Susanna Soeberg: Saunas, Cold Therapy, and Winter Swimming — Full Transcript

00: 00 Thank you so much for inviting me. Uh, listen, I love your book and one of the things that I love. Yeah. One of the things that I love the most about this book, Winter Swimming, is that you didn't entitle it, you didn't call it the science of cold plunging or you didn't call it uh the benefits of ice bathing or something like that. You call it winter swimming, which conveys this idea of connecting to nature. Um, would you say that winter swimming in a natural body of water is like the gold standard of cold plunging, of cold exposure? I would say this is where it really originates and uh, thank you for the compliment on the title of the book because I really think that you with that address something that nobody else I don't think people really notice it, but winter swimming doesn't need anything else. It's kind of where everything originated with this whole trend. And now I'm doing the science and

01: 00 trend. And now I'm doing the science and cold exposure. But really what we actually did go into is the concept of winter swimming. What is it? And this book is not only about the science, it's also about the feeling. What do you get out of this? This is a cultural thing, right? So it's also something embodied. So you really go out into the nature and you submerge into nature. So winter swimming is more the whole concept of it. It's not only the science and that's why it's only called winter swimming. So you get some of these benefits when you plunge into a an a top or some a co-plunch, but you don't get the whole concept of submerging into nature. So that's why it's called winter swimming. That's that's the idea I got from it. That's why it really caught my attention. Um and I love it. um how did you first um got into cold and what's the story behind this book? Supervisor was asked can you write a book about this and she said well I

02: 00 book about this and she said well I cannot write a book about it but I know someone who can and she asked me very politely do you want to write a book about it and I was like actually no I was not sure whether this is going to be a book which is about why winter swimming is unhealthy for you or healthy for you. So at this stage I actually didn't know and I was not a winter swimmer. So I didn't have I was not biased in that sense. I didn't want to go out and prove something. I didn't really care. I was just a scientist trying to figure out whether cold or heat or whatever could activate our metabolism. And then I dived into the research to figure out is winter swimming or cold exposure actually healthy or unhealthy for us. And that became the working title of the book that you just read which is called winter swimming. So that's why the safety is actually in there as well because I researched whether it's actually dangerous or is it actually healthy. So it's both the size you kind of need to know right so I wanted to tell people that but eventually I said yes

03: 00 eventually I said yes and obviously the conclusion is that yes it is beneficial for our health. Maybe we can start with the very very basics which are the physiological benefits of winter swimming. uh the the physiological benefits of winter swimming um are multiple. So you can say there's the metabolic benefits which is uh when you submerge it in cold water you will have this activation of your sympathetic nervous system right so you will have an increase in heart rate you have increase in your metabolic rate and for those people are thinking what is the metabolic rate even that is when you burn your fat and your sugar from your bloodstream because you have cells in your body which are trying to keep you warm and for that it needs fuel just like an engine, right? So these cells in the body takes glucose and it takes so that is sugar and fat from the bloodstream as fuel to activate heat in the body and the tissue which is doing that is something called the brown fat

04: 00 that is something called the brown fat and the brown fat is keeping your temperature in your body at the perfect temperature balance so you won't get too warm or too cold. And that takes energy from the body. So that's why when going out in extreme temperatures, you can actually activate that engine uh making sure that you have the perfect temperature for your vital organs and that burns calories just like going to the gym. So and it's all it's not only when you are in the water it actually works. The the cells afterwards are trying to um adapt to this situation. So when you next time you do it, it's already prepared for it, right? It's just like when you go to the gym, you you use your muscles. When the muscles are break broken down a little bit, it makes it so stronger um with this inflammatory condition because it tries to like rebuild itself. Um and that's why it hurts in your muscles when you have done a workout. And the same is when you go out in the cold water or you actually also go into the sauna you will

05: 00 actually also go into the sauna you will create that hormetic stress the healthy stress in the cells which create this adaptation makes it stronger for the next time. So that's why the metabolism is definitely activated when you go out in the cold water. So that's only the metabolism part but there are more of course and beyond these um physiological benefits it's clear that for anybody who has done a little bit of cold exposure exposure winter swimming that this has a an obvious and non-negligible positive effect on mood this like this boosting in our mood after that um what's the reason behind it why is this happening yeah it's so This benefit that you get out of going into the water and the metab the metabolism side of it is of course not something that you feel right away. But what you do feel is the mood. You have a change in your mood immediately. I always say that it's

