperatures that it doesn't like to be temperatures that it doesn't like to be too hot or too cold. Heating up too much too hot or too cold. Heating up too much is just plain bad. It's not just bad for is just plain bad. It's not just bad for physical performance, it's bad for all physical performance, it's bad for all tissue health. cells stop functioning. tissue health. cells stop functioning. They stop being able to generate energy. They stop being able to generate energy. They stop being able to digest things. They stop being able to digest things. You stop being able to think and You stop being able to think and eventually those cells start dying off eventually those cells start dying off entirely. Now, you don't want to become entirely. Now, you don't want to become hypothermic either. You can die from hypothermic either. You can die from hypothermia just like you can die from hypothermia just like you can die from hyperothermia. However, that you have a hyperothermia. However, that you have a lot more range to be cold than you do to lot more range to be cold than you do to be too warm. Okay? And in general, the
be too warm. Okay? And in general, the idea is to keep the body and brain in a idea is to keep the body and brain in a particular range. But anytime we do particular range. But anytime we do anything, our body temperature can anything, our body temperature can shift. So for instance, if you were to shift. So for instance, if you were to stand next to a campfire or you were stand next to a campfire or you were outside on a hot day, various things outside on a hot day, various things would happen to dump heat from your would happen to dump heat from your body. Now, what are those things? Well, body. Now, what are those things? Well, there are a huge category of them, but there are a huge category of them, but the simplest way to think about this the simplest way to think about this process is that when we get cold, we process is that when we get cold, we tend to vasoc constrict. We tend to our tend to vasoc constrict. We tend to our blood vessels tend to constrict and we blood vessels tend to constrict and we tend to push energy toward the core of tend to push energy toward the core of our body to preserve our core organs. our body to preserve our core organs. Okay? So, our periphery, our hands and Okay? So, our periphery, our hands and our feet and our toes and our legs our feet and our toes and our legs become colder and our core therefore can become colder and our core therefore can maintain blood to that area and we are maintain blood to that area and we are insulating our core. insulating our core. Conversely, when we heat up, our blood Conversely, when we heat up, our blood vessels vasoddilate. They expand a bit vessels vasoddilate. They expand a bit and more blood flows to our periphery and more blood flows to our periphery and more blood can move throughout the and more blood can move throughout the body generally and we will persspire. We body generally and we will persspire. We will sweat. Water will actually get will sweat. Water will actually get pulled out of the blood to some extent pulled out of the blood to some extent moved up through sweat glands and will moved up through sweat glands and will be brought to the skin surface so that be brought to the skin surface so that it can be dumped. We are dumping heat. it can be dumped. We are dumping heat. So it's very important that if you want So it's very important that if you want to understand how you can leverage to understand how you can leverage temperature for physical performance, temperature for physical performance, you have to understand that you have you have to understand that you have vasoc constriction to conserve heat, vasoc constriction to conserve heat, vasoddilation to dump heat, that you vasoddilation to dump heat, that you have sweating to dump heat and you have have sweating to dump heat and you have conservation of fluids in order to conservation of fluids in order to preserve preserve heat. That's the most important thing in heat. That's the most important thing in terms of understanding the mechanisms of terms of understanding the mechanisms of maintaining and dumping heat. And now maintaining and dumping heat. And now the most important thing to understand the most important thing to understand is that if you get too hot, your ability is that if you get too hot, your ability to contract your muscles stops. Okay, to contract your muscles stops. Okay, I'm going to repeat this because it's I'm going to repeat this because it's vitally important. vitally important. ATP is involved in the process of ATP is involved in the process of generating muscle contractions. The generating muscle contractions. The range of temperatures within which ATP
range of temperatures within which ATP can function and muscles can contract is can function and muscles can contract is very narrow. somewhere around 39 or 40° very narrow. somewhere around 39 or 40° C, it drops off and you will not be able C, it drops off and you will not be able to generate more contractions. Now, it's to generate more contractions. Now, it's pretty hot, but it can that temperature pretty hot, but it can that temperature can be generated locally really fast. can be generated locally really fast. Put simply, if you get too hot, you stop Put simply, if you get too hot, you stop exercising. You may not even realize it, exercising. You may not even realize it, but your will to exercise further. Your but your will to exercise further. Your ability to push harder is entirely ability to push harder is entirely dependent on the heat of the muscle, dependent on the heat of the muscle, both locally and your whole system. If both locally and your whole system. If you can keep temperature in range, you can keep temperature in range, however, in a proper range, you will be