WHOOP Podcast - Embracing the Cold: Dr. Susanna Søberg on the Benefits of Cold Therapy

Episode Date: February 1, 2023

This week’s episode focuses on the recovery benefits of cold therapy and cold plunges. Winter swimming expert and best-selling author Dr. Susanna Søberg joins WHOOP VP of Performance Science, Kristen Holmes, for a discussion around one of the top growing recovery behaviors. She has a Ph.D. in metabolism, is the founder of the “Søberg Institute,” and is the leading mind behind the #SøbergPrinciple. Susanna and Kristen will discuss what happens to the skin during cold exposure (4:00), how to best adapt to cold shock (9:18), the difference between brown fat in men and women (13:14), the other ways to activate brown fat through cold exposure (16:10), how scientists first discovered brown fat (22:13), the best time in the day to do cold plunges (26:50), how cold exposure impacts sleep (31:20), how long people should be submerged in cold water (36:15), the #SøbergPrinciple (46:40), the optimal water temperature to benefit from cold therapy (49:30), combining cold therapy with your workout routine (55:32), and how to get over the mental barrier of the cold (1:01:14).Resources:Winter SwimmingThe Søberg InstituteSupport the showFollow WHOOP: www.whoop.com Trial WHOOP for Free Instagram TikTok YouTube X Facebook LinkedIn Follow Will Ahmed: Instagram X LinkedIn Follow Kristen Holmes: Instagram LinkedIn Follow Emily Capodilupo: LinkedIn

What's up, folks? Welcome back to the WOOP podcast, where we sit down with the best of the best to learn what they are doing to perform at their peak. I'm your host, Will Amit, founder and CEO of Woop, and we're on a mission to unlock human performance. We've got a great podcast this week. I want to start by giving a shout out, though, to two of our professional athletes, Rory McElroy and Patrick Mahomes, who both. Both had big Sundays this past weekend. Rory McElroy winning the Dubai Desert Classic in dramatic fashion. And Patrick Mahomes leading the Chiefs to the Super Bowl.

I always find myself a little biased rooting for Wob athletes, but it's very easy to be rooting for Rory and Patrick. Congratulations, guys, on a phenomenal weekend. All right, on this week's episode, our VP of Performance Science, Kristen Holmes is joined by scientist and winter swimming expert, Dr. Susanna Soberg, who has a PhD in metabolism from the University of Copenhagen and is the founder of the Soberg Institute and her science-backed program, The Thermalist Cure. Her methodology and science are derived from the Scandinavian traditions of cold water swimming and its positive impact on the mind and body.

One of her principles is to end cold to increase metabolism and prolong the benefits of chemicals in the brain, a principle that Dr. Andrew Huberman from Stanford University named after her, the Soberg Principle. She's a best-selling author thanks to her book, Winter Swimming, and her research has been featured on the Huberman Lab podcast, the Lex Friedman podcast, the Joe Rogan Experience podcast, and more. Kristen and Susanna will discuss the benefits of cold and heat. therapy, the body's reaction to cold plunges, tips on how to build up the habit of using cold therapy, the methodology of the sober principle, the impact of cold plunges and winter swimming on sleep and recovery, the science of brown fat and its importance to metabolism. Before we dive

into this innovative recovery behavior, I'm excited to share that WOOP is launching a new two-way integration with Hyper-Rice. Connect your WOOP and Hyperize apps through Apple Health to understand the impact of using Hypervolt massage or Norma Tech air compression on your recovery, plus get personalized hyper-ice recommendations based on your WOOP activities, sleep, and recovery data. Pretty awesome, huge fan of Hyper-Ice and check out that integration. Also, if you're new to Woop, you can use the code Will when you're checking out and get a $60 credit on WOOP accessories. You can use that for bands, battery packs, and more.

If you have a question, you want to see answered on the podcast, email. us podcast at whoop.com, call us at 508-443-4952, and it might just be answered on a future episode. Here are Kristen Holmes and Dr. Susanna Sober. I am thrilled to welcome Dr. Susanna Sober to the Whoop podcast. Susanna, through her groundbreaking research and her beautiful book, Winter Swimming, has helped us gain a deeper understanding of our metabolism, brown fat specifically, and its purpose in adults, as well as the outsized benefits that cold exposure can have on our physical and mental health resilience. Based on the depth of her scientific research and experience, Susanna has programs and protocols with the aim of

lowering stress, improving sleep, and increasing both mental and physical health. Susanna, welcome to the Woof podcast. Thank you so much. Thank you for inviting me. Oh, of course. You're making such an impact. I'm just beyond excited for the discussion today. I thought we could start just with the basics of, you know, what's actually happening? when the cold hits our skin. So when the cold hits our skin, we have cold receptors in the skin, and that will be activated as soon as you actually just take your bathroom off

on the daddy or just by your outside in the wind. And it doesn't have to be that cold, actually, for the cold receptors to send this emergency signal to the brain. And in the brain, there's this temperature regulating center in the hypothalamus, which will send them no adrenaline out and they activate our hormones of cortisol and all the stress hormones will go up and activate the sympathetic nervous system. And part of that is also activating the brown fat. So the brown fat is going to be activated immediately as soon as you take the robot.

So you don't have to think, oh, I have to activate my brown fat and then sit for 10 minutes in a hot, in a bathtub with ice in it. You don't have to do that. your brown fat is activated immediately as soon as you just get a temperature change in your skin. So as soon as you get cold on your skin, the cold sensitive receptors will activate brown fat. It will activate all your neurotransmitters in the brain. So noropanathrin will go up by 2.5 o within just a few minutes as soon as you go into your ice bath. and that will make

an huge activation of your brown fat which will then generate heat in your body. That is the main purpose of the brown fat. So the brown fat has to be there to save us as soon as we get cold. And that is also before you go into your ice bath

but also when you're in it. So the first initial minutes it's going to be the brown fat which is trying to keep your temperature in your core up. And that is not the only thing that needs to happen to actually keep you alive or make sure that you don't die. So the sympathetic nervous system is this biological system that we gained during evolution

because we were born, you can say, in the cold and in the heat. So we need to have a system to actually get rid of the heat and also heat ourselves up. So the brown fat is born in that way. So we are born with the brown fat, but we still have it, even though we don't use it outside. live outside to use it anymore. So, but we can activate it in the ice bath, though, when we went to swim or when we go outside, just in the t-shirt. So the vessels will contract because you also need to make a kind of a surface around yourself and make the block go to your core to make sure that your vital organs are not cooled down too fast. And because that's, it's going to kill

you if you don't do that. Right. So the, the blood is going to go to your core. Your neuropenethrine will activate your fight-and-flight system, which then will make your heart rate goes up. Your blood pressure will go up. It's not much. It's only 9 to 12-millimeter mercury. So it's very little, actually, that science show that the blood pressure goes up, and it's very brief that it goes up. Because what else happens is that the sympathetic nervous system is only part of the cold shock. Because what I just described exactly what happens in the cold shot.