06: 00 immediately. I always say that it's impossible to go out in the cold water and have the same state of mind when you go out again. It's impossible because you just change your brain chemistry. When you change your brain chemistry like that to the more positive side, you also view whatever you are thinking about, whatever you are worried about in a different way when you go out again. And I think that is so this this is so important. So, if you're not going for the long-term benefits of your metabolism or your your immune system or whatever, you just want to have a shift in your mood, then take a cold shower or you could go out in the cold water, do a cold plunge because it really t I called this the control delete effect. And I think it's in the book even um or maybe it's my new book, but it's in some book I wrote. I I've seen so many uh interviews and I've read so many things uh to prepare for this that I don't know where I've read what I've read you know uh we have

07: 00 read what I've read you know uh we have um seen an a lot of uh social media posts on like people ice bathing and people going into nature and winter swimming and all this and it's great but I was thinking that um even though this is awesome and and like I I do it and a lot of people uh do it. Will you do it? I'm sorry. Yeah, you you do it yourself. Oh, yeah, I've been doing that for a long time. Even before I I knew about all this. Yeah. Like uh swimming in the ocean in the winter. It's like an old practice where I live. A lot of people do it. Fantastic. Yeah. Um but now I understand better why it has these benefits that it has, you know. Yeah. But my my question is for those people who maybe are not inclined to go and get into the ocean water in January or getting into an ice bath, what is the minimum effective dose of getting um of getting into the cold? Meaning, is there

08: 00 getting into the cold? Meaning, is there a practice that being softer can give us like 80% of the benefits without having to do the whole logistics of filling the bathtub with uh with ice or going in people that don't have access to a beach or a lake or a river? So, is there like a minimum effective dose that we can um practice every day to get most of the benefits? Yeah. So I would say a cold shower is accessible to most people. Um ending your your hot shower on a cold uh so just turning to the cold water for 30 seconds that could actually give you that boost in your mood and it will also activate your metabolism. So you would get some of the benefits. It's not completely the same because you you don't activate your full nervous system um like you would do when you submerge into cold water. And it's a little bit technical, but when you submerge into cold water, you will also have an activation of your parasympathetic part of your nervous system, which is the the

09: 00 of your nervous system, which is the the part of your nervous system, which is the rest system. And when you dive into the cold water, not dive, but submerge your body into it, you will activate your diving reflex. So, you don't completely do that with the cold shower, but you will get some of the benefits from activating the fight and flight system of your uh nervous system. And some people are like, "Oh, but that's that's stress and that's not good." But that's kind of like a one of the misconceptions I think there's out there. People being too afraid of being stressed. And being stressed is not the same as being chronically stressed. This is good stress. Short-term stress. 30 seconds of cold shower will actually increase these dopamine and no adrenaline in your brain which will keep you in a good mood or get you in a good mood. give you the energy and drive to get through the day. So, you can benefit from this in your work life, in your family life, in in your social life because it's also something that makes you more um

10: 00 you more um uh give you the energy to be more approachable. Maybe maybe you are more you have the energy to go out and talk more to people. Um and some people need that extra drive to go out and do that. So the kick from the cold is definitely something people can benefit from right away. Um and it's accessible. So So do I conclude correctly if I um summarize saying that yes like a cold shower can give you a substantial part of the benefits but if you want the full picture it's better to go into the water. Is that what it is? Yeah, I would say it there's definitely also more studies on um going in submerging into cold water compared to uh to the scientific stud studies in in showers. We don't have that much research on it yet. Um it seems that um if you compare it that it it's that the activates

11: 00 it that it it's that the activates activation of the full autonomic nervous system is there when you submerge into cold water compared to when you only do a shower. So there are definitely benefits of both and I think if you don't have a top you don't have the ocean or lake nearby then do whatever is ne accessible to you. So yeah so okay so for those who do want to go all the way in into the practice tell me about how long and how often is like the sweet spot in which we get the benefits without harming ourselves. So how often should we do it and for how long in the water? Yeah. So this question is of a lot of debate apparently. H I would say most people why it's debated is mostly because people don't know. I would say there is not a lot that long-term cold water immersion has any health benefits for you and people. It doesn't. There is no research showing

