Everything You Need To Know About How To Use Heat Exposure To Enhance Performance, Burn Fat, Gain Muscle And Think Better.

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Hey folks, it's Ben Greenfield and I'd like to welcome you to week three in which my podcast sidekick Brock is still off exploring Europe somewhere. Probably, I don't know, in some salt mine off the coast of Portugal or maybe off catching sardines in Norway, I don't know. But either way, I once again am here relegated to having to sail sit around with yet another amazing special guest. And I'm going to introduce my guest to you in just a second. But before I do, I want to remind you that something I've talked about before on the podcast is the fact that I go to the sauna. And I go to the sauna about once a week. And sometimes in the winter when it's cold here in the frozen tundra of Spokane, Washington, I'll go twice a week and I'll get this huge pile of magazines and journals that I subscribe to like ESPN and Fast Company and Mother Earth News is another one that I read. Sometimes I'll even grab a book that I don't mind destroying and I settle in for like a good 30 to 45 minutes of a sweat session in the sauna. And usually it's after about 25 minutes that it gets really tough and my heart rate and my core temperature start to go up and I eventually get so hot that I have to stop reading and just start. Start like staring at the wall and doing deep meditative breathing to sit things out for as long as I can. And sometimes I'll pretend I'm like in some kind of a Native American sweat lodge or like some, some prisoner of war tossed into a heat torture chamber, even though I'm really in the in the YMCA where there's a water fountain about 10ft away. But anyways, then I get out of the sauna and I generally take a cold shower right afterwards. And then I feel freaking amazing for the rest of the day. And I've used this strategy to train for everything from racing ironman in the lava fields of Hawaii to prepping my body for tennis tournaments where I know I'm going to be in a stifling indoor hot tennis court stadium. But, you know, when it comes to heat, there's some pretty cool physiological adaptations that actually occur. Like, the biology of heat is actually pretty cool.

It's.

It can work to enhance performance. It can build muscle, it can burn fat. It can even make you smarter. There are some really interesting things that heat does, but it's hard to understand what the best kind of heat is. You know, saunas or steam rooms or those dorky sauna suits, how to use heat, how long you need to do heat for. So this all leads into who I have on the show with me today. And her name is Dr. Rhonda Patrick. And Dr. Patrick is actually a pretty amazingly smart woman. She has a PhD in biomedical sciences. She's got a bachelor's of science in biochemistry and chemistry. She's done a bunch of research on things like aging and cancer and nutrition. She did graduate research on the link between mitochondrial metabolism and cancer. And she's also got some videos that she's published on heat stress. And by the way, I will link to those in the show notes. She's currently a postdoctoral fellow at the Children's Hospital in Oakland, where she does clinical trials looking at the effects of micronutrients like vitamins and minerals on metabolism and inflammation and DNA and aging. She's done research on anti aging at an institute for biological sciences. She's investigated the role of vitamins, vitamin D and brain function. Just a ton of different areas when it comes to physiology and pretty much all things nutritional. Geek dome. She's actually, she's immersed herself in quite a bit. So like I mentioned today, she's going to talk to us about what she knows about heat. So, Dr. Patrick, thanks for coming on the call.

Thanks for having me, Ben, and thanks for that excellent introduction.

So, yeah, I feel like I just talked for the first 10 minutes of our podcast.

Well, I was sitting there, like, totally relating to your sauna experience. I'm like, oh, my God, that's exactly, exactly my experience.

Yeah, and it really is interesting because it is one of those things where I know it's good for me. I feel all sorts of cool adaptations occur. I mean, frankly, as dumb as this sounds, I even see my veins get bigger when I start doing my sauna training. So I know there's some pretty cool cardiovascular adaptations that are occurring, too, But I want to delve into those. And before we even get into that stuff. How the heck did you come to study heat? I mean, it seems like kind of a weird thing to study, like what sitting around in a sauna does, right?

Well, so my interest in the sauna came through experience. When I was in graduate school, I lived across the street from a YMCA for a long time. And I also then moved to another apartment complex which had a sauna in the the building. So I was using the sauna, you know, just because I had access to it on a. On a pretty regular basis. And what I started to notice, I would go into the sauna early in the morning before I would go into the lab to do my research. And one of the really profound effects I started to notice is, like you said, I started to feel amazing. Like after my sauna session, the stress from graduate school, the stress from my experiments going wrong, everything throughout the day was so much easier for me to handle. If I went to the sauna like before I started my day, it was very, very noticeable. So that sort of sparked my interest in the sauna. It actually had nothing to do with muscle or endurance or any of that. It was actually brain, the effects on my brain. And that to me was very noticeable and interesting. So I started to read about it. You know, being a scientist, I have access to, you know, these scientific journals and I also obviously know how to.

Did you take your journals into the.

Sauna like I do, so it totally did. And it's so funny because I start out the first, you know, 20 minutes I'm reading my journals and, you know, then the heart starts, you know, my heart rate starts to increase and it's really pretty much like cardiovascular exercise. Notice.

Yeah, yeah, no, I've gotten my heart rate up to about 160 in the sauna before.

Wow. Yeah. I've never actually measured. Measured mine, but I mean, it's very obvious after about 20 minutes of sitting in there that it starts to kick up. And then after a while I begin to experience so much pain that I can no longer read.

Right.

So I am sitting there just sort of like, you know, meditating in a way. And it's very, very interesting the effects that occur after that pain that I feel.

You brought it up first. So let's jump in right there. Let's talk about the brain and what happens to your brain when it's subjected to heat stress. Because I know we want to talk a little about muscle gain and endurance and stuff like that, but why don't we start right in with the neurological adaptations? What are the effects of hyperthermia or sauna treatment or heat stress on the brain.

