Harnessing Thermal Stress: The Science Behind Saunas and Cold Plunges for Longevity - Full Transcript

00:00Could extreme temperatures boost my Could extreme temperatures boost my metabolism? Yes. A lot of things are metabolism? Yes. A lot of things are metabolism? Yes. A lot of things are going on in your body when you go into going on in your body when you go into going on in your body when you go into the sauna or into the cold water. the sauna or into the cold water. the sauna or into the cold water. Extreme cold exposure or heat will Extreme cold exposure or heat will Extreme cold exposure or heat will correspond to having a cardiovascular correspond to having a cardiovascular correspond to having a cardiovascular workout even without moving a muscle. workout even without moving a muscle. workout even without moving a muscle. And that is really good for your And that is really good for your And that is really good for your metabolism. And how often a week do you metabolism. And how often a week do you metabolism. And how often a week do you need to do that in order to get need to do that in order to get need to do that in order to get benefits? benefits? benefits? So Dr. Susanna Soberg's research on So Dr. Susanna Soberg's research on So Dr. Susanna Soberg's research on Norwegian swimmers cemented her as the Norwegian swimmers cemented her as the Norwegian swimmers cemented her as the leading expert in the field of thermal leading expert in the field of thermal leading expert in the field of thermal stress. stress. stress. Immersing yourself into cold water will Immersing yourself into cold water will Immersing yourself into cold water will mean that you will put this big stressor mean that you will put this big stressor mean that you will put this big stressor on your body, sending a rapid signal to on your body, sending a rapid signal to on your body, sending a rapid signal to your brain that now you are in danger. your brain that now you are in danger. your brain that now you are in danger. But in my research, I had a group of But in my research, I had a group of But in my research, I had a group of winter swimmers who were doing cold winter swimmers who were doing cold winter swimmers who were doing cold plunges. What we found was that they had plunges. What we found was that they had plunges. What we found was that they had a better insulin sensitivity and a a better insulin sensitivity and a a better insulin sensitivity and a faster glucose clearance from the blood. faster glucose clearance from the blood. faster glucose clearance from the blood. She's joined by Professor Tim Spectre,

01:00She's joined by Professor Tim Spectre, She's joined by Professor Tim Spectre, one of the world's top 100 most cited one of the world's top 100 most cited one of the world's top 100 most cited scientists, a professor of epidemiology scientists, a professor of epidemiology scientists, a professor of epidemiology at King's College London, and my at King's College London, and my at King's College London, and my scientific co-founder at Zurich. scientific co-founder at Zurich. scientific co-founder at Zurich. How can this be having any impact on my How can this be having any impact on my How can this be having any impact on my microbiome? And is it Tim? Your microbes microbiome? And is it Tim? Your microbes microbiome? And is it Tim? Your microbes pick up on the signals coming from the pick up on the signals coming from the pick up on the signals coming from the body. So if the body is getting just the body. So if the body is getting just the body. So if the body is getting just the right levels of stress, then I think we right levels of stress, then I think we right levels of stress, then I think we should see this translated into reducing should see this translated into reducing should see this translated into reducing inflammation and a happier microbiome. inflammation and a happier microbiome. inflammation and a happier microbiome. I've heard that there's a sort of hack I've heard that there's a sort of hack I've heard that there's a sort of hack that can get you some access to a cold that can get you some access to a cold that can get you some access to a cold plunge without actually doing a cold plunge without actually doing a cold plunge without actually doing a cold plunge. Yes. Welcome to Zoe Science and Nutrition, Welcome to Zoe Science and Nutrition, where worldleading scientists explain where worldleading scientists explain where worldleading scientists explain how their research can improve your how their research can improve your how their research can improve your health. Susanna, we'd like to kick off our show Susanna, we'd like to kick off our show here at Zoey with a rapid fire Q&A with here at Zoey with a rapid fire Q&A with here at Zoey with a rapid fire Q&A with questions from our listeners. Are you questions from our listeners. Are you questions from our listeners. Are you willing to give it a go? Of course. We willing to give it a go? Of course. We willing to give it a go? Of course. We have some very strict rules. You can say

02:00have some very strict rules. You can say have some very strict rules. You can say yes or no, or if you have to, you can yes or no, or if you have to, you can yes or no, or if you have to, you can have a sentence. Okay. Ready to go? have a sentence. Okay. Ready to go? have a sentence. Okay. Ready to go? Ready? Ready? Ready? Can a hot sauna mimic the effects of Can a hot sauna mimic the effects of Can a hot sauna mimic the effects of mild exercise? Yes. Can shivering boost mild exercise? Yes. Can shivering boost mild exercise? Yes. Can shivering boost my metabolism? my metabolism? my metabolism? Yes. Yes. Yes. Tim, could extreme temperatures change Tim, could extreme temperatures change Tim, could extreme temperatures change my gut microbiome? Possibly. my gut microbiome? Possibly. my gut microbiome? Possibly. Tim, is my metabolism mainly about my Tim, is my metabolism mainly about my Tim, is my metabolism mainly about my weight? No. weight? No. weight? No. Susanna, are there rules that we should Susanna, are there rules that we should Susanna, are there rules that we should follow before braving extreme hot or follow before braving extreme hot or follow before braving extreme hot or cold? Yes. That was great. Now you get cold? Yes. That was great. Now you get cold? Yes. That was great. Now you get like a whole sentence. What's the like a whole sentence. What's the like a whole sentence. What's the biggest misconception about extreme biggest misconception about extreme biggest misconception about extreme temperature exposure? The biggest temperature exposure? The biggest temperature exposure? The biggest misconception around extreme misconception around extreme misconception around extreme temperatures is that women shouldn't temperatures is that women shouldn't temperatures is that women shouldn't cope plunch. I'm really excited by this cope plunch. I'm really excited by this cope plunch. I'm really excited by this episode. It is one of the ones we've had episode. It is one of the ones we've had episode. It is one of the ones we've had like the most questions from members like the most questions from members like the most questions from members about over the last six months I would

03:00about over the last six months I would about over the last six months I would say and I think that's because sauners say and I think that's because sauners say and I think that's because sauners and cold plunges are popping up and cold plunges are popping up and cold plunges are popping up everywhere right now. On the other hand, everywhere right now. On the other hand, everywhere right now. On the other hand, I'm going to be honest Susanna my I'm going to be honest Susanna my I'm going to be honest Susanna my experience of stepping into freezing experience of stepping into freezing experience of stepping into freezing water is it is absolutely awful. I hate water is it is absolutely awful. I hate water is it is absolutely awful. I hate it. I can't imagine why anyone would it. I can't imagine why anyone would it. I can't imagine why anyone would want to do it. I want to understand want to do it. I want to understand want to do it. I want to understand basically why everyone's got so excited basically why everyone's got so excited basically why everyone's got so excited about this and whether it's just like about this and whether it's just like about this and whether it's just like the latest fad or there's actually any the latest fad or there's actually any the latest fad or there's actually any reason to believe that making oneself reason to believe that making oneself reason to believe that making oneself miserable can possibly be good for miserable can possibly be good for miserable can possibly be good for oneself. Why don't we start with a oneself. Why don't we start with a oneself. Why don't we start with a sauna? Like what's happening in a sauna sauna? Like what's happening in a sauna sauna? Like what's happening in a sauna and why is it that it sort of makes me and why is it that it sort of makes me and why is it that it sort of makes me feel sleepy and makes me want to slow feel sleepy and makes me want to slow feel sleepy and makes me want to slow down when I go in one? The thing about down when I go in one? The thing about down when I go in one? The thing about sauna is that you actually both activate sauna is that you actually both activate sauna is that you actually both activate your sympathetic nervous system. So that your sympathetic nervous system. So that your sympathetic nervous system. So that is your fight and flight system in your is your fight and flight system in your is your fight and flight system in your body. But you also activate your rest body. But you also activate your rest body. But you also activate your rest and digest part of your system and that and digest part of your system and that and digest part of your system and that is the what is called the is the what is called the is the what is called the parasympathetic nervous system. So when parasympathetic nervous system. So when parasympathetic nervous system. So when you go into the sauna and you sit there

04:00you go into the sauna and you sit there you go into the sauna and you sit there for a while, you will heat up from the for a while, you will heat up from the for a while, you will heat up from the inside and out and you will start to inside and out and you will start to inside and out and you will start to sweat. And if you can sit there long sweat. And if you can sit there long sweat. And if you can sit there long enough for your heart rate to go up, you enough for your heart rate to go up, you enough for your heart rate to go up, you will have a sweating that will will have a sweating that will will have a sweating that will correspond to having a mild workout. So correspond to having a mild workout. So correspond to having a mild workout. So the cardiovascular you can say activity the cardiovascular you can say activity the cardiovascular you can say activity corresponds to doing this mile kind of corresponds to doing this mile kind of corresponds to doing this mile kind of workout and that is stressing your workout and that is stressing your workout and that is stressing your system just a bit. And when you do that system just a bit. And when you do that system just a bit. And when you do that you actually also increased cortisol you actually also increased cortisol you actually also increased cortisol levels which people also levels which people also levels which people also misunderstanding that that is so oh so misunderstanding that that is so oh so misunderstanding that that is so oh so dangerous but it is not if you just do dangerous but it is not if you just do dangerous but it is not if you just do it acutely and then you will have that it acutely and then you will have that it acutely and then you will have that decrease in your stress response decrease in your stress response decrease in your stress response afterwards. And that is why maybe you afterwards. And that is why maybe you afterwards. And that is why maybe you get a little bit sleepy because you get a little bit sleepy because you get a little bit sleepy because you actually get a high increase in your actually get a high increase in your actually get a high increase in your temperature in the body and that is what temperature in the body and that is what temperature in the body and that is what you do when you actually want to go to you do when you actually want to go to you do when you actually want to go to sleep. So if you get a little bit sleepy sleep. So if you get a little bit sleepy sleep. So if you get a little bit sleepy afterwards, it's kind of natural. So afterwards, it's kind of natural. So afterwards, it's kind of natural. So taking a sauna maybe at a certain time taking a sauna maybe at a certain time taking a sauna maybe at a certain time of the day might be a good thing. So you of the day might be a good thing. So you of the day might be a good thing. So you can use it as a tool.

05:00can use it as a tool. can use it as a tool. You're saying just sitting in the You're saying just sitting in the You're saying just sitting in the sauna actually makes my body sort of go sauna actually makes my body sort of go sauna actually makes my body sort of go through a work sort of a workout because through a work sort of a workout because through a work sort of a workout because it's making my heart rate go up. Could it's making my heart rate go up. Could it's making my heart rate go up. Could you explain that for a minute? Yeah. And you explain that for a minute? Yeah. And you explain that for a minute? Yeah. And even without moving a muscle and that's even without moving a muscle and that's even without moving a muscle and that's kind of amazing. There is these cohort kind of amazing. There is these cohort kind of amazing. There is these cohort studies performed in Finland. So studies performed in Finland. So studies performed in Finland. So researchers there have followed more researchers there have followed more researchers there have followed more than 2,000 sona bthers and saw that than 2,000 sona bthers and saw that than 2,000 sona bthers and saw that after 15 to 20 years they could see that after 15 to 20 years they could see that after 15 to 20 years they could see that they actually had a better they actually had a better they actually had a better cardiovascular outcomes based on how cardiovascular outcomes based on how cardiovascular outcomes based on how many times they have done sess per week. many times they have done sess per week. many times they have done sess per week. So the more they did, the better So the more they did, the better So the more they did, the better cardiovascular outcomes they actually cardiovascular outcomes they actually cardiovascular outcomes they actually had and lower risk of developing had and lower risk of developing had and lower risk of developing cardiovascular diseases and even had a cardiovascular diseases and even had a cardiovascular diseases and even had a lower mortality risk when they measured lower mortality risk when they measured lower mortality risk when they measured this over 20 years. So when they then this over 20 years. So when they then this over 20 years. So when they then looked at comparison between how many looked at comparison between how many looked at comparison between how many times a week you go to the sauna and

06:00times a week you go to the sauna and times a week you go to the sauna and then also if you did exercise on top of then also if you did exercise on top of then also if you did exercise on top of that they did see this um additional or that they did see this um additional or that they did see this um additional or additive effect when you combine the additive effect when you combine the additive effect when you combine the two. So you can see sauna as a two. So you can see sauna as a two. So you can see sauna as a cardiovascular workout that is not um cardiovascular workout that is not um cardiovascular workout that is not um attributed to your muscles, but you attributed to your muscles, but you attributed to your muscles, but you still get that workout for your heart still get that workout for your heart still get that workout for your heart and that is really good for your and that is really good for your and that is really good for your cardiovascular system. Why does my heart cardiovascular system. Why does my heart cardiovascular system. Why does my heart have to do any work in the sauna? I can have to do any work in the sauna? I can have to do any work in the sauna? I can see I need to sweat a lot so I don't see I need to sweat a lot so I don't see I need to sweat a lot so I don't die. That I can understand. But what die. That I can understand. But what die. That I can understand. But what what's going on? Why does it make my what's going on? Why does it make my what's going on? Why does it make my heart rate go up? When you get warm on heart rate go up? When you get warm on heart rate go up? When you get warm on your skin, the temperature sensors are your skin, the temperature sensors are your skin, the temperature sensors are going to send a signal to your going to send a signal to your going to send a signal to your temperature regulating sensor in the temperature regulating sensor in the temperature regulating sensor in the brain. And there the sensors say, well, brain. And there the sensors say, well, brain. And there the sensors say, well, it are you getting warmer or colder than it are you getting warmer or colder than it are you getting warmer or colder than you were before. And depending on that, you were before. And depending on that, you were before. And depending on that, they will send out signals in the body they will send out signals in the body they will send out signals in the body saying, whoa, no, you're getting too saying, whoa, no, you're getting too saying, whoa, no, you're getting too warm. And send out no adrenaline. And warm. And send out no adrenaline. And warm. And send out no adrenaline. And these are our stress hormones. So these are our stress hormones. So these are our stress hormones. So noradrenaline is released in your body, noradrenaline is released in your body, noradrenaline is released in your body, which will make your heart rate go up.