12: 00 It doesn't. There is no research showing that staying in long-term in cold water has any benefits, health benefits for you mentally or physically or anything. So please listen, you can do with just a few minutes. When you submerge into cold water, you activate your sympathetic nervous system, your parasympathetic nervous system. And if you can breathe yourself through the cold shock, which is where when you start to like hyperventilate and your heart rate increases and then if you can breathe through that, you would decrease your heart rate and you would get into that calm state where you actually decrease your stress in the body. And there are studies showing that when you um when you do cold water immersions on a regular basis, you would decrease your levels of cotisol. And if people don't really know what what is that exactly? Well, it's actually the stress hormone which we want to decrease on a long-term basis. Do we want to increase cortisol

13: 00 basis. Do we want to increase cortisol on a short-term basis? Right. Acutely, yes, of course, we want to do that because that's what you do when you go to the gym also. and and some people also have a small increase when you go into the cold water, but only when you're new to it, it seems from scientific studies, you actually decrease the long-term cortisol levels on a long term. So, you do want to do that because that decreases also the risk of lifestyle diseases. We know that there is this is correlated cortisol levels being high then you also increase the risk of obesity, type 2 diabetes and even all mental diseases as well. So you do want to decrease that. Submerging into cold water is something that people will benefit from. But shortly shortly. What does that mean? I'm going to try to push you in the corner. Just a few minutes. 2 minutes. 1 2 3 something like that. You don't have to uh I mean look at your watch. Have something that shows you how long you stayed in the water. Because suddenly

14: 00 stayed in the water. Because suddenly when you have practiced this a few times then you'll be sitting there for my maybe 8 10 minutes and it's not necessary. You you must know it's right it's like time vanishes from you but what happens when you stay in the cold water for that long is that you decrease the temperature too much in your core. Um, and it's not like it does that immediately. But when you cool your skin that much, you don't have to cool it that much actually to activate these cold receptors that is necessary to get the health benefits. But when you stay there for a longer time, you just cool your inner organs. Eventually when you get up, you will have the something called the after drop. And the after drop is cooling your inner organs. So stay away from long-term exposure. Even though some people think it's a competition or they should stay longer, longer is better, but it's not when it comes to cold and heat. These are extreme temperatures and that is something that we can benefit from if we just use it in a small dose. I hope it's clear.

15: 00 I hope it's clear. Yeah. So people, this is not a competition. Just a few minutes. More is not better. Um, what about less is more, Less is more in this case, right? Uh what about uh is it is there any difference in the effects by doing it in the morning in the evenings? I know this is very specific but people love to know these things. Is it better to do it in the morning or in the evenings? Is there any difference? I actually I love this this way of thinking about it. So when I did this research I and when I started to become a winter swimmer myself, I had to try it out. I mean they they were all all the winter swimmers in Denmark were like writing me, hey Susanna, you have to do this when you're doing the research. And I was not a winter swimmer. I was just looking or just standing on the jetty like observing them and being like, "Wow, this is so this looks so dangerous and looks so weird. Why are people so happy about this?" I started doing winter swimming and eventually I started out doing it in the morning which gave me all this drive and energy and I

16: 00 me all this drive and energy and I because then I had all that all day and by the afternoon I could feel that if I started to do it in the afternoon again I would just have that energy and drive in the evening. So one day I tried it out and it was just like coffee for me. Coffee is something I don't drink after 4 or 5 in the afternoon. Definitely not after five because then I cannot sleep. And then I found out that it's the same with the cold exposure. And when you then look at the literature, it looks it's completely making sense. So when you go into the cold water, you have an increase in dopamine and nor adrenaline. And no adrenaline is something that gives you energy and dopamine as well. You don't want that kick uh in the evening before you go to bed. Mhm. What you can do is doing your cold exposure in the morning, your cold shower in the morning, but then in the evening you should do something else. You should do the sauna. Do something with heat. It could also be a sauna blanket. This is something you can