Right. So there's actually quite a few different effects on the brain. The one, the effect that I was describing where I felt really great the rest of the day, and what you also noticed actually has to do with the manipulation of the opioid system in the brain. And this is actually related to the runner's high as well. So your brain has different opioid receptors. People are probably most familiar with the. The endorphin system. Right. I mean, that's what I think most people are familiar with. Endorphins, beta endorphins, and how they make you feel good and how you release them after exercise. Well, actually, so there's another part of this opioid system that is the counter to endorphin, and that's called dynorphin. And dynorphin, it's responsible for that feeling of dysphoria. So obviously, when you're running or you're doing really intense exercise or you're even sitting in the heat, stress, you start to feel that uncomfortable dysphoric feeling. And that's actually you're releasing dynorphin. And dynorphin binds to a receptor in the brain called kappa opioid receptor. And the binding of dynorphin to this kappa opioid receptor actually has interesting feedback mechanisms on the endorphin system. Endorphins bind to something called the mu opioid. Mu opioid receptor is what things like morphine derivatives bind to. So it blocks that pain message. You know, it's sort of. It's involved in the antinociption and when. So bringing it back to the kappa opioids, when you activate that kappa opioid, that painful feeling, you actually upregulate the mu opioid receptors and you sensitize them to endorphin. So what happens is the more pain you feel, the more discomfort you feel. Later on, when you release the endorphins, you're going to be more sensitive to them. And so you're going to experience an even better endorphin high. And so it really physiologically translates to the more pain, the more discomfort you feel during physical exercise, the more intense it is. The more intense the heat stress, the better the runner's high is going to be after the better that endorphin response is going to be.

Do you know how long these endorphins stick around after you do a sauna session?

So I don't know exactly how long they stick around. I know that you do also dump a bunch of dynorphin, sorry, endorphin as well. But because you're more sensitive to them, just like other things that cause endorphin release, you're gonna feel more. You're gonna be more sensitive to that endorphin throughout the day.

Right. So very similar to the whole idea behind if you have, say, a test or. Or something that is mentally demanding later on in the day can help to go out and spark endorphin release by going out on a run in the morning. You could do the same thing by doing a sauna session.

Yeah, absolutely. I've actually done that. So if I'm giving a big talk, I'll do well. I used to. I don't have as great access to a sauna right now as I did previously, but I would go into the sauna before giving a talk, and it was like, amazing, amazing response where it's like, I felt like dealing with that stress was so much easier for me. Part of the mechanisms by which you know why heat is important for this opioid system is they actually regulate body temperature. So if you inject dynorphin, like into a rat, it cools the body temperature. So it makes sense that when you're experiencing extreme heat stress, your body's gonna have a biological homeostatic mechanism response where it's going to try to cool itself. And dynorphine is that mechanism that actually cools the body temperature. And if you notice when you're anxious or when you're feeling anxiety before you're having a talk or whatever's stressing you out, sometimes your hands will get cold and clammy. That's dynorphin. That's the dynorphin. Yeah, it's very interesting. That's just one of the really cool effects on the brain that I really found interesting because I personally experienced it.

What else happens to the brain?

So heat stress also activates or causes the release of norepinephrine, which is interesting because norepinephrine is what's involved in focus and attention. And actually, if we talk a little bit about thermogenesis later, I can kind of come back to that because norepinephrine does a lot of other interesting things as well. But what I find interesting is the effects on improving attention and focus, because for me, sometimes I have a problem with becoming very distracted. I get very interested in a lot of things. And so it's like, oh, my goodness. It's like I'll read one thing and then I'll go on to the next. And instead of kind of diving down deeper, deeper, which I'll do. But, you know, sometimes it's hard for me to do that because I find myself distracted by a lot of interesting things. So the norepinephrine release is cool. And also what's really cool is that heat stress has been shown to also increase the storage of norepinephrine. What that means is that when you.

Interesting.

Yeah. You can actually, when you're storing norepinephrine, then it's available for later release.

Where do you store it?

And vesicles? I mean, I don't know. Yeah, I don't know the exact. The exact mechanisms of all that, but I do know that it does increase the storage of it. So.

Okay, interesting. So basically like in like a synaptic ending or something like that, you just have more epinephrine, like stored up, ready for release.

Ready for release, yeah. And it's not being metabolized and turned over as readily reuptaked. Okay, so it's not being reuptaked. Yeah. So the other really cool thing on the brain is brain derived neurotrophic factor, which is something that exercise also is known to increase.

Bdnf.

Exactly. Yeah. Bdnf. So heat also increases bdnf, which is, I think, part of the reason why exercise can increase it, because when you're exercising, you're elevating your core body temperature. So a lot of these heat stress mechanisms are very common in exercise because exercise is elevating your core body temperature. So, yeah, BDNF is cool because it's an important growth factor for growing new neurons. And that's obviously been shown to be important for learning and memory and also for. Well, the cool thing about the learning thing is we're finding some new mechanisms by which increasing neurogenesis actually helps you forget things that you want to forget. So it plays a role in forgetting things that make you anxious. Yeah.

So total sedgeway here. But we all know that alcohol kills brain cells. And sometimes people will go into a sauna to detox and feel better after they drink. Do you think that there's some type of a repair, like a neuronal repair of alcohol induced brain cell damage that could occur if you were doing a sauna session?

Yeah, well, it's important to not do a sauna session while you're drinking alcohol that actually can lead to death. So, like, seriously, that but you know, yes, if you are going into the sauna, post alcohol induced neuronal cell death, increasing your brain derived neurotrophic factor obviously is going to help you grow new neurons. So, you know, I definitely think that would be a beneficial thing to do.

But from a pure biohacking standpoint, for the people out there who are using things like say modafinil or aniracetam or phosphatidylcholine or any of these smart drugs, they could actually get a pretty good benefit from the dynorphin, from the brain derived neurotrophic factor and from the norepinephrine just by doing something like potentially using sauna instead of supplements or maybe as an adjunct to supplements.

Absolutely, absolutely. Interesting. Yeah.