It will last for a minute or so when you've been. go in. But the parasympathic nervous system is also activated. And that is because you submerge yourself into the cold water and activates your diving reflex. And that will make your parasympatic nervous system activate, which and your vagus tone as well will be activated. So that will make your heart rate and your blood pressure go down. So that could also make this a little bit of a conflict in the system. And that is also why we say that if you have heart problems or you have unregulated high blood pressure, you should be careful about doing ice baths and just consult the doctor because we cannot say if you can do this on an individual level. So just be aware

of that. Yeah. I think that's a really important call out, you know, that there, you know, some folks could respond negatively to the shock of the cold water and that they, you know, probably need to consult a doctor before taking on any of these kind of protocols. But If we can talk a little bit more about the autonomic nervous system, because I think that's a really important, you know, we obviously track heart variability, which is a function of the heart, but originates the autonomic nervous system. And I think we're, you know, always thinking about, you know, how do we achieve more autonomic balance? And clearly cold exposure is a path to taking more control over your autonomic nervous system in the sense that you're kind of creating a balance between these two systems. So you mentioned, you know, kind of one minute before you actually go from sympathetic activation to parasympathetic activation. Is that kind of, is that where you found in your research?

Is that kind of an approximation? So folks need to stay in the water for at least a minute and then assuming, you know, another maybe 30 seconds to a minute in order to kind of get this dual benefit of, you know, this both sympathetic and paracynthetic activation. Yeah, so there are studies showing that depending on if you are a new winter swimmer or cold exposure cold water in swimmer, then you will definitely have a longer cold shock than if you are adapted. And that is because during adaptation, you will have a more damp response to the cold because you are adapted to it. And that is a process that happens in your metabolism. And also in the way the blood vessels can constrict, because the constriction will also increase the ability to actually constrict the vessels will increase with cold adaptation. So the one minute is just approximately because we cannot really take everyone under one

and say, it's always one minute because it's not. It's going to be between one and two minutes, depending on how adapted you are. Right. Is it the skin receptors that adapt? Like, what exactly is adapting to kind of this shock response? Yeah. So the adaptation goes for multiple systems. So one thing is the adaptation is the metabolism.

So how fast you can, how well your body is at heating itself up, keeping or minimizing the heat loss, you can say. And that is the main purpose for the body when, once you go. into the cold. It has one purpose, just reduce heat loss. And the body gets better and better at that, the more you actually expose yourself to the cold. So the adaptation goes to the constriction of the vessels in your skin. That is one thing. And the other thing is in your metabolism. So the brown fat activation, how fast can you increase your metabolism by activating brown fat, how fast can you activate your muscles, the shivering. Over time, the muscle shivering will actually subside a bit and you have probably experienced this, that you cannot see your

muscles shivering anymore. And people often ask me this question. So don't we get all the benefits out of it? They do. It's just because when you increase, when you get adapted to the cold, the muscles also increase mitochondria and the cells. And they just get more efficient at increasing heat. So they don't have to shiver that viciously or what is that called it so much as they did in the beginning. And also the brown fat is much more efficient because they have increased the amount of mitochondria in the cells. So they are efficient at eating you box. So adaptation goes for the constriction of the vessels, your metabolism, and also how good your capillars are at actually show.

shutting down the blood supply to your skin. And this is also very much an equation about how much fat layer you actually have. How good of a shield can you make on your body to keep the heat inside of you and keep the cold out? But you will always lose in this battle. That is just because if you stay there, the cold water will always win. So it's not like, yeah, it's not like you should try and defeat it or something because you can never built a shield good enough for you to heat up the bathtub in ice water. So the cold adaptation will happen over time, but you should always keep in mind what is healthy

for you. So, and that's kind of like what my research was about, what is actually enough. Right. And it will dig into the exact kind of protocol. What differences that be found in men versus women in terms of brown fat activation and kind of recruiting brown fat? adipose tissue. So in my research, we didn't look at the difference in men and women, but we do see in research

that published from other groups that women actually have more brown fat than men. And I found this very interesting already from the beginning of my research. Yeah, because why do they have more brown fat? But I think today, and this is also something that I write a bit about in my book, that women have more brown fat. That's my hypothesis at least because we don't really have an answer to this. I just want to state that

because there is no, this is just me reflecting, okay? So women have a large, you can say, surface ratio to their mass, right? Because if we are smaller, we have less muscle mass than men have, and muscle generate heat. So men have this other system, which can generate heat in the body that we don't have as much as they do.

So there are two tissues in the body which can generate heat, and that is the brown fat and the muscles. And those two are working together as soon as we go into the cold top. So first thing is the brown fat activating and then the muscles and then the muscle sends a signal to the brown fat about keeping it activated and then they work together to keep you alive. But in women, because we are also colder, because we don't have as much muscle mass as men, we will have colder hands. And this is also what science shows. We have colder hands, colder feet, and we have a smaller heart.

So this all makes sense, I think, because I've looked at the physiology, so we have a smaller heart, which as efficiently as in men, can pump the blood around in your circulation. So that makes sense that the women have a little bit of colder. hands we have actually also colder ears than men do just in general so maybe we have more brown fat because of that because then we are exposed to more cold temperatures or the same cold temperatures but we have to activate our heating system in the body to keep the same temperature at our core as the men you can imagine that they don't have to do as much in the body as we do so So I think...

Right, because they have more muscle mass. Yeah. Yeah. More, they have more muscle mass and probably not as much brown fat because of that because the muscle mass is going to help them keep. Also, they have just more mass to keep the temperature. Wow, that's really interesting. So I suppose, you know, there are other ways to activate brown fat.

You know, what would be outside, obviously, you know, cold exposures undoubtedly like the, the most physiological effective regimen to activate and recruit brown fat? What are some other things that people could do to activate brown fat? So actually, the brown fat is also activated in the heat. The brown fat is not only our temperature regulator on the cold side, it's also our temperature regulator on the heating side, meaning that it is going to levelate our temperature in the body. So if you're getting super hot on your skin,

the body tries to get rid of your heat in your body, because the temperature receptors in the skin is going to send a signal to the brain saying, oh, my skin is getting really, really hot now. I want to get rid of some heat from the body. Then the brown side is going to activate from the inside so you open your vessels and you can let out some the heat yet you have built up. You are about to build up in your body. So heat is definitely one thing that is going to activate the brown side as well.