however, in a proper range, you will be able to do more work, you will be able able to do more work, you will be able to create greater output. You'll be able to create greater output. You'll be able to lift more weight, more sets, more to lift more weight, more sets, more reps, and you'll be able to run further. reps, and you'll be able to run further. Now, there are data that I'm going to Now, there are data that I'm going to talk about in a little bit that are talk about in a little bit that are absolutely striking that underscore that absolutely striking that underscore that statement. They are data from my statement. They are data from my colleague Craig Heler's lab in the colleague Craig Heler's lab in the department of biology at Stanford. Many department of biology at Stanford. Many if not all the NFL teams are now using if not all the NFL teams are now using this technology as well as military uses this technology as well as military uses it and not just for sports performance it and not just for sports performance but also firefighters, construction but also firefighters, construction workers, other professions where workers, other professions where elevated heat becomes a barrier to elevated heat becomes a barrier to performance and you can leverage this to performance and you can leverage this to really improve your workouts. So how do really improve your workouts. So how do you dump heat in order to perform longer you dump heat in order to perform longer safely? Well, in order to understand safely? Well, in order to understand that, you have to understand that the that, you have to understand that the body has three main compartments for body has three main compartments for regulating temperature. Okay? We don't regulating temperature. Okay? We don't just have a center and a periphery. We just have a center and a periphery. We have three main compartments. And have three main compartments. And there's one compartment in particular there's one compartment in particular that all of you or most all of you, I that all of you or most all of you, I have to assume, have to assume, have you can understand how that works, have you can understand how that works, you can do tremendous things for your you can do tremendous things for your performance and for your recovery. One performance and for your recovery. One is your core. We already talked about is your core. We already talked about that. your core organs, your heart, your that. your core organs, your heart, your lungs, your your pancreas, your liver, lungs, your your pancreas, your liver, the core of your body. The other is your the core of your body. The other is your periphery, which are obviously your arms
periphery, which are obviously your arms and your legs and your feet and your and your legs and your feet and your hands. But then there's a third hands. But then there's a third component, which is there are three component, which is there are three locations on your body that are far locations on your body that are far better at passing heat out of the body better at passing heat out of the body and bringing cool into the body such and bringing cool into the body such that you can heat up or cool your body that you can heat up or cool your body everywhere. very quickly. Those three everywhere. very quickly. Those three areas are your face, the palms of your areas are your face, the palms of your hands, and the bottoms of your feet. hands, and the bottoms of your feet. Now, the skin on your hands and on the Now, the skin on your hands and on the bottoms of your feet and to some extent bottoms of your feet and to some extent on your face are called glaborous skin. on your face are called glaborous skin. That's G L A B O R O U S. Glaborous That's G L A B O R O U S. Glaborous skin. And what's special about those skin. And what's special about those areas of your body and the glabberous areas of your body and the glabberous skin is that the arrangement of vascule skin is that the arrangement of vascule of blood vessels, capillaries, and of blood vessels, capillaries, and arteries that serve those regions is arteries that serve those regions is very different than it is elsewhere in very different than it is elsewhere in your body. In these three regions of your body. In these three regions of your hands, your face, and the bottoms your hands, your face, and the bottoms of your feet, we have what are called of your feet, we have what are called AVAs. AVAs are a very special pattern of AVAs. AVAs are a very special pattern of vascule. AVAs are arteriovenenous vascule. AVAs are arteriovenenous aimosis. A r t e r i o arterio venus. V aimosis. A r t e r i o arterio venus. V e n o u s e n o u s arteriovenenous anastimosis. A n a s t o arteriovenenous anastimosis. A n a s t o m o ses. Arteriovenus aimosis. Okay, you m o ses. Arteriovenus aimosis. Okay, you want to know about arteriovenous want to know about arteriovenous aimosis. Trust me. AVAs are direct aimosis. Trust me. AVAs are direct connections between the small arteries connections between the small arteries and the small veins. They bypass the and the small veins. They bypass the capillaries to some extent. They are capillaries to some extent. They are little short vessel segments. They have little short vessel segments. They have a big large inner diameter and they have a big large inner diameter and they have this very thick muscular wall and they this very thick muscular wall and they get input from what are called adinuric get input from what are called adinuric neurons. They get input from neurons neurons. They get input from neurons that release norepinephrine and