07:00which will make your heart rate go up. which will make your heart rate go up. It will also activate your brown fat It will also activate your brown fat It will also activate your brown fat actually to make you heat up so you can actually to make you heat up so you can actually to make you heat up so you can sweat better because the only thing the sweat better because the only thing the sweat better because the only thing the body wants to do now is survive. Survive body wants to do now is survive. Survive body wants to do now is survive. Survive this heat because the body doesn't know this heat because the body doesn't know this heat because the body doesn't know when you will ever get out again because when you will ever get out again because when you will ever get out again because you are in control. You know yourself you are in control. You know yourself you are in control. You know yourself that you can sit there for a while but that you can sit there for a while but that you can sit there for a while but the body doesn't know that. So it wants the body doesn't know that. So it wants the body doesn't know that. So it wants to get rid of all that heat. And to do to get rid of all that heat. And to do to get rid of all that heat. And to do that we need to increase the heart rate. that we need to increase the heart rate. that we need to increase the heart rate. You also dilate your blood vessels. So You also dilate your blood vessels. So You also dilate your blood vessels. So the blood needs to get pumped around in the blood needs to get pumped around in the blood needs to get pumped around in a longer way. So the body has to get a longer way. So the body has to get a longer way. So the body has to get more blood flowing around and for that more blood flowing around and for that more blood flowing around and for that you would need to increase your heart you would need to increase your heart you would need to increase your heart rate. And Tim, as you're listening to rate. And Tim, as you're listening to rate. And Tim, as you're listening to this, are there any reasons to be this, are there any reasons to be this, are there any reasons to be concerned about that activity or is this concerned about that activity or is this concerned about that activity or is this all like great and healthy and natural? all like great and healthy and natural? all like great and healthy and natural? It is putting a strain on the It is putting a strain on the It is putting a strain on the cardiovascular system. So if you are cardiovascular system. So if you are cardiovascular system. So if you are unwell, it's probably not a great idea unwell, it's probably not a great idea unwell, it's probably not a great idea to do it in a proper hot sauna. So I to do it in a proper hot sauna. So I to do it in a proper hot sauna. So I think we have to take that in mind and

08:00think we have to take that in mind and think we have to take that in mind and and there are probably individual and there are probably individual and there are probably individual differences. You know some people do differences. You know some people do differences. You know some people do faint more easily when the their faint more easily when the their faint more easily when the their circulatory system is changing. You know circulatory system is changing. You know circulatory system is changing. You know it might be on blood pressure it might be on blood pressure it might be on blood pressure medications which mean when it goes up medications which mean when it goes up medications which mean when it goes up or down it can be it can drop more than or down it can be it can drop more than or down it can be it can drop more than others. So yeah I think certainly the others. So yeah I think certainly the others. So yeah I think certainly the first few times people are doing it it's first few times people are doing it it's first few times people are doing it it's very you know do it for short times. You very you know do it for short times. You very you know do it for short times. You be rather careful underdo it rather than be rather careful underdo it rather than be rather careful underdo it rather than overdo it. But as long as you're overdo it. But as long as you're overdo it. But as long as you're sensible when you're starting, you sort sensible when you're starting, you sort sensible when you're starting, you sort of build it up gradually that you know of build it up gradually that you know of build it up gradually that you know the risks are pretty minimal. Uh and the risks are pretty minimal. Uh and the risks are pretty minimal. Uh and most people are going to get benefit most people are going to get benefit most people are going to get benefit rather than than any risk. rather than than any risk. rather than than any risk. One of the things I've learned running a One of the things I've learned running a One of the things I've learned running a datadriven health company is this. Small datadriven health company is this. Small datadriven health company is this. Small actions create compounding actions create compounding actions create compounding impact. Your hitting subscribe is one of impact. Your hitting subscribe is one of impact. Your hitting subscribe is one of those small actions. It tells the those small actions. It tells the those small actions. It tells the algorithm that this show matters. It algorithm that this show matters. It algorithm that this show matters. It helps us reach more people and it lets helps us reach more people and it lets helps us reach more people and it lets us bring you more sciencebacked advice.

09:00us bring you more sciencebacked advice. us bring you more sciencebacked advice. If this episode gave you value, If this episode gave you value, If this episode gave you value, subscribing is how you give a little subscribing is how you give a little subscribing is how you give a little back and we'll keep showing up every back and we'll keep showing up every back and we'll keep showing up every week to return the favor. Okay, now back week to return the favor. Okay, now back week to return the favor. Okay, now back to the show. I think the first time I to the show. I think the first time I to the show. I think the first time I ever went in a sauna was when I went to ever went in a sauna was when I went to ever went in a sauna was when I went to Finland. My grandmother thought this was Finland. My grandmother thought this was Finland. My grandmother thought this was completely mad, Susanna. It was like, completely mad, Susanna. It was like, completely mad, Susanna. It was like, why would you choose to like get put in why would you choose to like get put in why would you choose to like get put in the oven as she put? Um, and so I think the oven as she put? Um, and so I think the oven as she put? Um, and so I think it's fascinating that you're explaining it's fascinating that you're explaining it's fascinating that you're explaining that there's these things that we that there's these things that we that there's these things that we understand, um, this stress, these understand, um, this stress, these understand, um, this stress, these changes, and you're saying they can be changes, and you're saying they can be changes, and you're saying they can be beneficial. Before we unpack, I guess, beneficial. Before we unpack, I guess, beneficial. Before we unpack, I guess, why those stresses could be beneficial. why those stresses could be beneficial. why those stresses could be beneficial. Could you talk about the opposite of Could you talk about the opposite of Could you talk about the opposite of this? So, one is going into the sauna, this? So, one is going into the sauna, this? So, one is going into the sauna, but I know you're a big believer also in but I know you're a big believer also in but I know you're a big believer also in the cold plunge. What happens when, the cold plunge. What happens when, the cold plunge. What happens when, like, I'm thinking about my own personal like, I'm thinking about my own personal like, I'm thinking about my own personal experience of like going into the sea in experience of like going into the sea in experience of like going into the sea in in England, which I've done once cuz it in England, which I've done once cuz it in England, which I've done once cuz it was way too cold. it it's very was way too cold. it it's very was way too cold. it it's very unpleasant. What's going on in your body unpleasant. What's going on in your body unpleasant. What's going on in your body as you do that? Yeah, a lot of things as you do that? Yeah, a lot of things as you do that? Yeah, a lot of things are going on in your body when you go are going on in your body when you go are going on in your body when you go into the cold water. So, it's very into the cold water. So, it's very into the cold water. So, it's very different from a cold shower also, but

10:00different from a cold shower also, but different from a cold shower also, but we can get back to that. So, immersing we can get back to that. So, immersing we can get back to that. So, immersing yourself into cold water will mean that yourself into cold water will mean that yourself into cold water will mean that you will put this very very big stressor you will put this very very big stressor you will put this very very big stressor on your body because the body is in a on your body because the body is in a on your body because the body is in a natural temperature. You don't want to natural temperature. You don't want to natural temperature. You don't want to get too cold. But this is so potent get too cold. But this is so potent get too cold. But this is so potent because it surrounds your body because it surrounds your body because it surrounds your body immediately with no air of course. So immediately with no air of course. So immediately with no air of course. So the potent of activating your cold the potent of activating your cold the potent of activating your cold receptors in the skin is like 100%. And receptors in the skin is like 100%. And receptors in the skin is like 100%. And that is like a huge stressor sending a that is like a huge stressor sending a that is like a huge stressor sending a rapid signal to your brain that now you rapid signal to your brain that now you rapid signal to your brain that now you are definitely in a um situation where are definitely in a um situation where are definitely in a um situation where you are in in danger actually. So the you are in in danger actually. So the you are in in danger actually. So the body acts as if you are in danger even body acts as if you are in danger even body acts as if you are in danger even though you do it deliberately and sends though you do it deliberately and sends though you do it deliberately and sends a signal to the brain to regulate your a signal to the brain to regulate your a signal to the brain to regulate your body so that you can better survive body so that you can better survive body so that you can better survive this. So it sends out no adrenaline um this. So it sends out no adrenaline um this. So it sends out no adrenaline um to activate your brown fat. And Susanna to activate your brown fat. And Susanna to activate your brown fat. And Susanna can you explain exactly what is brown can you explain exactly what is brown can you explain exactly what is brown fat? We have two kind of fat tissues

11:00fat? We have two kind of fat tissues fat? We have two kind of fat tissues also in the body. Um, and one of them is also in the body. Um, and one of them is also in the body. Um, and one of them is the white fat, which we know it's on our the white fat, which we know it's on our the white fat, which we know it's on our belly, it's on our thighs, and we want belly, it's on our thighs, and we want belly, it's on our thighs, and we want to get rid of that because it can grow to get rid of that because it can grow to get rid of that because it can grow and it's so difficult to activate it and and it's so difficult to activate it and and it's so difficult to activate it and get rid of those um fat pearls, you can get rid of those um fat pearls, you can get rid of those um fat pearls, you can say, because it's all fat pearls just say, because it's all fat pearls just say, because it's all fat pearls just stuck together. So, that stores our stuck together. So, that stores our stuck together. So, that stores our energy in the body. Quite opposite to energy in the body. Quite opposite to energy in the body. Quite opposite to that, we have the brown fat. The brown that, we have the brown fat. The brown that, we have the brown fat. The brown fat actually increases our metabolism. fat actually increases our metabolism. fat actually increases our metabolism. So the brown fat can uh burn the white So the brown fat can uh burn the white So the brown fat can uh burn the white fat. So it's kind of like a good fat and fat. So it's kind of like a good fat and fat. So it's kind of like a good fat and we could say that the white fat is a bad we could say that the white fat is a bad we could say that the white fat is a bad fat but we also need some of that white fat but we also need some of that white fat but we also need some of that white fat. But the brown fat we want to fat. But the brown fat we want to fat. But the brown fat we want to increase so that we can have a higher increase so that we can have a higher increase so that we can have a higher metabolism or um energy expenditure uh metabolism or um energy expenditure uh metabolism or um energy expenditure uh both when we are on purposely activating both when we are on purposely activating both when we are on purposely activating it but also when we are just sitting it but also when we are just sitting it but also when we are just sitting here or when we are asleep. The more we here or when we are asleep. The more we here or when we are asleep. The more we have of the brown fat, the better. It's

12:00have of the brown fat, the better. It's have of the brown fat, the better. It's just like you can compare it to the just like you can compare it to the just like you can compare it to the muscles. So, we all agree and know today muscles. So, we all agree and know today muscles. So, we all agree and know today that we it's good to have a lot of that we it's good to have a lot of that we it's good to have a lot of muscle mass because there's a lot of muscle mass because there's a lot of muscle mass because there's a lot of mitochondria in the in the muscle fibers mitochondria in the in the muscle fibers mitochondria in the in the muscle fibers and the more we have of those the the and the more we have of those the the and the more we have of those the the better it's functioning and it increases better it's functioning and it increases better it's functioning and it increases our insulin sensitivity. And it's the our insulin sensitivity. And it's the our insulin sensitivity. And it's the same with the brown fat cells. The more same with the brown fat cells. The more same with the brown fat cells. The more we have of brown fat cells, the more we have of brown fat cells, the more we have of brown fat cells, the more mitochondria we have, the better insulin mitochondria we have, the better insulin mitochondria we have, the better insulin sensitivity we have. And also it can sensitivity we have. And also it can sensitivity we have. And also it can burn more fat in our body. Not only when burn more fat in our body. Not only when burn more fat in our body. Not only when we are activating it on purpose, but we are activating it on purpose, but we are activating it on purpose, but also when we are just like sitting here. also when we are just like sitting here. also when we are just like sitting here. So our basic metabolic rate will So our basic metabolic rate will So our basic metabolic rate will actually go up if we have more brown actually go up if we have more brown actually go up if we have more brown fat. So just like the muscles, it can fat. So just like the muscles, it can fat. So just like the muscles, it can grow if we use it, you can say. And if grow if we use it, you can say. And if grow if we use it, you can say. And if we don't use it, we will lose it. So, we don't use it, we will lose it. So, we don't use it, we will lose it. So, it's something that we can grow and you it's something that we can grow and you it's something that we can grow and you can also shrink. Firstly, where is my can also shrink. Firstly, where is my can also shrink. Firstly, where is my brown fat? Cuz I didn't realize I had brown fat? Cuz I didn't realize I had brown fat? Cuz I didn't realize I had any. So, I'm now really curious. And

13:00any. So, I'm now really curious. And any. So, I'm now really curious. And secondly, you mentioned the brown fat secondly, you mentioned the brown fat secondly, you mentioned the brown fat because it's linked to this discussion because it's linked to this discussion because it's linked to this discussion around like the sauna and the cold around like the sauna and the cold around like the sauna and the cold plunge. Could you just help me again to plunge. Could you just help me again to plunge. Could you just help me again to understand that link and listeners too? understand that link and listeners too? understand that link and listeners too? The brown fat is located six different The brown fat is located six different The brown fat is located six different places in the body and the biggest you places in the body and the biggest you places in the body and the biggest you can say depo uh is located under your can say depo uh is located under your can say depo uh is located under your clavvicular bones. So so actually uh clavvicular bones. So so actually uh clavvicular bones. So so actually uh under here down your neck and out to under here down your neck and out to under here down your neck and out to your shoulders all the time feeling what your shoulders all the time feeling what your shoulders all the time feeling what temperature are you in making sure that temperature are you in making sure that temperature are you in making sure that you have blood to your brain and warm you have blood to your brain and warm you have blood to your brain and warm blood to your brain and warm blood to blood to your brain and warm blood to blood to your brain and warm blood to your uh your heart and your liver and your uh your heart and your liver and your uh your heart and your liver and your kidneys. So your vital organs. So, your kidneys. So your vital organs. So, your kidneys. So your vital organs. So, it's centered around your central it's centered around your central it's centered around your central nervous system, which is kind of smart nervous system, which is kind of smart nervous system, which is kind of smart from nature, right? Because then when from nature, right? Because then when from nature, right? Because then when you get a little bit cold from walking you get a little bit cold from walking you get a little bit cold from walking outside in the wind, and there was outside in the wind, and there was outside in the wind, and there was actually studies on this showing that if actually studies on this showing that if actually studies on this showing that if you walk outside with just a t-shirt, you walk outside with just a t-shirt, you walk outside with just a t-shirt, you will activate your brown fat. So,

14:00you will activate your brown fat. So, you will activate your brown fat. So, it's so sensitive making sure that we it's so sensitive making sure that we it's so sensitive making sure that we are in the perfect temperature balance are in the perfect temperature balance are in the perfect temperature balance in our body so we don't get too cold or in our body so we don't get too cold or in our body so we don't get too cold or too warm. And we by doing so actually it too warm. And we by doing so actually it too warm. And we by doing so actually it uses fuel uh from the body which is uses fuel uh from the body which is uses fuel uh from the body which is sugar so glucose and fat which is the sugar so glucose and fat which is the sugar so glucose and fat which is the white fat to um increase this heat in white fat to um increase this heat in white fat to um increase this heat in the body. So it's like an engine that the body. So it's like an engine that the body. So it's like an engine that where it takes the fuel of sugar and fat where it takes the fuel of sugar and fat where it takes the fuel of sugar and fat from the bloodstream and that is where from the bloodstream and that is where from the bloodstream and that is where we see that if we activate the brown fat we see that if we activate the brown fat we see that if we activate the brown fat um it can actually increase our insulin um it can actually increase our insulin um it can actually increase our insulin sensitivity and it can also clear the sensitivity and it can also clear the sensitivity and it can also clear the blood sugar from our bloodstream and blood sugar from our bloodstream and blood sugar from our bloodstream and this is shown both in mice studies but this is shown both in mice studies but this is shown both in mice studies but it's also shown in in human studies as it's also shown in in human studies as it's also shown in in human studies as well. So the the code is like shut out well. So the the code is like shut out well. So the the code is like shut out in a way to your best you can say you in a way to your best you can say you in a way to your best you can say you are only human you are not made of are only human you are not made of are only human you are not made of metal. So that means that very quickly metal. So that means that very quickly metal. So that means that very quickly you will cool your um your inner tissue. you will cool your um your inner tissue. you will cool your um your inner tissue. So that is why I'm very very much a big

