Sauna Benefits Time: Heat Protocols That Work | Vitruvian

Video·MindVoice Production·9 min read·June 20, 2026

A grounded guide to how deliberate heat exposure works, why sauna protocols are linked with longevity, and how to approach heat as a careful ritual for resilience and recovery.

Heat as a Signal

Heat is not only a temperature on a wall. It is a signal the body reads, interprets, and answers. When you enter a sauna, hot bath, or any deliberately warm environment, your skin warms first, and your core follows according to intensity, time, and your own capacity for heat.

you don't get to heat up the brain and body very much before you start getting into the realm of neuron damage.

This distinction matters. The skin is the shell, the surface that meets the world. The core is deeper: organs, nervous system, spinal cord, and the inner terrain that must remain within a narrow range. A precise heat protocol respects both.

Your brain tracks the shell before directing the body to heat up or cool down. It is not waiting for a number on a device alone. It is reading the lived condition of your body in the room, then adjusting circulation, sweat, behavior, and effort to protect equilibrium.

That protection is essential because heat has a smaller margin than cold. The brain and spinal cord do not tolerate much overheating before risk rises. Deliberate heat exposure can build resilience, but it asks for attention, humility, and a clear exit before intensity becomes strain.

The strongest practice begins with response, not bravado. A sauna set between 80 and 100°C can be useful for one person and excessive for another. Time, temperature, hydration, and recent training all change the experience. Your body gives useful information before the protocol does.

Approach heat as a ritual of calibration. You are not proving tolerance. You are learning the boundary where warmth becomes adaptation, where discomfort stays deliberate, and where recovery is supported without overwhelming the system. Mastery begins with listening.

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Welcome to Huberman Lab Essentials, where we revisit past episodes for the where we revisit past episodes for the [music] most potent and actionable [music] most potent and actionable science-based tools for mental health, science-based tools for mental health, physical health, and performance. physical health, and performance. I'm Andrew Huberman, and I'm a professor I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at of neurobiology and ophthalmology at Stanford School of Medicine. Today we Stanford School of Medicine. Today we are talking about the science of heat. are talking about the science of heat. Heat is a remarkable stimulus, meaning Heat is a remarkable stimulus, meaning when we are in a hot environment, it has when we are in a hot environment, it has a profound effect on our biology. So, a profound effect on our biology. So, we're going to talk about the science of we're going to talk about the science of heat and heating, both in terms of their heat and heating, both in terms of their mechanisms, and as I know many of you mechanisms, and as I know many of you are interested in, the tools related to are interested in, the tools related to the use of heat. Things like sauna, how the use of heat. Things like sauna, how often to do sauna, how long to be in the often to do sauna, how long to be in the sauna, how hot to be in the sauna for sauna, how hot to be in the sauna for particular goals and outcomes. We heat particular goals and outcomes. We heat up two ways. up two ways. We heat up from the outside, meaning the We heat up from the outside, meaning the things that we come into contact with, things that we come into contact with, the clothing that we put on our body, the clothing that we put on our body, whether or not there's heat in the room whether or not there's heat in the room or whether or not it's cold outside or

or whether or not it's cold outside or cold in a room, and we heat up from the cold in a room, and we heat up from the inside. At every point across your inside. At every point across your entire lifespan, you have two distinct entire lifespan, you have two distinct temperatures. One is the temperature on temperatures. One is the temperature on your skin, what scientists call your your skin, what scientists call your shell, shell, and the temperature of your core, your and the temperature of your core, your viscera, meaning your organs, your viscera, meaning your organs, your nervous system, and your spinal cord. It nervous system, and your spinal cord. It is vitally important to understand that is vitally important to understand that you have those two temperatures, and you have those two temperatures, and that your brain is constantly sending that your brain is constantly sending out signals to your body out signals to your body as to whether or not it should heat up as to whether or not it should heat up or cool down depending on the or cool down depending on the temperature of the shell. So, anytime temperature of the shell. So, anytime we're talking about heat, meaning we're talking about heat, meaning deliberate heat exposure, things like deliberate heat exposure, things like sauna, sauna, it's very important to understand not it's very important to understand not just the stimulus, how hot something is, just the stimulus, how hot something is, how long you're in a sauna, etc., but how long you're in a sauna, etc., but the effect that has on your shell and on the effect that has on your shell and on your core. If you can understand that, your core. If you can understand that, you can design protocols that are you can design protocols that are literally perfect for your goals. A literally perfect for your goals. A brief warning now, and another brief brief warning now, and another brief warning later. Anytime you're talking warning later. Anytime you're talking about heating up your body, you need to

about heating up your body, you need to be very cautious because unlike cooling be very cautious because unlike cooling down where you have a fairly broad range down where you have a fairly broad range of cold temperatures that you can go of cold temperatures that you can go into before it's damaging to tissue, into before it's damaging to tissue, well, you don't get to heat up the brain well, you don't get to heat up the brain and body very much before you start and body very much before you start getting into the realm of neuron damage. getting into the realm of neuron damage. And And neurons in the central nervous system, neurons in the central nervous system, the brain and spinal cord, once they're the brain and spinal cord, once they're damaged, they don't come back. So, damaged, they don't come back. So, hypothermia is a serious thing to avoid. hypothermia is a serious thing to avoid. There's a very basic circuit, meaning There's a very basic circuit, meaning neurons that exist in the skin, in the neurons that exist in the skin, in the brain, and in the body that communicate brain, and in the body that communicate with one another that allow you to heat with one another that allow you to heat up if you need to and cool down if you up if you need to and cool down if you need to. Once you understand this need to. Once you understand this circuit and the way it's structured, circuit and the way it's structured, then you are going to be in a great then you are going to be in a great position to use the tools related to position to use the tools related to heating. So, here's how this circuit is heating. So, here's how this circuit is structured. structured. You have this shell, which is basically You have this shell, which is basically skin, and within the skin you have skin, and within the skin you have neurons, nerve cells. Those nerve cells neurons, nerve cells. Those nerve cells have channels or receptors on them. have channels or receptors on them. They're called trip channels, there are They're called trip channels, there are some other ones as well, which basically some other ones as well, which basically sense changes in heat. So, if I were to

sense changes in heat. So, if I were to put a hot object on your hand or your put a hot object on your hand or your arm, or for instance, if I were to put a arm, or for instance, if I were to put a hot object on your hand or arm and then hot object on your hand or arm and then remove that hot object, those neurons remove that hot object, those neurons would respond to that. They would send would respond to that. They would send electrical signals into your spinal electrical signals into your spinal cord, and that's where the next station cord, and that's where the next station of the circuit resides. of the circuit resides. In your spinal cord, you've got a little In your spinal cord, you've got a little cluster of neurons that exists at the cluster of neurons that exists at the top part of your spinal cord top part of your spinal cord called the dorsal horn. The name again called the dorsal horn. The name again doesn't matter. And those neurons doesn't matter. And those neurons specifically relay heat information up specifically relay heat information up to another area of your brain. Now, to another area of your brain. Now, here's where we get into some fancy here's where we get into some fancy names. It's the lateral parabrachial names. It's the lateral parabrachial area. You don't need to know lateral area. You don't need to know lateral parabrachial area, but it's a relay parabrachial area, but it's a relay station. The lateral parabrachial area station. The lateral parabrachial area sends electrical signals to the POA. And sends electrical signals to the POA. And I would like you to know POA. The POA I would like you to know POA. The POA stands for preoptic area. Neurons in the stands for preoptic area. Neurons in the preoptic area basically reside over the preoptic area basically reside over the roof of your mouth. These are neurons roof of your mouth. These are neurons within the hypothalamus. within the hypothalamus. And neurons in the preoptic area have

And neurons in the preoptic area have the ability to send signals out to the the ability to send signals out to the rest of your brain and body to get you rest of your brain and body to get you to heat up and actually to change your to heat up and actually to change your behavior. So, there are all these behavior. So, there are all these different mechanisms by which we dump different mechanisms by which we dump heat. Some of those are purely heat. Some of those are purely physiological, physiological, below our conscious control, things like below our conscious control, things like sweating, sweating, which you can't just make yourself sweat which you can't just make yourself sweat on demand. Maybe you can through a set on demand. Maybe you can through a set of stressful thoughts, but you can't of stressful thoughts, but you can't just make yourself sweat. just make yourself sweat. That is autonomic. It's below your That is autonomic. It's below your conscious control. Things like conscious control. Things like vasodilation, the dilation of your vasodilation, the dilation of your veins in particular and capillaries in veins in particular and capillaries in particular. And of course, there are particular. And of course, there are these behavioral, somewhat voluntary these behavioral, somewhat voluntary aspects of dumping heat. aspects of dumping heat. And the lethargy, the kind of tiredness And the lethargy, the kind of tiredness that we feel on a really hot day, that's that we feel on a really hot day, that's also controlled by this circuit that I also controlled by this circuit that I just described. The impulse to get just described. The impulse to get yourself out of a very hot environment yourself out of a very hot environment is the consequence of the POA is the consequence of the POA communicating with your amygdala. And communicating with your amygdala. And the amygdala then in turn activating the amygdala then in turn activating your adrenal glands, which are sit right