But everything that actually activates your sympathetic nervous system that is increasing your norophenephrine. because as soon as norapentin goes up, you will have an activation of the brown fat. So when you do exercise, you also increase your heat in your body, and you will activate the brown fat, but you also activate your sympathetic nervous system. Noropenarine goes up, and you have an activation of that. So it's kind of like contraintuitive that you are going for a run, and then you have a sympathetic activation, and then you increase your brown fat activation,

and you heat off from the inside. But that makes you sweat, and that makes you sweat, Yeah. And that makes you sweat and it makes you hyperventilate. And that's how you actually lose weight as well, because that's how you get rid of fat from your blood, from your system. Right. Is there, so would you say the quickest,

if people have to choose between hot therapy and cold therapy, cold therapy would, I would imagine be the fastest route to brown activation? Is that, would that be correct? I don't know, actually. There's no studies comparing... Is cold better than hot, I guess? At activating brown fat? So as the literature goes now, we know that the cold is a very potent stimulator of the brown fat.

Because we have more cold sensitive receptors in the skin, that's going to send a signal that is lightning fast directly from the cold receptors in the skin, directly to the brown fat, and also through a pathway up to the brain. So we definitely know that there are more pathways going from the cold receptor, the sensitive receptors in the skin to the brown fat. But I don't think that we have enough research on the heat. Because I imagine that it could also be that the heat receptors is going to have some pathway also to the brown fat.

But if you think about this from an evolutionary point of view, it's like, would you faster die? from cold that you would from heat, definitely. So it means it does make sense if the brown fat is activated much faster during colds than heat. Yeah, right. But we're guessing here. I mean, I cannot. Yeah, totally. Yeah, no, I know you can't say, but I mean, I think that it does make a lot of sense from an evolutionary perspective, certainly. I, you know, it's funny when I look at my, my hoop data, you know, my heart rate variability and I look at it from a seasonal perspective, um,

am way, way healthier in the winter, which is interesting. And I don't know, you know, it's, you know, I have, I work out outside all the time, you know, a year round. But my body, for some reason, seems to respond better to the cold than it does the heat in terms of my heart rate and heart rate variability. Okay. Even my exercise capacity is better in, in the cold. And, And I wonder, you know, I'll often work out, you know, just in a t-shirt, you know, it will be 30 degrees Fahrenheit, you know, and I'll just be in my t-shirt and in kind of taking on the cold exposure whilst exercising. And that seems to be a really potent combination. Yeah. Is that something that you'd kind of recommend for folks looking to really try to, you know, amplify the effect of kind of this brown fat activation?

Oh, absolutely. Absolutely. I'm not really for any specific type of cold. I just think that if people can increase their health in a way with activating your metabolism, then I really think that you should think about cold exposure in a more broad sense than just going into an ice bath. So if people can go more outside in a T-shirt, I know it's going to, it could also look weird. So I find a place where you would think it's reasonable. I'm in a t-shirt where it's snowy or something. I mean, in your own garden or something, then it could be fine. You could also go out with bare feet. Actually, I just did that in Denmark.

In my own garden, I took a run in the garden with my kids around in bare feet and snow. And that's, I really mean this. This is morning and it has snowed in Denmark. We don't have a lot of snow here. So it's cold, but we don't even have 10 days of snowing just in average in Denmark. So we were happy. We were just running around. And this gave us such an energy boost because it activates your sympathetic nervous system and also an increase in neuropan aspirin.

We got this one feeling inside afterwards. So the feet were only cold for us, very short, a brief amount of time. Right. So I find it very, you can say, healthy for you. If you can go out in a T-shirt, exercise in T-shirt, even though it's a little bit cold, just move a little more, then you will be fine. Yeah. Yeah, I love it. So, Susanna, let's talk a little bit about insulin.

And, you know, in your book, you do talk a lot about the role, you know, of just how cold exposure impacts our metabolic health. If you can just kind of dig into that for a second and just, again, hopefully as another reason why people should take on this behavior of cold exposure just because it's impact on our blood glucose levels. Yeah, so the brown fat is kind of like this very mystical tissue that we have in our body. And I would just want to go back a little bit if it's okay, because I think it has a really, really fun story. And I don't think that many people know the story of brown fat, but it was this kind of mystery, a tissue that was discovered in 1551 by a natural scientist called, his name was Conrad Gesner. And he discovered this in a hibernating animal. And what he also discovered was that this tissue was very different from other tissues in the body. It wasn't like the fat, the white fat, and it wasn't like the muscle.

But it had mitochondria in the cells. So it was kind of like brownish. It was a brown color, but not like the fat and it was not like a muscle tissue. So it was kind of like very different for everything else in the body. And it was only activated with cold, he found out. And in hypernative animals. The researchers then started looking into this, and they found that it was regulating our temperature. And that is very cool to discover, and they did even more into that and found out that it was not only there in hibernating animals, but also in mammals.

So they kind of like lost a bit of the hypothesis around this, that it was only in hibernating animals. So it was kind of laid on a shelf for a bit, the science, but if we just fast, forward to 1966 where a researcher discovered actually the brown fat in humans in infants they saw in autopsies that they had this very large piece of brown fat on the back and they figured wow this is very amazing it's because the infants the babies can shiver in the muscles so it makes sense that they have this kind of tissue with a lot of mitochondria inside it's not like the muscles it can be activated with just a little bit cold on the skin and then it will heat up the baby so it doesn't freeze to death because it's so small in its mass but it has a very large surface right so it's

very exposed you can say but it was not only until it was only until the millennium that people that researchers got really interested in the brown fat so it's a very new kind of science you can say because we didn't know why we had this and we like thought well if infants have this, but adults have lost it. So we kind of decrease the amount of brown fat as we grow up. But in around a millennium, they found that adults also have this. And they saw that if it's activated, that it uses fat and sugar from the bloodstream to keep it activated. And that increases your metabolism. And that was kind of a major breakthrough because they also saw that in obese subjects were exposed to cold, that they can also increase their insulin sensitivity

and also in humans who are not just healthy, that if they were exposed to longer times of cold, they can increase the metabolism and insulin sensitivity, which is kind of like a measure of how good your metabolism is and how healthy you are. So if you can increase your metabolism just by being cold and you can make your brown fat eat your calories in that way, That is why it's really healthy in a good way. And without even taking any pills, it's just supernatural way of increasing your health. Wow. I love it.