17: 00 blanket. This is something you can purchase online somewhere. Uh and these can actually help you increase the temperature in your body and that will make your body scream to just dump all the heat because you want to dump the heat to fall asleep. your core temperature needs to decrease to fall asleep. So, it's kind of like counterintuitive in the evening that you want to decrease your core temperature and then you should expose yourself to some some kind of heat. But actually, it works. It does work. You you sleep like a baby when you have a sauna in the evenings. Yeah. You sleep like a baby. Do you have a sauna? Yes. Um yeah, I'm I'm like full in the whole practice. Fantastic. Right. I'm falling into the hot practice. Um uh something that I read in your book also that was very interesting to me that I didn't know is that there is a threshold um as the water uh water temperature goes down there is a threshold beyond which the feeling of how cold the water

18: 00 which the feeling of how cold the water is increases very suddenly. Meaning that as the temperature of the water goes down, the perception of how cold it is, it's not linear. All of a sudden, at 15 °, you explain in the book, at 15 °, it really feels cold all of a sudden. And when I read it, it's like, yeah, it's so true. Like, if you go to the beach and the water is at 24 ° and the following day is at 20 °, you don't feel that much of a difference. But if one day you go and the water is like 18 and the following day is at 14, it's the same four degrees, but it feels like another world of how much colder it is, right? Yeah. Do do you think there is a physiological reason or like an evolutionary reason for this? Why why is that? Because it does like I realize that is true, but I've been asking myself why would that be physiologically? Is there a reason for this? Yes, I would say it's about adaptation. So when we adapt to a situation, we are

19: 00 So when we adapt to a situation, we are built to adapt. That is like built into our DNA. We were involved in in cold and heat and we survived ice ages and heat uh waves. So our DNA is made to be able to balance that uh that temperature um uh you can say extremes. So we have to be able to adapt. So as soon as you expose your body to some kind of danger, we would try to adapt to that situation because it might happen again and then we want to be stronger and prepared so we can survive. So the body just prepares itself. So when you go into unit mentioned uh let's say 24 ° C uh hot water I would say um the body reacts to it as if it's like oh this is a nut situation compared to the air temperature and then it adapts to

20: 00 air temperature and then it adapts to that then you go out again the next day in 20 ° Celsius uh hot cold water something between um and the body would be like oh I tried this before it's a bit colder let's adapt to that and then When you go into cold water which is 15 ° C, the body will be more adapted to the situation. This is familiar to the body. The temperature might be colder but you have done it before. So the body gets faster and faster at adapting to the situation because the environmental factors is submerging into cold water or submerging into water and you just get adapted to that. And our body is so fast at adapting to new situations. We are built to this. You're built for ad adaptation. It doesn't matter if it's cold water or if it's a heat in the sauna. We are so fast at adapting to the situation. But that is also a slippery slope, right? So it might be that some

21: 00 slope, right? So it might be that some that shorter is better and necessarily not colder is better. You don't have to go down to zero degrees. Some people think that this is a dose of temperature going down and timing going up, which will be better for you. So, it's a slippery slope where you at at the end cannot really feel the code anymore because you're so adapted to it. Your blood vessels are getting so good at contracting that you don't even feel it anymore. So, just keep being mindful around what is healthy and what is not healthy. H eventually it could become something that which has nothing to do with health. So the body needs to be reminded of the cold. Let's say it that way. Reminded of the cold and the adaptation slowly is super good. So if you live in a country where you are able to use the seasons then just keep going from the summer and then you will adapt uh to the cold water um much more lightly I would say. Yeah. Progressively. Yeah. So you were um talking about adapt

22: 00 Yeah. So you were um talking about adapt adapting to the cold to what extent like obviously when you start doing this for a while you get used to it and it's easy it become it gets easier and but I have always asked myself in what proportion this is physiological adaptation of the body and to what extension it is a mental game so to what extension you just you get used to suffering in a way or you it's familiar it's a familiar feeling so you just don't think about And to what extent is the physiological adaptation? Is this 50 / Is there what part is mental and what part is physical? Yeah, I like that question because I think they follow along. So one thing is in the beginning, let's say your first the first time you go into cold water, you will be anxious and that means your body will react to that. So you will have an increase in your heart rate and that's going to affect your breathing as well. So what you think and what you um what you're anxious about is going to

