Essentials: Supercharge Exercise Performance & Recovery with Cooling

**Andrew Huberman** (0:00)
Welcome to Huberman Lab Essentials, where we revisit past episodes for the most potent and actionable science-based tools for mental health, physical health and performance.
I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. This podcast is separate from my teaching and research roles at Stanford. It is however, part of my desire and effort to bring you zero cost to consumer information about science and science related tools to the general public. We just closed out the episodes on hormones. Now we are going to talk about how to optimize physical performance and skill learning. There are so many variables to physical performance, and we can manage physical performance and skill learning from a variety of contexts. I made just a short list of some of the things that come to mind that can powerfully impact physical performance and skill learning. Some of them are what I would consider foundational. They allow you to show up with your current ability. And if you were to disrupt those, you would perform less well. So things like getting a good night's sleep, things like being properly hydrated, things like being well nourished. There are supplements, there are drugs, there are different ways to breathe. There are so many tools related to mindset visualization. It's just a vast space, but it's not infinite. And there are a few things in the list of things that can impact and even optimize physical performance and skill learning that have an outsized effect that any of you can use. So today we are going to focus on what I believe to be one of the most powerful tools to improve physical performance and skill learning and recovery. We'll talk about why that's important. And that's temperature. Believe it or not, temperature is the most powerful variable for improving physical performance and for recovery. There are two aspects to temperature, of course. There's heat and there's cold. We are mainly going to focus on cold as a way to buffer heat. We're going to talk about cold from the standpoint of thermal physiology. This is a literature that's rich in scientific information that goes back very deep into the last century where physiologists and neuroscientists figured out that there are different compartments in your body that heat and cool you differently and that you can leverage those in order to double, even triple or quadruple your work output, both strength, repetitions and endurance. So this is not weak sauce, as they say, this is the stuff that can really shift the needle quite a bit. And it's not just about performing well once, it's about being able to perform well and recover from that performance so that you do even better when you're not incorporating these tools on days where, for instance, you can't access cold or an ice pack or an ice bath or things of that sort. I'd like to take a quick break and acknowledge our sponsor, AG1. AG1 is a vitamin mineral probiotic drink that also includes prebiotics and adaptogens. As somebody who's been involved in research science for almost three decades and in health and fitness for equally as long, I'm constantly looking for the best tools to improve my mental health, physical health and performance. I discovered AG1 way back in 2012, long before I ever had a podcast or even knew what a podcast was, and I've been taking it every day since. I find that AG1 greatly improves all aspects of my health. I simply feel much better when I take it. AG1 uses the highest quality ingredients in the right combinations and they're constantly improving their formulas without increasing the cost. Whenever I'm asked if I could take just one supplement, what would that supplement be? I always say AG1. If you'd like to try AG1, you can go to drinkag1.com/huberman to claim a special offer. Right now they're giving away five free travel packs plus a year supply of vitamin D3 K2. Again that's drinkag1.com/huberman to claim that special offer. Let's start by talking about temperature. How does temperature impact the body and its ability to perform, including learn new skills? So everyone probably remembers or has at least heard of the word homeostasis, right? That the body wants to remain in a particular range of temperatures, that it doesn't like to be too hot or too cold. Heating up too much is just plain bad. It's not just bad for physical performance, it's bad for all tissue health. Cells stop functioning, they stop being able to generate energy, they stop being able to digest things, you stop being able to think, and eventually those cells start dying off entirely. Now, you don't want to become hypothermic either. You can die from hypothermia just like you can die from hyperthermia. However, that you have a lot more range to be cold than you do to be too warm, okay? And in general, the idea is to keep the body and brain in a particular range, but anytime we do anything, our body temperature can shift. So for instance, if you were to stand next to a campfire or you were outside on a hot day, various things would happen to dump heat from your body. Now, what are those things? Well, there are a huge category of them, but the simplest way to think about this process is that when we get cold, we tend to vasoconstrict. Our blood vessels tend to constrict and we tend to push energy toward the core of our body to preserve our core organs. Okay, so our periphery, our hands and our feet and our toes and our legs become colder and our core therefore can maintain blood to that area and we are insulating our core. Conversely, when we heat up, our blood vessels vasodilate. They expand a bit and more blood flows to our periphery and more blood can move throughout the body generally and we will perspire. We will sweat. Water will actually get pulled out of the blood to some extent, moved up through sweat glands and will be brought to the skin surface so that it can be dumped. We are dumping heat. So it's very important that if you want to understand how you can leverage temperature for physical performance, you have to understand that you have vasoconstriction to conserve heat, vasodilation to dump heat, that you have sweating to dump heat, and you have conservation of fluids in order to preserve heat. That's the most important thing in terms of understanding the mechanisms of maintaining and dumping heat. And now the most important thing to understand is that if you get too hot, your ability to contract your muscles stops, okay? I'm going to repeat this because it's vitally important. ATP is involved in the process of generating muscle contractions. The range of temperatures within which ATP can function and muscles can contract is very narrow. Somewhere around 39 or 40 degrees Celsius, it drops off, and you will not be able to generate more contractions. Now that's pretty hot, but that temperature can be generated locally really fast. Put simply, if you get too hot, you stop exercising. You may not even realize it, but your will to exercise further, your ability to push harder is entirely dependent on the heat of the muscle, both locally and your whole system. If you can keep temperature in range, however, in a proper range, you will be able to do more work. You will be able to create greater output. You'll be able to lift more weight, more sets, more reps, and you'll be able to run further. Now, there are data that I'm going to talk about in a little bit that are absolutely striking that underscore that statement. They are data from my colleague Craig Heller's lab in the Department of Biology at Stanford. Many, if not all the NFL teams are now using this technology, as well as military uses it, and not just for sports performance, but also firefighters, construction workers, there's other professions where elevated heat becomes a barrier to performance. And you can leverage this to really improve your workouts. So how do you dump heat in order to perform longer safely? Well, in order to understand that, you have to understand that the body has three main compartments for regulating temperature, okay? We don't just have a center and a periphery, we have three main compartments. And there's one compartment in particular that all of you, or most all of you, I have to assume have. And if you can understand how that works, you can do tremendous things for your performance and for your recovery. One is your core. We already talked about that. Your core organs, your heart, your lungs, your pancreas, your liver. The core of your body. The other is your periphery, which are obviously your arms and your legs and your feet and your hands. But then there's a third component, which is there are three locations on your body that are far better at passing heat out of the body and bringing cool into the body such that you can heat up or cool your body everywhere very quickly. Those three areas are your face, the palms of your hands and the bottoms of your feet. Now the skin on your hands and on the bottoms of your feet and to some extent on your face are called glabrous skin. That's G-L-A-B-O-R-O-U-S, glabrous skin. And what's special about those areas of your body and the glabrous skin is that the arrangement of vasculature of blood vessels, capillaries and arteries that serve those regions is very different than it is elsewhere in your body. In these three regions of your hands, your face, and the bottoms of your feet, we have what are called A-V-A's. A-V-A's are a very special pattern of vasculature. A-V-A's are arteriovenous astemoses, A-R-T-E-R-I-O, arteriovenous, V-E-N-O-U-S, arteriovenous anastemoses, A-N-A-S-T-O-M-O-S-E-S.