That's a great explanation. And I think just for folks listening, again, you know, insulin sensitivity is good. We want to be sensitive and insulin resistance is bad, just so people know the difference. Yeah. Thank you. That's amazing. what would you say when we think about cold therapy, you know, I just, when you were kind of talking about obesity, and it made me think about, you know, the timing of eating and, you know,

and how that kind of impacts, you know, when folks, when we look at kind of obese populations, folks that don't eat breakfast tend to eat a lot more in the evening when they're during their inactive phase of the circadian rhythm. I'm wondering if, you know, cold therapy kind of has a similar play in that, you know, is it better to do earlier in the day or in the evening? You know, how would you, what would you recommend in terms of timing of cold exposure? I don't think that we have enough research on how exactly the cold exposure, this kind of cold shock and acute stress to the body affects our rhythm of the day, so our circadian rhythm. I think that we need a little bit more research on that

to say exactly when, on what time of the day would be optimal. But if we just look into what does the code do in our body, we can maybe do some assumptions on when could it be good for some people to do it in the morning if, for example, this is also why it's so different. And I think different protocols could apply to different people, So if you are a person who maybe find it very hard to get up in the morning because you probably don't have as high a spike of cortisol in the morning

where we actually see that very natural to wake up, you could take a cold shower. Cold shower will wake you up and that's going to keep you fresh for many hours and then you are already up and running. You can say in your system and you have a natural boost of that. If you are a person who maybe doesn't find it that easy to sleep, It could be very good, maybe in the afternoon, because then you have some hours to, you can say, get your adrenaline levels down again. But at the same time, you have just given your metabolism boost and then also your muscles, and then you get a little bit tired some hours later.

It's at least very natural to do that. But I've heard people say also they do it before they go to bed, and that makes them sleep very well. So I would say we could definitely need some more research on that. Okay, yeah. You know, I think just, you know, considering just the loop data that we have, you know, where there's thousands of people kind of logging this behavior, it would be interesting to see the timing of when they logged it, you know, and just to see if there is any, you know, kind of impact on how that might impact some other behaviors.

Exactly. Yeah. Yeah. I think, yeah, I think there's, there's a lot to, to dig in there. Again, I think you make an important point that it is so, there's a lot of individual variation, right? And, but I know, you know, for me personally, like, I would, I'd never do an ice bath during the kind of, I would do an ice bath during the active phase of my circadian rhythm. So when the sun is up generally is, is when I would engage in an ice bath just because of the, you know, all the, the, the kind of hormones that it activates and, you know, just these, it makes me feel. It makes me feel. very alert. And I think, you know, it was interesting looking at the ice bat data. And we also looked at it in relationship to our to sleep. So the individuals who log these ice baths, you know, on those days, what actually happened to their sleep? So we looked at sleep efficiency. We looked at sleep architecture. They're kind of overall performance, you know, which is basically how

much sleep they got compared to how much sleep they needed. And then we also looked at sleep consistency. Okay. And the only thing that cold moved around. And again, we don't know that we didn't examine the timing of the cold, which I think I'm going to go back in and look at. We didn't look at the timing of the cold because I think there is probably some sort of circadian component there that would be interesting. But we saw that the individuals with the largest change that we saw was in sleep consistency, which of course, is a behavior of when we go to bed and kind of when we wake up. And we saw that consistency, average sleep consistency, increased 2.6% when members recorded taking an ice bath that day.

So I think it, you know, you've mentioned when you go into the ice, into the, you know, a cold, when you go to cold exposure, you get the spike in cortisol. So I'm wondering kind of the relationship between kind of kelk cortisol and melatonin, if in fact, you know, this kind of extra spike in cortisol is in some way affecting melatonin production at night in that, you know, it's kind of more amplified. So the signaling that happens when, you know, it's almost like amplifying the signal, I guess, the pathways, right? When we're getting exposed to this, you know, cold exposure in the same way, potentially, that exercise kind of helps us maybe fall asleep or feel sleepy kind of more naturally. I don't know.

I'm curious of just this relationship if there's anything there. Yeah, so I still think that we more research on that in order to maybe. say so much more about that. I think that it's really, really interesting data. And I think it could be really interesting also to do a study on that so that we can look at the correlation also and see, because in my study, we did see that the winter swimmers, who were, they were adapted winter swimmers, they've had been swimming for two seasons. And the control group were matched on age and due to max so fitness level. And also they were pretty good matched these two groups, but the winter swimming group adapted to cold water, they had this spike of cortisol

in the morning, which was higher than the control group, which could indicate that they have a better metabolism, they have a better circadian rhythm, they have a better waking up, you can say clop in the in the body to get up and get started with the day. So it definitely has some kind of relation there, but we need to know more. But I think melatonin is a really good one to look into, it also increases in the cold. So it would be interesting to see what's the relationship there. A lot of hypothesis here. I know, I know.

I mean, I think it's interesting. I, you know, yeah, because the melatonin basically promotes recruitment of brown fat tissue, right? Yeah. Which obviously increases thermogenesis. And yeah, and that has a circadian component. Yeah. Yeah.

Yeah, I feel like this is really interesting. It is really interesting. The brown fat has a circadian rhythm, which we didn't really know, but we found that in my study in humans. We did see it in my studies. There was at least one study published at that time showing that there was a circadian rhythm. And also that this circadian rhythm could be, you can say, amplified with cold exposure. So it was, the mice were exposed to cold and they had a circadian rhythm, which we didn't know at that time. But we did see in my study that the circadian rhythm of the brown fat was actually not following the core temperature,

which was a bit surprising because usually the core temperature is what is setting, you can say, the temperature. And the body really tells us whether your metabolism is up and whether it's down, are you sleeping or not? So that's your rhythm. But the brown fat was not, didn't decrease, you can say, in the same rhythm as the core. temperature before night and it increased actually before the brown fat activation increased so the temperature of the brown fat increased before the cold temperature so the brown fat temperature was not controlled by the cold temperature apparently it was maybe the other way around but again we need more research on this yeah more researched yeah this is great this is just two researchers just

exploring what can we do and this is so much fun i know i know i I know. Well, yeah, I mean, I think that it's kind of always getting to that next layer, you know, of really trying to understand what exactly is happening. And I think to your point, like, you know, this is all like very novel research, you know, like there just isn't a lot of research, you know, in this area of kind of cold and what's actually happening mechanistically. And I mean, you've uncovered so much, you know, but I think what's interesting is that there's, you know, these, it ends up impacting potentially other behaviors that are also health promoting, you know, sleep consistency we know is. one of the most important behaviors that we can take on in terms of, and because of its relationship or kind of correlation to kind of mental and physical health resilience. And I see this a lot in the research that we're doing here at WOOP on my team is doing. So it's, you know, I'm kind of always interested in, you know, how do these behavior like cold exposure? How does that impact other systems in our body that actually, you know, potentially subconsciously is kind of pushing us towards the other behaviors that are really health promoting? For example, you know, because we,