Now how in these studies that we're talking about right now, how long are we talking? Like, because, you know, we, you and I were talking about how we will do like 30 minutes, you know, I'll usually max out at 45. The longest I've ever stayed in a sauna was an hour. And it was horrible.

Right. It's really hard.

I had to like play videos inside my head of me riding my bicycle down the lava fields in Ironman to just motivate me to make it that long. But in these studies, are we talking about like 10 minutes, 20 minutes? What are they looking at?

Right, so the effects of the sauna, heat stress on the brain and also on other mechanisms that improve muscle growth and such do depend on the time and temperature spent in the sauna. So if you do, they've shown that like if you're in a sauna, so most saunas, dry saunas, at least I think they range between like 140 and 100, 180 degrees Fahrenheit, maybe, maybe some of them reach get up to 200 as well. So having like a 22, 20 minute sauna sessions back to back. So you can like do a 20 minute session, get out for like five or 10 minutes and then go back in and you can have some of these effects, you know, from heat stress occur.

Do you think that heat, cold contrast, like hot, cold contrast in a situation like that would make it even more beneficial, like going sauna into cold shower?

Yeah, yeah.

Actually cause it cause a nitric oxide release or anything like that?

Yeah, it does. And it does cause nitric oxide release. And it also, I've seen a study where they did sauna and then cold, cold shower and it caused an even more robust release of norepinephrine from the glucose corolleus so that I found very, very interesting because, you know, I'm interested in norepinephrine for one. So there are, I think people like the Russians, don't they do this heat stress and then jump into a cold ocean or something like that after. Or maybe the Finns do it as well.

Yeah, they do a lot of those crazy countries with, with, with amazing warriors who are, who are super tough. Like, like Vladimir Putin.

Right. But I mean, honestly, to get back to your question in terms of the time spent in the sauna, you know, it really does. When you're in the sauna, you'll feel, you know, your heart rate elevate, you'll feel that dynorphin that you're expressing where it's uncomfortable. And that's really the key, getting to that point where it's just uncomfortable enough for you to want to get out. They've shown like in studies that when they put people in the sauna and they let them stay into that point, whether it's physiologically and psychologically hard for them to stay in, that's the point where they start to have all these mechanisms kick in where their hypothalamus related mechanisms kick in.

That makes sense because you don't get a runner's high if you're out in an easy jog. You only get a runner's high high after you go through the discomfort.

Exactly.

And actually I interviewed Steven Kotler who wrote the Rise of Superman, and he talks about this, how the theta brainwave release necessary for you to tap into the runner's high and get into his, what he calls the zone, that you actually have to have physical discomfort present.

You do, you absolutely do. And that's part of that dynorphin endorphin system that I discussed earlier. But I think that people, people will know when you're in there and if you're, you know, if it's easy for you to stay, stay in there. You have to kind of get to that point where you and I talked about where it's like you can't, it's, it's no longer comfortable and you're, it's really hard to stay in. That's the point where you start to get. All these mechanisms start to kick in. So, you know, I think. And you don't want to push it too much. I mean, obviously, you know, heat stroke is a very serious thing, so you don't want to staying in there an hour. You know, I've done it as well, and sometimes I'll Take a big mason jar, you know, glass jar of, like, water in there with me to help.

Yeah, yeah. You have to push it. Like, honestly, like, I hear what you're saying, like, we don't want to recommend that a bunch of people go do this and then have. Well, I'm just saying that for selfish reasons, I don't want to lose podcast listeners to heat stroke. Right. Because that'll affect my podcast download numbers. But basically, I feel the best when I get myself to the point where I am just a little bit dizzy, like, just slightly, slightly scared that maybe I stayed in for too long. That's when I feel the best when I actually get out. So I think you do have to tap into some amount of discomfort. But, yeah, like you said, I mean, obviously, you got to be smart, too. And what were you saying about taking the mason jars?

Oh, yeah. So I take a big mason jar of water in there, and. And it helps me, you know, stay in longer because I have some water to drink.

And, you know, do you ever dump the water on the sauna rocks if.

You'Re on a. Yeah, yeah, yeah, I have.

And then.

And then it gets really hot.

I. I did that the other day, and a guy who was sitting there started to get angry with me because he said that the chlorine in the water was getting vaporized and would wind up in your lungs.

Interesting.

Yeah, I thought that was an interesting take on. I didn't care because I actually had filtered water from my home and there wasn't chlorine in it anyways. And I explained that to him, but I thought that was interesting that maybe if you are dumping water on the coils in a dry sauna, tell me. Yeah, maybe you want to be careful about where the water came from. So, anyways, though, I want to talk a little bit here. Kind of flip around from the brain and talk a little bit about endurance, because we've got a lot of listeners who are athletes who are doing everything from marathons to triathlons. Can you talk a little bit about the actual biological mechanism that would occur via which heat could theoretically actually help with endurance?

Yeah, yeah. So, I mean, obviously, this is your expertise being an endurance athlete, but heat. So heat, stress from the sauna will. What it does is it causes vasodilation, and you get increased plasma volume and increase blood flow to a variety of different tissues in your body, including your heart, your skeletal muscles, and also your skin. And what ends up happening is that you. These biological mechanisms kick in where you train your body to be able to deal with this heat stress. So for example, if we're talking about increased plasma and blood volume to the heart, what happens is you're now reducing the cardiovascular strain on the heart so that the amount of blood that you're. It's easier for your heart to move blood to various tissues. Right. So it lowers cardiovascular strain, which is one of the biological mechanisms by which heat stress can improve endurance. It also increases the blood flow to your skeletal muscles. So that's obviously carrying things like esterified fatty acids and glucose as well as oxygen to your muscles. And what's been shown is that if you're increasing the amount of sterified fatty acids and glucose going to your muscles, then at that point where your endurance athletes usually have to rely on their local glycogen stores when they've basically exhausted, when you're running a marathon or something like that, your body will rely on local glycogen stores as a source of energy for your muscles. What they've shown is that endurance athletes that train in heat, they'll actually rely on glycogen stores less because they increase blood flow to the muscle, skeletal muscle carrying.