your adrenal glands, which are sit right above your kidneys, the release of above your kidneys, the release of adrenaline, and this feeling of adrenaline, and this feeling of agitation like you want to move. agitation like you want to move. Usually, you want to move out of Usually, you want to move out of whatever hot environment you happen to whatever hot environment you happen to be in. So, now you know the circuit. be in. So, now you know the circuit. Again, it's simple. It goes from skin to Again, it's simple. It goes from skin to spinal cord, one brain area to another spinal cord, one brain area to another brain area, that's the key one in this brain area, that's the key one in this discussion, which is the POA, the discussion, which is the POA, the preoptic area. If you can conceptualize preoptic area. If you can conceptualize that circuit, or if you can even just that circuit, or if you can even just understand what I just said, even at a understand what I just said, even at a top contour level, you're going to be in top contour level, you're going to be in a great position to understand the rest a great position to understand the rest of the information and the tools that of the information and the tools that follow. As many of you know, I've been follow. As many of you know, I've been taking AG1 for nearly 15 years now. I taking AG1 for nearly 15 years now. I discovered it way back in 2012, long discovered it way back in 2012, long before I ever had a podcast, and I've before I ever had a podcast, and I've been taking it every day since. The been taking it every day since. The reason I started taking it, and the reason I started taking it, and the reason I still take it, is because AG1 reason I still take it, is because AG1 is to my knowledge the highest quality is to my knowledge the highest quality and most comprehensive of the and most comprehensive of the foundational nutritional supplements on foundational nutritional supplements on the market. It combines vitamins, the market. It combines vitamins, minerals, prebiotics, probiotics, and minerals, prebiotics, probiotics, and adaptogens into a single scoop that's adaptogens into a single scoop that's easy to drink and it tastes great. It's

easy to drink and it tastes great. It's designed to support things like gut designed to support things like gut health, immune health, and overall health, immune health, and overall energy. And it does so by helping to energy. And it does so by helping to fill any gaps you might have in your fill any gaps you might have in your daily nutrition. Now, of course, daily nutrition. Now, of course, everyone should strive to eat nutritious everyone should strive to eat nutritious whole foods. I certainly do that every whole foods. I certainly do that every day. But, I'm often asked if you could day. But, I'm often asked if you could take just one supplement, what would take just one supplement, what would that supplement be? And my answer is that supplement be? And my answer is always AG1 because it has just been oh always AG1 because it has just been oh so critical to supporting all aspects of so critical to supporting all aspects of my physical health, mental health, and my physical health, mental health, and performance. I know this from my own performance. I know this from my own experience with AG1, and I continually experience with AG1, and I continually hear this from other people who use AG1 hear this from other people who use AG1 daily. If you would like to try AG1, you daily. If you would like to try AG1, you can go to drinkag1.com/huberman can go to drinkag1.com/huberman to get a special offer. For a limited to get a special offer. For a limited time, AG1 is giving away six free travel time, AG1 is giving away six free travel packs of AG1 and a bottle of vitamin packs of AG1 and a bottle of vitamin D3K2 with your subscription. Again, D3K2 with your subscription. Again, that's drinkag1 with the numeral that's drinkag1 with the numeral one.com/huberman one.com/huberman to get six free travel packs and a to get six free travel packs and a bottle of vitamin D3K2 with your bottle of vitamin D3K2 with your subscription. The use of deliberate heat subscription. The use of deliberate heat exposure can be a very powerful way to exposure can be a very powerful way to improve health and longevity. There's a

improve health and longevity. There's a wonderful study on this that was wonderful study on this that was published in 2018 that includes a lot of published in 2018 that includes a lot of data from a lot of participants in a lot data from a lot of participants in a lot of different conditions. For instance, of different conditions. For instance, people that only did sauna once versus people that only did sauna once versus two to three times a week versus four to two to three times a week versus four to seven times a week and so on, and seven times a week and so on, and compares all those. The title of the compares all those. The title of the study is "Sauna Bathing Is Associated study is "Sauna Bathing Is Associated With Reduced Cardiovascular Mortality With Reduced Cardiovascular Mortality and Improves Risk Prediction in Men and and Improves Risk Prediction in Men and Women: A Prospective Cohort Study." Women: A Prospective Cohort Study." This is one of several papers that This is one of several papers that clearly demonstrate that regular use of clearly demonstrate that regular use of sauna or other forms of deliberate heat sauna or other forms of deliberate heat exposure exposure can reduce mortality to cardiovascular can reduce mortality to cardiovascular events, but also to other events, things events, but also to other events, things like stroke and other things that like stroke and other things that basically can kill us. What I like so basically can kill us. What I like so much about this and the related studies much about this and the related studies is that they involve a lot of is that they involve a lot of participants. So, for instance, in this participants. So, for instance, in this particular paper, which was published in particular paper, which was published in BMC Medicine, they looked at a sample of BMC Medicine, they looked at a sample of 1,688 1,688 participants

participants who had a mean age of 63, but there was who had a mean age of 63, but there was a range of ages around 63. And of whom a range of ages around 63. And of whom 51.4% were women, the rest were men. So, 51.4% were women, the rest were men. So, it's a pretty nicely varied study in it's a pretty nicely varied study in terms of the populations that they terms of the populations that they looked at. Basically, what they found looked at. Basically, what they found was the more often that people do sauna, was the more often that people do sauna, the better their health is and the lower the better their health is and the lower the likelihood they will die from some the likelihood they will die from some sort of cardiovascular event. Now, what sort of cardiovascular event. Now, what do we mean by sauna? We need to define do we mean by sauna? We need to define some of the parameters around sauna, and some of the parameters around sauna, and I promise to provide you some I promise to provide you some alternative ways to access some of the alternative ways to access some of the health benefits that were observed in health benefits that were observed in this and related studies without the this and related studies without the need to have a sauna, cuz I do realize need to have a sauna, cuz I do realize that a lot of people don't have access that a lot of people don't have access to sauna. First off, the temperature to sauna. First off, the temperature ranges that were used in this study and ranges that were used in this study and pretty much all the studies that I'm pretty much all the studies that I'm going to talk about, unless I say going to talk about, unless I say otherwise, otherwise, are between 80° C, are between 80° C, meaning 176° meaning 176° F, F, and 100° C, and 100° C, meaning 212° meaning 212° F. F. So, somewhere in that range. How hot

So, somewhere in that range. How hot should you make the sauna or the should you make the sauna or the environment that you get into should you environment that you get into should you decide to use these tools? Well, that decide to use these tools? Well, that will depend on your tolerance for heat, will depend on your tolerance for heat, how heat adapted you are. Yes, some how heat adapted you are. Yes, some people are better at sweating than people are better at sweating than others, and over time, we all get better others, and over time, we all get better at sweating. Meaning, if you go into the at sweating. Meaning, if you go into the sauna more frequently, you become a sauna more frequently, you become a better sweater. Not a sweater you wear, better sweater. Not a sweater you wear, but the verb sweater. You get better at but the verb sweater. You get better at sweating, at dumping heat through the sweating, at dumping heat through the loss of water. loss of water. So, it's going to depend. I recommend So, it's going to depend. I recommend starting on the lower end of the starting on the lower end of the temperature scale, and if that's too hot temperature scale, and if that's too hot for you, that you even lower the for you, that you even lower the temperature further. Now, how long were temperature further. Now, how long were people exposing themselves to these hot people exposing themselves to these hot environments? Anywhere from 5 to 20 environments? Anywhere from 5 to 20 minutes per session. In this particular minutes per session. In this particular study, they compared the effects of study, they compared the effects of people that did sauna once a week, two people that did sauna once a week, two or three times per week, or four to or three times per week, or four to seven times per week. What they observed seven times per week. What they observed was that people who went into the sauna was that people who went into the sauna two or three times per week were 27% two or three times per week were 27% less likely to die of a cardiovascular

less likely to die of a cardiovascular event than people that went into the event than people that went into the sauna just once a week. And today, we're sauna just once a week. And today, we're mainly going to talk about exposures mainly going to talk about exposures between 10 and 20 minutes at between 10 and 20 minutes at temperatures between, again, 8° and 100° temperatures between, again, 8° and 100° C, 176° F, or 212° F. And in fact, the C, 176° F, or 212° F. And in fact, the benefits were even greater for people benefits were even greater for people that were going into the sauna four to that were going into the sauna four to seven times per week. Those people were seven times per week. Those people were 50% less likely to die of a 50% less likely to die of a cardiovascular event compared to people cardiovascular event compared to people that went into the sauna just once a that went into the sauna just once a week. What's particularly nice about week. What's particularly nice about this study and the related study is that this study and the related study is that they looked at a number of potentially they looked at a number of potentially confounding variables. Things like confounding variables. Things like whether or not people smoked, things whether or not people smoked, things like whether or not people were like whether or not people were overweight, whether or not they tended overweight, whether or not they tended to exercise or not exercise, and they to exercise or not exercise, and they were able to separate out those were able to separate out those variables. So, the percentages that I variables. So, the percentages that I described earlier, those effects really described earlier, those effects really do seem to be the consequence of the do seem to be the consequence of the sauna exposure and not some other effect sauna exposure and not some other effect that's correlated with sauna exposure, that's correlated with sauna exposure, like like going to the gym where people are going to the gym where people are working out seven times a week and then working out seven times a week and then also happen to get into the sauna, or

also happen to get into the sauna, or quitting smoking right about the same quitting smoking right about the same time they adopt a time they adopt a sauna protocol, these sorts of things. sauna protocol, these sorts of things. And now, there have been additional And now, there have been additional analyses of the use of sauna for analyses of the use of sauna for improving health, or I should say for improving health, or I should say for offsetting mortality, offsetting mortality, that have found that it's not just that have found that it's not just reductions in cardiovascular events, but reductions in cardiovascular events, but so-called all-cause mortality. This is so-called all-cause mortality. This is kind of medical geek speak for saying kind of medical geek speak for saying how likely are you or somebody to die how likely are you or somebody to die from a cardiovascular event, but maybe from a cardiovascular event, but maybe also from some other event, some other also from some other event, some other health-related event, like cancer or health-related event, like cancer or something of that sort. And in every something of that sort. And in every case, regular exposure to sauna, case, regular exposure to sauna, starting at about two or three times per starting at about two or three times per week, all the way up to seven times per week, all the way up to seven times per week, greatly improves, meaning week, greatly improves, meaning statistically significant improvements statistically significant improvements in longevity in the sense that they in longevity in the sense that they people are less likely to die of people are less likely to die of cardiovascular events and other things cardiovascular events and other things that kill us. You don't have to use a that kill us. You don't have to use a sauna in order to get these benefits. It sauna in order to get these benefits. It is simply a matter of making sure that