we've got this amplification of cortisol, you know, release, you know, that somehow impacts our melatonin, which makes us feel sleepy and it allows us to kind of go to bed at a stable time, you know, each day. So I'm interested in kind of these relationships and I think that there's, yeah, there's a lot of really exciting things to explore there. It's so interesting. Yeah. So exciting. One of the, you know, we've, so we've talked a lot of, you know, just about just winter swimming. It may be before I want to talk about cold showers and just the difference between, you know, of winter swimming where you're getting you're surmerging you know neck down basically in the cold and and you you've mentioned that it's it's different for

everyone but how long on average should people be spending in the water to kind of get all these benefits if they're doing winter swimming and then we'd love to talk about the answer dam study and kind of go into kind of cold showers and the benefits there and the differences yeah so so cold immersion is definitely affecting your body in a totally different way from going into a cold shower. So when you do cold immersion, cold water immersion, you will activate your sympathetic nervous system and also the parasympatic nervous system and your vagus nerve. So you will get the activation of the energy and you will also get the more calm and resting

mental balance afterwards because you have activated your serotonin and you have that release in the brain as well. So you would get this calm and nice and resting feeling afterwards where you just feel very good and you feel very happy because of all these happiness hormones also being activated. For example, dopamine going up by 2.5x and the neuropenaphrin going up also 2.5x and up to 500 or 5 times about baseline. And this is within minutes just by subverting yourself into cold water. So going into an ice bath or winter.

swimming is definitely going to impact your whole autonomic and nervous system and you will get the benefits of all that. But when you go into a cold shower, you will activate the sympathetic nervous system because you won't get that submersion into a cold water which will activate your diving response. So you will get some other benefits from going into a cold shower. And a study from Amsterdam, which you just mentioned, but the study from Amsterdam is the only cold showers study that we have is a randomized control trial, where they had looked into different groups where they put people into cold showers for 30 days and saw warm showers only group and a group who did warm showers and then turned the handle over to a cold shower

for 30 seconds and then 60 seconds and also 90 seconds. And they did see that the group who did the cold showers at the end had fewer sick days from work. So this could indicate that they had an increase in their immune defense or immune system. So they had this better immune defense in the body going. But in the control group, they didn't have that. So they were still going with the same rate as they usually do with the sick rate. But the sick leave in the other group was actually. lower. But this could also be not only because of the immune system being boosted. It could

also be because they just got happier and it could be because they got a better feeling about themselves. So being maybe a little bit sick, but being happy at least, that being more positive-minded around just the world and yourself will make you get up in the morning and go to work. So it could also be an impact on all of these things that actually don't think is that important, whether it's only one thing or another. I just think it's the behavior of this, I think is amazing because you got up, you get, you did go to work. It could be a combination of the good hormones, the happiness hormones going in your, in your brain, but it could also be the activation of your immune system. So the activation of the immune system happens because

when you go into the cold water, you have a boost of lucosurts and monosurts in the body, which will then also clean up some of the, you can say, inflammation in the body and that is kind of like the main thing for our lifestyle diseases these days in our modern world we have one like root cause for all this that is inflammation. So if we can get rid of some of the inflammation by boosting our immune system, that is also one reason why you should definitely start. So you will have immediately you will have benefits from going into the cold shower and going into a cold. or going with winter swimming.

You will have immediately health benefits from the first time you go. But if you continue, then you have the long-term benefits. And that's what I really think is very interesting. And that's what I've studied in my research. I love it. Well, I want to talk more about information in a second. But if you would, so if you'd say if we're doing a cold shower, for example, you know, versus winter swimming, like what would be the, you know,

if we look at total minutes across the week for maximum benefit, you know, what would be, you know, kind of that threshold of just how much time do we have to spend, you know, how many days do we have to do it? Is there kind of a sweet spot that you found in your research? Yeah. So, and this was kind of like not what I actually were looking for, but I wanted to figure out when I did. No, but it was like I did want to find some kind of like a method or something because I was not a winter swimmer when I started. So I wanted to do a study where I kind of like looked at the lowest threshold but finding the good benefits.

Amazing. So no one else had done a study where they have looked at activation of the brown fat with cold water. They have looked at cold air. They have looked at how the effect is with wearing a cooling vest or sleeping in a cold room and stuff like that. But never had there been any studies. with the cold water, which is a very much more potent activator of our immune system and of our metabolism and everything. So it was kind of like a new thing going into that research. So what

I wanted to do was to look comparing two groups, one that is already adapted to cold and the other one who has never taken an ice bath or winter swimming at all. But the groups, on the other hand, just were very equal or very matched on age and gender and also on fitness level. And they were. So what we found in the study was actually that because I monitored how much they went to swimming and how much they actually also went into the sauna, because I wanted them to do the Nordic way of doing this cold exposure, which was also with the hint.

And I had this kind of feeling that the brown fat is not only an activator of the cold, it is a temperature nevulator in our body. So the heat might as well be activating our metabolism. So I didn't want to rule that out. So they did both. And we saw that 11 minutes of

cold exposure, we saw that 11 minutes of cold water immersion per week, not in one time, but divided on two to three days, actually activated our brown fat and also increased our insulin sensitivity in

these healthy subjects that we looked into. We also saw that they had a faster glucose metabolism when we gave them sugar drink. We saw that they faster got rid of the sugar in the bloodstream. They also were just warmer. We saw that the brown fat activation was increased, but also they were just warmer in general. And not only when they went into the cold or after, but just in general, because we measured that over a couple of days actually in that. So we saw that people who were men and very equal, these two groups, were just a warmer group and a not so warm group.