So what are they using instead of glycogen?

Well, they're using the glucose and stuff still because of the increased blood flow to the skeletal muscles.

Okay. So you basically got more glucose and theoretically, I guess if you were eating like a decent diet, like more glucose, more fatty acids, obviously you have to deliver less glycogen breakdown.

Right. I mean, you know, the point is that you're, you know, at some point you might end up relying on the glycogen stores no matter what. But if you are having that increased blood flow to them, then it's just getting more of it there quicker basically. So it is interesting. It is interesting.

Has that. Do you know if they've actually looked at that like, like from say like a muscle biopsy level? I mean, I know that there are so many studies that should be done that haven't been done yet, but have they looked at like heat treated versus non heat treated athletes and actually checked out to see if during exercise they're, they're maintaining higher levels of muscle glycogen during exercise?

I think there might be a study that did do that. I'd have to look back at my references because I can't remember off the top of my head. If there is, I'll link you to it, I'll send it to you.

That'd be interesting, right?

That would be a really good way to directly show that.

Yeah, I'M actually looking at a reference here from the 80s from Journal of Applied Physiology. Late 80s substrate utilization in leg muscle of men after heat acclimation. I wonder if they actually did a muscle biopsy to look at whether or not you had higher glycogen levels after heat acclimation.

Right. Yeah, I think they might have, actually.

That's pretty cool. I had no idea they were actually studying stuff like that. That's very cool. It is cool. So we've got better maintenance of muscle glycogen. We've obviously got increased amount of plasma, and so we've got higher blood volume, which is obviously a great cardiovascular improvement. What else?

Right. And thermoregulatory mechanisms. So when you're training your body to heat stress the hypothalamus, so the heat sensing neurons in your hypothalamus get activated. And what ends up happening is the more you condition your body to that, they get activated at a lower core body temperature. So you actually begin to dissipate some of that heat earlier, you know, at a lower core body temperature. And also you can maintain it for a longer period. And so you end up cooling your core body temperature. And I don't know if you've noticed this, but I know that I sweat because I'm pretty athletic as well. I end up sweating easier. I think a lot of athletes might notice that. Yeah. So that has to do with. Because when you're exercising, you're obviously also elevating your core body temperature and the same heat sensing neurons are getting activated and such. So it's another mechanism by which you're able to maintain this thermoregulatory homeostatic mechanism that helps you deal with this elevated core body temperature. I mean, that's part of the reason a lot of endurance, when you're going for a long run, when you're getting super, super hot, you just want to stop. There's something going on at that level of the brain that you're just like, God, I can't take this.

Yeah. If the central governor begins to shut your brain down, I mean, there's a few different things. Well, two of the things that the central governor senses, two of the biggest things are your core temperature. And then, interesting. Also your blood levels of amino acids. That's another one. That your brain will tend to shut things down pretty quickly once your blood levels of amino acids drop. And actually, this is kind of interesting. They've done studies on muscle glycogen and found that the infamous bonk that we've all thought was just Due to pure carbohydrate depletion, you still have carbohydrates stored when you bonk, but if that's in the presence of very, very low blood levels of amino acids, you'll still bonk.

So interesting. That is interesting.

Total sedgeway. But yeah, yeah. Now I have to ask this question because I'm sure some people are wondering it like this is all great that it increases plasma and maybe staves off some depletion of muscle glycogen and improves thermoregulatory control. But does it make you faster? Like have they actually looked and found out like you know, are the folks who are doing heat acclimation actually faster?

Yeah, so faster. I'm not sure that one of the studies they looked at runner, male runners that did a 30 minute sauna session two times a week for three weeks after their workout. What they found is that when they had those runners run to exhaustion that they could run longer. So.

So increased time to exhaustion basically.

Right, yeah, yeah. Which would make sense based on the mechanisms that I just described. And they also noticed that these people had, these runners had an increase obviously their plasma volume increased but they also had an increase in the red blood cell count which they think was a. If you're increasing your plasma volume there's a compensatory mechanism. Your body will obviously wants to maintain homeostasis. So it increases red blood cell count also to keep that hematocrit count.

Right. So if your plasma volume is going up, you'd theoretically it doesn't do you any good if your plasma volume goes up if you don't have more red blood cells.

Right, exactly, yeah. And they've theorized that the increase in RBC count is due to increase in epo but they haven't actually proven that yet. But the faster I did some experimenting with it like I said back in graduate school I was really, really doing lot of sauna sauna training with, with my running as well and I noticed you know, increase in my personal running time. So I would. So you know that. And that's totally anecdotal.

Yeah, no, myself as well. Just from an N equals one standpoint I've totally noticed that it makes a big, big difference especially when you are actually exercising in the heat. Like that's where I've seen a huge difference. I did the whole minimalist training for Ironman Hawaii last year where I tried to train eight hours a week to be able to complete Ironman in less than 10 hours. And I actually this was kind of a Cheat. I didn't include the time that I spent sitting around in the sauna reading magazines like as part of that, that eight hours. But I still think that that played a huge role in my ability to be able to tolerate the heat stress without excessive amounts of exercise. So. Yeah, but you know, that that's just totally anecdotal. Now, what about people who are maybe not so interested in endurance but are wanting to go after this from like a muscle gain type of standpoint or hypertrophy standpoint?