that release norepinephrine and epinephrine which allows them to epinephrine which allows them to contract or dilate. Now, there's some contract or dilate. Now, there's some rules of physics that talk about how the rules of physics that talk about how the radius of a pipe and small changes in radius of a pipe and small changes in the radius of a pipe leads to massive the radius of a pipe leads to massive increases in the rate and amount of increases in the rate and amount of stuff that can flow through that pipe. stuff that can flow through that pipe. Okay, it's a rule of physics that says Okay, it's a rule of physics that says essentially that uh the radius is uh essentially that uh the radius is uh proportional to the amount of stuff that proportional to the amount of stuff that can flow through something to the fourth can flow through something to the fourth power. What you need to know, even if power. What you need to know, even if you don't want to know any of the you don't want to know any of the underlying physics, is that these AVAs underlying physics, is that these AVAs allow more heat to leave the body more allow more heat to leave the body more quickly and more cool to enter the body quickly and more cool to enter the body more quickly more quickly than other venous arterial capillary than other venous arterial capillary beds throughout the body. In other beds throughout the body. In other words, you can heat up best at the face, words, you can heat up best at the face, the palms, and the bottoms of the feet. the palms, and the bottoms of the feet. And you can cool down best at the face, And you can cool down best at the face, the palms, and the bottoms of the feet the palms, and the bottoms of the feet than you can anywhere else on your body. than you can anywhere else on your body. These three compartments of your body, These three compartments of your body, palms, bottoms of the feet, and face are palms, bottoms of the feet, and face are your best leverage points for your best leverage points for manipulating temperature to vastly manipulating temperature to vastly improve physical performance. So, what improve physical performance. So, what Craig and his colleagues did really Craig and his colleagues did really illustrates perfectly what these body illustrates perfectly what these body surfaces can do and surfaces can do and why. They were studying overheating in why. They were studying overheating in athletes and in military and in athletes and in military and in construction workers and trying to construction workers and trying to prevent it. What they essentially found prevent it. What they essentially found was that cooling the palms palmer was that cooling the palms palmer cooling allowed people, athletes and cooling allowed people, athletes and recreational athletes to run much recreational athletes to run much further to lift more weight and to do further to lift more weight and to do more sets and reps to a absolutely more sets and reps to a absolutely staggering degree. staggering degree. Let's talk for a second a bit more about Let's talk for a second a bit more about why we stop, why we shut off effort when why we stop, why we shut off effort when we get too hot. When muscle heats
we get too hot. When muscle heats up, enzymes start getting disrupted and up, enzymes start getting disrupted and ATP and muscles can't work so well and ATP and muscles can't work so well and those muscles can't contract. The enzyme those muscles can't contract. The enzyme that's involved here is something called that's involved here is something called pyuvate kinase. And pyuvate pyuvate kinase. And pyuvate kinase is essentially a rate limiting kinase is essentially a rate limiting step. It's a critical step that you step. It's a critical step that you can't bypass if you want muscles to can't bypass if you want muscles to contract. And it's very temperature contract. And it's very temperature sensitive. Therefore, if you can keep sensitive. Therefore, if you can keep temperature lower, you can do more work temperature lower, you can do more work per unit time. You can do more pull-ups. per unit time. You can do more pull-ups. What they essentially did is they What they essentially did is they brought someone into their laboratory brought someone into their laboratory who could do 10 pull-ups on the first who could do 10 pull-ups on the first set and they were able to get 10 rest set and they were able to get 10 rest two or three minutes get another 10 rest two or three minutes get another 10 rest two or three minutes and if you've ever two or three minutes and if you've ever tried this what you find is that you tried this what you find is that you start dropping to 8 7 6 etc. Now the start dropping to 8 7 6 etc. Now the person might not necessarily feel o like person might not necessarily feel o like they're overheating but the muscle is they're overheating but the muscle is heating up. Then with their knowledge heating up. Then with their knowledge that these AVAs that these that these that these AVAs that these that these portals in the palms are a great way to portals in the palms are a great way to both heat the body but also to dump heat both heat the body but also to dump heat from the body. They used a device and from the body. They used a device and I'll talk about what you can do at home I'll talk about what you can do at home but a device where they had people hold but a device where they had people hold on to what was essentially a cold tube. on to what was essentially a cold tube. Now this is crucial. The tube can't be Now this is crucial. The tube can't be so cold that it causes vasoc so cold that it causes vasoc constriction because then the cold won't constriction because then the cold won't pass from the tube to the hand and to pass from the tube to the hand and to the the core. But if it's the right temperature, core. But if it's the right temperature, it's neither too hot nor too cold. That it's neither too hot nor too cold. That cool from the cold tube passes into the cool from the cold tube passes into the hand, these so-called palmer regions, hand, these so-called palmer regions, and then cools the core. And in theory, and then cools the core. And in theory, by lowering body temperature would allow by lowering body temperature would allow the person or the athlete to do more the person or the athlete to do more work. And indeed, that's what they work. And indeed, that's what they saw. The actual data, the specific data saw. The actual data, the specific data showed that subjects could do, at least