And they went to swimmers a bit contra-intuitively, but they were actually warmer than those who didn't want to seek the cold. So the message here is definitely, so if you are a cold-sissy or you are very frightened of the cold, you should definitely go to the cold because that's going to make you warm. It will activate your brown fat and your metabolism, and it will make you healthier because it decreases your inflammation in the body, which is the root cause of many diseases today. So you can call the cold water immersion is kind of like, I see it as a way of preventing multiple diseases that we have found today is the root cause of disease. lifetime, lifestyle, diseases today is depression. It's type 2 diabetes. It's high blood pressure. All these diseases are partly because of inflammation. But inflammation is definitely root cause of many of those diseases. So if we can get rid of the inflammation, you have kind of like touched upon your prevention for multiple diseases, but also you have boosted

your brain in a way to be more fresh and more better at it remembering. And that is also because of the neurotransmitters. So it affects the whole body, not only the metabolism, but it's like a connection between the brain and the metabolism. Hopefully we get to a point where doctors are actually prescribing cold water therapy to their patients. You know, I mean, I think about it, you know, in terms of treating addiction and that, you know, depression. And, you know, it just seems just because of its impact on our nervous system and its ability to kind of regulate our nervous system, it just seems like such a, you know, kind of a no-brainer in terms of modality that we want to try to incorporate into our lives. And I think it's wonderful to hear that, you know, getting outside and the cold weather and exposing your skin along with cold showers, you know, or also, because that's, you know, pretty much everyone can do that, you know, so not everyone maybe is going to be able to get into a cold or a cold weather. cold bath even, you know, just hurting the cold. I mean, it's, it's pretty much everyone has it, you know, has the ability to do those things, you know, so we can impact our health in a really

powerful way, you know, just by engaging in this behavior. So it's truly encouraging. So 11 minutes of cold water per week, broken up into kind of three to four sessions. Would you say, you know, what? I know we've got the sober principle, which was coined by Dr. Andrew Ruben. He's actually a science advisor to whoop so we get to interact. with him a fair amount and yeah so he's he's so wonderful but I love that he coined this this this phrase so what exactly is the sober principle I love that so great so he's great I mean this was the biggest surprise ever I mean I was just interviewed and the first like international interview I ever did it's a great place to start a week out I was so surprised I was like can

I get a principle? Yeah, but I kind of like just always had this idea about the brown fat metabolism that if you end on the cold, because I really needed to figure this out during my research and figure out, do I ask my participants to do a plunge or do they end in the sauna? And then I was thinking about what does the body actually do in the heat and what does it do in the cold? That's why I've read all the literature and my supervisor asked me to make the book that you have been reading because I was told to do that at the beginning and I was like, well, I don't

think I can, but I had read all the literature and found out that or figured out in a way that if it's increased by cold by activating the brown fat, then, and my hypothesis really is real, then you must end on the cold to force your body to heat up naturally. Because if you do that, then you force your body to spend more energy and you will burn it. more calories of glucose and fat from your bloodstream. So it's kind of like a long weight loss that you do after your cold exposure. So you don't have to think about your cold exposure as just happening when you are out there outside. If you end on cold, on the superb principle apparently, so then you will keep this activation going in the body also when you get inside.

The one thing that I want to also touch upon is just if you end up, on the cold and you go home, then I'll ask you to keep moving because it's also one thing that's going to help you increase your heat again in the body because the muscle will help you a bit because it's really, it's really not something that is that easy at the beginning. So you have to adapt to this and you will have muscle sivering for a couple of hours after. That will happen and it's completely natural and it's not dangerous as long as you don't stay too long in the water. So your after drop won't be too high. And the after drop is when your cold temperature decreases too much. And you will have a visceral shivering at home, but just keep moving. And then you

will be fine and you will have a high increase in your metabolism. So end on cold to have more activation in your metabolism. Amazing. How cold does it need to be? What would be, you know, and again, it probably matters based on how adapted an individual is. I would think. but what is the temperature at which we can get, realize these benefits that you're talking about? Yeah, so cold water is, cold water, you can define cold water at 15 degrees Celsius and below, I would say. And that is based on the studies that I have read where you see that people have drowned, meaning that they became hypothermic. So these are based on statistics of hypothermia and also drowning accidents.

So if we have the statistics and saying that from 15 degrees water and below, we can have accidents, then I would say that cold and activating your cold shock must be from 15 degrees and below. Okay. So actually it's 59 degrees of Fahrenheit just for folks for the conversion because we get a lot of U.S. folks. Yeah. Thank you.

actually it doesn't have to be that code to activate your coat shock. But just to keep your brown fat activated, you don't have to do that code actually. So going outside at 19 degrees in a T-shirt will activate your brown fat as well. So you can kind of like play around with these temperatures. And that is kind of like one of my principles as well is to not get too stuck on the temperatures, just vary them because the variation is going to make your metabolism increase and then you change the homesis in the cells because then you maybe had a cold top or a cold plunge for at 10 degrees and then you Celsius and then you have it at 2 degrees Celsius and you will

have to help me convert this a bit but but just vary the temperatures down to make the freezing point and then go up again a bit because that's going to increase your metabolism. It's not, then you won't get adapted to just one temperature. Why I say that is because there are studies showing that if you get adapted to cold showers at a certain temperature, 15 degrees, then if you go and take a cold plunge at 10 degrees Celsius, then you will still have a cold shock. But if you go into 15 degrees, which was the same as the cold showers, then you won't have as much of a cold shop as if you vary the temperature. So the variation is going to be your trading gear for your cells to create the homesis in the cells.

And homesis means, for those who, the humesis is actually what is happening in the cells. So the cold shop is a bit toxic. It's a little bit of toxicity in your body, actually also the heat. It's actually toxic for us. And what happens is that the hometic stress, which it is, will increase heat shock proteins in the cells, and that will make your cells stronger. So this is based on science from Hans C. who actually discovered the sympathetic nervous system, the shock. So you can say, that if you have the stress syndrome activated, then you only need a little bit because if you overdo it, you will exhaust the cells. And that is his research showing that. If you exhaust the cells,

then they will age too fast. Right. And that is not in the cells only. That is also in your system, meaning that if you stay too long in a very cold top, then you will actually also maybe put too much stressure

on the heart, and on your cardiovascular system. That is why I am trying to promote this micro-stressing, which my research is also about. So micro-stressing at different temperatures, just vary them. That would definitely keep your metabolism going in a healthy way. I love it. You know, as you're kind of talking through this, like so many of the mechanisms and, you know, the principles, I think, are similar to exercise, you know, in that we want to modulate our volume and intensity and frequency, you know, of exercise. And cold is, it feels very similar to me, you know, in terms of, you know, just what you outlined, you know, and I think,

you know, all these kind of formitic kind of effects, I think, you know, that are, you know, present with cold, I think, you know, are obviously present with exercise. And it's, it's no surprise that they impact brown fat kind of similarly, you know, in our metabolism in a similar way. Yeah, I find that really interesting. One note just on inflammation, I just wanted to go back to this. Because I think, you know, I've experimented a lot with this in terms of just, you know, do a cold before, you know, as a coach for many, many years, a Division I feel-lucky coach, and we would do ice plunges during our preseason after the practice to try to accelerate recovery next day. Now, we found that really beneficial, of course, but when you're trying to