Yeah, really one of the cool things about the sauna, or you know, what I'm calling hyperthermic conditioning, where you're conditioning your body to heat stress in order to be able to deal with heat stress later on, obviously better. I think that this is sort of like a hormetic response. You know, it's really actually a classical example of hormesis where you're giving your body amount of, you know, eustress, good stress. You know, exercise is a good example of that. Heat is also can be a eustress. As long as you're not doing the, you know, overdoing it. You can, you're actually going to activate some genes that help you deal with, with heat stress or help you deal with stress in general. And one of the really cool genes that get activated in response to heat is called heat shock factor one. And it's a transcription factor that activates a variety of different downstream genes that encode for heat shock proteins. These are called HSPs. These heat shock proteins are really, really cool. They play a role in making sure the proteins in your cells are in their right structure, meaning they're properly folding and doing what they're supposed to do. They also have antioxidant activity, so they can scavenge radicals and alleviate a lot of that oxidative stress that occurs from normal metabolism. It occurs during exercise. So having a high expression of these heat shock proteins is a good thing. That was one of the things that I found really cool about heat stress is that it very robustly activates these heat shock proteins. And the heat shock proteins have been shown to play a role in preventing the degradation of proteins, specifically in muscle tissue. So if you think about it, could.

You have too many heat shock proteins? Could you overdo it?

Well, I mean, having true, if it.

Is a hormetic effect, this just makes me think about this just because this whole hormetic effect thing is based on, on damage. Right. And so I'm just wondering if you could, if you did like a sauna session Every day get so much heat shock protein produced that it would potentially cause, like some kind of an immune system bounce back or something like that.

Heat stress does actually can depress the immune system because it is a very strong stress. The heat shock protein response is actually the good thing that you want, you know, to counter some of the. Because heat stress can induce apoptosis, it can induce damage. And the heat shock protein response is what counters that. And actually they've shown that people that have polymorphisms in their genes that encode for heat shock proteins that make them more functionally active have increased longevity. So I think having more of the heat shock proteins itself would be a good thing. But I do think that you might have doing something like the sauna every day would be such a strong stress that even having those heat shock proteins won't be able to counter that at a certain point. Okay, cool.

Yeah, so if you're listening in, don't go download four hours worth of podcasts and subscribe to 18 magazines and go visit the sauna for like two hours a day. Like, yeah, it's not. Definitely not a more is better type of thing.

Yeah, that's a little bit extreme.

So in addition to heat shock proteins, what else can happen?

So also, there's been a really robust induction of growth hormone. And this, this has been, you know, this is part of the, I think, stress response as well. They've shown that, you know, if you, if you're in the sauna for 30 minutes, for example, you can express, you know, you can increase your growth hormone by like twofold over baseline. In some cases, they can, they can activate it like 16 fold, but that's pushing it to an extreme case where you probably don't want to. You don't want to do that. But obviously. So heat shock proteins are important because they've been shown in mice to prevent the oxidative stress that increases protein turnover or protein degradation in skeletal muscle. So if you're exercising and you're having an increase in oxidative stress, the heat shock proteins can sort of sequester that and prevent them from breaking down muscle.

So what if you were already injured? Do you think that the production of heat shock proteins could assist with more rapid healing of injury? If you'd use SANA as an injury healing protocol?

Yeah, so they've shown that. They've shown that in mice, when they immobilize a mouse, they'll put a little cast on its leg, on its little hind limb and keep it immobilized. Yeah, keep it immobilized for like a week. And so what they've shown is that if you take these mice and you either heat shock them a group or you don't, and heat shocking being like 30 minute hyperthermic treatment, so sort of like a little mini sauna for the mouse, that what happens is that after immobilization, when they measure, when they look, when they sacrifice the mice and they look at the soleus muscle, they find that the ones that were heat treated had 30, they basically lost less of their muscle. And also what they've shown is that after immobilization, when they allow the mice to run around again to regrow their muscle, that those mice that were heat treated can grow more muscle, in fact like 30% more muscle after the immobilization. So they've definitely shown that heat shock proteins play a role in that. I've noticed myself when I've been injured and I've been sitting in the sauna as a sort of surrogate way of getting some sort of at least some sort of cardio exercise. And in my mind at least sitting in there, I get my heart rate up. I've noticed that I've lost less muscle when I'm using the sauna as opposed to when I don't, when I'm injured and I just can't do anything. And that's totally anecdotal, like I said.

I think this whole heat shock protein thing is interesting though, because you talked about how it increases endorphins and there's this physician and I've had him on the podcast before. His name is Dr. Mark Serkis and, and he lives in Brazil now and he's actually written books on hyperthermia for cancer. And he's talked before on our podcast about heat shock proteins and activation of T cells and lymphocytes and how it can have like this anti cancer effect. To use hyperthermia treatments. He uses infrared saunas and infrared masks. Like he has his patients lie on these. Actually, I have one on my bed, it's called a biomat. But he uses infrared for cancer and immune system activation. And he says it's because of the heat shock protein.

Yeah, that's interesting. What I know about heat shock and cancer cells. So cancer cells are primed, they are expressing a lot of what's called apoptotic proteins that are making them, you know, that are priming them to cell death. However, they've countered that by expressing a lot of these anti apoptotic proteins and that's how they sort of keep going. Because there's a balance between these pro death and anti death proteins that they're expressing. So because they have a high amount of these high, you know, these pro death proteins, any sort of stress that can push them over that edge can induce cell death. And because heat stress is a very severe type of stress, it can actually induce apoptosis in cancer cells. And I know that, for example, they use that in conjunction with chemotherapy as well because it does kill cancer cells much, much better. When you have stress plus stress, it equals death. Eustress a little bit of stress, you get hormesis. But too much stress, you're going to get cell death. But in terms of the heat shock proteins and the immune system, that's an interesting angle that I wasn't aware of.

Yeah, well, I actually bought one. Maybe I'll ask you more about the type of sauna that works well. But I bought one of these infrared mats and I sleep on it in the afternoon and I wake up feeling like a million bucks. I don't know if it's because of the dynorphins and the endorphins or the heat shock proteins or what, but I think even that is giving me a little bit of a heat effect.

Yeah, heat shock proteins are awesome.

Yeah, Yeah. I wish we could just bottle them up and drink them. Okay, so what else? When it comes to like muscle gain or endurance or. Cool. Physiological effects occur with exposure to heat.