showed that subjects could do, at least the subjects they worked with, on their the subjects they worked with, on their first day with no cooling, about a 100 first day with no cooling, about a 100 pull-ups across the the the very the pull-ups across the the the very the time frame that they had. Then they came time frame that they had. Then they came back and did the cooling. They did it back and did the cooling. They did it the very next day, which if you've ever the very next day, which if you've ever trained a muscle the very next day, trained a muscle the very next day, typically you wouldn't do as well in its typically you wouldn't do as well in its training if it took any damage from the training if it took any damage from the previous sessions or you at least do as previous sessions or you at least do as well, but you probably wouldn't do what well, but you probably wouldn't do what they then observed, which was they they then observed, which was they started cooling after every other set. started cooling after every other set. The person would just hold the cold The person would just hold the cold tube, cool down the body after every tube, cool down the body after every other set, rest. Everything else was other set, rest. Everything else was kept the same. And they found that they kept the same. And they found that they went to 180 pull-ups, which is went to 180 pull-ups, which is incredible. It's a near doubling. Now, incredible. It's a near doubling. Now, you may be you may be asking, what about endurance? With asking, what about endurance? With endurance, similar increases have been endurance, similar increases have been shown. And the way that they would do shown. And the way that they would do those tests are a little bit different. those tests are a little bit different. And they also point to a really And they also point to a really important mechanism of why we stop doing important mechanism of why we stop doing work at all when we perceive that we are work at all when we perceive that we are putting in too much effort. So, it gets putting in too much effort. So, it gets right to the heart of the relationship right to the heart of the relationship between temperature in muscles and your between temperature in muscles and your willpower. Those are directly related. willpower. Those are directly related. Your body heat and your willpower are Your body heat and your willpower are linked in a physiological way. Okay. So, linked in a physiological way. Okay. So, let's talk about willpower and heat and let's talk about willpower and heat and how heat shuts you down. In other words, how heat shuts you down. In other words, if you are cool, if your body if you are cool, if your body temperature is in a particular range, temperature is in a particular range, not only can you go further, but you not only can you go further, but you will go further if you want will go further if you want to. Said differently, if you heat up too to. Said differently, if you heat up too much, you will stop or you will die. much, you will stop or you will die. But there's a But there's a reflex that relates the body to the reflex that relates the body to the brain and the brain to the body that brain and the brain to the body that shuts off our effort when we get too shuts off our effort when we get too hot. So what Craig and his colleagues hot. So what Craig and his colleagues and now others have done is to do a test and now others have done is to do a test in the laboratory where rather than ask in the laboratory where rather than ask people to run outside until they people to run outside until they absolutely don't want to run anymore, absolutely don't want to run anymore, you put them on a treadmill and you set you put them on a treadmill and you set the speed. Okay? So they have to keep up
the speed. Okay? So they have to keep up with the treadmill and at some point with the treadmill and at some point they they quit and you take groups and you do quit and you take groups and you do those in different temperature those in different temperature environments. So some people are running environments. So some people are running in a nice chilly laboratory. They get in a nice chilly laboratory. They get their heart rate up. So they get into a their heart rate up. So they get into a steady state cadence or rhythm and their steady state cadence or rhythm and their heart is beating at more or less a heart is beating at more or less a steady state. People will continue at steady state. People will continue at that temperature and at that heart rate that temperature and at that heart rate unless you start turning up the unless you start turning up the temperature in the room and at some temperature in the room and at some point they will stop and they'll stop point they will stop and they'll stop much earlier when it gets hot because of much earlier when it gets hot because of something called cardiac drift. Okay, so something called cardiac drift. Okay, so let's say I'm running and I'm running at let's say I'm running and I'm running at a steady cadence on this treadmill and a steady cadence on this treadmill and my heart rate is 85 beats per minute or my heart rate is 85 beats per minute or 100 beats per minute, doesn't matter. 