is simply a matter of making sure that your shell and your core your shell and your core heat up properly. Not too much, not too heat up properly. Not too much, not too little, but they heat those up. So, the little, but they heat those up. So, the question is how are you heating up your question is how are you heating up your environment? And I realize that there environment? And I realize that there are dry saunas, there are steam saunas, are dry saunas, there are steam saunas, there are infrared saunas. There are hot there are infrared saunas. There are hot tubs, and there are simply rooms that tubs, and there are simply rooms that you crank up the heat, okay? you crank up the heat, okay? There are also ways in which you can There are also ways in which you can increase your shell and your core increase your shell and your core temperature by moving around a lot and temperature by moving around a lot and doing that wearing a lot of clothing. doing that wearing a lot of clothing. There's nothing special about any one of There's nothing special about any one of these approaches or protocols. It's just these approaches or protocols. It's just so happens that sauna is one of the more so happens that sauna is one of the more convenient ways to do this. And convenient ways to do this. And certainly for the studies that I've certainly for the studies that I've talked about, not just the ones I talked about, not just the ones I referenced before, but all the studies referenced before, but all the studies that I researched looking at this that I researched looking at this episode, episode, it makes sense why they would use sauna it makes sense why they would use sauna because it's very hard, for instance, to because it's very hard, for instance, to create conditions where you have, you create conditions where you have, you know, five people go out jogging wearing know, five people go out jogging wearing heavy sweaters and hats, wool hats on in heavy sweaters and hats, wool hats on in the middle of summer. It's very hard to

the middle of summer. It's very hard to set up those conditions in a way that's set up those conditions in a way that's controlled for everybody. Whereas, it's controlled for everybody. Whereas, it's pretty straightforward to have a sauna pretty straightforward to have a sauna where you have one or several people where you have one or several people just get into that one uniformly hot just get into that one uniformly hot environment. That's a much easier study environment. That's a much easier study to run. You could, however, immerse to run. You could, however, immerse yourself in a hot tub or hot water bath yourself in a hot tub or hot water bath up to your neck. That's another way to up to your neck. That's another way to approach it. If you didn't have access approach it. If you didn't have access to either of those, you could also to either of those, you could also put on put on a a hoodie or a wool hat and a hoodie or a a hoodie or a wool hat and a hoodie or you could do like the wrestlers do and you could do like the wrestlers do and you could actually buy one of these you could actually buy one of these plastic suits. They're literally called plastic suits. They're literally called plastics that plastics that wrestlers or other athletes that wish to wrestlers or other athletes that wish to drop water weight will wear and then go drop water weight will wear and then go jogging in that. All of those will jogging in that. All of those will increase your shell and your core body increase your shell and your core body temperature, right? Especially if you do temperature, right? Especially if you do it on a hot day, but of course be it on a hot day, but of course be careful, hydrate and don't overheat, careful, hydrate and don't overheat, don't become excessively hyperthermic don't become excessively hyperthermic cuz you can get heat stroke and you can cuz you can get heat stroke and you can potentially die. So, what happens when potentially die. So, what happens when you get into a hot environment? What are you get into a hot environment? What are the mechanisms that allow for the the mechanisms that allow for the various health effects of that? So, various health effects of that? So, blood flow increases, plasma volume of blood flow increases, plasma volume of your blood increases, and stroke volume,

your blood increases, and stroke volume, the volume of blood that is mobilized the volume of blood that is mobilized with each beat of your heart also with each beat of your heart also increases. And your heart rate increases increases. And your heart rate increases to anywhere between 100 to 150 beats per to anywhere between 100 to 150 beats per minute. That general constellation of minute. That general constellation of effects looks a lot like cardiovascular effects looks a lot like cardiovascular exercise. And in fact, exercise. And in fact, for all intents and purposes, it really for all intents and purposes, it really is cardiovascular exercise except that is cardiovascular exercise except that there isn't the mobilization and the there isn't the mobilization and the loading of joints and limbs and things loading of joints and limbs and things of that sort. And of course there are of that sort. And of course there are additional benefits of cardiovascular additional benefits of cardiovascular exercise that relate to impact on the exercise that relate to impact on the ground, improvements in bone density, ground, improvements in bone density, etc., etc. But basically your heart etc., etc. But basically your heart starts beating, more blood starts starts beating, more blood starts circulating, circulating, your vasculature changes shape literally your vasculature changes shape literally to accommodate those increases in heart to accommodate those increases in heart rate and blood volume, and you're rate and blood volume, and you're basically getting a cardiovascular basically getting a cardiovascular workout in that hot environment even if workout in that hot environment even if you're just sitting down. Another set of you're just sitting down. Another set of positive effects related to being in positive effects related to being in these hot environments

these hot environments are hormone effects. Shifts in the are hormone effects. Shifts in the output of hormones both from your output of hormones both from your adrenals and possibly from the testes adrenals and possibly from the testes and ovaries and even within the brain. and ovaries and even within the brain. One of the more striking examples of One of the more striking examples of that comes from a study that was that comes from a study that was published in 2021. The title of the published in 2021. The title of the study is endocrine effects of repeated study is endocrine effects of repeated hot thermal stress and cold water hot thermal stress and cold water immersion in young adult men. And immersion in young adult men. And indeed, the study was in this case just indeed, the study was in this case just done on men. I'll just briefly describe done on men. I'll just briefly describe the protocol they used. the protocol they used. They had these men attend four sauna They had these men attend four sauna sessions of 12 minutes each. So again, sessions of 12 minutes each. So again, well within that range of 5 to 20 well within that range of 5 to 20 minutes, 12 minutes. minutes, 12 minutes. The temperature of those saunas was 90 The temperature of those saunas was 90 to 91° C. to 91° C. That's 194° F, That's 194° F, and they did that four times. and they did that four times. Afterwards, they had a 6-minute Afterwards, they had a 6-minute cool-down break during which they did cool-down break during which they did get into some cool water or cold water get into some cool water or cold water of about 10°, which is of about 10°, which is 10° C is 50° F. 10° C is 50° F. And then they measured hormones at

And then they measured hormones at various times throughout this study, various times throughout this study, before, during, and after. The major before, during, and after. The major effect of this study is a significant effect of this study is a significant decrease in cortisol output in these decrease in cortisol output in these subjects. subjects. I think this is really interesting and I think this is really interesting and important because many people suffer important because many people suffer from acute, meaning immediate, and from acute, meaning immediate, and long-term stress and are looking for long-term stress and are looking for ways to control their stress. ways to control their stress. Controlling your cortisol is tricky. Controlling your cortisol is tricky. Many people are overworked, they're Many people are overworked, they're overstressed. For one reason or another, overstressed. For one reason or another, they're subjected to many, too many they're subjected to many, too many stressors, or their level of stress stressors, or their level of stress resilience isn't high enough to keep resilience isn't high enough to keep their cortisol levels clamped at a their cortisol levels clamped at a healthy level. So the protocol I healthy level. So the protocol I described of 12-minute exposures to 90° described of 12-minute exposures to 90° environment, that's again 90° C, environment, that's again 90° C, followed by followed by followed by a 6-minute cool-down break followed by a 6-minute cool-down break in cool water, 50° or so, that's pretty in cool water, 50° or so, that's pretty cold. cold. I can imagine that you could also just I can imagine that you could also just take a cool shower or a cold shower take a cool shower or a cold shower afterwards. That had a very significant afterwards. That had a very significant effect on lowering cortisol. So there effect on lowering cortisol. So there you have a tool that's not a completely you have a tool that's not a completely zero-cost tool cuz you need to heat the zero-cost tool cuz you need to heat the water, you need to have access to hot

water, you need to have access to hot and cold water, at least hot and cold and cold water, at least hot and cold contrast of some sort, but it's fairly contrast of some sort, but it's fairly minimal cost it for most people, minimal cost it for most people, especially if you start getting creative especially if you start getting creative about maybe taking a 12-minute jog about maybe taking a 12-minute jog wearing a lot of clothing if it's hot wearing a lot of clothing if it's hot out, then getting into a cool shower. out, then getting into a cool shower. You might not get the same extreme You might not get the same extreme or significant reduction in cortisol or significant reduction in cortisol that was observed here with these very that was observed here with these very specific protocols, but it's likely that specific protocols, but it's likely that you would get a similar result overall. you would get a similar result overall. So, if you're seeking to use sauna to So, if you're seeking to use sauna to reduce stress, I think this is a very reduce stress, I think this is a very interesting and potentially useful interesting and potentially useful research-backed protocol. And again, we research-backed protocol. And again, we will provide a link to the paper uh if will provide a link to the paper uh if you'd like to read more about the data. you'd like to read more about the data. I'd like to take a quick break and I'd like to take a quick break and acknowledge one of our sponsors, acknowledge one of our sponsors, Element. Element is an electrolyte drink Element. Element is an electrolyte drink that has everything you need and nothing that has everything you need and nothing you don't. That means the electrolytes, you don't. That means the electrolytes, sodium, magnesium, and potassium in the sodium, magnesium, and potassium in the correct amounts, but no sugar. Proper correct amounts, but no sugar. Proper hydration is critical for optimal brain hydration is critical for optimal brain and body function. Even a slight degree and body function. Even a slight degree of dehydration can diminish cognitive of dehydration can diminish cognitive and physical performance. It's also and physical performance. It's also important that you get adequate important that you get adequate electrolytes. The electrolytes, sodium,