Yeah. So I mentioned the growth hormone, which is another really cool. You know, obviously going to. They've shown that, you know, growth hormone can, you know, prevent the breakdown of proteins in the muscle. Right. So if you're looking at a balance between muscle breakdown and muscle synthesis, you know, or protein synthesis, I guess would be more accurate, then, you know, anything that can prevent the breakdown will have a net increase in protein synthesis. And Also, you know, IGF1, which is downstream mediator of growth hormone, activates MTOR, which is really important to make proteins. So you're talking about being able to increase protein synthesis at the level of actually producing or making proteins through mtor. So that's another, I think, interesting effect of heat stress. But it does depend on the amount of heat stress. So you really have to push it to that, like we were talking about to that degree where you're like uncomfortable.

So does that mean that there could be like some kind of an anti aging or longevity effect?

There absolutely is an anti aging. But by the way, when I'm talking about like the effects on muscle growth, you obviously need to you know, be applying a workforce like a force to your muscle tissue. So you obviously, in combination with working out, lifting weights, I mean, you can't just sit in the sauna and expect to, like, grow muscle. Like, that's not how it works.

You can't just go to Whole foods every day day and do yoga every morning and then visit the sauna and turn into a beast.

Yeah. I mean, you obviously need to be applying a workforce to your muscles to make them grow. But I'm saying in combination with that can help. But anyways, to your longevity thing. Yeah, it's really interesting. I did some research. Some of my early research was on aging. And one of my first publications that I was a part of was a science and published in science. And it actually had to do with heat shock proteins and the role heat shock proteins played in preventing the aggregation of amyloid beta protein, which is known to be one of the toxic proteins involved in Alzheimer's disease, where it aggregates in the brain. And what we found is that when we were using this worm model for Alzheimer's, it's kind of funny because worms don't really have brains. We would actually transgenically make them express amyloid beta proteins in their muscle tissue. And what would happen is as these worm age, they express this. Amyloid beta would start to aggregate in their muscle tissue and they become paralyzed like they couldn't move anymore because this protein was just toxic and aggregating in their muscle tissue. And what we found is that when we genetically engineered them to express high levels of heat shock proteins, this ameliorated that effect where it delayed the onset of the paralysis. Like it. Because the heat shock proteins were able to help the amyloid beta protein properly fold and help it not aggregate. These worms were actually. It delayed the onset of that.

Well, with amyloid beta proteins. And I think it was. Do you know who Nora Gidgautis is?

I do not.

Okay. She wrote this book called Primal Body, Primal Mind. She talks about brain inflammation. And one of the things that she talks about with aging is formation of amyloid plaques in oral tissue. Is that related to these amyloid beta proteins?

That's exactly what it is. Yeah.

Okay.

We were using the same protein and making worms express a high level of.

Theoretically here you could stave off the accumulation of plaques in the brain that can lead to accelerated brain aging. If you were to do something like make sauna a practice.

Yeah. And also exercise, because exercise also induces heat shock proteins because you're also elevating your core body temperature. And I think that's part of the mechanisms by which exercise can protect against brain aging. So heat shock proteins, you know, they've shown in worms and they've also shown in mice, when you genetically engineer them to express more of them, it extends their lifespan. And so that's, you know, and then in people, if you look at people, I think I mentioned this earlier in the podcast, people that have polymorphisms in their heat, the genes that encode for their heat shock proteins such that it makes them express more of them, they're more functionally active. It's associated with longevity and living to be in your hundreds. So heat shock proteins play a very interesting role in aging. We, as we age, express less, so the gene expression goes down. So anything that you can do to increase their gene expression, in my mind, is really good. And they've shown that there's an epigenetic mechanism by which heat actually increases the expression of it. So, you know, people, for those listeners out there that are like, what is epigenetics? And, you know, things, you can actually change the expression of your genes through different environmental signals. You know, things like exercise, heat, sleep, what you eat, you can change how much of your gene is expressed. And this happens through mostly through methylation of regions of your gene that are important for activation or also acetylation. Methylation is often associated with decreasing the expression of the gene, and acetylation is often associated with increasing expression. What they've shown is that heat stress will. They've shown this in chickens, actually, and also in mice. What ends up happening is when you heat stress, the promoter region, which is that region that's important for activation of a gene, gets acetylated in heat shock proteins, genes that encode for heat shock proteins. And so you end up getting more activation, not only like when you're heat stressed, but also just under normal physiological levels. So just under normal conditions, when you train yourself to be, you know, when you're conditioning yourself to heat stress, you will then express higher levels of heat shock proteins. And this is really cool. They've shown it in chickens and also in rats. They did a really cool experiment where they took, like, baby chicks that were like three days old and they exposed them to heat, and then they exposed them to heat again at one week. And what they found is that they had higher levels of heat shock proteins in general. And also when they were adults, when they exposed them to a really, really severe heat stroke, like stress, like the bad sitting in the sauna for two hours kind of thing, it protected them from mortality. So from heat stroke induced mortality compared to the chickens that were not conditioned to heat early on. So there's really a cool epigenetic mechanism in play that conditioning your body to heat stress. You can express more of these heat shock proteins.

That's really. I'm going to start driving around everywhere in my car with my heater turned.

On.

And if any of my passengers ask why, I'm going to tell them because I want to lift to be 100.

Yeah, it's also cool heat shock proteins, it does protect against some of the toxins. So. So your question about the alcohol and killing brain cells. Well, the thing is that if you express more heat shock proteins, it's been shown that the heat shock response can actually protect from that neuronal cell death that's induced by things like alcohol or even heavy metals and other xenobiotics. Obviously, the heat shock response is part of that hormetic response. So when you are taking things like EGCGs, these little things that are a little toxic to the body that induce this hormetic response, heat shock proteins are part of that and they do protect against some of those toxic effects. Really, I think I want to just draw the parallel again between exercise and sauna, because the point is that exercise also induces the same physiological effects that heat stress does. Because when you're exercising your heating your body. Right. I mean, that's part of the cool thing about exercise. And I really think that some of these benefits of exercise come down at the molecular level to heat shock protein.