100 beats per minute, doesn't matter. Let's say 100 just for sake of example. Let's say 100 just for sake of example. Well, just making the room hotter is Well, just making the room hotter is going to increase my heart rate further going to increase my heart rate further even though I'm at the same output. And even though I'm at the same output. And the brain does a computation. It somehow the brain does a computation. It somehow figures out that there's a heat figures out that there's a heat component that's increasing heart rate component that's increasing heart rate and there's an effort component from and there's an effort component from running that's driving heart rate. And running that's driving heart rate. And if the heat component and the and the if the heat component and the and the heart rate output from the effort get to heart rate output from the effort get to hit a certain threshold, I stop. hit a certain threshold, I stop. Increasing Increasing temperature increases the rate of temperature increases the rate of quitting in part, not entirely, but in quitting in part, not entirely, but in part because of this thing called part because of this thing called cardiac drift. Heat increases heart cardiac drift. Heat increases heart rate. Effort increases heart rate. At a rate. Effort increases heart rate. At a steady effort, you'll have a steady steady effort, you'll have a steady heart rate. If you increase the heat in heart rate. If you increase the heat in the environment that you're engaging in the environment that you're engaging in that steady heart rate, your heart rate that steady heart rate, your heart rate will now go up due to cardiac drift and will now go up due to cardiac drift and you will quit. Okay. So Heler and you will quit. Okay. So Heler and colleagues have done experiments where colleagues have done experiments where they do Palmer cooling under these they do Palmer cooling under these environments. And that's wonderful environments. And that's wonderful because not only does it enable people because not only does it enable people to go further and to go further and faster for much longer, that's been faster for much longer, that's been shown statistically significant every
shown statistically significant every time. But it also protects the brain and time. But it also protects the brain and body against hypothermia, overheating, body against hypothermia, overheating, coma, nerve injury, nerve death, and coma, nerve injury, nerve death, and actual death. Okay. So, you can see why actual death. Okay. So, you can see why this is such a a valuable tool. So, how this is such a a valuable tool. So, how can you start to incorporate this? Well, can you start to incorporate this? Well, first of first of all, I always get asked, how cold should all, I always get asked, how cold should the water be? Should it be ice water? the water be? Should it be ice water? Should it be very cold water? The answer Should it be very cold water? The answer is is no. If you want to experience some of no. If you want to experience some of this effect without a device, one thing this effect without a device, one thing you could do would be, for instance, to you could do would be, for instance, to do, I don't know, I'll use the the the do, I don't know, I'll use the the the gym or the treadmill as an example. You gym or the treadmill as an example. You could do your maximum number of could do your maximum number of pull-ups, stop, and then you could pull-ups, stop, and then you could actually put your hands into or on the actually put your hands into or on the surface of a sink that is presumably surface of a sink that is presumably stopped up with cool water. So, not ice stopped up with cool water. So, not ice water, not freezing cold, but cool water, not freezing cold, but cool water. Slightly cooler than body water. Slightly cooler than body temperature before you started training temperature before you started training would be a good place to start. You do would be a good place to start. You do that for 10 to 30 seconds. that for 10 to 30 seconds. Then you could go back and do your next Then you could go back and do your next set. You would repeat the cooling. You set. You would repeat the cooling. You would want to extend the amount of would want to extend the amount of cooling somewhat. So you might want to cooling somewhat. So you might want to do that for 30 seconds to a minute. This do that for 30 seconds to a minute. This is not going to be perfect. You're going is not going to be perfect. You're going to have to play with how cold to make it to have to play with how cold to make it in order to get the optimal effect. But in order to get the optimal effect. But you ought to see an effect nonetheless. you ought to see an effect nonetheless. The same is true if you're running and The same is true if you're running and you're fatiguing. Obviously, you don't you're fatiguing. Obviously, you don't want to become hypothermic. Cooling the want to become hypothermic. Cooling the hands or the bottoms of your feet or the hands or the bottoms of your feet or the face would be the ideal way to dump heat face would be the ideal way to dump heat in order to be able to generate more in order to be able to generate more output. Now, the face is something that output. Now, the face is something that we haven't talked a lot about. we haven't talked a lot about. Everything I've told you up until now Everything I've told you up until now also says that if you are somebody who also says that if you are somebody who tends to get cold when you are outside, tends to get cold when you are outside, say in the winter or even in the fall, say in the winter or even in the fall, you tend to run cold, warming your face you tend to run cold, warming your face is going to be the most important thing is going to be the most important thing that you can do. Now you understand the that you can do. Now you understand the principle and the locations at which to principle and the locations at which to deliver heat and cold. So let's say that