23: 00 what you're anxious about is going to affect your will give some physiological uh reactions and that will have an impact on how long you will stay in the water or or your experience going into the cold water. But as you adapt physiologically you will also adapt mentally. So when you feel that that oh I can recognize this situation now I've done it maybe three times four times five times then you will stop being so anxious about it and then mentally you will also be more relaxed doing it because you kind of know what you're doing now right you've done it a few times. So just just be mindful that of course the first time is going to be a little bit more stressful um and also maybe second and third time but then your body will start to recognize the situation even more and it goes so fast the adaptation is incredible fast and the body remembers this a whole year later. There's actually research showing this. So yeah, so even if you get pregnant and you don't want to do the

24: 00 pregnant and you don't want to do the cold water immersion, and I don't recommend that you do, um, just want to pop that in. Um, yeah. Uh, but but as a pregnant woman, just take a pause on it and, uh, wait the ninth month or maybe three more and just, uh, go start up again because this is something that is once in a lifetime. You are pregnant and you don't want to harm your baby. uh you we frankly don't really know what's happening when the little baby is in there. So, but after that I would say it's mentally and it's physically and they work together. Now that you u make that comment on pregnant woman I I wanted to ask you later about this but now that we have opened that um box of worms let's just lean into it. Um there there has been some backslash uh to the practice lately over the past few years like some people suggesting that well there are many people already with compromised immune systems and with low thyroid function

25: 00 systems and with low thyroid function and and people are overstressed and under slept and all these things that that adding this stress of cold exposure could be more harmful than beneficial. I mean this is how people say that some people uh what's your take on on this or who else beyond pregnant woman would you not recommend that they go into this type of practice or what is your take on all this? Yeah. So first of all I say we mentioned the pregnant woman I would also suggest that or advise that people with heart diseases and high or low unregulated blood pressure should also not do the cold water immersion. Um this is due to the heart uh and uh the activation of the sympathetic nervous system and the activation of the parasympathetic part of the nervous system as well where the heart rate goes up and the heart rate wants to go down and that is a conflict for the heart

26: 00 for the heart to the heart which is no problem. If you are uh healthy and there's nothing wrong with your heart then that is uh okay because it's very short-term and it doesn't create any harm to you. So this is tested but if you have heart diseases um or unregulated uh high blood pressure or low blood pressure then this might be not a good thing for you. So, um I think there's been a lot of like and and of course this happens that people talk online and they create their own narratives and this but I think there's lacking a lot of research when it goes specifically to some specific diseases and whether this is good or bad for you. We still need to uh be humble about that and say, "Hey, there's there's that we don't know." But as as well as I'm as a researcher saying we don't know, then I also think that people online should stop saying they know because I mean they can guess all they want. But if you just just a

27: 00 they want. But if you just just a general advice from me is that um if you are very stressed let's say you have a burnout complete burnout I would not recommend that you start up doing uh cold water immersion because putting this although it's very small kind of intense stress on top of whatever stress you also have might not be good for you. So you need to relax. you know, to find other ways to just take the top of the burnout and then start doing the cold water immersions as part of uh maybe um the journey that you want to go on to regulate your your stress. But stress definitely is not only chronic stress, right? It's also good stress, but good stress when you go to the gym, you would also not use that kind of stress on top of a burnout. So in that sense stress is also just stress. So if

28: 00 sense stress is also just stress. So if you have some kind of h stressed organ in your body this could be many. Um when I say stressed organ in your body it could be you just been diagnosed with some kind of disease. You would want to get that regulated before you start something very stressful like uh cold water immersion. But as soon as you get things under control, then you're good for it. Could a a could a person with type one diabetes or type two diabetes do cold water emotions? Definitely they can. if they have themselves regulated on their medication and also they measure their blood sugar levels on a regular basis. And I would say especially for people uh having type 1 uh diabetes when you go into the sauna you have to measure your blood sugar levels as soon as you get out because that would increase your blood cir sugar levels when you go into