actually make fitness gains, that inflammation, of course, from the exercise is really important, and we don't necessarily want to blunt that inflammation with cold. We want to allow allow that to exist in our body. So we, you know, kind of all the processes that we would activate to, you know, get stronger, you know, kind of get strength and hypertrophy, you know, happen because of that inflammation to a degree. So what would be your kind of take on, you know, do we, you know, so for me, like I do cold before exercise and I get, you know, all the things that you describe, you know, this burst of cortisol and agenda and epinephrine and I think just pulling my muscles as well. Like I feel like almost superhuman during my workout. Like I feel really

good. And some of that could be placebo. I'm just going to roll with it. But I'd love to hear just your thoughts on, you know, where do we actually sequence the cold if, in fact, we're interested in, you know, in recovery and if in fact we're interested in getting, you know, kind of stronger and faster and, you know, fitter, you know, does it matter before or after the workout? Yes. There's a pretty good question. I think that going to the question about, you know, hypertrophy. I think that it is really, really good thing that you do your cold exposure before you actually do the workout. And this has two reasons. So the one reason being that it is this, it is actually an energy boost that is much greater than drinking coffee or energy drinks

or whatever before you go to your workout. Exercise capacity never do. It's insane. Yeah, exactly. Truly. It's incredible. It is the energy boost that you actually actually need because in the training center or when you go for a run or what you do for your exercise, doing a cold shower or just doing a quick cold dip is going to put your energy through the roof and you will, you won't, you'll be unstoppable. Yeah, totally. So I think that I think it's a really good order to do it in. And also for the second reason being that if you take a cold shower or mostly if you do a cold plunge

after your workout, you will kind of stop this inflammation in the muscles, which is exactly what you want to have if you are building muscles. But it will then recover your muscles better, which means that you will have less pain in the muscles after your workout. So I would say it depends again who you are. If you are not looking for growing your muscles, and I don't say that it's a lot impact that it has. But if you're looking, if you are competitive or competing and doing a lot of sport maybe every day, then it could be a good thing to go to a cold brunch after your workout, just to recover. Yeah. Yeah. Yeah. Because you, you need to compete the next day or something like that. But if you just want to grow your muscles and you want to get fitter, then it's a really

good idea to put your cold brunch on the other side of your workout. So in the beginning or before, actually, or just push it a few days after. I mean, you could divide your weak days up into what days do you go to work out and what days do you go and take your cold flunches. So, but you can put heat in. That would be a really good thing to do right after your workout. Right. That's another thing.

But the cold, I would divide it if I'm building muscles, but for people not doing that are not competing, I think it's a good thing. Just take a plunge after. Yeah, I think it's definitely, you know, I work with a lot of professional athletes and kind of in that space a fair amount. And I don't really hear of anyone leveraging cold as just a performance enhancer. So I feel like this, I'm hoping, you know, with this podcast, we can kind of, you know, get the word out that indeed, you know, there's huge benefits to incorporating, you know, building this into your routine, you know, before a match or a game or, you know,

a workout where you really want to try to, you know, maximize your output. Yeah, I just feel like it's it's totally under leveraged on books probably you know we hear a lot about using cold plunge as a way to you know improve recovery but I think it does have these potential downside effects you know if we're looking to really improve our fitness levels and build muscle it's you know the sequencing really does matter so I think that that's that's important I think for folks to to understand who are calibrated in our lives around a lot of these mode modalities there is a lot I mean there's

there is so much to explore here and so much to say and I mean when I go on these podcasts I often end up thinking afterwards I didn't say all this

I know I mean I said a fraction but it's like what about all this yeah that's actually one of the reasons why I have

why I have made the Super Institute because I want to teach people some of all these things of why they should do the cold why should they do the heat

So they know exactly why to do it because people would do it for different reasons, but they should also know how to do it, why to do it, and what does it affect? And if people don't know, I mean, then they won't do it. Yeah, exactly. So I'm just trying to spread some knowledge there. So that's why I've made a course about that, called the Thermalus Cure. Oh, okay. Yeah.

And I really didn't think that I was going to do that because I do talk a lot when I'm on the podcast and so forth, but people keep writing me, can you tell me, can you show me, can you? And then eventually I was like, well, maybe I should just do a course and just show people and go more into death with the reasons why and why is this healthy if you are looking for a painkiller, if you're looking for a way to increase your training and if you're increasing your mood or it's definitely different from people to people. So the course is also about finding your why in this. Oh, I love that.

That's so great. I, you know, and maybe that's a great place to, you know, to end, you know, how do, you know, people can listen to this podcast and they can hear about all the benefits and, you know, but cold water is painful, you know. And how do we, you know, what would be your recommendations on just overcoming the panic, you know, of feeling that excruciating cold? on her skin. And, you know, how do we, how does one breathe through that? You know, like, what, what would you, how would you guide a person who is, you know, okay, this is going to be good for me, but

it's so painful. Like, how do we get over that mental barrier? Yeah, that is a really good question. And I think that you just said, right, it's actually very toxic for the body going into cold. So it's not going to be your friend, but it's going to be, it's not going to be your friend in that way, but it's going to be like a toxic friend, you can say, which you want to visit sometimes, but not stay there for that long because then it gets dangerous. You just run off again. Just say a quick high and then run off again. So it's kind of like the cold is super good for us in a short amount of time. So one of the things that we need to do or need to think about is just you only need to do it for a short amount of time. So going into the water and get

a hold of your nervous system by doing breathwork. So with your breathing, you can lower your system. And when you can do that, you'd get over your cold shock and then you can stay there maybe for a little bit of time, two minutes is enough actually, and then you can go up. As soon as you get over the cold shock and you get into this more calm and activation of the parasympatic nervous system, then you have already, you can say get, you already get the benefits from all the neurotransmitters and also activation of the brown fat, which we just talked about. So you don't have to stay longer than that. But what you do is actually that you lower your nervous system by controlling your breath.

So deep, low and slow, I always say. And it's a thing that you can use in your everyday life. So this is also one of the things that I teach in my school, that's how to lower your nervous system, how to get into the cold water, and also how to breathe. Because the breathing is the key to lower a racing mind and a racing heart. Right, right.