deliver heat and cold. So let's say that you are out for a run and you want to you are out for a run and you want to incorporate this cooling mechanism. I incorporate this cooling mechanism. I talked to Craig about this. I said, talked to Craig about this. I said, "What would be the kind of uh uh poor "What would be the kind of uh uh poor person's approach to this one?" He said, person's approach to this one?" He said, "Well, you you could take a uh a frozen "Well, you you could take a uh a frozen uh juice can if you have one of those or uh juice can if you have one of those or a very cold can of soda and you would a very cold can of soda and you would want to pass it back and forth between want to pass it back and forth between your two hands. The reason the passing your two hands. The reason the passing back and forth is really important is back and forth is really important is because you again you don't want to be because you again you don't want to be so cold that you constrict those venous so cold that you constrict those venous portals that will allow cold to go into portals that will allow cold to go into the body. Now there are certainly people the body. Now there are certainly people that are working on bike handles and that are working on bike handles and that can actually cool the hands. Here's that can actually cool the hands. Here's what you don't want to do. You don't what you don't want to do. You don't want to cool the core if you want to want to cool the core if you want to cool the body. Right? If it's a very hot cool the body. Right? If it's a very hot day and you're going to train, getting day and you're going to train, getting into an ice bath first, sure, it will it into an ice bath first, sure, it will it will cool you down, but that's not going will cool you down, but that's not going to be as effective as cooling the palms, to be as effective as cooling the palms, the bottoms of the feet, and the face. the bottoms of the feet, and the face. The one that I've tried because in The one that I've tried because in anticipation of this episode was the anticipation of this episode was the dips where then I would cool my hands. I dips where then I would cool my hands. I actually decided to cool the bottoms of actually decided to cool the bottoms of my feet as well because it just feels my feet as well because it just feels good and it's particularly hot out good and it's particularly hot out lately. So, no shoes or socks on. Put my lately. So, no shoes or socks on. Put my feet into uh the bottoms of my feet just feet into uh the bottoms of my feet just kind of hovering about a centimeter or kind of hovering about a centimeter or two below the surface of a bucket of two below the surface of a bucket of water that was just slightly it felt water that was just slightly it felt cool, slightly cooler than um body cool, slightly cooler than um body temperature um or so. Just basically temperature um or so. Just basically what came out of the spigot after I let what came out of the spigot after I let it run for a little bit. And indeed, I it run for a little bit. And indeed, I saw a 60% increase in the number of dips saw a 60% increase in the number of dips I can do in a single session. So, it's I can do in a single session. So, it's actually a quite significant effect. And actually a quite significant effect. And you don't have to be perfectly precise you don't have to be perfectly precise in order to do it. So, up until now, in order to do it. So, up until now, we've been talking about how to use cold we've been talking about how to use cold during a workout in order to improve during a workout in order to improve performance. Now, I want to talk about performance. Now, I want to talk about the use of temperature, in particular, the use of temperature, in particular, cold, to improve the speed and the depth cold, to improve the speed and the depth of recovery. Recovery is obviously of recovery. Recovery is obviously vital, right? During a weight training
vital, right? During a weight training session or during an endurance session, session or during an endurance session, that's just the stimulus for getting that's just the stimulus for getting better the next time. And if you don't better the next time. And if you don't recover, you not only won't get better, recover, you not only won't get better, but you'll get worse. but you'll get worse. There's a lot of interest in the use of There's a lot of interest in the use of cold in order to improve recovery in the cold in order to improve recovery in the short term. We see this and probably the short term. We see this and probably the best example of this would be fighters best example of this would be fighters in combat sports between rounds or in combat sports between rounds or athletes during uh in between quarters athletes during uh in between quarters or halftime. That's one form of or halftime. That's one form of recovery. the ability to go back into recovery. the ability to go back into the sport very soon on an order of the sport very soon on an order of minutes anywhere from like one minute in minutes anywhere from like one minute in between rounds in typical combat sports between rounds in typical combat sports or several minutes and a halftime etc. or several minutes and a halftime etc. And then of course there's recovery that And then of course there's recovery that occurs from session to session. So occurs from session to session. So outside of the game or the match or the outside of the game or the match or the or the exercise um session and many or the exercise um session and many people are now relying on things like people are now relying on things like cryotherapy which requires a lot of cryotherapy which requires a lot of expensive equipment big you know um