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spelled drinklmn t.com/huberman, to claim a free Element sample pack with to claim a free Element sample pack with a purchase of any Element drink mix. a purchase of any Element drink mix. Again, that's drinkelement.com/huberman Again, that's drinkelement.com/huberman to claim a free sample pack. to claim a free sample pack. One of the more dramatic and important One of the more dramatic and important effects of going into a hot environment effects of going into a hot environment for some period of time for some period of time is the activation of so-called heat is the activation of so-called heat shock proteins or HSPs. Heat shock shock proteins or HSPs. Heat shock proteins are a protective mechanism in proteins are a protective mechanism in your brain and body your brain and body to rescue proteins that would otherwise to rescue proteins that would otherwise misfold. Now, what do I mean by this? misfold. Now, what do I mean by this? Well, Well, most of you are familiar with the fact most of you are familiar with the fact that if you have protein in the kitchen, that if you have protein in the kitchen, like a steak or a piece of chicken or a like a steak or a piece of chicken or a piece of fish, and you heat it up, it piece of fish, and you heat it up, it changes its texture, right? Raw meat is changes its texture, right? Raw meat is different than cooked meat. Heat changes different than cooked meat. Heat changes the quality of proteins, not just in the quality of proteins, not just in terms of how they taste, but the way in terms of how they taste, but the way in which they which they are configured. Changes it right down at are configured. Changes it right down at the molecular level. When your body goes the molecular level. When your body goes through changes in temperature in through changes in temperature in response to hot environments or cold response to hot environments or cold environments, heat shock proteins are environments, heat shock proteins are deployed to go and rescue and prevent

deployed to go and rescue and prevent the changes in proteins that would be the changes in proteins that would be detrimental to your health. So, at least detrimental to your health. So, at least in the short term, activating heat shock in the short term, activating heat shock proteins is a good thing. You don't want proteins is a good thing. You don't want heat shock proteins to be activated for heat shock proteins to be activated for long periods of time because that gets long periods of time because that gets to be problematic for other reasons, but to be problematic for other reasons, but these heat shock proteins, of which these heat shock proteins, of which there are many varieties, basically have there are many varieties, basically have the job of traveling in your brain and the job of traveling in your brain and body and making sure that cells that body and making sure that cells that contain proteins that are misfolding contain proteins that are misfolding because they got heated up too much because they got heated up too much don't misfold, and they also serve a don't misfold, and they also serve a protective mechanism making sure that protective mechanism making sure that proteins within the cells of your brain proteins within the cells of your brain and body and body don't fold in the wrong ways. Um again, don't fold in the wrong ways. Um again, I'm describing this in very general I'm describing this in very general terms, but it's well-established in terms, but it's well-established in animal models and in humans that sauna animal models and in humans that sauna exposure of the sort that I described exposure of the sort that I described earlier activates these heat shock earlier activates these heat shock proteins. There have been interesting proteins. There have been interesting studies done in humans examining some of studies done in humans examining some of the downstream molecular pathways of the downstream molecular pathways of deliberate heat exposure deliberate heat exposure that point to the mechanisms by which that point to the mechanisms by which deliberate heat exposure can help

deliberate heat exposure can help protect against different forms of protect against different forms of mortality, improve health overall, and mortality, improve health overall, and possibly, and I want to highlight possibly, and I want to highlight possibly, possibly, possibly extend life. possibly extend life. One such mechanism involves a genetic One such mechanism involves a genetic program involving a molecule called program involving a molecule called FoxO3. FoxO3 is a very interesting FoxO3. FoxO3 is a very interesting molecule because it's involved in DNA molecule because it's involved in DNA repair pathways. repair pathways. DNA repair is part of the process of DNA repair is part of the process of remaining healthy. You know, we'd all remaining healthy. You know, we'd all like to think that we're born and based like to think that we're born and based on the genes we have, we are healthy on the genes we have, we are healthy healthy healthy then eventually we age healthy healthy then eventually we age and then we die. But from the time we're and then we die. But from the time we're born until the time we die, there's a born until the time we die, there's a constant repair of our proteins in our constant repair of our proteins in our cells and a modification of the genes cells and a modification of the genes that are being expressed. You know, that are being expressed. You know, puberty being the most dramatic example, puberty being the most dramatic example, right? You see a kid before puberty and right? You see a kid before puberty and after puberty looks like a different after puberty looks like a different kid, sounds like a different kid, thinks kid, sounds like a different kid, thinks like a different kid. In fact, basically like a different kid. In fact, basically is a different human being, right? It's is a different human being, right? It's not just the hormones, it's that not just the hormones, it's that hormones themselves have the capacity to hormones themselves have the capacity to turn on and turn off certain genes, turn on and turn off certain genes, literally converting certain tissues and

literally converting certain tissues and cells in the brain and body to do cells in the brain and body to do entirely different things. And DNA, the entirely different things. And DNA, the stuff of genes, stuff of genes, gets damaged in that process. FoxO3 gets damaged in that process. FoxO3 sits upstream in a pathway related to sits upstream in a pathway related to DNA repair and again clearing of these DNA repair and again clearing of these senescent cells. senescent cells. Sauna exposure, Sauna exposure, in particular sauna exposure two to in particular sauna exposure two to three times or ideally four to seven three times or ideally four to seven times per week in that 80 to 100 degree times per week in that 80 to 100 degree Celsius range, has been shown to Celsius range, has been shown to upregulate levels of FoxO3. upregulate levels of FoxO3. FoxO3 in turn upregulates pathways FoxO3 in turn upregulates pathways related to DNA repair and clearing out related to DNA repair and clearing out of these senescent or dead cells, which of these senescent or dead cells, which is known to be important for various is known to be important for various aspects of maintaining cognition and aspects of maintaining cognition and other aspects of maintaining health. So, other aspects of maintaining health. So, these are the likely biological these are the likely biological mechanisms for the improvements in mechanisms for the improvements in lifespan or I rather I should say, these lifespan or I rather I should say, these are the biological mechanisms that are the biological mechanisms that apparently offset some of the

apparently offset some of the cardiovascular risk and other forms of cardiovascular risk and other forms of mortality that were described earlier. mortality that were described earlier. One especially interesting thing about One especially interesting thing about FOXO3, FOXO3, there are individuals out there that there are individuals out there that have either additional copies of FOXO3 have either additional copies of FOXO3 or who have versions of FOXO3 that are or who have versions of FOXO3 that are hyperactive, hyperactive, so to speak. so to speak. Those people Those people tend to be 2.7 times more likely to live tend to be 2.7 times more likely to live to 100 years of age or longer. So, these to 100 years of age or longer. So, these are people that were just naturally and are people that were just naturally and fortunately for them endowed with more fortunately for them endowed with more FOXO3, more clearance of senescent FOXO3, more clearance of senescent cells, more DNA repair, etc. Deliberate cells, more DNA repair, etc. Deliberate heat exposure is one way that you can heat exposure is one way that you can increase FOXO3 activity. increase FOXO3 activity. There is no sauna protocol designed There is no sauna protocol designed specifically to reduce cortisol or specifically to reduce cortisol or specifically to increase FOXO3 or specifically to increase FOXO3 or specifically to activate heat shock specifically to activate heat shock proteins. Any deliberate heat exposure proteins. Any deliberate heat exposure is likely to impact all of those is likely to impact all of those mechanisms. Again, I encourage you to mechanisms. Again, I encourage you to use this guide of 80 to 100° C

use this guide of 80 to 100° C as your kind of bookends for what you as your kind of bookends for what you can tolerate and where you want to start can tolerate and where you want to start and eventually transition to in terms of and eventually transition to in terms of deliberate heat exposure. And deliberate heat exposure. And I would encourage you to use that 5 to I would encourage you to use that 5 to 20 minutes per session 20 minutes per session for the sauna as your rough guide of how for the sauna as your rough guide of how long to remain in the sauna. long to remain in the sauna. Now, I'd like to talk about the use of Now, I'd like to talk about the use of sauna to increase growth hormone. Growth sauna to increase growth hormone. Growth hormone hormone impacts metabolism and growth of cells impacts metabolism and growth of cells and tissues of the body. It is and tissues of the body. It is responsible for tissue repair as well. responsible for tissue repair as well. And the growth spurt that everyone And the growth spurt that everyone experiences during puberty is the experiences during puberty is the consequence of growth hormone. What I'm consequence of growth hormone. What I'm about to describe is a study that found about to describe is a study that found dramatic, really dramatic I should say, dramatic, really dramatic I should say, increases in growth hormone. But, I also increases in growth hormone. But, I also want to emphasize that these increases want to emphasize that these increases in growth hormone were not of the sort in growth hormone were not of the sort that are observed in puberty or in that are observed in puberty or in infants becoming adolescents or infants becoming adolescents or adolescents growing into teenagers. adolescents growing into teenagers. Those levels of growth hormone that are Those levels of growth hormone that are associated with those massive

associated with those massive transformations, excuse me, of body transformations, excuse me, of body morphology, of shape, are far greater morphology, of shape, are far greater than the sorts that I'm talking about than the sorts that I'm talking about here. And yet, here. And yet, as all of us age, as all of us age, when we go from adolescence to our when we go from adolescence to our teenage years and then into young teenage years and then into young adulthood, but then starting in our adulthood, but then starting in our early 30s or so, early 30s or so, the amount of growth hormone that we the amount of growth hormone that we secrete is greatly diminished. secrete is greatly diminished. Normally, we would release growth Normally, we would release growth hormone every night after we go to hormone every night after we go to sleep, in particular in the early part sleep, in particular in the early part of the night when our sleep is comprised of the night when our sleep is comprised mostly of slow wave sleep. As we age, mostly of slow wave sleep. As we age, less growth hormone is released during less growth hormone is released during that slow wave sleep. Certain forms of that slow wave sleep. Certain forms of deliberate heat exposure using sauna can deliberate heat exposure using sauna can stimulate very large increases in growth stimulate very large increases in growth hormone output, which for people in hormone output, which for people in their 30s, 40s, and beyond could be very their 30s, 40s, and beyond could be very useful and may also be useful for people useful and may also be useful for people who are just trying to stimulate the who are just trying to stimulate the release of more growth hormone in order release of more growth hormone in order to, for instance, recover from exercise to, for instance, recover from exercise or stimulate fat loss or muscle growth or stimulate fat loss or muscle growth or repair of a particular injury. or repair of a particular injury. The title of this paper is endocrine