15:00So that is why I'm very very much a big So that is why I'm very very much a big speaker for only short-term cold speaker for only short-term cold speaker for only short-term cold exposure because the long-term cold exposure because the long-term cold exposure because the long-term cold exposure has no benefits. There is no exposure has no benefits. There is no exposure has no benefits. There is no research showing that sitting in a cold research showing that sitting in a cold research showing that sitting in a cold bath for a very long time has any bath for a very long time has any bath for a very long time has any benefits. But the brown fat is keeping benefits. But the brown fat is keeping benefits. But the brown fat is keeping you warm. And if you cannot keep you warm. And if you cannot keep you warm. And if you cannot keep yourself warm enough with just brown fat yourself warm enough with just brown fat yourself warm enough with just brown fat activation, you will also start to use activation, you will also start to use activation, you will also start to use your muscles to shiver and uh the brown your muscles to shiver and uh the brown your muscles to shiver and uh the brown fat and the muscles are the only two you fat and the muscles are the only two you fat and the muscles are the only two you can say thermogenic tissues in our body can say thermogenic tissues in our body can say thermogenic tissues in our body and they will signal to each other. So and they will signal to each other. So and they will signal to each other. So kind of like talk to each other actually kind of like talk to each other actually kind of like talk to each other actually and make sure that it's activated. So and make sure that it's activated. So and make sure that it's activated. So the the muscles are sending signals to the the muscles are sending signals to the the muscles are sending signals to the brown fat and the other way around the brown fat and the other way around the brown fat and the other way around to make sure that both thermogenic to make sure that both thermogenic to make sure that both thermogenic tissue is keeping you warm. And Susanna, tissue is keeping you warm. And Susanna, tissue is keeping you warm. And Susanna, when you say thermogenic tissue, what when you say thermogenic tissue, what when you say thermogenic tissue, what does that mean? Thermogenic tissue is does that mean? Thermogenic tissue is does that mean? Thermogenic tissue is you can think about it as tissue in your you can think about it as tissue in your you can think about it as tissue in your body which will make sure that you are body which will make sure that you are body which will make sure that you are in the right temperature for your cells

16:00in the right temperature for your cells in the right temperature for your cells in your body to have the right in your body to have the right in your body to have the right activation and and function. It's funny, activation and and function. It's funny, activation and and function. It's funny, I'm thinking of my grandmother, my nanny I'm thinking of my grandmother, my nanny I'm thinking of my grandmother, my nanny again. uh who always like, "Well, it's again. uh who always like, "Well, it's again. uh who always like, "Well, it's cold. You have to wear a scarf." And now cold. You have to wear a scarf." And now cold. You have to wear a scarf." And now I'm thinking like, "My scarf, is that I'm thinking like, "My scarf, is that I'm thinking like, "My scarf, is that literally going around my brown fat literally going around my brown fat literally going around my brown fat because that's somehow I'm more because that's somehow I'm more because that's somehow I'm more sensitive." Or is this like entirely by sensitive." Or is this like entirely by sensitive." Or is this like entirely by chance? No, it could be by chance. But chance? No, it could be by chance. But chance? No, it could be by chance. But if you are a a cold which I'm not if you are a a cold which I'm not if you are a a cold which I'm not afraid to say that I used to be a cold afraid to say that I used to be a cold afraid to say that I used to be a cold but maybe you are a cold but maybe you are a cold but maybe you are a cold because you never expose yourself to the because you never expose yourself to the because you never expose yourself to the cold. So you get colder by staying you cold. So you get colder by staying you cold. So you get colder by staying you can say too warm, too comfortable. When can say too warm, too comfortable. When can say too warm, too comfortable. When you are comfortable then you get colder. you are comfortable then you get colder. you are comfortable then you get colder. So it's difficult for you to temperature So it's difficult for you to temperature So it's difficult for you to temperature regulate yourself. And the purpose of regulate yourself. And the purpose of regulate yourself. And the purpose of the brown fat is to make you survive. the brown fat is to make you survive. the brown fat is to make you survive. And if you use your brown fat then you And if you use your brown fat then you And if you use your brown fat then you will get better at temperature will get better at temperature will get better at temperature regulating your body. And for that it regulating your body. And for that it regulating your body. And for that it needs fuel. That is why the brown fat is needs fuel. That is why the brown fat is needs fuel. That is why the brown fat is so closely connected to your metabolism.

17:00so closely connected to your metabolism. so closely connected to your metabolism. So if you go out and expose yourself to So if you go out and expose yourself to So if you go out and expose yourself to the coat like I did years ago, now it's the coat like I did years ago, now it's the coat like I did years ago, now it's 10 years ago. And I started doing that. 10 years ago. And I started doing that. 10 years ago. And I started doing that. It was horrible really. I used to sit It was horrible really. I used to sit It was horrible really. I used to sit with blankets and layers and layers. And with blankets and layers and layers. And with blankets and layers and layers. And today I don't have to do that. I don't today I don't have to do that. I don't today I don't have to do that. I don't have cold hands and feet anymore. And I have cold hands and feet anymore. And I have cold hands and feet anymore. And I don't pack up in in layers anymore like don't pack up in in layers anymore like don't pack up in in layers anymore like I used to do. And I can actually do cold I used to do. And I can actually do cold I used to do. And I can actually do cold water swimming today, which was so water swimming today, which was so water swimming today, which was so difficult in the beginning because I difficult in the beginning because I difficult in the beginning because I actually don't think that my brown fat actually don't think that my brown fat actually don't think that my brown fat was really like activated or I didn't was really like activated or I didn't was really like activated or I didn't use it that much because I kept packing use it that much because I kept packing use it that much because I kept packing myself in in warm clothing and yeah, myself in in warm clothing and yeah, myself in in warm clothing and yeah, maybe I was just very comfortable. Maybe maybe I was just very comfortable. Maybe maybe I was just very comfortable. Maybe I just resembled a lot of the modern I just resembled a lot of the modern I just resembled a lot of the modern people today like we are so scared of people today like we are so scared of people today like we are so scared of getting cold. So my personal journey getting cold. So my personal journey getting cold. So my personal journey definitely helped me understand this definitely helped me understand this definitely helped me understand this tissue much better and how temperature tissue much better and how temperature tissue much better and how temperature regulating ourself is actually something regulating ourself is actually something regulating ourself is actually something that we can contribute to and how our

18:00that we can contribute to and how our that we can contribute to and how our metabolism work is definitely something metabolism work is definitely something metabolism work is definitely something that has everything to do with our that has everything to do with our that has everything to do with our choices in our everyday life. Can you choices in our everyday life. Can you choices in our everyday life. Can you explain to me Susan? A lot of the explain to me Susan? A lot of the explain to me Susan? A lot of the science was done on on mice and rats science was done on on mice and rats science was done on on mice and rats that have a lot of brown fat and it's that have a lot of brown fat and it's that have a lot of brown fat and it's easy to study them and clearly it works easy to study them and clearly it works easy to study them and clearly it works for these rodents and it's a really for these rodents and it's a really for these rodents and it's a really crucial part of their survival crucial part of their survival crucial part of their survival mechanisms. But for humans that I think mechanisms. But for humans that I think mechanisms. But for humans that I think I don't know what the latest data was I don't know what the latest data was I don't know what the latest data was but it was something like only half a but it was something like only half a but it was something like only half a percent or something of our fat is brown percent or something of our fat is brown percent or something of our fat is brown fat compared to our white fat. it's a fat compared to our white fat. it's a fat compared to our white fat. it's a tiny amount that we're expecting the tiny amount that we're expecting the tiny amount that we're expecting the same results from, you know, mice and same results from, you know, mice and same results from, you know, mice and and and rats in humans. Is it really and and rats in humans. Is it really and and rats in humans. Is it really that important in humans or do you think that important in humans or do you think that important in humans or do you think we've overestimated it from, you know, we've overestimated it from, you know, we've overestimated it from, you know, these animal studies or is that still these animal studies or is that still these animal studies or is that still the best explanation that we have of the best explanation that we have of the best explanation that we have of how, you know, humans control their how, you know, humans control their how, you know, humans control their their blood their temperature or you their blood their temperature or you their blood their temperature or you think there could be other mechanisms we think there could be other mechanisms we think there could be other mechanisms we don't know about? I think there's don't know about? I think there's don't know about? I think there's definitely a lot we don't know yet, but

19:00definitely a lot we don't know yet, but definitely a lot we don't know yet, but brown fat has been one of these research brown fat has been one of these research brown fat has been one of these research areas for hundreds of years that we have areas for hundreds of years that we have areas for hundreds of years that we have known about. But it was not until known about. But it was not until known about. But it was not until actually the millennium that we actually the millennium that we actually the millennium that we discovered that a little bit of cold discovered that a little bit of cold discovered that a little bit of cold exposure could actually change our exposure could actually change our exposure could actually change our metabolism. So our glucose balance and metabolism. So our glucose balance and metabolism. So our glucose balance and our insulin sensitivity in humans. This our insulin sensitivity in humans. This our insulin sensitivity in humans. This is actually not about the size of the is actually not about the size of the is actually not about the size of the tissue. There was actually research in tissue. There was actually research in tissue. There was actually research in humans and this is so fascinating. It's humans and this is so fascinating. It's humans and this is so fascinating. It's a study from 2014 a study from 2014 a study from 2014 uh showing where the researchers had uh showing where the researchers had uh showing where the researchers had people who had a bad insulin sensitivity people who had a bad insulin sensitivity people who had a bad insulin sensitivity and some of them were obese and some of and some of them were obese and some of and some of them were obese and some of them had type 2 diabetes and they had them had type 2 diabetes and they had them had type 2 diabetes and they had them sleep in a room which was them sleep in a room which was them sleep in a room which was 24° Celsius for a month and then they 24° Celsius for a month and then they 24° Celsius for a month and then they measured their brown fat. Then they measured their brown fat. Then they measured their brown fat. Then they slept at 19 degrees for a month and then slept at 19 degrees for a month and then slept at 19 degrees for a month and then again measured their brown fat and also again measured their brown fat and also again measured their brown fat and also insulin sensitivity. And what they found insulin sensitivity. And what they found insulin sensitivity. And what they found was that sleeping in a room at night at

20:00was that sleeping in a room at night at was that sleeping in a room at night at 19° C actually increased their insulin 19° C actually increased their insulin 19° C actually increased their insulin sensitivity and their glucose clearance sensitivity and their glucose clearance sensitivity and their glucose clearance got better. And when you then looked at got better. And when you then looked at got better. And when you then looked at the measure of the brown fat, you can the measure of the brown fat, you can the measure of the brown fat, you can see that it had had increased. And that see that it had had increased. And that see that it had had increased. And that was just from sleeping at 19° in a cold was just from sleeping at 19° in a cold was just from sleeping at 19° in a cold room uh for a month. So it's a very room uh for a month. So it's a very room uh for a month. So it's a very potent uh tissue which when activated potent uh tissue which when activated potent uh tissue which when activated you can actually increase it and when you can actually increase it and when you can actually increase it and when you're not using it it shows also that you're not using it it shows also that you're not using it it shows also that it decreases. What they did after that it decreases. What they did after that it decreases. What they did after that month was having them sleep at 24° again month was having them sleep at 24° again month was having them sleep at 24° again measured the brown fat and then at measured the brown fat and then at measured the brown fat and then at 27°C and measured that again and then 27°C and measured that again and then 27°C and measured that again and then they could see so it actually shrked they could see so it actually shrked they could see so it actually shrked when the temperature got warmer. So when the temperature got warmer. So when the temperature got warmer. So comfortable temperatures make the body comfortable temperatures make the body comfortable temperatures make the body tell this tissue that it's really not tell this tissue that it's really not tell this tissue that it's really not needed right now. So it it's like the needed right now. So it it's like the needed right now. So it it's like the muscles then they shrink. So if you use muscles then they shrink. So if you use muscles then they shrink. So if you use the muscles and you go to the gym and the muscles and you go to the gym and the muscles and you go to the gym and you lift your weights then you are

21:00you lift your weights then you are you lift your weights then you are telling your muscles we need you. And telling your muscles we need you. And telling your muscles we need you. And the same thing you can do with your with the same thing you can do with your with the same thing you can do with your with your brown fat. tell your brown fat that your brown fat. tell your brown fat that your brown fat. tell your brown fat that it's needed to help me keep a balance in it's needed to help me keep a balance in it's needed to help me keep a balance in my metabolism and keep my insulin my metabolism and keep my insulin my metabolism and keep my insulin sensitivity high because that is exactly sensitivity high because that is exactly sensitivity high because that is exactly you can say the epi the pandemic that we you can say the epi the pandemic that we you can say the epi the pandemic that we have right now that people's insulin have right now that people's insulin have right now that people's insulin sensitivity is just out of tune sensitivity is just out of tune sensitivity is just out of tune completely completely completely I would love to maybe take this point to I would love to maybe take this point to I would love to maybe take this point to talk about your own research I think talk about your own research I think talk about your own research I think you've painted this wonderful picture you've painted this wonderful picture you've painted this wonderful picture about this brown fat I had no idea I had about this brown fat I had no idea I had about this brown fat I had no idea I had you emphasize a lot I the stress of both you emphasize a lot I the stress of both you emphasize a lot I the stress of both the cold plunge and the sauner, why can the cold plunge and the sauner, why can the cold plunge and the sauner, why can stress be good for me? And maybe we stress be good for me? And maybe we stress be good for me? And maybe we could look at that through your own could look at that through your own could look at that through your own research because I know this, you know, research because I know this, you know, research because I know this, you know, when we were trying to figure out who to when we were trying to figure out who to when we were trying to figure out who to talk about this topic, very few people talk about this topic, very few people talk about this topic, very few people have really been studying this properly have really been studying this properly have really been studying this properly scientifically and you're one of them. scientifically and you're one of them. scientifically and you're one of them. Could you tell us about Scandinavian Could you tell us about Scandinavian Could you tell us about Scandinavian winter swimming? Yes, I would love to. winter swimming? Yes, I would love to. winter swimming? Yes, I would love to. Uh, Scandinavian winter swimming is is