29: 00 blood cir sugar levels when you go into the sauna and you might crash afterwards. So have that pen with you, have your um fructose with you, have some kind of sugar. Always be prepared when you do temperature uh um exposure like this, cold or hot, you will clear your blood sugar levels. You will clear fat from your bloodstream, but especially the sugar that is important for people with with any kind of um diabetes. So, but that only shows what I have shown in my research, which is that you get a faster glucose clearance from your bloodstream. And this is super good news, but you just have to be mindful if you have some kind of disease. But you asked about diseases, but on a reg I would say in general this is good for people. We are in a obesity pandemic globally. So, we want to find new ways to clear that sugar from the bloodstream and find new ways to activate the white uh fat cells in our body and we can do

30: 00 uh fat cells in our body and we can do that if we uh use temperature um training or therapy as a way of activating our metabolism. Yeah, I guess people there are some people just want to find excuses not to make an effort. You know, I'm sure that there there are a lot of people that maybe should be careful with this type of practice. I'm sure. But um I'm also know or understand or I've seen enough humans to understand that human nature works in certain ways. So a lot of people also like are looking for excuses not to make an effort and do things. But anyways, let's just um go on. Um tell me about shivering. Um I've heard you talk about this before um and I thought it was very interesting. We're all we always heard this story that when we go into the cold, either cold plunging or ice bathing or whatever it is, that we should relax and try to breathe into the cold and try not to shiver. But I've heard you say that

31: 00 shiver. But I've heard you say that maybe it's not such a good idea to forcefully avoid shivering. So tell me more about this. What what's the strategy to follow? Yeah, you you should not avoid uh the shivering uh when you get out of the water. Uh but waiting in the water until you shiver is not a good idea because when you start to shiver in the water, this depends on how adapted you are. Uh and the more adapted you get, the less you shiver. M so I have seen people sitting there in the cold water online and you see these videos and people like I don't shiver yet so I will just stay in the cold water until I shiver which is a bad thing. Uh don't do that because as you get adapted to the cold your muscles start to shiver less and less you build more mitochondria in the cells and these mitochondrial these are the energy fabrics in your cells that you have in your muscle fibers. You

32: 00 that you have in your muscle fibers. You have them in your brown fat cells and these are are there to increase um energy burning but also increase the heat in your body. So increase the temperature. But as you expose yourself to something that would decrease the temperature in your body which is the cold water you your body would try to adapt and the adaptations that is increasing the amount of mitochondria in the cells and when you have more mitochondria you don't shiver as much. Okay? So when you're in the water, you don't sit there and wait until you shiver. You go up after a few minutes. But I always say if you do contrast therapy, so when you alternate between the cold and the heat, um that could be a sauna that then end with the cold dip because then you force your body to uh reheat naturally and that is a super good thing. Yeah. And I don't think many people know this, but when you end on the cold, your activation of your whole metabolism

33: 00 activation of your whole metabolism starts to like go up and you can get dressed and you can just go home and just keep moving. Uh because that will also help your body to get back to that basic temperature which the body wants to. But it takes energy and that is what you have to think about. is a workout for your body where you're not really doing anything but you're just getting the extra money out of your cold exposure and you can stop that by going into the sauna. You can do that but I would just suggest that you don't let your body reheat naturally because that is so good exercise for your body. I did want to ask you about that about the sober principle. Uh maybe you can tell me more. It has a name even. It has a name. Um but before that um and I didn't invent it. I just want to say that I did I invented the concept but I didn't name it. So yeah, somebody did this sober principle. Yeah. Professor Andrew Hooperman. We we want to say that. Thank you. Andrew, was he the one that actually that gave you the name?