The title of this paper is endocrine effects of repeated sauna bathing. And effects of repeated sauna bathing. And this is a paper that was published in this is a paper that was published in 1986, which is some years ago, but 1986, which is some years ago, but nonetheless serves as a basis for a lot nonetheless serves as a basis for a lot of other studies that followed. They of other studies that followed. They used an 80° C environment, so that's used an 80° C environment, so that's 176° F. 176° F. They had subjects do this sauna for 30 They had subjects do this sauna for 30 minutes four times per day. So, that's 2 minutes four times per day. So, that's 2 hours total in 1 day. 30 minutes in the hours total in 1 day. 30 minutes in the sauna, period of cool down rest, 30 sauna, period of cool down rest, 30 minutes in the sauna again, cool down minutes in the sauna again, cool down rest a third and a fourth time, okay? rest a third and a fourth time, okay? So, So, 2 hours total in this 80° C environment. 2 hours total in this 80° C environment. So, that's a lot, but what they observed So, that's a lot, but what they observed was really quite significant. And I was really quite significant. And I should mention they had both male and should mention they had both male and female subjects in this study. female subjects in this study. And the entire study lasted a week. They And the entire study lasted a week. They did this 2 hours of sauna exposure on did this 2 hours of sauna exposure on day one, day three, and day seven of day one, day three, and day seven of that week. And they measured a lot of that week. And they measured a lot of different hormones. I'll just cut to the different hormones. I'll just cut to the chase and tell you the effects on growth chase and tell you the effects on growth hormone. In subjects that did this hormone. In subjects that did this 2-hour a day 80° C

2-hour a day 80° C protocol, protocol, experienced 16-fold increases in growth experienced 16-fold increases in growth hormone. So, they measured growth hormone. So, they measured growth hormone before the sauna and after the hormone before the sauna and after the sauna, and growth hormone levels went up sauna, and growth hormone levels went up 16-fold, which is obviously an enormous 16-fold, which is obviously an enormous and, it turns out, statistically and, it turns out, statistically significant effect. One important caveat significant effect. One important caveat here. Remember earlier when I talked here. Remember earlier when I talked about about people who did sauna once a week versus people who did sauna once a week versus two to three times a week versus four to two to three times a week versus four to seven times a week, and the more often seven times a week, and the more often people did sauna, people did sauna, the less likely they were to die of the less likely they were to die of cardiovascular events or other things of cardiovascular events or other things of that sort? Well, in this case, the that sort? Well, in this case, the effects of sauna exposure on growth effects of sauna exposure on growth hormone hormone actually went down the more often that actually went down the more often that people did this deliberate heat people did this deliberate heat exposure. So, as I mentioned, they did exposure. So, as I mentioned, they did this 2-hour a day divided into 30-minute this 2-hour a day divided into 30-minute sessions protocol on day one, day three, sessions protocol on day one, day three, and day seven and day seven of a week. And what they found was on of a week. And what they found was on day one, there was a 16-fold increase in day one, there was a 16-fold increase in growth hormone. On day three, however, growth hormone. On day three, however, there was there was still a significant effect on growth

still a significant effect on growth hormone as compared to before sauna, but hormone as compared to before sauna, but that effect was basically cut by 2/3. that effect was basically cut by 2/3. Okay? So, now, instead of getting a Okay? So, now, instead of getting a 16-fold increase, it was more like a 16-fold increase, it was more like a three or fourfold increase, which is three or fourfold increase, which is still a huge increase, but not as great still a huge increase, but not as great as the increase observed on day one. And as the increase observed on day one. And then on day seven, there appeared to be then on day seven, there appeared to be a two, maybe a three-fold increase, but a two, maybe a three-fold increase, but not as great as the one observed on day not as great as the one observed on day one. The fact that that result one. The fact that that result diminished over time either means that diminished over time either means that the circuit was not as efficient in the circuit was not as efficient in communicating that shift in temperature, communicating that shift in temperature, or that that shift in temperature was of or that that shift in temperature was of less impact because the downstream less impact because the downstream effectors effectors were not engaged to the same extent were not engaged to the same extent because it wasn't as much of a shock. because it wasn't as much of a shock. And I think the latter explanation is And I think the latter explanation is far more likely. This is very much akin far more likely. This is very much akin to weight training or cardiovascular to weight training or cardiovascular exercise where if you run up a hill very exercise where if you run up a hill very fast for instance and your lungs are fast for instance and your lungs are burning and you're heaving and breathing burning and you're heaving and breathing hard on the first day hard on the first day it's a very painful thing but if you do it's a very painful thing but if you do it every day or every other day provide

it every day or every other day provide you allow yourself to recover pretty you allow yourself to recover pretty soon you're running up that hill and soon you're running up that hill and you're not breathing as hard. There you're not breathing as hard. There isn't much burning in your muscles etc. isn't much burning in your muscles etc. etc. Your body adapts. So if you're etc. Your body adapts. So if you're going to use deliberate heat exposure in going to use deliberate heat exposure in order to try and trigger massive order to try and trigger massive increases in growth hormone you're going increases in growth hormone you're going to need to be careful about not doing it to need to be careful about not doing it more than let's say once a week. Now I'm more than let's say once a week. Now I'm extrapolating from this study maybe once extrapolating from this study maybe once every 10 days would be even better but every 10 days would be even better but if you start getting heat adapted it's if you start getting heat adapted it's very unlikely that you're going to get very unlikely that you're going to get these massive increases in growth these massive increases in growth hormone. So I don't mean to be hormone. So I don't mean to be discouraging of using deliberate heat discouraging of using deliberate heat exposure to access growth hormone exposure to access growth hormone increases but if that's your specific increases but if that's your specific goal or your main goal then I think it's goal or your main goal then I think it's reasonable to say that you don't want to reasonable to say that you don't want to do deliberate heat exposure at least not do deliberate heat exposure at least not of the sort that I described here more of the sort that I described here more than once a week or maybe even once than once a week or maybe even once every 10 days and that you would want to every 10 days and that you would want to time that to other events in your life time that to other events in your life maybe hard workouts or if you're trying maybe hard workouts or if you're trying to push through a fat loss barrier or to push through a fat loss barrier or simply in order to access growth hormone simply in order to access growth hormone at peak levels maybe three times per

at peak levels maybe three times per month or four times per month. If you month or four times per month. If you start doing deliberate heat exposure start doing deliberate heat exposure more often you'll still get increases in more often you'll still get increases in growth hormone but they are not going to growth hormone but they are not going to be nearly as large as the increases in be nearly as large as the increases in growth hormone that you're going to growth hormone that you're going to experience if you shock your system with experience if you shock your system with deliberate deliberate heat exposure deliberate deliberate heat exposure every once in a while. I'd like to take every once in a while. I'd like to take a quick break and acknowledge our a quick break and acknowledge our sponsor Eight Sleep. sponsor Eight Sleep. >> [snorts] >> [snorts] >> Eight Sleep makes smart mattress covers >> Eight Sleep makes smart mattress covers with cooling heating and sleep tracking with cooling heating and sleep tracking capacity. One of the best ways to ensure capacity. One of the best ways to ensure you get a great night's sleep is to make you get a great night's sleep is to make sure that the temperature of your sure that the temperature of your sleeping environment is correct and sleeping environment is correct and that's because in order to fall asleep that's because in order to fall asleep and stay deeply asleep your body and stay deeply asleep your body temperature actually has to drop by temperature actually has to drop by about 1 to 3 degrees and in order to about 1 to 3 degrees and in order to wake up feeling refreshed and energized wake up feeling refreshed and energized your body temperature actually has to your body temperature actually has to increase by about 1 to 3°. Eight Sleep increase by about 1 to 3°. Eight Sleep automatically regulates the temperature automatically regulates the temperature of your bed throughout the night of your bed throughout the night according to your unique needs. I've according to your unique needs. I've been sleeping on an Eight Sleep mattress been sleeping on an Eight Sleep mattress cover for nearly 5 years now, and it has cover for nearly 5 years now, and it has completely transformed and improved the completely transformed and improved the quality of my sleep. The latest Eight quality of my sleep. The latest Eight Sleep model is the Pod 5. This is what