22:00Uh, Scandinavian winter swimming is is Uh, Scandinavian winter swimming is is definitely special. I I feel it is it's definitely special. I I feel it is it's definitely special. I I feel it is it's something that we have had for hundreds something that we have had for hundreds something that we have had for hundreds of years here but uh we've been doing it of years here but uh we've been doing it of years here but uh we've been doing it because it's it feels nice. It's a good because it's it feels nice. It's a good because it's it feels nice. It's a good community thing to do. Uh but recently community thing to do. Uh but recently community thing to do. Uh but recently we are also starting to look more into we are also starting to look more into we are also starting to look more into the uh you can say the health benefits the uh you can say the health benefits the uh you can say the health benefits of it. Can we actually prove that it has of it. Can we actually prove that it has of it. Can we actually prove that it has any benefits which all the winter any benefits which all the winter any benefits which all the winter swimmers in the Nordic countries are swimmers in the Nordic countries are swimmers in the Nordic countries are saying. So uh one thing is like there's saying. So uh one thing is like there's saying. So uh one thing is like there's something that we can feel. You feel something that we can feel. You feel something that we can feel. You feel better. You get more clarity in your better. You get more clarity in your better. You get more clarity in your brain. You don't feel the brain fog brain. You don't feel the brain fog brain. You don't feel the brain fog anymore. You have more drive. And those anymore. You have more drive. And those anymore. You have more drive. And those things you can feel. But there are also things you can feel. But there are also things you can feel. But there are also things which you cannot really feel things which you cannot really feel things which you cannot really feel until at once. And those were the things until at once. And those were the things until at once. And those were the things that I was interested in. So the that I was interested in. So the that I was interested in. So the metabolism can this extreme cold metabolism can this extreme cold metabolism can this extreme cold exposure or heat actually um create what exposure or heat actually um create what exposure or heat actually um create what is called homemetic stress. So this is is called homemetic stress. So this is is called homemetic stress. So this is what we call the good stress. Acute what we call the good stress. Acute what we call the good stress. Acute stress can be a good thing for you

23:00stress can be a good thing for you stress can be a good thing for you because it activates your mitochondrias because it activates your mitochondrias because it activates your mitochondrias and it tells your body that you need to and it tells your body that you need to and it tells your body that you need to waken up and you need to do something to waken up and you need to do something to waken up and you need to do something to protect yourself and that is a good protect yourself and that is a good protect yourself and that is a good thing because you activate your your thing because you activate your your thing because you activate your your metabolism which is the brown fat metabolism which is the brown fat metabolism which is the brown fat muscles all your mitochondria heat shock muscles all your mitochondria heat shock muscles all your mitochondria heat shock proteins in the cells everything is proteins in the cells everything is proteins in the cells everything is activated. erh in my research I wanted activated. erh in my research I wanted activated. erh in my research I wanted to figure out something else that to figure out something else that to figure out something else that besides exercise which I think we have besides exercise which I think we have besides exercise which I think we have established now that is healthy for us. established now that is healthy for us. established now that is healthy for us. Is there something else that we can go Is there something else that we can go Is there something else that we can go out and say here you have some more out and say here you have some more out and say here you have some more healthy stress you can do um every day healthy stress you can do um every day healthy stress you can do um every day or almost every day and that would also or almost every day and that would also or almost every day and that would also help on your metabolism. I figured, help on your metabolism. I figured, help on your metabolism. I figured, well, we actually in Denmark, super well, we actually in Denmark, super well, we actually in Denmark, super lucky, we have winter swimmers going lucky, we have winter swimmers going lucky, we have winter swimmers going into the cold water and they might into the cold water and they might into the cold water and they might actually have more brown fat because the actually have more brown fat because the actually have more brown fat because the brown fat is activated by the most brown fat is activated by the most brown fat is activated by the most potent stressor, which is the coat. What potent stressor, which is the coat. What potent stressor, which is the coat. What if their metabolism was actually faster

24:00if their metabolism was actually faster if their metabolism was actually faster or better or in some sense we could see or better or in some sense we could see or better or in some sense we could see a difference between a group who were a difference between a group who were a difference between a group who were winter swimmers and between a group who winter swimmers and between a group who winter swimmers and between a group who was not? And so, Susanna, what did you was not? And so, Susanna, what did you was not? And so, Susanna, what did you discover? What we found was that the discover? What we found was that the discover? What we found was that the winter swimmers who were adapted to the winter swimmers who were adapted to the winter swimmers who were adapted to the cold water swimming uh did short-term cold water swimming uh did short-term cold water swimming uh did short-term cold exposure, so very short dips and cold exposure, so very short dips and cold exposure, so very short dips and they had a a better insulin uh they had a a better insulin uh they had a a better insulin uh sensitivity and a faster glucose sensitivity and a faster glucose sensitivity and a faster glucose clearance from the blood. So we tested clearance from the blood. So we tested clearance from the blood. So we tested that by giving them a a you can say um a that by giving them a a you can say um a that by giving them a a you can say um a glass of sugar water and they drink that glass of sugar water and they drink that glass of sugar water and they drink that fasted and then we measure insulin and fasted and then we measure insulin and fasted and then we measure insulin and glucose over two hours in both the glucose over two hours in both the glucose over two hours in both the groups and that showed that the winter groups and that showed that the winter groups and that showed that the winter swimmers really rapidly had this swimmers really rapidly had this swimmers really rapidly had this increase in in glucose but also cleared increase in in glucose but also cleared increase in in glucose but also cleared it very fast from the blood. And when we it very fast from the blood. And when we it very fast from the blood. And when we looked at how much insulin they had in looked at how much insulin they had in looked at how much insulin they had in the blood, they had lower insulin levels

25:00the blood, they had lower insulin levels the blood, they had lower insulin levels compared to the control group. And some compared to the control group. And some compared to the control group. And some might think, why is this good for me? might think, why is this good for me? might think, why is this good for me? Well, it's shows that their body don't Well, it's shows that their body don't Well, it's shows that their body don't need to produce as much insulin to get need to produce as much insulin to get need to produce as much insulin to get the sugar into the cells. And that is a the sugar into the cells. And that is a the sugar into the cells. And that is a good thing because when you are um good thing because when you are um good thing because when you are um insulin resistant which is a state that insulin resistant which is a state that insulin resistant which is a state that we want to avoid then the body we want to avoid then the body we want to avoid then the body overproduces insulin because the the overproduces insulin because the the overproduces insulin because the the cells cannot really feel the sugar. So cells cannot really feel the sugar. So cells cannot really feel the sugar. So um getting more insulin sensitive means um getting more insulin sensitive means um getting more insulin sensitive means that you don't have to produce as much that you don't have to produce as much that you don't have to produce as much insulin and that is what we saw in our insulin and that is what we saw in our insulin and that is what we saw in our winter swimmers. They had lower levels winter swimmers. They had lower levels winter swimmers. They had lower levels of insulin and a faster glucose of insulin and a faster glucose of insulin and a faster glucose clearance from the blood. They also had clearance from the blood. They also had clearance from the blood. They also had a faster activation of the brown fat and a faster activation of the brown fat and a faster activation of the brown fat and a higher activation of the brown fat. So a higher activation of the brown fat. So a higher activation of the brown fat. So they were actually in a better they were actually in a better they were actually in a better temperature balance all the time and temperature balance all the time and temperature balance all the time and they were warmer peripherilally. That they were warmer peripherilally. That they were warmer peripherilally. That was another found uh because when we I

26:00was another found uh because when we I was another found uh because when we I was done with the winter swimming study, was done with the winter swimming study, was done with the winter swimming study, I invited them to another study where we I invited them to another study where we I invited them to another study where we studied um their circadian rhythms. So studied um their circadian rhythms. So studied um their circadian rhythms. So we had them sleep at our facility for a we had them sleep at our facility for a we had them sleep at our facility for a couple of days and we found out that the couple of days and we found out that the couple of days and we found out that the winter swimmers were peripherilally winter swimmers were peripherilally winter swimmers were peripherilally actually warmer. And Sandra, is that a actually warmer. And Sandra, is that a actually warmer. And Sandra, is that a good thing to be warmer? It is a good good thing to be warmer? It is a good good thing to be warmer? It is a good thing to be warmer on your skin. It thing to be warmer on your skin. It thing to be warmer on your skin. It shows that you can actually get a better shows that you can actually get a better shows that you can actually get a better blood circulation of your skin and you blood circulation of your skin and you blood circulation of your skin and you really want that. So if I understand really want that. So if I understand really want that. So if I understand this rightly, having done all this this rightly, having done all this this rightly, having done all this study, you're saying you have these sort study, you're saying you have these sort study, you're saying you have these sort of two groups of people who are matched of two groups of people who are matched of two groups of people who are matched on everything else and the ones who were on everything else and the ones who were on everything else and the ones who were suffering the freezing cold Scandinavian suffering the freezing cold Scandinavian suffering the freezing cold Scandinavian like sea were just basically healthier like sea were just basically healthier like sea were just basically healthier than the other group and you were and than the other group and you were and than the other group and you were and that was based on quite short periods of that was based on quite short periods of that was based on quite short periods of time. Also they weren't sort of going time. Also they weren't sort of going time. Also they weren't sort of going for a half hour swim. How long did you for a half hour swim. How long did you for a half hour swim. How long did you have to be in the water to qualify in have to be in the water to qualify in have to be in the water to qualify in this group and get this benefit? After a this group and get this benefit? After a this group and get this benefit? After a year following them, we saw that they

27:00year following them, we saw that they year following them, we saw that they did 11 minutes of cold water immersion did 11 minutes of cold water immersion did 11 minutes of cold water immersion per week um divided on two to three days per week um divided on two to three days per week um divided on two to three days and also 57 minutes of sauna per week and also 57 minutes of sauna per week and also 57 minutes of sauna per week also divided on these two to three days. also divided on these two to three days. also divided on these two to three days. And on each of these days they did three And on each of these days they did three And on each of these days they did three dips in the water and two sauna dips in the water and two sauna dips in the water and two sauna sessions. So if you divide this out, it sessions. So if you divide this out, it sessions. So if you divide this out, it corresponds to 1 to two minutes in the corresponds to 1 to two minutes in the corresponds to 1 to two minutes in the cold water and only 10 to 15 minutes in cold water and only 10 to 15 minutes in cold water and only 10 to 15 minutes in the ser per session. So just to play it the ser per session. So just to play it the ser per session. So just to play it back, I go in the sauna for 10 minutes. back, I go in the sauna for 10 minutes. back, I go in the sauna for 10 minutes. I get really really hot. Then I go into I get really really hot. Then I go into I get really really hot. Then I go into the freezing sea for about 60 seconds. the freezing sea for about 60 seconds. the freezing sea for about 60 seconds. I'm now really cold. I go back to the I'm now really cold. I go back to the I'm now really cold. I go back to the sauna, get myself warm, and I basically sauna, get myself warm, and I basically sauna, get myself warm, and I basically repeat that three times. And these repeat that three times. And these repeat that three times. And these people were doing this twice a week. So people were doing this twice a week. So people were doing this twice a week. So it was about a sort of half an hour it was about a sort of half an hour it was about a sort of half an hour session between these two twice a week session between these two twice a week session between these two twice a week and that was enough that you really saw and that was enough that you really saw and that was enough that you really saw this difference between these two this difference between these two

28:00this difference between these two groups. Yes. So they they did it very groups. Yes. So they they did it very groups. Yes. So they they did it very briefly and you might ask yourself how briefly and you might ask yourself how briefly and you might ask yourself how can something that is so short and so can something that is so short and so can something that is so short and so brief have any like longer term effects brief have any like longer term effects brief have any like longer term effects but that just shows how potent the cold but that just shows how potent the cold but that just shows how potent the cold and the heat is. Extreme temperature can and the heat is. Extreme temperature can and the heat is. Extreme temperature can be a very good tool to activate your be a very good tool to activate your be a very good tool to activate your metabolism and that is what we want to metabolism and that is what we want to metabolism and that is what we want to do because it it activates more do because it it activates more do because it it activates more mitochondria in our body and we want to mitochondria in our body and we want to mitochondria in our body and we want to increase our mitochondrias in the body increase our mitochondrias in the body increase our mitochondrias in the body because that is how we keep our cells because that is how we keep our cells because that is how we keep our cells younger and healthier and how we younger and healthier and how we younger and healthier and how we activate something more nerdy called the activate something more nerdy called the activate something more nerdy called the heat shock proteins in our cells and uh heat shock proteins in our cells and uh heat shock proteins in our cells and uh these heat shock proteins can can these heat shock proteins can can these heat shock proteins can can actually repair our cells from the actually repair our cells from the actually repair our cells from the inside. So it's a way of keeping our uh inside. So it's a way of keeping our uh inside. So it's a way of keeping our uh cells younger or healthier and they will cells younger or healthier and they will cells younger or healthier and they will survive longer and then that is your survive longer and then that is your survive longer and then that is your longevity you can say. So the cold is longevity you can say. So the cold is longevity you can say. So the cold is very potent. The heat is very potent but very potent. The heat is very potent but very potent. The heat is very potent but just be mindful how we use it. It's not

29:00just be mindful how we use it. It's not just be mindful how we use it. It's not more is better. That is definitely also more is better. That is definitely also more is better. That is definitely also a misconception out there that I'm a misconception out there that I'm a misconception out there that I'm trying to help people with. Um less is trying to help people with. Um less is trying to help people with. Um less is more. I mean, I've done some cold more. I mean, I've done some cold more. I mean, I've done some cold plunges. Um, unlike Jonathan, that's plunges. Um, unlike Jonathan, that's plunges. Um, unlike Jonathan, that's because I'm a cold I've now because I'm a cold I've now because I'm a cold I've now established that. You're definitely a established that. You're definitely a established that. You're definitely a cold It's okay. So, why is the cold It's okay. So, why is the cold It's okay. So, why is the first 30 seconds the worst? And and what first 30 seconds the worst? And and what first 30 seconds the worst? And and what changes after that 30 seconds? Is it the changes after that 30 seconds? Is it the changes after that 30 seconds? Is it the brown fat or is it just your brain brown fat or is it just your brain brown fat or is it just your brain saying, "Okay, I'm not going to die. saying, "Okay, I'm not going to die. saying, "Okay, I'm not going to die. This is fine. I can carry on." This is fine. I can carry on." This is fine. I can carry on." Why is sort of this there's a general Why is sort of this there's a general Why is sort of this there's a general rule about 3 minutes in a you know in rule about 3 minutes in a you know in rule about 3 minutes in a you know in something that's you know less than 8° something that's you know less than 8° something that's you know less than 8° or or whatever the the ice bath is. Um or or whatever the the ice bath is. Um or or whatever the the ice bath is. Um that seems to be optimum. And the other that seems to be optimum. And the other that seems to be optimum. And the other one I've heard is that after a cold one I've heard is that after a cold one I've heard is that after a cold plunge you should naturally try and plunge you should naturally try and plunge you should naturally try and rewarm rather than jumping into a sauna rewarm rather than jumping into a sauna rewarm rather than jumping into a sauna or a hot shower. So we have to describe or a hot shower. So we have to describe or a hot shower. So we have to describe it for Jonathan because you can only