In this modern world, we really need this. Yeah. Yeah. So a good rule of thumb, like you get into the cold water and basically once you, you're going to be, you know, breathing, you know, kind of. Yeah, you're going to be hyperventimited. Yeah, you're going to be hyperventilating. But once you get your breath under control, that is a signal that you're decreasing your heart rate. You're activating the parasympic branch of the nervous system. So you've gone from the sympathetic to the parasympathetic, which you've outlined as that's kind of the kind of holy grail. That's what we're really after. We want to try to get both this activation and. deactivation happening within the session right and yeah and that's kind of the the goal so I think that's a good you know that's a good framework I suppose for folks who are trying to think okay like if they're in the shower they don't have a timer you know but but just all right once I get my breath down and my heart rate you know decreases that means that I'm activating the person of branched

the nervous system and I'm getting the benefits okay yeah I think it's amazing and people don't don't have to do this in their first plunge and in their first cold shower. They should fill this up very slow. 15 seconds. But you can see it as a goal and building up to these few minutes where you can go over the cold shock and use your breath to lower your nervous system. But it's definitely not something you have to do in the first try. Nobody does that. And even though even people who are adapted to the cold, they don't like the cold. Nobody likes the cold. If they do, then I'm a little bit afraid. You know, totally. So I think people who are starting out, like they can even just submerge their hands in really cold water or their face, you know, just in the sink, like just starting to kind of test it. And then, you know, in the shower going from, you know, warm to cold and just seeing how far they can go. And, you know, and I think, I think to your point, like, just even smaller bouts, you know, are really cause for wins and, you know, just trying to increase it over time, you know, to get to that point where they can really, you know,

you know, work through that hyperventilation and get to a point where they have controlled breath, you know, is I guess the goal. And I think, I think the other point that I just want to emphasize that I think is really important that I haven't heard you talk a ton about and other forums is just the variety, you know, and I think what's beautiful about swimming is that the season kind of takes care of that variation. You know, I know when I go into the lake and it's, you know, zero degrees, 32 degrees, Fahrenheit, it's cold. It's cold. but I've got the wind temperature, you know, the wind and the air temperature, right? When the air temperature is warmer than the water, that is brutal for me.

I prefer to have the air temperature kind of colder than the water. It just seems less painful. And I don't know if there's anything real to that. And it is. Is that, okay, yeah. Yeah, yeah. Actually, the summer can be brutal for some people because you get so hot on your skin. Right.

And then you quit to the water. And you get even more surprised because you were not prepared. totally totally that the difference was that big i know my friend and i were we were in boston and it was may and of course in the northeast it's it's pretty darn cold the water was i think definitely below below um 50 degrees Celsius you know so probably in the 50 you know low 50s Fahrenheit and but it was a warm day it was like 80 degrees and we did a workout on the beach and then we went to the ocean and it was like i mean it felt like it might as well been you know zero degrees or 32 degrees Fahrenheit it felt freezing um

But I think that that's like what's so exciting about winter swimming is that it's going to be different every time you explore it. It will be completely different. And I think to me, that's what like gets me so excited about about just winter swimming is just, you know, being out in the nature. And sometimes, you know, the rocks have ice on them. Sometimes they have snow on them. You know, sometimes you have to cut through the icy water. A hole, you know. But I think all of that, you know, gets you out in nature, you know, gets you out of your comfort zone.

And I think I would love to just end on, you know, and you've kind of throughout, I've talked a little bit about the mental benefits, but, you know, just this idea of mental resilience. You know, I think for a lot of people, this is a hard thing, you know, and I think as a society, we're kind of inoculated, I think, to a degree from environmental stressors, right? Because we're in homes that are perfectly, you know, lit and they're perfectly, you know, temperature controlled, you know, and there's just this incredible opportunity to invite. this beautiful stress into our system. So maybe just talk a little bit about just the mental health resilience aspect of this. Yeah. So I really think that you can get these health benefits, the mental benefits from going just into the cold, but adding the nature component. So this is definitely going to help because the nature component. I also write about this in my book, in winter swimming, because in Denmark, that is what we have in the north. We have open sea and we have so much water in Denmark.

Everyone in Denmark can drive to the sea, and we only have 50 kilometers, just in average, to some water. Wow. So it's really easy for us to get into just open water. When you are in nature, you actually decrease your stress level by just taking a walk for 20 minutes, and this is shown by science, that 20 minutes walk is called forest bathing, actually. So you go into the forest and you go for a walk for 20 minutes, and then you decrease your norophanaphrin levels by 20. And you will also decrease your cortisol levels on, on, you can say, a daily decrease on, I think it's 17%. So you would definitely have your stress level down just by going out in nature.

It's as if nature is rewarding us from coming back home in a way. And I think that's very, very beautiful. So when you go out and take a winter swim in the ocean or in the lake, you have both. You go into nature, which is very relaxing for us. But you also have the looking at the horizon, so you look very far away. And for some reason, that is also something that is calming for our nervous system. And this is tested in studies where they have subjects looking at the pictures of just nature. And that actually did decrease the nervous system,

so had lower stress hormones in the bloodstream and very quickly, actually. So if you are stressed, taking a walk in nature is going to help. help you, but combining that with the winter swim is definitely going to help you do that in a profound way. So you are stressing up when you go into the water, but that is to stress down. So keeping that resilience in the water is something that you need to build up, but the nature is going to help you out there, definitely. I love it. Well, this has been such a fascinating conversation. I could talk to you for days. So hopefully we can talk again in the near future and just appreciate all your time today.

And where's the best place for folks to find you? So they can find me on Instagram, Susanna Soberg, and also on other social media. I'm also there, Facebook and on TikTok. And also on my web page, it's called the Soberg Institute.com, where you can see my courses and you can read about my background, my research, and also find my books. Yeah. So amazing. Well, thank you so much for the time today. Yeah, thank you for inviting me. It has been a great conversation, I think. It was so nice to talk to you. Oh, I appreciate it. So much came up and so many good ideas. We could go on, I think. I know. I think so. Thank you to Dr. Susanna Soberg for joining the show and for sharing her insights on cold therapy. I seriously recommend you all try it. I've been really into the cold now for a number of years.

I think it has huge benefits. And for me, at least mainly cognitively, the fact that I just feel so good and so happy after doing cold therapy. So, highly recommend it. If you enjoyed the episode of the WOOP podcast, please leave a rating or review. You can check us out on social at WOOP at Will Ahmed. If you have a question you want to see answered on the podcast, email us, podcast at WOOP.com. Call us 508-443-49-2.

New members can use the code Will W-I-L-L-L and get a $60. credit on whoop accessories. And that's a wrap, folks. We will see you next time on the WOOP podcast. Stay healthy and stay in the green.