Sleep model is the Pod 5. This is what I'm now sleeping on, and I absolutely I'm now sleeping on, and I absolutely love it. It has so many incredible love it. It has so many incredible features. For instance, the Pod 5 has a features. For instance, the Pod 5 has a feature called autopilot, which is an AI feature called autopilot, which is an AI engine that learns your sleep patterns, engine that learns your sleep patterns, and then adjusts the temperature of your and then adjusts the temperature of your sleeping environment across different sleeping environment across different sleep stages. It'll even elevate your sleep stages. It'll even elevate your head if you're snoring, and it makes head if you're snoring, and it makes other shifts to optimize your sleep. If other shifts to optimize your sleep. If you'd like to try Eight Sleep, go to you'd like to try Eight Sleep, go to eightsleep.com/huberman eightsleep.com/huberman to get up to $350 off the new Pod 5. to get up to $350 off the new Pod 5. Eight Sleep ships to many countries Eight Sleep ships to many countries worldwide, including Mexico and the UAE. worldwide, including Mexico and the UAE. Again, that's eightsleep.com/huberman Again, that's eightsleep.com/huberman to save up to $350. to save up to $350. When you decide to do sauna or cold When you decide to do sauna or cold exposure for that matter, exposure for that matter, is going to be important. Why? Well, if is going to be important. Why? Well, if you were to make the surface of your you were to make the surface of your body cold, at least in the immediate body cold, at least in the immediate period after that, your body temperature period after that, your body temperature will increase, and that can make it hard will increase, and that can make it hard for some people to fall asleep. Now, if for some people to fall asleep. Now, if you're very, very tired, because you've you're very, very tired, because you've been working hard or training hard or been working hard or training hard or both throughout the day, it might not both throughout the day, it might not throw off your sleep so much. I've gone throw off your sleep so much. I've gone through bouts where I'm just so, so busy through bouts where I'm just so, so busy from morning till night that the only

from morning till night that the only time I can get into the ice bath or the time I can get into the ice bath or the cold shower is late in the evening, and cold shower is late in the evening, and I have no trouble sleeping after that. I have no trouble sleeping after that. If you're going to use deliberate heat If you're going to use deliberate heat exposure, exposure, you'd be wise to do it later in the day you'd be wise to do it later in the day because when you get into a warm because when you get into a warm environment, sure, the surface of your environment, sure, the surface of your body, the shell, heats up, the core of body, the shell, heats up, the core of your body heats up, but then it also your body heats up, but then it also activates cooling mechanisms through the activates cooling mechanisms through the preoptic area. And when you get out of preoptic area. And when you get out of that hot environment, sauna or that hot environment, sauna or otherwise, your body will continue to otherwise, your body will continue to cool down, and so many people find that cool down, and so many people find that if they do sauna in the later half of if they do sauna in the later half of the day or even the day or even just before sleep and then take a just before sleep and then take a warmish shower afterwards, then they warmish shower afterwards, then they find it easier to fall asleep and that find it easier to fall asleep and that makes sense because their body makes sense because their body temperature is dropping. And in fact, if temperature is dropping. And in fact, if your goal is to really promote the your goal is to really promote the maximum amount of growth hormone maximum amount of growth hormone release, that's also going to be the release, that's also going to be the best time of day to do it, especially if best time of day to do it, especially if you haven't eaten in the 2 hours before you haven't eaten in the 2 hours before sleep. Okay? So, if you're really going sleep. Okay? So, if you're really going for growth hormone release, you're for growth hormone release, you're really trying to optimize sleep and the really trying to optimize sleep and the two things are actually linked because two things are actually linked because of the release of growth hormone that of the release of growth hormone that happens from the pituitary in the early

happens from the pituitary in the early night's sleep, well, then you would be night's sleep, well, then you would be wise to do your sauna maybe once or wise to do your sauna maybe once or maybe twice a week in the evening or at maybe twice a week in the evening or at night time then taking a warm or cool night time then taking a warm or cool shower just briefly, just enough to kind shower just briefly, just enough to kind of rinse off all the sweat from the of rinse off all the sweat from the sauna, and then get ready for sleep. And sauna, and then get ready for sleep. And to do that, not necessarily fasted, but to do that, not necessarily fasted, but to try and keep your levels of glucose to try and keep your levels of glucose and insulin somewhat low in your and insulin somewhat low in your bloodstream. The reason I say that is bloodstream. The reason I say that is that having elevated blood glucose and that having elevated blood glucose and or insulin or insulin tends to blunt or reduce growth hormone tends to blunt or reduce growth hormone release and that's true for any number release and that's true for any number of different stimuli, including exercise of different stimuli, including exercise and including sauna. If you really want and including sauna. If you really want to crank out the most amount of growth to crank out the most amount of growth hormone in response to sauna, do it hormone in response to sauna, do it fasted or at least not having ingested fasted or at least not having ingested any food in the two or three hours any food in the two or three hours before. You don't have to be deep into a before. You don't have to be deep into a fast. I think for fast. I think for 90% of people 90% of the time, just 90% of people 90% of the time, just getting into the sauna once or twice or getting into the sauna once or twice or three times a week is going to be three times a week is going to be beneficial for the number of reasons beneficial for the number of reasons that I described earlier and you don't

that I described earlier and you don't want to obsess too much about the exact want to obsess too much about the exact conditions you need in order to get the conditions you need in order to get the greatest effect out of that sauna greatest effect out of that sauna treatment. Now, regardless of what time treatment. Now, regardless of what time of day you do sauna or how frequently of day you do sauna or how frequently you do it, you're going to want to you do it, you're going to want to hydrate after going in the sauna. hydrate after going in the sauna. When you go in the sauna, you lose water When you go in the sauna, you lose water and when you lose water, you need to and when you lose water, you need to replace it. Why? Well, you need water replace it. Why? Well, you need water for all your cells, but you also need for all your cells, but you also need electrolytes. So, make sure that you're electrolytes. So, make sure that you're replacing the water that you lose in the replacing the water that you lose in the sauna. Now, there's no exact formula of sauna. Now, there's no exact formula of how much water to drink and whether or how much water to drink and whether or not you need electrolytes in that water not you need electrolytes in that water or not. it's going to depend on how much or not. it's going to depend on how much you sweat, meaning how heat adapted you you sweat, meaning how heat adapted you are, it's going to depend on how much are, it's going to depend on how much salt you tend to excrete in your sweat. salt you tend to excrete in your sweat. Huge amount of variation, but in Huge amount of variation, but in general, one way to approach this would general, one way to approach this would be to make sure that you drink at least be to make sure that you drink at least 16 oz of water for every 10 minutes that 16 oz of water for every 10 minutes that you happen to be in the sauna. You could you happen to be in the sauna. You could do that before, and during, and after. do that before, and during, and after. You could do it during and after, or you You could do it during and after, or you could do it after. Now, there are other could do it after. Now, there are other reasons to do deliberate heat exposure reasons to do deliberate heat exposure that have improvements in mood and

that have improvements in mood and mental health. In fact, the data related mental health. In fact, the data related to sauna and other forms of deliberate to sauna and other forms of deliberate heat exposure improving mood are very heat exposure improving mood are very impressive both at the mechanistic level impressive both at the mechanistic level and in terms of the long-term and in terms of the long-term consequences that people experience. consequences that people experience. First of all, we need to ask how is it First of all, we need to ask how is it that deliberate heat exposure can that deliberate heat exposure can improve our mood and well-being? Well, improve our mood and well-being? Well, it turns out that it improves mood and it turns out that it improves mood and well-being, but it also improves our well-being, but it also improves our capacity to feel good in response to capacity to feel good in response to things that would ordinarily make us things that would ordinarily make us feel somewhat good. Now, this is not a feel somewhat good. Now, this is not a situation where you're going to be situation where you're going to be walking around grinning ear to ear in walking around grinning ear to ear in response to nothing at all simply response to nothing at all simply because you went in a sauna. What I'm because you went in a sauna. What I'm talking about is the upregulation of talking about is the upregulation of pathways, meaning chemical pathways in pathways, meaning chemical pathways in your brain and body, that allow you to your brain and body, that allow you to experience pleasure in all its fullness. experience pleasure in all its fullness. Many of you have probably heard of Many of you have probably heard of endorphins. Endorphins are a category of endorphins. Endorphins are a category of molecules that are made naturally in molecules that are made naturally in your brain and body and that are your brain and body and that are released in response to different forms released in response to different forms of stressors. That's right. In response

of stressors. That's right. In response to stressors. So, if ever you've gone to stressors. So, if ever you've gone out on a long run and at some point in out on a long run and at some point in that run you feel like you're aching and that run you feel like you're aching and your joints hurt or maybe you have shin your joints hurt or maybe you have shin splints and you push through that, splints and you push through that, part of the reason that you experience a part of the reason that you experience a lack of pain at some point, usually, or lack of pain at some point, usually, or you experience a euphoria during or you experience a euphoria during or after that exercise, is the after that exercise, is the exercise-induced exercise-induced effects on endorphin release. Or rather, effects on endorphin release. Or rather, to be more specific, I should say the to be more specific, I should say the exercise-induced exercise-induced consequences on the stress system, which consequences on the stress system, which in turn trigger the release of in turn trigger the release of endorphin. In other words, when we endorphin. In other words, when we experience short-term or acute stress, experience short-term or acute stress, the endorphin system is activated. Now, the endorphin system is activated. Now, the endorphin system is not just about the endorphin system is not just about feeling good, believe it or not, it's feeling good, believe it or not, it's also about feeling bad. And there two also about feeling bad. And there two general categories of endorphins. The general categories of endorphins. The first are the ones that you normally first are the ones that you normally hear about, endorphins, things that bind hear about, endorphins, things that bind for instance to receptors like the mu for instance to receptors like the mu opioid receptor. We make endorphins that opioid receptor. We make endorphins that naturally act as pain relievers and that