30:00it for Jonathan because you can only it for Jonathan because you can only imagine you see what it's like. But it imagine you see what it's like. But it imagine you see what it's like. But it it's everything is screaming at you to it's everything is screaming at you to it's everything is screaming at you to get out. Basically, your whole body, get out. Basically, your whole body, get out. Basically, your whole body, your whole evolution, everything's your whole evolution, everything's your whole evolution, everything's saying you're in the wrong place. Yeah. saying you're in the wrong place. Yeah. saying you're in the wrong place. Yeah. Everything hurts. There's like a tight Everything hurts. There's like a tight Everything hurts. There's like a tight band around your chest. It's like you band around your chest. It's like you band around your chest. It's like you can't breathe. Uh, you know, get me out can't breathe. Uh, you know, get me out can't breathe. Uh, you know, get me out of here. Exactly. And if you last that, of here. Exactly. And if you last that, of here. Exactly. And if you last that, if you can stay there or someone's if you can stay there or someone's if you can stay there or someone's forcing you to stay in, then it suddenly forcing you to stay in, then it suddenly forcing you to stay in, then it suddenly gets easier. And I I'm interested to see gets easier. And I I'm interested to see gets easier. And I I'm interested to see what why we think that is. Yeah. So um what why we think that is. Yeah. So um what why we think that is. Yeah. So um so when we we activate the cold shock so when we we activate the cold shock so when we we activate the cold shock response and we do that immediately as response and we do that immediately as response and we do that immediately as we go into the cold water and if you're we go into the cold water and if you're we go into the cold water and if you're new to this you will also activate your new to this you will also activate your new to this you will also activate your your gasping reflex. So that's why you your gasping reflex. So that's why you your gasping reflex. So that's why you have might have seen newbies go that have might have seen newbies go that have might have seen newbies go that might be you Jonathan and I can tell you might be you Jonathan and I can tell you might be you Jonathan and I can tell you I've been there many times you'll be I've been there many times you'll be I've been there many times you'll be like and the the it's okay. So just take like and the the it's okay. So just take like and the the it's okay. So just take the whole journey in and be okay with the whole journey in and be okay with the whole journey in and be okay with whatever comes out. The code shock is whatever comes out. The code shock is whatever comes out. The code shock is where your brain goes, "Oh my god, it's

31:00where your brain goes, "Oh my god, it's where your brain goes, "Oh my god, it's a control at delete button." What that a control at delete button." What that a control at delete button." What that is what I call it because nothing in is what I call it because nothing in is what I call it because nothing in your body wants to do anything else but your body wants to do anything else but your body wants to do anything else but just survive. Even your brain is just survive. Even your brain is just survive. Even your brain is actually zooming in totally on the now, actually zooming in totally on the now, actually zooming in totally on the now, which is a good thing because all your which is a good thing because all your which is a good thing because all your worries, everything you just thought worries, everything you just thought worries, everything you just thought about before just is totally deleted. about before just is totally deleted. about before just is totally deleted. It's gone. It's away. And your body and It's gone. It's away. And your body and It's gone. It's away. And your body and brain is in the now. And after the 30 brain is in the now. And after the 30 brain is in the now. And after the 30 seconds of cold shock where you have to seconds of cold shock where you have to seconds of cold shock where you have to breathe through it, your body goes into breathe through it, your body goes into breathe through it, your body goes into an activation of parasympathetic an activation of parasympathetic an activation of parasympathetic activation. And that is because you are activation. And that is because you are activation. And that is because you are activating your diving response as well activating your diving response as well activating your diving response as well because you're submerging cold water, because you're submerging cold water, because you're submerging cold water, right? And when you do that, you will right? And when you do that, you will right? And when you do that, you will feel like you went from this awful feel like you went from this awful feel like you went from this awful stressful situation which you could stressful situation which you could stressful situation which you could almost not breathe yourself through. And almost not breathe yourself through. And almost not breathe yourself through. And then suddenly you feel like the world is then suddenly you feel like the world is then suddenly you feel like the world is like stopping or you're standing still like stopping or you're standing still like stopping or you're standing still and you cannot even understand how you

32:00and you cannot even understand how you and you cannot even understand how you were almost panicking 30 seconds ago or were almost panicking 30 seconds ago or were almost panicking 30 seconds ago or 1 minute ago. I feel like this is the 1 minute ago. I feel like this is the 1 minute ago. I feel like this is the point where you have to build yourself point where you have to build yourself point where you have to build yourself up to. It took me at least five attempts up to. It took me at least five attempts up to. It took me at least five attempts or even more I would say uh before I was or even more I would say uh before I was or even more I would say uh before I was at that stage where I felt completely at that stage where I felt completely at that stage where I felt completely calm. Gut health is health. Become a calm. Gut health is health. Become a calm. Gut health is health. Become a Zoey member and start listening to your Zoey member and start listening to your Zoey member and start listening to your gut with a comprehensive at home test gut with a comprehensive at home test gut with a comprehensive at home test kit and personalized nutrition program. kit and personalized nutrition program. kit and personalized nutrition program. Our personalized food scores change how Our personalized food scores change how Our personalized food scores change how you think about food for good. And photo you think about food for good. And photo you think about food for good. And photo food logging lets you instantly see how food logging lets you instantly see how food logging lets you instantly see how meals score for your body. You can't put meals score for your body. You can't put meals score for your body. You can't put a price on your health, but if you did, a price on your health, but if you did, a price on your health, but if you did, Zoe's worth it. Most of what we've been Zoe's worth it. Most of what we've been Zoe's worth it. Most of what we've been told about food is wrong. Listen to your told about food is wrong. Listen to your told about food is wrong. Listen to your gut and feel better in weeks. Become a gut and feel better in weeks. Become a gut and feel better in weeks. Become a Zoey member today. You've talked quite a Zoey member today. You've talked quite a Zoey member today. You've talked quite a lot about sort of metabolic health, lot about sort of metabolic health, lot about sort of metabolic health, about how it's helping me with my my my about how it's helping me with my my my about how it's helping me with my my my blood sugar and my insulin. Are there blood sugar and my insulin. Are there blood sugar and my insulin. Are there any other benefits in your mind from

33:00any other benefits in your mind from any other benefits in your mind from doing this in terms of my health? I doing this in terms of my health? I doing this in terms of my health? I think so. Yeah. So there is also the the think so. Yeah. So there is also the the think so. Yeah. So there is also the the mental health part of it but why I talk mental health part of it but why I talk mental health part of it but why I talk so much about the metabolism is because so much about the metabolism is because so much about the metabolism is because your mental health is so connected to your mental health is so connected to your mental health is so connected to your metabolism. So we know that if we your metabolism. So we know that if we your metabolism. So we know that if we can activate also our metabolism we can can activate also our metabolism we can can activate also our metabolism we can decrease inflammation and we know that decrease inflammation and we know that decrease inflammation and we know that depression anxiety and we know that depression anxiety and we know that depression anxiety and we know that Alzheimer's disease are connected to to Alzheimer's disease are connected to to Alzheimer's disease are connected to to as an as an inflammatory state also of as an as an inflammatory state also of as an as an inflammatory state also of the brain. So we do really want to the brain. So we do really want to the brain. So we do really want to activate the brown fat because that's activate the brown fat because that's activate the brown fat because that's going to affect our mental health as going to affect our mental health as going to affect our mental health as well. But what it you can say the the well. But what it you can say the the well. But what it you can say the the cold water does immediately for your cold water does immediately for your cold water does immediately for your mental health is activating dopamine mental health is activating dopamine mental health is activating dopamine which will give you that drive and that which will give you that drive and that which will give you that drive and that energy and no adrenaline which is our energy and no adrenaline which is our energy and no adrenaline which is our stress response also will also give you stress response also will also give you stress response also will also give you that energy. So the the clarity and uh that energy. So the the clarity and uh that energy. So the the clarity and uh it would give you afterwards that is it would give you afterwards that is it would give you afterwards that is something you would feel immediately. Um

34:00something you would feel immediately. Um something you would feel immediately. Um you cannot feel immediately that your you cannot feel immediately that your you cannot feel immediately that your inflammation is going down right but inflammation is going down right but inflammation is going down right but it's all connected. So the immediate it's all connected. So the immediate it's all connected. So the immediate response of your um mental health is response of your um mental health is response of your um mental health is there when you leave and you can feel there when you leave and you can feel there when you leave and you can feel that drive that energy and you will be that drive that energy and you will be that drive that energy and you will be definitely more focused. I'd love to tie definitely more focused. I'd love to tie definitely more focused. I'd love to tie this back now to our initial questions this back now to our initial questions this back now to our initial questions at the beginning because Tim I asked you at the beginning because Tim I asked you at the beginning because Tim I asked you this question that seemed mad and you this question that seemed mad and you this question that seemed mad and you and you said well actually maybe it's and you said well actually maybe it's and you said well actually maybe it's true which is how this might impact our true which is how this might impact our true which is how this might impact our gut microbiome and I think anybody who's gut microbiome and I think anybody who's gut microbiome and I think anybody who's been listening to a lot of our shows been listening to a lot of our shows been listening to a lot of our shows knows that the gut microbiome is really knows that the gut microbiome is really knows that the gut microbiome is really central to our health and we understand central to our health and we understand central to our health and we understand that now but it seems to me like if that now but it seems to me like if that now but it seems to me like if there's one bit that ought to be there's one bit that ought to be there's one bit that ought to be insulated from hot or cold it ought to insulated from hot or cold it ought to insulated from hot or cold it ought to be my gut. How can this be having any be my gut. How can this be having any be my gut. How can this be having any impact on my microbiome? And and is it impact on my microbiome? And and is it impact on my microbiome? And and is it Tim? Well, your gut microbes are not Tim? Well, your gut microbes are not Tim? Well, your gut microbes are not going to feel the icy cold when you get going to feel the icy cold when you get going to feel the icy cold when you get in the bath, right? They are well in the bath, right? They are well in the bath, right? They are well insulated from that. And that's the insulated from that. And that's the insulated from that. And that's the reason they're there is they like a nice reason they're there is they like a nice reason they're there is they like a nice cozy home that keeps the thermostat very

35:00cozy home that keeps the thermostat very cozy home that keeps the thermostat very closely regulated. The acidity level is closely regulated. The acidity level is closely regulated. The acidity level is just right. You know, the mucus is nice just right. You know, the mucus is nice just right. You know, the mucus is nice and comfy. But of course, but your and comfy. But of course, but your and comfy. But of course, but your microbes pick up on the signals coming microbes pick up on the signals coming microbes pick up on the signals coming from the body. So they pick up on stress from the body. So they pick up on stress from the body. So they pick up on stress levels and as the microbes are talking levels and as the microbes are talking levels and as the microbes are talking to your immune system and your nervous to your immune system and your nervous to your immune system and your nervous system which are lining the gut, there's system which are lining the gut, there's system which are lining the gut, there's a two-way interaction. So they're a two-way interaction. So they're a two-way interaction. So they're picking up anything that the nerve picking up anything that the nerve picking up anything that the nerve system is is sending out as chemicals, system is is sending out as chemicals, system is is sending out as chemicals, anything the immune system is sending anything the immune system is sending anything the immune system is sending out as chemicals. So we've heard this out as chemicals. So we've heard this out as chemicals. So we've heard this low levels of stress which can be low levels of stress which can be low levels of stress which can be beneficial. This so-called hormesis is beneficial. This so-called hormesis is beneficial. This so-called hormesis is something and we know that microbes will something and we know that microbes will something and we know that microbes will respond to stress. If it's too much it respond to stress. If it's too much it respond to stress. If it's too much it they go in a bad way. But if the body is they go in a bad way. But if the body is they go in a bad way. But if the body is getting just the right levels of of getting just the right levels of of getting just the right levels of of stress and perhaps reducing stress and perhaps reducing stress and perhaps reducing inflammation, which I think is perhaps inflammation, which I think is perhaps inflammation, which I think is perhaps the critical thing here, then I think we

36:00the critical thing here, then I think we the critical thing here, then I think we should see this translated into a should see this translated into a should see this translated into a happier microbiome that that fits in happier microbiome that that fits in happier microbiome that that fits in with this. So I don't think we have any with this. So I don't think we have any with this. So I don't think we have any good studies to really show this yet, good studies to really show this yet, good studies to really show this yet, but theoretically this is how I think it but theoretically this is how I think it but theoretically this is how I think it could work. We know that the gut could work. We know that the gut could work. We know that the gut microbes are a bit of a barometer of microbes are a bit of a barometer of microbes are a bit of a barometer of what's going on in the body. And if what's going on in the body. And if what's going on in the body. And if they're in a bad way, they'll transmit they're in a bad way, they'll transmit they're in a bad way, they'll transmit anxiety, stress, inflammation, but also anxiety, stress, inflammation, but also anxiety, stress, inflammation, but also the other way round. If the body is in a the other way round. If the body is in a the other way round. If the body is in a good state, its environment is a good good state, its environment is a good good state, its environment is a good state. Just like it gets signals from state. Just like it gets signals from state. Just like it gets signals from food, it will also get signals from the food, it will also get signals from the food, it will also get signals from the environment about exercise and environment about exercise and environment about exercise and temperature. And as Suzanne is saying, temperature. And as Suzanne is saying, temperature. And as Suzanne is saying, it's a bit like, you know, having your it's a bit like, you know, having your it's a bit like, you know, having your body is having a bit of a workout. And body is having a bit of a workout. And body is having a bit of a workout. And if that workout is just right, then it's if that workout is just right, then it's if that workout is just right, then it's getting the right signals and should getting the right signals and should getting the right signals and should improve it. But it'd be lovely to do improve it. But it'd be lovely to do improve it. But it'd be lovely to do some really large scale studies on this, some really large scale studies on this, some really large scale studies on this, you know, maybe with the Zoey data set you know, maybe with the Zoey data set you know, maybe with the Zoey data set as these practices get more common and

37:00as these practices get more common and as these practices get more common and more people are getting hot and cold more people are getting hot and cold more people are getting hot and cold therapies. therapies. therapies. Just very much on my mind as I'm Just very much on my mind as I'm Just very much on my mind as I'm listening to this, I have a friend who listening to this, I have a friend who listening to this, I have a friend who suffered from depression in the past and suffered from depression in the past and suffered from depression in the past and he absolutely swears that his mood is he absolutely swears that his mood is he absolutely swears that his mood is dramatically lifted by a cold plunge. dramatically lifted by a cold plunge. dramatically lifted by a cold plunge. And this is a friend who has now bought And this is a friend who has now bought And this is a friend who has now bought one, you know, for his garden, is one, you know, for his garden, is one, you know, for his garden, is absolutely committed. It's clear it absolutely committed. It's clear it absolutely committed. It's clear it works for him. But is there any evidence works for him. But is there any evidence works for him. But is there any evidence more broadly about whether this affects more broadly about whether this affects more broadly about whether this affects mood and particularly people have like mood and particularly people have like mood and particularly people have like sort of real mood disorders? sort of real mood disorders? sort of real mood disorders? Yeah. So there there is actually there Yeah. So there there is actually there Yeah. So there there is actually there is a study I think it was from is a study I think it was from is a study I think it was from 2024 came out showing that people doing 2024 came out showing that people doing 2024 came out showing that people doing cold plunges change the way that they cold plunges change the way that they cold plunges change the way that they have negative emotions. So they have have negative emotions. So they have have negative emotions. So they have more positive emotions or positive more positive emotions or positive more positive emotions or positive thinking and positive emotions uh after thinking and positive emotions uh after thinking and positive emotions uh after they have done a cold plunge. It makes they have done a cold plunge. It makes they have done a cold plunge. It makes sense in when you think about it because sense in when you think about it because sense in when you think about it because when you go into the cold and you will when you go into the cold and you will when you go into the cold and you will have that increase in dopamine and nor have that increase in dopamine and nor have that increase in dopamine and nor adrenaline oxytocin which is also part