Yeah. The interesting thing is, I think I already mentioned when I was talking about the central governor, Timothy Noakes, this South African exercise physiologist, he's done studies on core temperature, and specifically he started doing the studies to disprove the idea that staying hydrated during exercise would somehow keep your core temperature regulated. And the fact is that he was kind of right. We have to drink way less than what we've been led to believe to keep our core temperature low during exercise. But what he also found was that you got to be exercising pretty freaking hard to get your core temperature up. And so I don't want to turn this into the. The go into sufferfest mode in a sauna and then destroy yourself in the weight room or on the treadmill type of podcast. But I think it does point out the whole idea here that discomfort is a good thing. Like in many cases, mild amounts of discomfort are a good thing. And it sounds like in the case of whether it's a sauna or exercise Part of it is not just whatever, breathing hard or movement of blood flow, but it's the actual increase in temperature causing these heat shock proteins to be produced.

Absolutely, it absolutely is. And I think that, you know, the.

Sauna make it hurt, People make it hurt.

Exactly. In combination with exercise, I think the sauna can have, you know, really, really good benefits like the ones that we've already discussed. So it's something, it's something to keep in mind.

Yeah, there's this, there's this guy, he's the 70 plus year old Ironman world champion and he has this rule, he says go anaerobic every day. I love that. So that's a, it's a good way to get, get the heat up. So I'm curious, when we're talking about heat, like you and I have talked about saunas a lot, like just these basic dry saunas that you're going to find in the YMCA or a health club or wherever. But have they ever looked at the effects of different kinds of heat? Like because we have steam rooms, we've got saunas, we've got those dorky sauna suits. There are now of course in health circles, like I already mentioned, like, like, you know, I sleep on a, on an infrared mat and there are people installing like infrared saunas in their homes. I've even seen these, these nerdy looking like pop up infrared saunas that you just like put in your living room and stick your head out of and just kind of sit there for a little while in your infrared. Like have you ever looked at all these different kinds of heats and, or specifically has research ever looked at this stuff and found any one type to be most beneficial?

Right. So I haven't seen studies directly comparing infrared sauna compared to like a normal dry sauna in terms of the heat shock, protein response or you know, the effects of norepinephrine or growth hormone or bdnf. I haven't seen studies directly comparing those two types of heat stress. But I will say that, you know, the whole point is heat stress and getting to the point where it's physiologically uncomfortable, you know, and so if you think about something like a steam room, I do think that, you know, these types of heat stress responses can be, you know, achieved from various types of saunas that, you know, or even a steam room in general I think can do that. However, I don't like, I've done a steam, I've sat in a steam room before and I can't get to that point of discomfort that I can get to in a sauna, I think, because for one, the steam room is like wet and so your skin starts to burn. Like you can't stay in as long because it's like you don't, you know, you don't want your skin burning, you know, because of the water.

No, I agree. You get a much greater amount of topical discomfort. And I agree. Like, it seems like you can't get your core temp down before. Just like your skin gets too hot or your lungs get all annoyed by the excessive humidity.

Yeah, So I do think you can. It's not like a steam room won't have any of these benefits, but I don't think they'll be as robust. And this is pure speculation because I haven't seen studies directly comparing them in terms of like.

Well, in exercise research, they have looked at wet heat versus dry heat for physiological adaptations for performance. I know that in exercise they've always found dry heat to be better.

Interesting. Yeah, I have to look at those studies.

But if you look at professional ironman athletes like Chris McCormick and Craig Alexander and these guys training for Kona, they'll set up their bike or a treadmill in a dry heat setting.

Interesting. Yeah. So, yeah, in terms of the infrared sauna, I know there's a lot of marketing hype out there on, well, this. A lot of it has to do with them talking about detoxification. And there are some things that you do sweat out with the sauna. Now, whether or not the infrared sauna does it better, I really can't say that I've seen convincing evidence of that. Honestly, scientific evidence that I find compelling.

I don't sweat at all. When I sleep on that biomat or when I've used infrared saunas, I don't sweat. But what they say with those is that the far infrared rays basically penetrate deeper into the tissue. So you get this hyperthermic effect quicker without. Without sweat. But I don't know, I just feel. I feel like there's more of a performance enhancing effect from a dry sauna and like, maybe more. Maybe there's more of a therapeutic effect from. From using something like infrared. But I can tell you infrared is definitely not as uncomfortable. And I never feel that same type of just like distinct performance enhancing effect from something like infrared.

Yeah, it kind of makes sense to me. My in laws have an infrared sauna in their garage and I've used it. And compared to the dry sauna, which I use more frequently, I don't notice as much discomfort as well. And I think that part of that discomfort, I know part of that discomfort is what's important to activate that hormetic response. It's important to activate that HSP response. It's important to activate a lot of these dynorphin mechanisms we're talking about. So I don't know. I'm not saying that there aren't benefits from using the infrared sauna. I just don't know if it is better in terms.

I definitely think there's benefits. I personally think that the combination of both is really good. That's what I do. I go to the sauna once or twice a week and then I use infrared. Well, almost every day I use infrared. But you know, we've been, we've been going for almost an hour. But I want to touch also on kind of the total opposite of what we've just got done talking about. And that's cold because I've had like Wim Hof the Iceman on the show who takes folks up into like the, the mountains to do these, these yoga cold sessions where they're like sitting in the snow doing power breathing. And, and Ray Chronox, who's been in Wired magazine for his big cold lab for enhancing fat loss through cold exposure. Have you ever run into any of that or studied any cold exposure or cold thermogenesis for biological enhancement?