naturally act as pain relievers and that make us feel mildly euphoric. We also make us feel mildly euphoric. We also make endorphins such as dynorphin, make endorphins such as dynorphin, that's d y n o r p h i n, dynorphin, that's d y n o r p h i n, dynorphin, that actually make us feel worse in that actually make us feel worse in response to stressors. response to stressors. When we get into a hot sauna or a hot When we get into a hot sauna or a hot environment of any kind, dynorphins are environment of any kind, dynorphins are liberated in the brain and body. And I liberated in the brain and body. And I should mention that dynorphins are made should mention that dynorphins are made by many neurons in many different areas by many neurons in many different areas of the brain. of the brain. So, you might think, well, why would I So, you might think, well, why would I want that? Why would I want to release want that? Why would I want to release dynorphin into my brain and body? Well, dynorphin into my brain and body? Well, first of all, when you get into an first of all, when you get into an uncomfortably hot situation, uncomfortably hot situation, uncomfortably hot scenario, oh gosh, uncomfortably hot scenario, oh gosh, this is sounding terrible, a a this is sounding terrible, a a deliberately hot environment that you deliberately hot environment that you are using to try and trigger some sort are using to try and trigger some sort of biological or psychological benefit, of biological or psychological benefit, I should say, the discomfort that you I should say, the discomfort that you feel, the desire to get out of the that feel, the desire to get out of the that environment is in part the consequence environment is in part the consequence of the release of dynorphin. of the release of dynorphin. It's also the consequence of the It's also the consequence of the activation of that sympathetic nervous activation of that sympathetic nervous system. Remember, the preoptic area can

system. Remember, the preoptic area can communicate with the amygdala and communicate with the amygdala and trigger that kind of fight or flight trigger that kind of fight or flight mode, I want to get out of the sauna, mode, I want to get out of the sauna, this is really really hot, but dynorphin this is really really hot, but dynorphin is also liberated from a certain number is also liberated from a certain number of neurons. Dynorphin binds to what's of neurons. Dynorphin binds to what's called the kappa called the kappa receptor. The kappa receptor receptor. The kappa receptor binds dynorphin and triggers pathways in binds dynorphin and triggers pathways in the brain and body that lead to the brain and body that lead to agitation, to stress, and believe it or agitation, to stress, and believe it or not, to a general sense of pain. This is not, to a general sense of pain. This is why you want to get out of the hot why you want to get out of the hot sauna. And remember, if it's unsafe sauna. And remember, if it's unsafe levels of hot, then you should get out levels of hot, then you should get out of that sauna or other hot environment. of that sauna or other hot environment. But, if you're working in a range or But, if you're working in a range or you're exposing yourself to a range of you're exposing yourself to a range of heat that's uncomfortable but safe to be heat that's uncomfortable but safe to be in, in, dynorphin will be liberated from these dynorphin will be liberated from these neurons, bind to the kappa receptor, neurons, bind to the kappa receptor, and as a downstream consequence of that, and as a downstream consequence of that, there will be an increase in the there will be an increase in the receptors that bind the other receptors that bind the other endorphins. The endorphins that make you endorphins. The endorphins that make you feel soothed, that make you feel happy, feel soothed, that make you feel happy, and that make you feel mild euphoria. and that make you feel mild euphoria. It's fair to say that every time we get

It's fair to say that every time we get into a hot environment that's into a hot environment that's uncomfortable or a cold environment uncomfortable or a cold environment that's uncomfortable, dynorphin is that's uncomfortable, dynorphin is likely released and binding to the kappa likely released and binding to the kappa receptor. receptor. But, over time, that binding of But, over time, that binding of dynorphin to the kappa receptor leads to dynorphin to the kappa receptor leads to downstream changes in the way that the downstream changes in the way that the feel-good endorphins, things like feel-good endorphins, things like endorphin binding to the mu-opioid endorphin binding to the mu-opioid receptor. And there are still other receptor. And there are still other feel-good endorphins, so to speak. feel-good endorphins, so to speak. That system becomes much much more That system becomes much much more efficient such that people feel an efficient such that people feel an elevation in their baseline level of elevation in their baseline level of mood. And when a good or happy event mood. And when a good or happy event comes along, they feel a heightened comes along, they feel a heightened level of happiness or joy or awe or level of happiness or joy or awe or improved mood in response to that. So, improved mood in response to that. So, what does it mean? It means that a what does it mean? It means that a little bit of discomfort as a little bit of discomfort as a consequence of deliberate heat exposure, consequence of deliberate heat exposure, while in the short term while in the short term doesn't feel good, by definition, doesn't feel good, by definition, it is activating pathways that are it is activating pathways that are allowing the feel-good molecules and allowing the feel-good molecules and neural circuitries that exist in your neural circuitries that exist in your brain and body to increase their brain and body to increase their efficiency, placing you in a better

efficiency, placing you in a better position to be joyful in response to the position to be joyful in response to the events of life. events of life. We're starting to see a general picture We're starting to see a general picture that using the sorts of sauna protocols that using the sorts of sauna protocols that I've described throughout this that I've described throughout this episode, right? 5 to 20 minutes or so, episode, right? 5 to 20 minutes or so, done one to seven times per week, done one to seven times per week, is associated with a general improvement is associated with a general improvement in cardiovascular health, a general in cardiovascular health, a general improvement in mental health. And it improvement in mental health. And it really points to the fact that yes, really points to the fact that yes, sauna sauna done acutely for three or four times a done acutely for three or four times a day, 30 minutes each session separated day, 30 minutes each session separated by a cooling, maybe getting into cold by a cooling, maybe getting into cold bath. Sure, that can potently increase bath. Sure, that can potently increase growth hormone. growth hormone. But done on a more regular basis can But done on a more regular basis can reduce cortisol, improve heart health, reduce cortisol, improve heart health, improve mental health. And for that improve mental health. And for that reason and the fact that for most people reason and the fact that for most people it is conceivable to come up with a way it is conceivable to come up with a way that you could get into deliberate heat that you could get into deliberate heat exposure for a minimum of cost, right? exposure for a minimum of cost, right? If it's a hot bath or if you had to If it's a hot bath or if you had to resort to, you know, bundling up and resort to, you know, bundling up and going for a jog, this sort of thing, or going for a jog, this sort of thing, or if you have access to it, a sauna of

if you have access to it, a sauna of some sort, some sort, that we're really talking about a that we're really talking about a stimulus to initiate a large number of stimulus to initiate a large number of different biological cascades that wick different biological cascades that wick out to improve multiple aspects of brain out to improve multiple aspects of brain and body health. Each protocol that I've and body health. Each protocol that I've talked about today, whether or not it's talked about today, whether or not it's 5 minutes or 20 minutes or four times in 5 minutes or 20 minutes or four times in a day or three times per week or seven a day or three times per week or seven times per week, is tickling or pushing, times per week, is tickling or pushing, or stomping, if you will, on a given or stomping, if you will, on a given pathway and really activating it to a pathway and really activating it to a mild or to severe degree. What I've mild or to severe degree. What I've tried to do today is to illustrate the tried to do today is to illustrate the general mechanisms by which heat in general mechanisms by which heat in particular can activate certain particular can activate certain biological pathways so that you can biological pathways so that you can devise protocols that are going to be devise protocols that are going to be optimal for you and your needs. So, just optimal for you and your needs. So, just to briefly recap, to briefly recap, if you want to get the greatest growth if you want to get the greatest growth hormone increases, do sauna or other hormone increases, do sauna or other deliberate heat exposure fairly seldom. deliberate heat exposure fairly seldom. Probably no more than once per week, Probably no more than once per week, maybe even less. And do it a lot that maybe even less. And do it a lot that day, just make sure that you break it up day, just make sure that you break it up into multiple sessions. In the study I into multiple sessions. In the study I described earlier, they did four described earlier, they did four sessions, 30 minutes each. But

sessions, 30 minutes each. But that was just once a week. If you're that was just once a week. If you're interested in the cardiovascular interested in the cardiovascular benefits and the potential longevity benefits and the potential longevity benefits of sauna, well then it's clear benefits of sauna, well then it's clear that doing it three to four, maybe even that doing it three to four, maybe even seven times per week is going to be more seven times per week is going to be more of beneficial than doing it just one or of beneficial than doing it just one or three times per week. And again, that three times per week. And again, that range of 80 to 100°C is going to be your range of 80 to 100°C is going to be your guide. And in terms of the mental health guide. And in terms of the mental health benefits, it seems that getting a little benefits, it seems that getting a little bit uncomfortable in that heat bit uncomfortable in that heat environment, sauna or otherwise, environment, sauna or otherwise, provided safe, is going to be the best provided safe, is going to be the best way to access those mental health way to access those mental health effects by way of increasing dynorphin, effects by way of increasing dynorphin, which, as you recall, will then increase which, as you recall, will then increase the ability of endorphin to have its the ability of endorphin to have its positive effects on mood after you get positive effects on mood after you get out of the sauna or other deliberate out of the sauna or other deliberate heat exposure. And in terms of timing, heat exposure. And in terms of timing, after a workout of any kind, after a workout of any kind, morning or afternoon, or morning or afternoon, or if you're not doing it after a workout, if you're not doing it after a workout, certainly in the later part of the day certainly in the later part of the day is going to be most beneficial as it is going to be most beneficial as it relates to sleep. But, of course, relates to sleep. But, of course, there's a caveat there, which I will there's a caveat there, which I will mention again, which is that for those