expensive equipment big you know um liquid nitrogen driven uh machine that liquid nitrogen driven uh machine that those aren't so common for most people those aren't so common for most people or accessible for most people but a lot or accessible for most people but a lot of people are using cold baths or ice of people are using cold baths or ice baths or cold showers and again that's baths or cold showers and again that's not going to optimize recovery. In fact, not going to optimize recovery. In fact, it's going to have an additional effect it's going to have an additional effect that is going to potentially block the that is going to potentially block the training stimulus. When you get into an training stimulus. When you get into an ice bath, you are indeed blocking some ice bath, you are indeed blocking some of the inflammation that occurs because of the inflammation that occurs because of the training session. But in doing of the training session. But in doing so, you also are blocking pathways such so, you also are blocking pathways such as mTor, mamalian targeted rapamyosin, as mTor, mamalian targeted rapamyosin, which are involved in the adaptation for which are involved in the adaptation for a muscle to become stronger or bigger. a muscle to become stronger or bigger. Put simply, covering the body in cold or Put simply, covering the body in cold or immersing the body in cold after immersing the body in cold after training can short circuit or prevent training can short circuit or prevent the hypertrophy or muscle growth the hypertrophy or muscle growth response. It has other effects that can response. It has other effects that can be positive, right? It can induce be positive, right? It can induce thermogenesis, etc. It can reduce thermogenesis, etc. It can reduce inflammation, but it can prevent some of inflammation, but it can prevent some of the positive effects of exercise. Now, the positive effects of exercise. Now, it hasn't been examined so much for
it hasn't been examined so much for endurance work, but let's say you come endurance work, but let's say you come back from a round of endurance work, a back from a round of endurance work, a run or a bike or a swim. Getting into a run or a bike or a swim. Getting into a cool bath or cooling the the palms, the cool bath or cooling the the palms, the bottoms of the feet or the face, in my bottoms of the feet or the face, in my opinion, based on the science, would be opinion, based on the science, would be better than completely immersing the better than completely immersing the body in the ice bath. If you can cool body in the ice bath. If you can cool the body back to its resting temperature the body back to its resting temperature for a and rest by resting temperature I for a and rest by resting temperature I mean within the range that you would see mean within the range that you would see at any time of waking day but not in at any time of waking day but not in exercise. If you can do that the sooner exercise. If you can do that the sooner you can do that after a workout the you can do that after a workout the sooner that the muscle will recover that sooner that the muscle will recover that the tendons will recover and that the the tendons will recover and that the person you can get back into more person you can get back into more endurance training more weight training endurance training more weight training etc. So cold actually can be a very etc. So cold actually can be a very powerful tool for recovery. But to powerful tool for recovery. But to maximize return to baseline levels of maximize return to baseline levels of temperature, just simply cooling the temperature, just simply cooling the entire body by jumping into an ice bath entire body by jumping into an ice bath or a cold shower is not the best way to or a cold shower is not the best way to go. You really want to rely on one of go. You really want to rely on one of these three glaborous skin portals of these three glaborous skin portals of the palms, the bottoms of the feet, or the palms, the bottoms of the feet, or the face. One of the more commonly used the face. One of the more commonly used compounds that's sold over the counter compounds that's sold over the counter are non-steroid anti-inflammatories. So are non-steroid anti-inflammatories. So things like Tylenol and Advil and other things like Tylenol and Advil and other trade names and neproxin sodium, things trade names and neproxin sodium, things of that sort. Almost all of those drop of that sort. Almost all of those drop body temperature to some extent. And body temperature to some extent. And that's why it's often recommended that that's why it's often recommended that people take them when they have a fever. people take them when they have a fever. Now, a number of athletes, especially Now, a number of athletes, especially endurance athletes, will rely on these endurance athletes, will rely on these non-steroid anti-inflammatory drugs non-steroid anti-inflammatory drugs specifically to keep body temperature specifically to keep body temperature lower during long bouts of exertion. lower during long bouts of exertion. This is a little bit of a pharmacologic This is a little bit of a pharmacologic version of dumping heat instead of using version of dumping heat instead of using Palmer cooling um or you know face ice Palmer cooling um or you know face ice pack cooling. They're relying on pack cooling. They're relying on pharmacology to drop their core body pharmacology to drop their core body temperature. That has certain obvious temperature. That has certain obvious advantages. Lower temperature allows you advantages. Lower temperature allows you to go further harder with more to go further harder with more intensity. intensity. However, they do have effects on the