34: 00 you the name? Yeah. He he coined the name. Yeah. He asked me about these question these practices and then I told him why people should end on the cold and he said that that's that's something he had heard about or read about in the literature. So he coined it the sober principle. So he coined it. I didn't know. Yeah. Oh, you thought I did that? No. I just thought somebody else did. Neither you nor him. Yeah. Um, tell me more about saunas and tell me about the Finnish sona cohort. It's so interesting. Yeah, I think so too. Yeah, that's Yeah, people need to know. Amazing, right? People need to know about this. Um, yeah, please go ahead. So uh the Finnish sona cohorts started uh yeah that's like 25 years ago and some researchers uh asked people in Finland where they do a lot of sauners um they do almost everybody is doing sauna there and it's a part of their culture. So they followed 2, 500 or 2, 300 uh sound bthers for these 20 25

35: 00 2, 300 uh sound bthers for these 20 25 years and made a follow-up each year to measure on all their health outcomes. And when they had done that for I think it was like 20 years uh in 2015 they published a paper where they looked at mortality if people who did sauna each day every every day or maybe just one two three four times a day or up to each day. So seven times a day a week I mean um if they had a better health outcome and what they found was so interesting. They saw that if you do two to three times per week, you will have a lower uh risk of cardiovascular diseases compared to if you only did one sauna each week. And that doesn't mean that one sounder each week is bad for you. It's just because they measured this up against a control group who already did s. And I think that is fantastic that they did that. They didn't choose a unhealthy

36: 00 that. They didn't choose a unhealthy population to measure up against because of course you have good resource but they actually measured it up against those who already did once a week and compared that. So two to three times a week had a 40 39% lower risk of cardiovascular diseases. And um if you did four to seven times sta each week then you will have an almost 30 an almost 50% lower risk of dying early compared to those who only did once a week. So it's like the enormous you could say health benefits that you get from doing sa uh almost on like a dose response relationship. So the more you can do uh or the often you can do it. So each day maybe then you will have a cardiovascular workout because that is actually the the explanation for this right. So when you do sauna, you will

37: 00 right. So when you do sauna, you will increase the heart rate, you will sweat and this is the physiological reaction which is increasing your health benefits or lowering the risk of cardiovascular diseases. And there's actually studies showing that this corresponds to a zone 2 workout. So you can actually do this workout without moving a muscle, just sitting in the sauna and have that. I I don't say that you should not work out. I just say you can add it on to that and you will have an additional um lowering component to your risk of uh diseases but also lowering that mortality is fantastic that you can do that just by sitting in the heat and I think people need to know this. This is like um a very long longitudinal study which is it's cold. We don't have that for the cold yet, but it would be very interesting to to have that one day. And we also need some more research which shows exactly what's going on with the women. Uh the the

38: 00 going on with the women. Uh the the health uh science in women is not as big or as great in this space. But there are some some research out there showing the difference between men and women when it comes to cold and heat exposure. And there's also some misconceptions out there. You mentioned some of them. But but for women, it's just the same. do just a couple of minutes and then you're also good. But within your cycle, you could also I'm just answering something else now, but because this study from Finland was just on men and that is why I want to say that's actually also the same for women, but the women should just think about it as you can do the same as men can do. It's just that you don't have to stay in the cold water, for example, as long uh as a few minutes or more than a few minutes. But it's the same recommendations that we do for men. The only thing I would say for for women is that when you are in your cycle, um

39: 00 is that when you are in your cycle, um be mindful about when you do the cold exposure and the heat exposure because you're more sensitive to stress when you have your period or you're in your new phase. So sorry for just busting that in on top of your sona study. I just wanted to get it in there because so many people ask me this. Yeah, good information is good information. Um um so given the health benefits and um mood boosting effects of cold um immersion and given the amazing benefits of sauna do you think oh there is any study about this uh if the compounding effects of both practices have some sort of exponential benefits meaning uh it's not arithmetically added like the benefits of cold benefits of sauna put it together is it has has it some sort of compounding effect by doing them together I don't know it makes sense the question

40: 00 I don't know it makes sense the question or if there is any studies that is a really good question and that is exactly what I researched uh in my PhD so yeah that that I didn't know that's a coincidence so h I researched in my PhD um contrast therapy So the alternation between the cold and the heat. And what we see here is when you push your body right after another, so one extreme temperature to the other extreme temperature, you are also pushing your cardiovascular system, which is a super good workout. If you're healthy, that is is completely fine. Um, and of course, it takes more energy. And as a PhD in metabolism, I always want to talk about energy. I want to talk about if we could burn some energy and also of course it's interesting what energy you put in but in my PhD we really went into burning energy so how could we lose