38:00adrenaline oxytocin which is also part adrenaline oxytocin which is also part of our stress response and oxytocin is of our stress response and oxytocin is of our stress response and oxytocin is our you could say love hormone in the in our you could say love hormone in the in our you could say love hormone in the in the body. When you increase those the body. When you increase those the body. When you increase those chemicals in the brain, it's got to be chemicals in the brain, it's got to be chemicals in the brain, it's got to be almost impossible to be at the same almost impossible to be at the same almost impossible to be at the same brain state as you were before. You will brain state as you were before. You will brain state as you were before. You will always have maybe the same problems. always have maybe the same problems. always have maybe the same problems. They don't disappear from cold water They don't disappear from cold water They don't disappear from cold water swimming. But you would have another way swimming. But you would have another way swimming. But you would have another way of thinking about them. We all have our of thinking about them. We all have our of thinking about them. We all have our problems and worries, but the way that problems and worries, but the way that problems and worries, but the way that you address them and think about them is you address them and think about them is you address them and think about them is how well you will handle them also. And how well you will handle them also. And how well you will handle them also. And I think this study shows that from these I think this study shows that from these I think this study shows that from these brain scans that the code actually brain scans that the code actually brain scans that the code actually changes the activation of those sensors changes the activation of those sensors changes the activation of those sensors of the brain where you think about of the brain where you think about of the brain where you think about negative emotions and and you have the negative emotions and and you have the negative emotions and and you have the the positive emotions. And there are the positive emotions. And there are the positive emotions. And there are also some new studies. I think we have a also some new studies. I think we have a also some new studies. I think we have a pilot study definitely also in Denmark pilot study definitely also in Denmark pilot study definitely also in Denmark on people with depression um going into on people with depression um going into on people with depression um going into cold water and they saw that they could cold water and they saw that they could cold water and they saw that they could also get rid of their medication or

39:00also get rid of their medication or also get rid of their medication or maybe not they could just go down in maybe not they could just go down in maybe not they could just go down in medication dose. Uh so it it seems that medication dose. Uh so it it seems that medication dose. Uh so it it seems that there are study coming also where we get there are study coming also where we get there are study coming also where we get more proof on pathology. So on diseases, more proof on pathology. So on diseases, more proof on pathology. So on diseases, brain diseases, it could be a brain diseases, it could be a brain diseases, it could be a depression, it could be the anxiety, it depression, it could be the anxiety, it depression, it could be the anxiety, it could be psychosis, it could be many could be psychosis, it could be many could be psychosis, it could be many things where they have used this cold things where they have used this cold things where they have used this cold water immersion. So I think more studies water immersion. So I think more studies water immersion. So I think more studies are coming. But there seems to be some are coming. But there seems to be some are coming. But there seems to be some good case studies also published one good case studies also published one good case studies also published one from UK where a woman had uh been from UK where a woman had uh been from UK where a woman had uh been swimming in cold water for three months swimming in cold water for three months swimming in cold water for three months and could actually lay off all her and could actually lay off all her and could actually lay off all her depression medication and she was depression medication and she was depression medication and she was apparently heavily medicated. Susanna, apparently heavily medicated. Susanna, apparently heavily medicated. Susanna, I'd love to switch to actionable advice I'd love to switch to actionable advice I'd love to switch to actionable advice now. I think our listeners have been now. I think our listeners have been now. I think our listeners have been very patient with me and like, "Yeah, very patient with me and like, "Yeah, very patient with me and like, "Yeah, yeah, I want to actually understand what yeah, I want to actually understand what yeah, I want to actually understand what to do." So, if someone's listening to to do." So, if someone's listening to to do." So, if someone's listening to this, they've never done it before. They this, they've never done it before. They this, they've never done it before. They didn't grow up in Scandinavia, so they didn't grow up in Scandinavia, so they didn't grow up in Scandinavia, so they weren't wild swimming and, you know, weren't wild swimming and, you know, weren't wild swimming and, you know, jumping into a sauna the other time. How jumping into a sauna the other time. How jumping into a sauna the other time. How can they integrate this into their

40:00can they integrate this into their can they integrate this into their lives? And I'm also very interested in lives? And I'm also very interested in lives? And I'm also very interested in like how can they start if they might be like how can they start if they might be like how can they start if they might be a cold like me? a cold like me? a cold like me? Yeah. So if you are co-sissy like you or Yeah. So if you are co-sissy like you or Yeah. So if you are co-sissy like you or me, um I think the best thing you can do me, um I think the best thing you can do me, um I think the best thing you can do is don't think too much about it. is don't think too much about it. is don't think too much about it. Actually if you want to try it out then Actually if you want to try it out then Actually if you want to try it out then go and try it out but don't have go and try it out but don't have go and try it out but don't have expectations like I have to sit there expectations like I have to sit there expectations like I have to sit there for a while. It this is not a for a while. It this is not a for a while. It this is not a competition. Um cold exposure is an competition. Um cold exposure is an competition. Um cold exposure is an inner journey. So you use some kind of inner journey. So you use some kind of inner journey. So you use some kind of cold exposure. I would say a cold plunge cold exposure. I would say a cold plunge cold exposure. I would say a cold plunge is definitely a good place uh to to go is definitely a good place uh to to go is definitely a good place uh to to go if you have that the ocean if you have if you have that the ocean if you have if you have that the ocean if you have that or if you don't then a cold shower that or if you don't then a cold shower that or if you don't then a cold shower is also fine to get started. So uh 30 is also fine to get started. So uh 30 is also fine to get started. So uh 30 seconds cold shower use your nose to seconds cold shower use your nose to seconds cold shower use your nose to calm your nervous system. So breathe in calm your nervous system. So breathe in calm your nervous system. So breathe in through your nose and out through your through your nose and out through your through your nose and out through your mouth if you need to. And uh if you can

41:00mouth if you need to. And uh if you can mouth if you need to. And uh if you can switch totally to nasal breathing that switch totally to nasal breathing that switch totally to nasal breathing that will help your nervous system to calm will help your nervous system to calm will help your nervous system to calm down as well. And you can use that also down as well. And you can use that also down as well. And you can use that also with coplunching. So breathe in through with coplunching. So breathe in through with coplunching. So breathe in through the nose uh to calm the nervous system. the nose uh to calm the nervous system. the nose uh to calm the nervous system. H never do any hyperventilating breath H never do any hyperventilating breath H never do any hyperventilating breath work before or during your cold plunges. work before or during your cold plunges. work before or during your cold plunges. That is also I think a important to to That is also I think a important to to That is also I think a important to to note. And head donking. Please don't do note. And head donking. Please don't do note. And head donking. Please don't do that because that would just decrease that because that would just decrease that because that would just decrease the blood flow to the brain and it the blood flow to the brain and it the blood flow to the brain and it actually also increases the risk of actually also increases the risk of actually also increases the risk of fainting and we also don't want that and fainting and we also don't want that and fainting and we also don't want that and you have no extra benefits of putting you have no extra benefits of putting you have no extra benefits of putting your head down in the water. You can your head down in the water. You can your head down in the water. You can splash some water to the face which will splash some water to the face which will splash some water to the face which will activate the vagus nerve but dunking activate the vagus nerve but dunking activate the vagus nerve but dunking your full head down doesn't do any your full head down doesn't do any your full head down doesn't do any health benefits for you. So take it slow health benefits for you. So take it slow health benefits for you. So take it slow and feel what is good for you. Breathe and feel what is good for you. Breathe and feel what is good for you. Breathe through 10 seconds and that is fine, but through 10 seconds and that is fine, but through 10 seconds and that is fine, but try to get over the cold shock. That is try to get over the cold shock. That is try to get over the cold shock. That is the goal. So try and get past the first

42:00the goal. So try and get past the first the goal. So try and get past the first 30 seconds. Yeah, I think the cold shock 30 seconds. Yeah, I think the cold shock 30 seconds. Yeah, I think the cold shock is it might actually be a little bit is it might actually be a little bit is it might actually be a little bit longer than that. For new people, it longer than that. For new people, it longer than that. For new people, it could be up to 1 minute and for some one could be up to 1 minute and for some one could be up to 1 minute and for some one and a half depending on um yeah, how and a half depending on um yeah, how and a half depending on um yeah, how cold adapted you actually are in the cold adapted you actually are in the cold adapted you actually are in the first place. So back to the question first place. So back to the question first place. So back to the question that Jonathan asked. So how how that Jonathan asked. So how how that Jonathan asked. So how how different is this from people to people? different is this from people to people? different is this from people to people? And it can be actually very different. And it can be actually very different. And it can be actually very different. So um if you are used to being much So um if you are used to being much So um if you are used to being much outside for example then you get very outside for example then you get very outside for example then you get very quickly adapted but if you are not very quickly adapted but if you are not very quickly adapted but if you are not very much outside an outdoors person then you much outside an outdoors person then you much outside an outdoors person then you would take a little bit longer to get would take a little bit longer to get would take a little bit longer to get adapted to the cold. So be gentle to adapted to the cold. So be gentle to adapted to the cold. So be gentle to yourself and don't compare yourself to yourself and don't compare yourself to yourself and don't compare yourself to others. And I like to have a sauna first others. And I like to have a sauna first others. And I like to have a sauna first but does it make much difference do you but does it make much difference do you but does it make much difference do you think? You can Tim start with the sona think? You can Tim start with the sona think? You can Tim start with the sona and I mean people should do it the way and I mean people should do it the way and I mean people should do it the way that they feel is best for them. But if that they feel is best for them. But if that they feel is best for them. But if you start in the cold water you will you start in the cold water you will you start in the cold water you will have that increase in oxytocin nor have that increase in oxytocin nor have that increase in oxytocin nor adrenaline dopamine would change how you

43:00adrenaline dopamine would change how you adrenaline dopamine would change how you sit in the sauna because it's sort of sit in the sauna because it's sort of sit in the sauna because it's sort of like a place where you meditate also in like a place where you meditate also in like a place where you meditate also in order to get the health benefits. Do I order to get the health benefits. Do I order to get the health benefits. Do I need to combine a cold plunge and a hot need to combine a cold plunge and a hot need to combine a cold plunge and a hot sauna together? No, you don't have to sauna together? No, you don't have to sauna together? No, you don't have to combine them. The thing about combine them. The thing about combine them. The thing about alternating between one extreme alternating between one extreme alternating between one extreme temperature and the other like this temperature and the other like this temperature and the other like this co-plunch and the sauna is that you push co-plunch and the sauna is that you push co-plunch and the sauna is that you push your cardiovascular system and that is a your cardiovascular system and that is a your cardiovascular system and that is a workout for all your blood vessels. That workout for all your blood vessels. That workout for all your blood vessels. That is one thing but also going from one is one thing but also going from one is one thing but also going from one extreme to the other will push your extreme to the other will push your extreme to the other will push your cells to either activate to generate cells to either activate to generate cells to either activate to generate heat or to shut down and that is also a heat or to shut down and that is also a heat or to shut down and that is also a workout for your body. So in that sense workout for your body. So in that sense workout for your body. So in that sense it's it has benefits doing it together. it's it has benefits doing it together. it's it has benefits doing it together. But if you just do cold plunges on one But if you just do cold plunges on one But if you just do cold plunges on one day and sus on other days that is also day and sus on other days that is also day and sus on other days that is also getting the benefits it's just more like getting the benefits it's just more like getting the benefits it's just more like divided you can say. Susanna can I ask divided you can say. Susanna can I ask divided you can say. Susanna can I ask um our US listeners will know all about um our US listeners will know all about um our US listeners will know all about cryotherapy and I was in Los Angeles

44:00cryotherapy and I was in Los Angeles cryotherapy and I was in Los Angeles recently and every shopping mall has a recently and every shopping mall has a recently and every shopping mall has a cryotherapy center now. So you can just cryotherapy center now. So you can just cryotherapy center now. So you can just pop in and do your 3minut cryotherapy pop in and do your 3minut cryotherapy pop in and do your 3minut cryotherapy session and go back to work. Uh so it's session and go back to work. Uh so it's session and go back to work. Uh so it's incredibly practical. You don't have to incredibly practical. You don't have to incredibly practical. You don't have to find a a lake in the middle of a city find a a lake in the middle of a city find a a lake in the middle of a city and uh you know and shiver and and yeah and uh you know and shiver and and yeah and uh you know and shiver and and yeah and it it's it's reverse because you go and it it's it's reverse because you go and it it's it's reverse because you go in and the first 30 seconds are quite in and the first 30 seconds are quite in and the first 30 seconds are quite fun and then and then it gets fun and then and then it gets fun and then and then it gets progressively colder because it's it's progressively colder because it's it's progressively colder because it's it's minus 100° in this freezer and you come minus 100° in this freezer and you come minus 100° in this freezer and you come out after 3 minutes. The last 30 seconds out after 3 minutes. The last 30 seconds out after 3 minutes. The last 30 seconds are tough, but I got a similar buzz are tough, but I got a similar buzz are tough, but I got a similar buzz after it. Um, but I wondered is there after it. Um, but I wondered is there after it. Um, but I wondered is there any science behind the difference? But, any science behind the difference? But, any science behind the difference? But, you know, is it as impressive as the you know, is it as impressive as the you know, is it as impressive as the cold water stuff? So, there are studies cold water stuff? So, there are studies cold water stuff? So, there are studies showing that the cryo uh therapy also showing that the cryo uh therapy also showing that the cryo uh therapy also activates your cold receptors, which activates your cold receptors, which activates your cold receptors, which means it also activates the brown fat. means it also activates the brown fat. means it also activates the brown fat. Um and uh I think that it's the 3

45:00Um and uh I think that it's the 3 Um and uh I think that it's the 3 minutes with these extreme temperatures, minutes with these extreme temperatures, minutes with these extreme temperatures, it would definitely help on your it would definitely help on your it would definitely help on your metabolism, but of course there are metabolism, but of course there are metabolism, but of course there are differences because when you submerge differences because when you submerge differences because when you submerge into cold water, you also have that into cold water, you also have that into cold water, you also have that hydrostatic pressure from the water. Uh hydrostatic pressure from the water. Uh hydrostatic pressure from the water. Uh which Yeah. And I didn't feel I was which Yeah. And I didn't feel I was which Yeah. And I didn't feel I was going to die either. That was the other going to die either. That was the other going to die either. That was the other thing. So I didn't get the gasping or thing. So I didn't get the gasping or thing. So I didn't get the gasping or the sort of the sort of the sort of lifethreatening feel of it. It's not lifethreatening feel of it. It's not lifethreatening feel of it. It's not because the body needs to feel like it's because the body needs to feel like it's because the body needs to feel like it's dying in order for you to get the dying in order for you to get the dying in order for you to get the benefits. you do get some benefits and I benefits. you do get some benefits and I benefits. you do get some benefits and I do think that the cryo actually has do think that the cryo actually has do think that the cryo actually has benefits. It's just another modality. benefits. It's just another modality. benefits. It's just another modality. It's just another dose that you get. But It's just another dose that you get. But It's just another dose that you get. But you can say when you submerge into cold you can say when you submerge into cold you can say when you submerge into cold water that is surrounding yourself with water that is surrounding yourself with water that is surrounding yourself with like the 100% molecules around your body like the 100% molecules around your body like the 100% molecules around your body in cold, you cannot be packed more into in cold, you cannot be packed more into in cold, you cannot be packed more into cold. So that's of course more potent to cold. So that's of course more potent to cold. So that's of course more potent to activate your metabolism and of of activate your metabolism and of of activate your metabolism and of of course also all your chemistry in the course also all your chemistry in the course also all your chemistry in the brain. So we had another common question brain. So we had another common question brain. So we had another common question around this actually which is does a around this actually which is does a around this actually which is does a cold shower work at all or does it need cold shower work at all or does it need cold shower work at all or does it need to be like a full plunge into icy water?