Yeah, I mean, I know a little bit about it just because I've looked into some of the uncoupling proteins and their effects on thermogenesis. I know that part. So when you're cold stressing your body, I'm going to bring this back to the norepinephrine which is released, it's released by heat stress, but also by cold shock. And I think there may even be a more robust release when you combine the heat stress first and then do the cold shock. At least in one of the studies that I saw there was norepinephrine.

Is that because of the back and forth blood flow?

Yeah, I think so. The norepinephrine causes an upregulation of UCP1, uncoupling protein 1. And this is really important because the uncoupling protein, so your mitochondria, it's expressed in mitochondria. And your mitochondria are, you know, as they're generating ATP, they're inducing what's called a mitochondrial membrane potential. So they're taking these electrons from, you know, NADH and FADH 2, which are made from the TCA cycle when we eat carbohydrates. And we convert everything to pyruvate, blah, blah, blah. We get into that whole cycle and we generate these electron reducing equivalents. Well, the mitochondria takes these electrons and passes it along this chain of proteins, ultimately reducing molecular oxygen to water. And using that as a source to, to make ATP. What happens is it pumps protons outside from the inner inside of the mitochondria to the outside and it generates this electrochemical gradient which is negatively charged on the inside and positive to be charged on the outside. And that gradient is really important because the mitochondria senses like when that gradient isn't happening properly, your mitochondria will ramp up and it will start producing more ATP. So UCP1 uncouples that mitochondrial membrane potential and all these protons start to flow back into the mitochondria. And so the mitochondria is like, oh my God. You know, it's sensing that it's just not making enough ATP, so it ramps up its metabolism. And this is part of the way, this is part of the thermogenic effect. So you know, when you have this uncoupling protein now the mitochondria starts ramping up its metabolism and you start to, to have that thermogenic effect where your metabolism is shooting up. And UCP1 also is involved in lipolysis. So anything that's going to increase in norepinephrine and then UCP1 will then affect thermogenesis, mitochondrial metabolism, and also you'll start to increase lipolysis.

So you get like a lipolytic fat burning effect.

Exactly, exactly. And so I think that makes sense why these people are seeing effects on fat burning. I guess when they're sitting in ice or cold shower or whatever it is they're doing. The other really interesting thing is that they've shown that the more repeated of norepinephrine release, so the more you're training your body to do this, you can actually express more of this UCP1. So UCP1 is in mitochondria, but it's mostly found in the brown adipose tissue.

Right, the back tissue.

Exactly. The bat tissue. And what they found is, you know, like, for a long time they didn't think that we as adults had brown adipose tissue, that we just had it as infants. But now we know we do have brown breast adipose tissue. But what's really interesting is that you can actually cause your white adipose tissue to express more UCP1. The more epinephrine that you're releasing, the more the white adipose tissue begins to express it and become brown, like, so to speak. And that. That's been shown in rats and mice. And I think that's a really cool adaptation.

It's very cool. I need to. I need to get you one of these cool fat burner vests that I wear. Like, I'll work on my computer. And it's this vest that you pack with ice, and it just puts the ice on specific areas where you have more brown adipose tissue, like your collarbone and your upper back. And you can just wear it while you're typing. So you can get that lipolytic effect.

Yeah, I've done the cold shock, the cold shower after the sauna. I don't do it routinely, but like you mentioned doing it. I've also done that a few times. And yeah, it's very interesting, the effects on the brain. Also, what I'm interested in, because not only does norepinephrine increase CCP1, but focus and attention, and I've definitely noticed it helped me with focus and attention.

Yeah. The thing that Ray Kronice does is he does five minutes in the morning and five minutes in the evening, and he does cold for 20 seconds and hot for 10 seconds. So it's called a hot, cold contrast shower. And that he'll have some days where that's all he does. And I've used this before when I'm at conferences, and I know I'm not gonna get a chance to exercise. I'll sneak up into my hotel room and just, like, take off all my clothes, jump in the shower, do hot 10 seconds, cold 20 seconds, and just stay in there for five minutes and then jump out, get dressed, and go back downstairs and you feel like a million bucks for the next couple hours. And I don't know if it's because you get a little bit of that dynorphin or the BDNF effect or what, but it actually does seem to work.

Oh, interesting. Yeah, that's cool.

Yeah. Women can't do that as easily as guys can, unfortunately. Just strip down, jump in the shower, and run back down. But, yeah, it's an interesting strategy. So over at foundmyfitness.com you have a really cool video. And I'll link to it in the show notes for this episode where you talk about heat, stress, and you've got a ton of other cool things over there as well. Do you put out a video, like, every day or how do you know?

I'm doing research full time, so I really work on these videos on weekends or evenings. So I've got this goal, I guess, that I'm trying to do two videos a month or four videos a month. And I guess people are kind of helping. They can patron pledge me like 25 cents a month to help me do that or like a dollar a month. And I've got these milestones that I'm trying to reach to help me to do that more frequently and that you can find that on foundmyfitness.com 25 cents a month.

You're really breaking people's banks, right?

It's pretty cheap. So I appreciate anything that people can help with. But yeah, I've also got a newsletter people can sign up for. And the videos that I put out, I also put out as podcasts as well.

Awesome. Well, I'll link to all that in the show notes. And by the way, I've been taking a few notes as Rhonda and I have been talking and what I'll do for anybody listening in, if you want to go check out Rhonda's video or her website or any other stuff that we've discussed, the URL to go to is BenGreenfieldFitness.com Hot. That's BenGreenfieldFitness.com hot. If you go over there, you can access the show notes for this episode. We'll have it transcribed and everything over there. So, Rhonda, thank you so much for coming on the call today. This is super fascinating stuff.

Yeah, my pleasure. Really interesting conversation, Ben.

All right, folks, well, if you have comments or questions or thoughts or feedback or anything like that, or you have your own special sauna strategy sessions that you use, go over to the comments@bengreenfieldfitness.com hot. I'd love to hear what you have to say. And until next time, this is Ben Greenfield and Dr. Rhonda Patrick signing out from BenGreenfieldFitness.com.

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