mention again, which is that for those of you that have no trouble sleeping of you that have no trouble sleeping because you're exhausted or you're just because you're exhausted or you're just one of these phenomenal sleepers, well, one of these phenomenal sleepers, well, then do it anytime of day or night. But then do it anytime of day or night. But for most people, doing it later in the for most people, doing it later in the day is going to be more beneficial day is going to be more beneficial because of the post-sauna cooling effect because of the post-sauna cooling effect and the relationship between cooling by and the relationship between cooling by a degree or more as a way to enter a degree or more as a way to enter sleep. Thank you for joining me today sleep. Thank you for joining me today for my discussion about the science of for my discussion about the science of heat and heating for health. heat and heating for health. And last, but certainly not least, And last, but certainly not least, >> [music] >> [music] >> thank you for your interest in science. >> [music] >> This episode is brought to you by Google >> This episode is brought to you by Google Health. Stop chasing someone else's Health. Stop chasing someone else's definition of health. What matters is definition of health. What matters is what's healthy for you. [music] Google what's healthy for you. [music] Google Health offers a new kind of coach built Health offers a new kind of coach built with Gemini for effortless tracking, with Gemini for effortless tracking, sleep insights, and holistic coaching sleep insights, and holistic coaching tailored to you. Visit google.store.com tailored to you. Visit google.store.com to learn more and start a new to learn more and start a new relationship with your health. Requires relationship with your health. Requires Google account, Google Health app, Google account, Google Health app, internet, and Google Health Premium internet, and Google Health Premium subscription. [music] Features subject subscription. [music] Features subject to change. Availability and results to change. Availability and results vary. Not intended for medical purposes.

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The Circuit That Keeps Equilibrium

The body keeps balance through a quiet circuit that begins in the skin. Heat-sensitive nerve cells detect changes at the surface and send electrical signals into the spinal cord. From there, the information moves upward through relay stations toward the brain areas that coordinate your response.

The preoptic area of the hypothalamus is central to that coordination. It receives heat information and directs the body to dump heat when needed. In plain terms, it helps convert sensation into action, preserving clarity and safety as the environment becomes more demanding.

Some of those actions happen beneath conscious control. Sweating increases water loss so the body can cool itself. Vasodilation widens blood vessels near the surface, moving warm blood outward so heat can leave the body. These changes support performance by protecting the core.

You do not decide to sweat in the way you decide to stand up. The body initiates it. This is why heat practice feels both intentional and automatic: you choose the exposure, then your physiology begins the work of keeping you steady.

Heat also changes behavior. On a hot day, lethargy can appear as the body tries to reduce effort. In a very hot room, agitation can rise, along with a clear urge to leave. That impulse is not weakness. It is information.

The preoptic area communicates with regions involved in threat and movement, which can activate the adrenal glands and release adrenaline. The felt outcome is alertness, urgency, and the desire to seek cooler conditions. When this signal grows sharp, the ritual has moved from useful stress toward excessive stress.

Understanding the circuit makes the protocol personal. One person may settle into stillness after ten minutes. Another may need less heat, a shorter session, or a longer cool-down. Precision comes from matching the external stimulus to the internal response.

We use science to refine attention, not replace it. Skin, spinal cord, brain, sweat, blood flow, and behavior all participate in the same conversation. A deliberate practitioner learns that conversation slowly, then builds consistency from there.

The impulse to get yourself out of a very hot environment is the consequence of the POA communicating with your amygdala.

Longevity Protocols

The longevity conversation around sauna is strongest when it stays specific. In a 2018 prospective cohort study published in BMC Medicine, researchers examined sauna bathing, cardiovascular mortality, and risk prediction in men and women. The study followed 1,688 participants with a mean age of 63.

The sample included both men and women, with 51.4% women. That matters because the findings were not drawn from a narrow group of young athletes or single-sex participants. The research looked at people closer to the age where cardiovascular risk becomes more visible.

The sauna conditions were traditional and hot. Across the study and related work discussed in the source, typical temperatures ranged from 80 to 100°C, or 176 to 212°F. Sessions commonly lasted 5 to 20 minutes, a window that invites structure rather than excess.

Frequency carried the signal. People who used sauna two to three times per week were 27% less likely to die of a cardiovascular event than those who used sauna once per week. People who used sauna four to seven times per week were 50% less likely compared with once weekly.

These numbers do not turn sauna into a guarantee. They do show that repeated exposure, practiced with care, aligns with meaningful differences in cardiovascular mortality. The value comes less from occasional intensity and more from a consistent protocol the body can adapt to over time.

The study also accounted for important variables, including smoking, body weight, and exercise habits. That strengthens the signal because it separates sauna use from other behaviors that often travel with health-conscious routines. The association remains focused on the heat exposure itself.

For practical purposes, this points toward a simple frame. Begin at the lower end of heat and duration. Use sessions that allow you to remain aware, steady, and able to leave before distress rises. Longevity is built through repetition, not spectacle.

A sauna ritual works because it is contained. The room is hot, the time is bounded, and the intention is clear. Within that container, you create a deliberate challenge for the cardiovascular system while preserving a sense of control. That balance is the work.

Access, Adaptation, and Stress

Sauna is useful because it creates a controlled hot environment. It is simple to study, simple to repeat, and simple to measure. Yet the core principle is broader than the room itself: you raise shell and core temperature enough to create adaptation, while staying inside a careful margin.

Other routes can serve the same aim when sauna is not available. Hot tubs, hot baths, warm rooms, layered clothing, or movement in heat can raise body temperature. Each method changes the texture of the experience, but the central signal remains heat.

Access should never come at the expense of control. A hot bath up to the neck feels different from a dry sauna. A warm room with movement feels different again. The right protocol is the one you can repeat safely, observe clearly, and recover from well.

You don't have to use a sauna in order to get these benefits.

Adaptation develops with exposure. Over time, many people become better at sweating, which improves the body’s ability to dump heat. Better heat tolerance does not mean ignoring discomfort. It means the system learns to respond with more skill, and you learn to read its signals with more precision.

Heat also creates cardiovascular-like effects from stillness. Heart rate can rise, blood flow increases, plasma volume increases, and stroke volume increases, meaning more blood moves with each beat. The plain outcome is a stronger internal demand on circulation, supporting resilience without joint loading.

In hot environments, heart rate may rise to 100 to 150 beats per minute. Blood moves, vessels adjust, and the body works to maintain balance. This can resemble cardiovascular exercise from the inside, even while you remain seated and quiet.

Heat practice can also intersect with stress. A 2021 study on repeated hot thermal stress and cold-water immersion used four sauna sessions of 12 minutes each at 90 to 91°C, or 194°F. Each heat exposure was followed by a six-minute cool-down in water around 10°C, or 50°F.

The study measured hormones before, during, and after the protocol, and the major reported effect was a significant decrease in cortisol output in young adult men. Cortisol is part of the body’s stress response; when it falls after repeated heat and cool cycles, the felt outcome can support calm, resilience, and steadier recovery.

That protocol does not require everyone to chase the same extremes. A cool shower after heat may offer a more accessible contrast. The principle is deliberate stress followed by deliberate recovery, repeated with enough consistency that the body learns the pattern.

The most refined heat ritual is disciplined, not dramatic. You heat with intention, cool with intention, and notice how your body responds across days and weeks. In that rhythm, sauna becomes more than an indulgence. It becomes a practice of equilibrium.

Wim's Wise Words

A second take, from someone who's lived it.

If you take one thing from this, let it be this: heat should leave you steadier, not emptied out. A good sauna session has a clean edge to it. You feel the demand, your breath changes, your skin opens, your mind gets quieter. Then you leave while you still have choice.

That last part matters. The mistake I see most often is treating heat like a test of character. It is not. Heat is a precise stress. Used well, it can train circulation, tolerance, and calm. Used carelessly, it becomes noise the body has to recover from.

I would rather see you do ten deliberate minutes three times a week than one heroic session that takes the rest of the day from you. Consistency builds adaptation. Drama usually builds avoidance.

Where I'd Start

Begin at the low end of your range. Not the room's range. Yours. If the sauna is hot enough that you spend the first minute negotiating with yourself, shorten the session or sit lower. The bench height, the humidity, the time of day, your last meal, and yesterday's training all change the dose.

My own rule is simple: I want heat to feel demanding by the middle, spacious by the end, and useful afterward. If I feel sharp agitation, pulsing in the head, dizziness, or the kind of urgency that narrows attention, I step out. That is not quitting. That is reading the signal clearly.

For most readers, I would start with 8 to 12 minutes, two or three times a week, followed by a quiet cool-down. Sit. Breathe through the nose if you can. Let your heart rate settle before you add cold. Contrast can be powerful, but stacking stress on stress without a pause misses the point.

If you want to go deeper on the temperature signals underneath this practice, read How the Body Reads Heat. If your interest is longevity, Heat as a Longevity Protocol is the cleaner next step.

I also like heat in the evening. Not always, and not too late, but often enough to notice the pattern. Twenty minutes of sauna can do what an evening drink pretends to do: soften the edge of the day, quiet the appetite for stimulation, and create a clean threshold into rest. None of this replaces sleep. It prepares you to respect it.

Hydration matters, but do not make it complicated. Drink before you go in. Replace fluids afterward. If you sweat heavily, consider minerals with your water. The goal is not to prove how much you can lose; the goal is to recover so the next session remains available.

The best heat practice feels almost modest from the outside. Same place. Similar time. Clear boundary. No performance. Over weeks, you learn the difference between useful discomfort and strain. That is where the value sits: not in hotter rooms or longer sessions, but in the quiet mastery of leaving at the right moment.