46:00to be like a full plunge into icy water? to be like a full plunge into icy water? So cold showers work because you do get So cold showers work because you do get So cold showers work because you do get cold of course and you activate your cold of course and you activate your cold of course and you activate your cold receptors. There's a study cold receptors. There's a study cold receptors. There's a study randomized control study from the randomized control study from the randomized control study from the Netherlands showing that if you do that Netherlands showing that if you do that Netherlands showing that if you do that for 30 seconds end your showers on 30 for 30 seconds end your showers on 30 for 30 seconds end your showers on 30 seconds cold showers you will have less seconds cold showers you will have less seconds cold showers you will have less sick days at work. It might be that it's sick days at work. It might be that it's sick days at work. It might be that it's not because you actually get less sick. not because you actually get less sick. not because you actually get less sick. It might actually be that you just get It might actually be that you just get It might actually be that you just get more energy to go to work. I'm not sure more energy to go to work. I'm not sure more energy to go to work. I'm not sure about what exactly is going on there, about what exactly is going on there, about what exactly is going on there, but um it's definitely not a bad thing but um it's definitely not a bad thing but um it's definitely not a bad thing that you feel fresh enough to go to that you feel fresh enough to go to that you feel fresh enough to go to work. So, it will activate your cold work. So, it will activate your cold work. So, it will activate your cold receptors, your brown fat. It will also receptors, your brown fat. It will also receptors, your brown fat. It will also activate nor adrenaline and dopamine and activate nor adrenaline and dopamine and activate nor adrenaline and dopamine and you will get that increase in your you will get that increase in your you will get that increase in your sympathetic nervous system. But it's sympathetic nervous system. But it's sympathetic nervous system. But it's probably not going to activate your probably not going to activate your probably not going to activate your parasympathetic part of your nervous parasympathetic part of your nervous parasympathetic part of your nervous system. And that is kind of what I would system. And that is kind of what I would system. And that is kind of what I would like people to experience that they have like people to experience that they have like people to experience that they have this kind of stress up and also the this kind of stress up and also the this kind of stress up and also the stress down. And what about the flip

47:00stress down. And what about the flip stress down. And what about the flip side which is the sauna? If you don't side which is the sauna? If you don't side which is the sauna? If you don't have a sauna, is there any way you can have a sauna, is there any way you can have a sauna, is there any way you can get access to that? Like can you have a get access to that? Like can you have a get access to that? Like can you have a really hot bath or something or is there really hot bath or something or is there really hot bath or something or is there no alternative? Yes. So hot baths are no alternative? Yes. So hot baths are no alternative? Yes. So hot baths are actually very good. Um there you also actually very good. Um there you also actually very good. Um there you also activate your parasympathetic part of activate your parasympathetic part of activate your parasympathetic part of your nervous system. You don't have to your nervous system. You don't have to your nervous system. You don't have to sit that long in a warm bath to h have sit that long in a warm bath to h have sit that long in a warm bath to h have also the metabolic benefits of insulin also the metabolic benefits of insulin also the metabolic benefits of insulin better insulin sensitivity and better better insulin sensitivity and better better insulin sensitivity and better glucose clearance. That is also shown uh glucose clearance. That is also shown uh glucose clearance. That is also shown uh in studies that hot baths are really in studies that hot baths are really in studies that hot baths are really good for your met metabolism. If you good for your met metabolism. If you good for your met metabolism. If you cannot sleep just do a hot bath before cannot sleep just do a hot bath before cannot sleep just do a hot bath before you you go to bed or do a hot sauna. uh you you go to bed or do a hot sauna. uh you you go to bed or do a hot sauna. uh that will increase your your core that will increase your your core that will increase your your core temperature and that will make your uh temperature and that will make your uh temperature and that will make your uh body go into the state of want wanting body go into the state of want wanting body go into the state of want wanting to sleep. So don't do your cold baths to sleep. So don't do your cold baths to sleep. So don't do your cold baths before you want to go to sleep because before you want to go to sleep because before you want to go to sleep because that increases your no adrenaline and that increases your no adrenaline and that increases your no adrenaline and then you maybe want to go for a run then you maybe want to go for a run then you maybe want to go for a run instead or you want to like start instead or you want to like start instead or you want to like start working. It gives you too much energy.

48:00working. It gives you too much energy. working. It gives you too much energy. So I always advise people to do the com So I always advise people to do the com So I always advise people to do the com cold plunges in the daytime. Now, if cold plunges in the daytime. Now, if cold plunges in the daytime. Now, if somebody's getting a little bit more somebody's getting a little bit more somebody's getting a little bit more committed, they're like, "No, I'm going committed, they're like, "No, I'm going committed, they're like, "No, I'm going to figure out where I can do like a cold to figure out where I can do like a cold to figure out where I can do like a cold plunge and a plunge and a plunge and a sauna." What is the minimum frequency? sauna." What is the minimum frequency? sauna." What is the minimum frequency? Like, how often a week do you need to do Like, how often a week do you need to do Like, how often a week do you need to do that? And do you need to do it three that? And do you need to do it three that? And do you need to do it three times backwards and forwards in the way times backwards and forwards in the way times backwards and forwards in the way you described in your study in order to you described in your study in order to you described in your study in order to get benefits? Is that what people should get benefits? Is that what people should get benefits? Is that what people should be looking to achieve? Um, I think that be looking to achieve? Um, I think that be looking to achieve? Um, I think that people should do what is possible. It's people should do what is possible. It's people should do what is possible. It's like exercise. So, if you can run 2 km like exercise. So, if you can run 2 km like exercise. So, if you can run 2 km or 5 km, it's definitely better than not or 5 km, it's definitely better than not or 5 km, it's definitely better than not doing it at all. So if you have time to doing it at all. So if you have time to doing it at all. So if you have time to do it once a week, then that is good. do it once a week, then that is good. do it once a week, then that is good. There's probably like a dose There's probably like a dose There's probably like a dose relationship here. So you can do it up relationship here. So you can do it up relationship here. So you can do it up to two, three times per week. But I also to two, three times per week. But I also to two, three times per week. But I also think that after doing that, it might think that after doing that, it might think that after doing that, it might also be too much for you. So we don't also be too much for you. So we don't also be too much for you. So we don't want to exhaust the cells in our body want to exhaust the cells in our body want to exhaust the cells in our body with too much stress. And Susanna, can I

49:00with too much stress. And Susanna, can I with too much stress. And Susanna, can I just ask a follow-up just to understand just ask a follow-up just to understand just ask a follow-up just to understand that? Because I think with exercise, that? Because I think with exercise, that? Because I think with exercise, we're a bit used to this idea that like we're a bit used to this idea that like we're a bit used to this idea that like more is somehow always better, but here more is somehow always better, but here more is somehow always better, but here it sounds like you're saying like cold it sounds like you're saying like cold it sounds like you're saying like cold plunging every day might not be a good plunging every day might not be a good plunging every day might not be a good idea. I don't know if every day is not a idea. I don't know if every day is not a idea. I don't know if every day is not a good idea, but we do see from my studies good idea, but we do see from my studies good idea, but we do see from my studies at least that doing two to three times a at least that doing two to three times a at least that doing two to three times a week is definitely enough to get the week is definitely enough to get the week is definitely enough to get the benefits. So doing more I don't know benefits. So doing more I don't know benefits. So doing more I don't know whether that is good for you and if it whether that is good for you and if it whether that is good for you and if it actually becomes too much of a stressor actually becomes too much of a stressor actually becomes too much of a stressor for you. It is very potent. It is not for you. It is very potent. It is not for you. It is very potent. It is not exactly like exercise because exercise exactly like exercise because exercise exactly like exercise because exercise is um you can say you can you can pause is um you can say you can you can pause is um you can say you can you can pause that and then you can lift your weights that and then you can lift your weights that and then you can lift your weights again or you can pause when you run. again or you can pause when you run. again or you can pause when you run. here you are getting the full thing at here you are getting the full thing at here you are getting the full thing at once and doing that every day that it once and doing that every day that it once and doing that every day that it might not leave room for recovery in might not leave room for recovery in might not leave room for recovery in your body and you also don't want to your body and you also don't want to your body and you also don't want to exhaust your nervous system. So that is exhaust your nervous system. So that is exhaust your nervous system. So that is why I just always say well at least we

50:00why I just always say well at least we why I just always say well at least we have studies showing two to three times have studies showing two to three times have studies showing two to three times a week is enough to get the benefits. a week is enough to get the benefits. a week is enough to get the benefits. Makes sense as well because exercise Makes sense as well because exercise Makes sense as well because exercise also generally suggested a a rest day in also generally suggested a a rest day in also generally suggested a a rest day in the week for your body to recover. So it the week for your body to recover. So it the week for your body to recover. So it sort of makes sense that we you don't sort of makes sense that we you don't sort of makes sense that we you don't overdo this as well and go crazy. And overdo this as well and go crazy. And overdo this as well and go crazy. And about the cortisol level because I think about the cortisol level because I think about the cortisol level because I think that all exercise or copun sauna all that all exercise or copun sauna all that all exercise or copun sauna all increases our cortisol level just a bit. increases our cortisol level just a bit. increases our cortisol level just a bit. But what we do see and I think this is But what we do see and I think this is But what we do see and I think this is like one of the misconceptions that I like one of the misconceptions that I like one of the misconceptions that I really want to get out there that the really want to get out there that the really want to get out there that the cortisol is something that we have to cortisol is something that we have to cortisol is something that we have to increase because that is our stress increase because that is our stress increase because that is our stress system. We are stressing the body a bit system. We are stressing the body a bit system. We are stressing the body a bit but acutely it's okay but in the long but acutely it's okay but in the long but acutely it's okay but in the long term we don't want cortisol levels to be term we don't want cortisol levels to be term we don't want cortisol levels to be high but what we see from cold exposure high but what we see from cold exposure high but what we see from cold exposure and also from sauna that cortisol level and also from sauna that cortisol level and also from sauna that cortisol level baseline go down in the long term when baseline go down in the long term when baseline go down in the long term when we do cold plunges and we do sauna. So

51:00we do cold plunges and we do sauna. So we do cold plunges and we do sauna. So there's a good reason for doing this on there's a good reason for doing this on there's a good reason for doing this on a regular basis. Uh and not only looking a regular basis. Uh and not only looking a regular basis. Uh and not only looking at oh when I do a cold plunge today and at oh when I do a cold plunge today and at oh when I do a cold plunge today and right now I have a little bit of an right now I have a little bit of an right now I have a little bit of an increase in my stress but that is a good increase in my stress but that is a good increase in my stress but that is a good thing because it's just acutely but in thing because it's just acutely but in thing because it's just acutely but in the long term it will decrease your the long term it will decrease your the long term it will decrease your stress. stress. Can I come back to your question at the Can I come back to your question at the Can I come back to your question at the very beginning where you said the very beginning where you said the very beginning where you said the biggest misconception was that this biggest misconception was that this biggest misconception was that this wasn't good for women. I didn't even wasn't good for women. I didn't even wasn't good for women. I didn't even realize that was a misconception. Do men realize that was a misconception. Do men realize that was a misconception. Do men and women respond differently? And is and women respond differently? And is and women respond differently? And is there any concern for women or for there any concern for women or for there any concern for women or for anybody else actually where what you're anybody else actually where what you're anybody else actually where what you're talking about today you would say talking about today you would say talking about today you would say actually that isn't safe? So the actually that isn't safe? So the actually that isn't safe? So the misconception that women shouldn't misconception that women shouldn't misconception that women shouldn't co-plunch is has come out there somehow co-plunch is has come out there somehow co-plunch is has come out there somehow and I think it's important to say that and I think it's important to say that and I think it's important to say that there is a difference in women's and there is a difference in women's and there is a difference in women's and men's physiology of course. So our men's physiology of course. So our men's physiology of course. So our metabolism acts differently when we go metabolism acts differently when we go metabolism acts differently when we go into cold water. So women have more into cold water. So women have more into cold water. So women have more brown fat than men and uh men have more

52:00brown fat than men and uh men have more brown fat than men and uh men have more muscle mass than women and that evens muscle mass than women and that evens muscle mass than women and that evens out you can say how we um defend out you can say how we um defend out you can say how we um defend ourselves to the cold. So when we go ourselves to the cold. So when we go ourselves to the cold. So when we go into cold water uh women have an ability into cold water uh women have an ability into cold water uh women have an ability to activate more brown fat but also vas to activate more brown fat but also vas to activate more brown fat but also vas constriction is better in women. So we constriction is better in women. So we constriction is better in women. So we can actually shut out the cold better can actually shut out the cold better can actually shut out the cold better than men can but men have more muscle than men can but men have more muscle than men can but men have more muscle mass to generate heat. So it evens out. mass to generate heat. So it evens out. mass to generate heat. So it evens out. So there's a study showing that men and So there's a study showing that men and So there's a study showing that men and women going into cold water, they women going into cold water, they women going into cold water, they activate their metabolism, meaning they activate their metabolism, meaning they activate their metabolism, meaning they defend the cold equally, but how they do defend the cold equally, but how they do defend the cold equally, but how they do it is just different. So that doesn't it is just different. So that doesn't it is just different. So that doesn't mean that women cannot do cold plunges. mean that women cannot do cold plunges. mean that women cannot do cold plunges. It just means that we act in a different It just means that we act in a different It just means that we act in a different way towards it. And then then there is way towards it. And then then there is way towards it. And then then there is the thing about our cycle. Women are the thing about our cycle. Women are the thing about our cycle. Women are more stressed uh when we are in our more stressed uh when we are in our more stressed uh when we are in our luial phase. So it's important that we luial phase. So it's important that we luial phase. So it's important that we think about when we do the cold plunge.