41: 00 burning energy so how could we lose body from the cold to the heat so contrasting is within a short time frame really really a a great workout for your body you need to adapt so quickly and when your body needs to adapt from one extreme temperature to the other extreme temperature that takes energy. You need to switch fast. The cells need to be fast at like either increasing the temperature in the body or actually get rid of heat in the body. So those two extremes are um energy demanding you can say. So that's where you burn all the energy. So what we did in my study um was that we wanted to look at whether our winter swimmers who were adapted to winter swimming for a couple of seasons, we compared those to a control group and what we saw was that the adapted winter swimmers um they actually had a better insulin um sensitivity. uh we saw that they had lower insulin production in the body uh and compared to the control group and they also were faster at

42: 00 group and they also were faster at clearing glucose from the bloodstream. Uh and that's amazing. This is what you want to see because then you're further away from getting diabetes and type 2 diabetes is really a problem these days. So you want to do some kind of um exercise which will help you get further away from that and as a so these two groups actually exercised both of them they were young healthy but what they did not have in common was the uh the winter swimming and using the sona and they did this two to three times per week. So, of course, for people who haven't done this before, doing this two to three times per week might be a be much to push into your calendar. Maybe you have family, maybe you have small children. I mean, start with one times a week. But what we saw was that only 11 minutes in total of cold water immersion per week divided on these two to three days and with multiple dips on these uh

43: 00 days and with multiple dips on these uh these two to three days um corresponding to one to two minutes. then you will have these benefits that I just mentioned for you um and even more activation of the brown fat. What we also saw that only 57 minutes of sauna per week was enough also divided on these two to three days and with multiple saers on these two to three days then we saw these health benefits. So pushing your body from one extreme temperature to the other is super good. But the next question I often get is what if you don't have a sauna and a co-plunch next to each other? Can we do it on different days? And you can of course you can and you would get so many health benefits out of that as well and some similar effects I would imagine. But doing it on the same day definitely pushes your body even more. So that's just logic. Yeah. The amplitude at which the body needs to adapt from one extreme to the

44: 00 needs to adapt from one extreme to the other adds up. Um, listen, I want to be respectful of your time. So, I'm just going to throw the very last question related to the sober principle. So, we do we don't have to, but it's recommended that we end on cold because of this um energy effort that the body needs to um make to bring us back to normal temperature. But when we do saunas and cold plunching, we do back and forth, Is there a better way to start? Is it better to start with the sauna or is it better to start with the cold? Because when I start with the cold then it takes forever um for me to start sweating in the sauna, right? So because the body temperature goes down so much and there's such a vaso constriction. So is that a good practice or should I better go straight into the sauna and then do the cold? Do you have an intake on? I think it's a good question and and I would say

45: 00 would say it would be great to have really like a rigid scientific study really I mean pointing this out but I recommend that you start in the cold okay that's kind of what I do actually yeah and when you start in the cold that is where you will activate um also your um no adrenaline dopamine you'll activate up oxytocin and oxytocin is really good because when you sit in the sauna, there's probably not much to do really, but when you sit there and you have this cold chamber afterwards that you sit there and you're like you feel so safe from uh from the cold when you sit in the summer, so you were safe by the heat, right? And you have this increase in oxytocin in your body. That is where you start to feel gratitude for life. You will have change your chemistry in your brain. You have better thoughts. So I always say start in the cold. You can sit longer in

46: 00 sit longer in dreadful feeling of oh my god I'm already too hot and then you go into the cold plunge. But I mean preferences that is up to people of course but this is my take on it. Great. So start with cold end with cold. Uh thanks a lot for taking the time. Where can people know more about your work or do you have a website? Are you on social media? Where do you think people would uh get the best out of Susana? sober and the best information. Yeah, not the best of me but the the best information. So they can find me on social media uh on Instagram uh on my name Susanna Soberg. Um and they can find me on my website which is soberinstitute. com. I have courses for people who just want to learn for themselves. I also have uh certifications for people who teach others in this. Grace Susanna Sorberg on social media and all the links to your website. Thank you very much for taking the time. We had some technical problems in the middle of it, but everything's going to be okay.

47: 00 it, but everything's going to be okay. I think so, too. Thank you, Susanna. Thank you so much for inviting me.

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