However, they do have effects on the liver and they can also have effects on liver and they can also have effects on the kidneys. And during long bouts of the kidneys. And during long bouts of exercise or even short bouts of exercise or even short bouts of exercise, water balance and salt balance exercise, water balance and salt balance are also going to be vital to maintain are also going to be vital to maintain in order to perform well, generate the in order to perform well, generate the best muscle contraction, stay mentally best muscle contraction, stay mentally alert, and also to stay alive. you alert, and also to stay alive. you probably want to think carefully about probably want to think carefully about whether or not you want to use whether or not you want to use non-steroid anti-inflammatories before non-steroid anti-inflammatories before any training session just for the any training session just for the performance augmentation effect unless performance augmentation effect unless you're working carefully with a coach. I you're working carefully with a coach. I personally am more a fan of cooling of personally am more a fan of cooling of the palms, cooling of the of the bottoms the palms, cooling of the of the bottoms of my feet, right? Uh by placing them of my feet, right? Uh by placing them into a bucket or uh into a cool bath into a bucket or uh into a cool bath after after training or cooling the face after after training or cooling the face after training or sometimes even during after training or sometimes even during training. It just seems like there's training. It just seems like there's more of a margin to play with the more of a margin to play with the variables to heat up the water or cool variables to heat up the water or cool it down a little bit. Um to include one it down a little bit. Um to include one palm or the other palm. There's just all palm or the other palm. There's just all sorts of uh good parameter space as we sorts of uh good parameter space as we call it in science that you can play call it in science that you can play with and work with to find what works with and work with to find what works for you. Whereas whereas when you pop a for you. Whereas whereas when you pop a pill, sure you can adjust the dose and pill, sure you can adjust the dose and you can adjust it next time, but once you can adjust it next time, but once it's in you, it's in you and there's it's in you, it's in you and there's going to be some period of time before going to be some period of time before you can modulate it. So it doesn't give you can modulate it. So it doesn't give you a lot of opportunity to play you a lot of opportunity to play scientist, which is what I like to do scientist, which is what I like to do because what I've always trying to do is because what I've always trying to do is trying to dial in the the best protocols trying to dial in the the best protocols possible based on the mechanisms and possible based on the mechanisms and data. And if you can do that moment to data. And if you can do that moment to moment, that places you in a position of moment, that places you in a position of power. Once again, we've covered a lot power. Once again, we've covered a lot of material. By now, after seeing this of material. By now, after seeing this episode or listening to this episode, episode or listening to this episode, you should understand a lot about how you should understand a lot about how your body heats and cools itself and the your body heats and cools itself and the value of that for physical performance. value of that for physical performance. I hope you'll also appreciate that you I hope you'll also appreciate that you have tools at your disposal to vastly have tools at your disposal to vastly improve your physical performance. I've improve your physical performance. I've given you specific protocols and some given you specific protocols and some direction, but I've also left it direction, but I've also left it slightly vague because, as I mentioned slightly vague because, as I mentioned earlier, I don't know all the earlier, I don't know all the environmental conditions. I don't know environmental conditions. I don't know how hot your yoga studio is or how cool how hot your yoga studio is or how cool your gym happens to be or your body
your gym happens to be or your body temperature or time of day. Remember, temperature or time of day. Remember, your temperature will vary according to your temperature will vary according to time of day. Going forward, we're going time of day. Going forward, we're going to talk more about temperature and other to talk more about temperature and other ways to improve physical performance and ways to improve physical performance and skill learning. We're going to talk skill learning. We're going to talk about specific ways to accelerate fat about specific ways to accelerate fat loss, to improve muscle growth, to loss, to improve muscle growth, to improve suppleness and improve suppleness and flexibility. These approaches and flexibility. These approaches and mechanisms are anchored deeply in mechanisms are anchored deeply in neuroscience and physiology and the neuroscience and physiology and the relationship between our peripheral relationship between our peripheral organs, which include our skin, and our organs, which include our skin, and our brain and all the organs in between. And brain and all the organs in between. And last but not least, I want to thank you last but not least, I want to thank you for your time and attention. I realize for your time and attention. I realize this is a lot of information. I hope this is a lot of information. I hope you'll find some of it to be actionable you'll find some of it to be actionable and useful for you and for people that and useful for you and for people that you know. And as always, thank you for you know. And as always, thank you for your interest in science.