53:00think about when we do the cold plunge. think about when we do the cold plunge. So uh if we have our ministration for So uh if we have our ministration for So uh if we have our ministration for example that is where we feel the most example that is where we feel the most example that is where we feel the most stressed and also people who do cold stressed and also people who do cold stressed and also people who do cold plunges or winter swimming they probably plunges or winter swimming they probably plunges or winter swimming they probably notice that there are times during their notice that there are times during their notice that there are times during their cycle where they feel a little bit more cycle where they feel a little bit more cycle where they feel a little bit more cold. They feel not able to conquer the cold. They feel not able to conquer the cold. They feel not able to conquer the stress in their everyday life as good as stress in their everyday life as good as stress in their everyday life as good as they did just three weeks ago. And that they did just three weeks ago. And that they did just three weeks ago. And that is because of our changes in hormones. is because of our changes in hormones. is because of our changes in hormones. So be gentle to yourself women when you So be gentle to yourself women when you So be gentle to yourself women when you are in that phase. Um and probably do are in that phase. Um and probably do are in that phase. Um and probably do cold plunges but very briefly or maybe cold plunges but very briefly or maybe cold plunges but very briefly or maybe just wait until you are over that phase. just wait until you are over that phase. just wait until you are over that phase. Um or maybe just take a cold shower so Um or maybe just take a cold shower so Um or maybe just take a cold shower so that people people need to figure that that people people need to figure that that people people need to figure that out for themselves. out for themselves. out for themselves. And is there And is there And is there anyone or any situation where you would anyone or any situation where you would anyone or any situation where you would tell people to be tell people to be tell people to be particularly cautious about this and be particularly cautious about this and be particularly cautious about this and be concerned about the safety implications? concerned about the safety implications? concerned about the safety implications? Yeah. So if you have heart diseases and

54:00Yeah. So if you have heart diseases and Yeah. So if you have heart diseases and if you have unregulated blood pressure, if you have unregulated blood pressure, if you have unregulated blood pressure, I don't recommend that you do these kind I don't recommend that you do these kind I don't recommend that you do these kind of stressors. And if you are pregnant of stressors. And if you are pregnant of stressors. And if you are pregnant also just skip it for these nine months. also just skip it for these nine months. also just skip it for these nine months. I mean if you were already doing cold I mean if you were already doing cold I mean if you were already doing cold and heat exposure then the body will and heat exposure then the body will and heat exposure then the body will remember it but you don't have to do it remember it but you don't have to do it remember it but you don't have to do it those nine months because we actually those nine months because we actually those nine months because we actually don't know exactly what will happen to don't know exactly what will happen to don't know exactly what will happen to the fetus and we want to of course the fetus and we want to of course the fetus and we want to of course protect that we cannot do studies where protect that we cannot do studies where protect that we cannot do studies where we randomize people uh but that is my we randomize people uh but that is my we randomize people uh but that is my advice to to that I've heard that advice to to that I've heard that advice to to that I've heard that there's a sort of hack with your face there's a sort of hack with your face there's a sort of hack with your face that can actually you know get you some that can actually you know get you some that can actually you know get you some access to a cold plunge without actually access to a cold plunge without actually access to a cold plunge without actually doing a cold plunge If you pour water to doing a cold plunge If you pour water to doing a cold plunge If you pour water to your face, so wash your face in cold your face, so wash your face in cold your face, so wash your face in cold water, you can activate your vagus nerve water, you can activate your vagus nerve water, you can activate your vagus nerve and that is activating the rest and and that is activating the rest and and that is activating the rest and digest part of your nervous system. Um, digest part of your nervous system. Um, digest part of your nervous system. Um, which is a good thing because that will which is a good thing because that will which is a good thing because that will stress you down. Of course, you will stress you down. Of course, you will stress you down. Of course, you will also feel energized by it because you also feel energized by it because you

55:00also feel energized by it because you will also activate your your sympathetic will also activate your your sympathetic will also activate your your sympathetic part of your nervous system, but part of your nervous system, but part of your nervous system, but eventually it would actually stress you eventually it would actually stress you eventually it would actually stress you down. So it's a good quicker like you down. So it's a good quicker like you down. So it's a good quicker like you say in the morning if you don't have say in the morning if you don't have say in the morning if you don't have time for cold plunge pour some cold time for cold plunge pour some cold time for cold plunge pour some cold water to the face and you will have also water to the face and you will have also water to the face and you will have also sort of like a a a quicky cold face sort of like a a a quicky cold face sort of like a a a quicky cold face plunge you can say. Yeah. Susanna final plunge you can say. Yeah. Susanna final plunge you can say. Yeah. Susanna final question. If you were going to say to question. If you were going to say to question. If you were going to say to somebody like this is the best way to somebody like this is the best way to somebody like this is the best way to start for someone who's never done this. start for someone who's never done this. start for someone who's never done this. What would you advise them as the best What would you advise them as the best What would you advise them as the best way to to get into all of this? If you way to to get into all of this? If you way to to get into all of this? If you are about to get started with cold are about to get started with cold are about to get started with cold plunging and sauna, I think you will plunging and sauna, I think you will plunging and sauna, I think you will need to figure out when to do it for need to figure out when to do it for need to figure out when to do it for firstly don't be in a situation where firstly don't be in a situation where firstly don't be in a situation where you feel that you are about to get sick. you feel that you are about to get sick. you feel that you are about to get sick. You you should feel well. You should You you should feel well. You should You you should feel well. You should also feel not too stressed uh because also feel not too stressed uh because also feel not too stressed uh because it's going to stress your body the first it's going to stress your body the first it's going to stress your body the first few times mostly. And think about the

56:00few times mostly. And think about the few times mostly. And think about the time of the day. Do it in the daytime. time of the day. Do it in the daytime. time of the day. Do it in the daytime. Preferably, I would say do it when you Preferably, I would say do it when you Preferably, I would say do it when you were about to take a cup of coffee. So, were about to take a cup of coffee. So, were about to take a cup of coffee. So, if you don't drink coffee after 5:00 in if you don't drink coffee after 5:00 in if you don't drink coffee after 5:00 in the afternoon, then don't do your cold the afternoon, then don't do your cold the afternoon, then don't do your cold plunches after 5:00 in the afternoon. plunches after 5:00 in the afternoon. plunches after 5:00 in the afternoon. Yeah. And always have someone with you Yeah. And always have someone with you Yeah. And always have someone with you because doing it alone is not safe. And because doing it alone is not safe. And because doing it alone is not safe. And use your breath to navigate your nervous use your breath to navigate your nervous use your breath to navigate your nervous system. It's your steering, can you say? system. It's your steering, can you say? system. It's your steering, can you say? Uh how to calm your nervous system down. Uh how to calm your nervous system down. Uh how to calm your nervous system down. Amazing. Susanna, Tim, thank you so Amazing. Susanna, Tim, thank you so Amazing. Susanna, Tim, thank you so much. I would like to try and do a quick much. I would like to try and do a quick much. I would like to try and do a quick summary and um please both of you summary and um please both of you summary and um please both of you correct me if if I got anything wrong. correct me if if I got anything wrong. correct me if if I got anything wrong. So, the first thing that's still So, the first thing that's still So, the first thing that's still sticking my mind is I actually do sticking my mind is I actually do sticking my mind is I actually do exercise by going to the sauna even exercise by going to the sauna even exercise by going to the sauna even though I just sit there and do nothing. though I just sit there and do nothing. though I just sit there and do nothing. But apparently my heart is racing and if But apparently my heart is racing and if But apparently my heart is racing and if I do this regularly, it's sort of like I do this regularly, it's sort of like I do this regularly, it's sort of like doing exercise without doing exercise. doing exercise without doing exercise. doing exercise without doing exercise. So, I love that cuz I'm always looking So, I love that cuz I'm always looking So, I love that cuz I'm always looking for a way to not have to do any

57:00for a way to not have to do any for a way to not have to do any exercise. So, uh, I'm I'm sold on that exercise. So, uh, I'm I'm sold on that exercise. So, uh, I'm I'm sold on that already. My second big takeaway, already. My second big takeaway, already. My second big takeaway, Suzanne, is I'm a cold Like, I Suzanne, is I'm a cold Like, I Suzanne, is I'm a cold Like, I knew that, but I didn't realize there knew that, but I didn't realize there knew that, but I didn't realize there was a technical term before. So, I am a was a technical term before. So, I am a was a technical term before. So, I am a cold But the good news is cold But the good news is cold But the good news is apparently you once were as well. So, it apparently you once were as well. So, it apparently you once were as well. So, it sounds like it is possible to start as sounds like it is possible to start as sounds like it is possible to start as one. It sounds like most of us probably one. It sounds like most of us probably one. It sounds like most of us probably do because it's normal because actually do because it's normal because actually do because it's normal because actually the whole experience is, you know, your the whole experience is, you know, your the whole experience is, you know, your body thinks it's going to die. We don't body thinks it's going to die. We don't body thinks it's going to die. We don't expect to do that. And so what you expect to do that. And so what you expect to do that. And so what you describe is like the first time gasping describe is like the first time gasping describe is like the first time gasping and screaming is all all right. You are and screaming is all all right. You are and screaming is all all right. You are stressing your body and the reason why stressing your body and the reason why stressing your body and the reason why you get these benefits is because you're you get these benefits is because you're you get these benefits is because you're creating this um stress and what tends creating this um stress and what tends creating this um stress and what tends to happen is you sort of have 30 second to happen is you sort of have 30 second to happen is you sort of have 30 second of this real shock. If you can get of this real shock. If you can get of this real shock. If you can get through that then I think you describe through that then I think you describe through that then I think you describe this wonderful meditative calm that you this wonderful meditative calm that you this wonderful meditative calm that you get out to on the other side. But even get out to on the other side. But even get out to on the other side. But even then, interestingly, you aren't saying then, interestingly, you aren't saying then, interestingly, you aren't saying then go and stay in this cold water for then go and stay in this cold water for then go and stay in this cold water for a really long time. Everything you're a really long time. Everything you're a really long time. Everything you're talking about is actually quite a short talking about is actually quite a short talking about is actually quite a short period of time. You know, one or two

58:00period of time. You know, one or two period of time. You know, one or two minutes in the cold, then coming back. minutes in the cold, then coming back. minutes in the cold, then coming back. And the sort of the optimum that you saw And the sort of the optimum that you saw And the sort of the optimum that you saw in this research that was really in this research that was really in this research that was really delivering the results was two to three delivering the results was two to three delivering the results was two to three times a week where people actually get times a week where people actually get times a week where people actually get in a habit where they were combining in a habit where they were combining in a habit where they were combining sauna and cold plunge which I think was sauna and cold plunge which I think was sauna and cold plunge which I think was about sort of 10 minutes sauna still about sort of 10 minutes sauna still about sort of 10 minutes sauna still just like one or two minutes of the cold just like one or two minutes of the cold just like one or two minutes of the cold plunge three times. There is an easier plunge three times. There is an easier plunge three times. There is an easier way to get into this. So you can just do way to get into this. So you can just do way to get into this. So you can just do a cold shower and that is going to a cold shower and that is going to a cold shower and that is going to already like create quite a few of those already like create quite a few of those already like create quite a few of those impacts. Make sure you're breathing impacts. Make sure you're breathing impacts. Make sure you're breathing through the nose because apparently if through the nose because apparently if through the nose because apparently if you're a cold like me, even that you're a cold like me, even that you're a cold like me, even that is going to be too much. Interestingly, is going to be too much. Interestingly, is going to be too much. Interestingly, a hot bath on the other hand, which I've a hot bath on the other hand, which I've a hot bath on the other hand, which I've never felt as scared about, has proven never felt as scared about, has proven never felt as scared about, has proven benefits uh and helps with sleep. And benefits uh and helps with sleep. And benefits uh and helps with sleep. And then I think final thing I'm taking away then I think final thing I'm taking away then I think final thing I'm taking away is cryotherapy might work. And I'll be is cryotherapy might work. And I'll be is cryotherapy might work. And I'll be honest, I've been a bit skeptical. I honest, I've been a bit skeptical. I honest, I've been a bit skeptical. I always feel that anything that appears always feel that anything that appears always feel that anything that appears in the mall like I don't know, I feel in the mall like I don't know, I feel in the mall like I don't know, I feel like I'm not sure I really believe it like I'm not sure I really believe it like I'm not sure I really believe it has a health impact. But you're saying has a health impact. But you're saying has a health impact. But you're saying it might work because there is a stress it might work because there is a stress it might work because there is a stress associated with it, but it's probably

59:00associated with it, but it's probably associated with it, but it's probably going to have less health impact than going to have less health impact than going to have less health impact than this ice plunge because actually you this ice plunge because actually you this ice plunge because actually you don't feel the full weight and pressure don't feel the full weight and pressure don't feel the full weight and pressure and there is very little data yet. So and there is very little data yet. So and there is very little data yet. So like you think it could well work, but like you think it could well work, but like you think it could well work, but there's not a lot of proof. The data is there's not a lot of proof. The data is there's not a lot of proof. The data is coming along more on sort of the cold coming along more on sort of the cold coming along more on sort of the cold plunge, but even then your research is plunge, but even then your research is plunge, but even then your research is sort of key here and it's still very sort of key here and it's still very sort of key here and it's still very early. So there's a lot more still to to early. So there's a lot more still to to early. So there's a lot more still to to explore. Beautiful resume. Yeah. explore. Beautiful resume. Yeah. explore. Beautiful resume. Yeah. Beautiful. Beautiful. Beautiful. Thank you so much, Tim. I want to hear Thank you so much, Tim. I want to hear Thank you so much, Tim. I want to hear more about the impact on the microbiome more about the impact on the microbiome more about the impact on the microbiome as we discover more about where that as we discover more about where that as we discover more about where that happens. And Susanna, I hope that as as happens. And Susanna, I hope that as as happens. And Susanna, I hope that as as your research continues, we can get you your research continues, we can get you your research continues, we can get you back again in the future. Of course. back again in the future. Of course. back again in the future. Of course. Thank you so much for having me. If you Thank you so much for having me. If you Thank you so much for having me. If you enjoyed this episode with Susanna and enjoyed this episode with Susanna and enjoyed this episode with Susanna and Tim all about sauners and cold plunges, Tim all about sauners and cold plunges, Tim all about sauners and cold plunges, I know you'll love watching this I know you'll love watching this I know you'll love watching this conversation with the late great Dr. conversation with the late great Dr. conversation with the late great Dr. Michael Mosley where cold showers are Michael Mosley where cold showers are Michael Mosley where cold showers are just one of the four habits that he just one of the four habits that he just one of the four habits that he recommends to improve your health. recommends to improve your health. recommends to improve your health. Thanks for watching and see you next Thanks for watching and see you next Thanks for watching and see you next time.

Sauna cold plunge and your health what the science says Dr Susanna S berg Tim Sp