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Oxygen Advantage Podcast with Dr. Susanna Søberg on cold exposure

Updated: Mar 15

Highlights from the Oxygen Advantage Podcast in a conversation they had with Dr. Susanna Søberg, who is an authority on cold and brown fat due to her PhD thesis on the topic. Suzanna explains that when you expose yourself to cold temperatures, it activates the sympathetic nervous system which releases norepinephrine, activating brown fat cells which increases heat in the body. Cold water swimming can also increase the volume of brown fat in rodents. Suzanna initially did not want to study cold temperatures and did not enjoy winter swimming, but she eventually built up her resilience to it. The speaker also mentions that winter swimming has benefits for mental health and that Suzanna's book on the topic is well-crafted and accessible to the general population.




Susanna Søberg | Chilling Ourselves to Boost Metabolism | OA podcast - YouTube


(00:05) hello everybody and uh yeah delighted to to talk with Suzanne who's hailing from Copenhagen and Daniel's just across the water in Malmo and Susanna has we met Susanna about two months ago face to face we were giving a workshop in Belfast and the whole topic of conversation come up about ice cold so it's really tropical out there and Susanna has a PHD thesis on it so she's an authority on all things cold and brown fat so Suzanne it's a pleasure to have you here it's it's great I think the conversation is

(00:40) going to be interesting now as I said I know nothing about coal so I'm going to really step back in this one and for me sometimes I just can't get my head around why anybody would bother to jump into an ice bath but I've done it a couple of times yeah um not so sure but uh convert me but uh tell us a little bit about your background how you got into it and uh let's go let's get the conversation flowing thank you thank you for having me it was so nice to see you a couple of months ago when I went to one of your workshops

(01:16) um and uh yeah so the code the water and the breathing is really connected and and it we can really benefit from from learning how to breathe calmly and and light uh doing a cold water immersion so but initially actually I started my PhD in the the brown fat the healthy fat um and that was the reason why I started looking into what is actually happened happening when you go into the cold cold air cold rooms or just getting cold on your skin but also going into the cold water so um my thesis is a is actually

(01:54) about our metabolism um and what happened was that the I had this science topic of the brown fat and figuring out how can I do a research study in humans because there's there's been some studies do in in the you could say rodents and also cell models saying that if you get cold on your skin then they will activate your brown fat because norepinephrine would be released from your nervous system because you activate the sympathetic nervous system and that will activate our Brown cells which will then increase our heat in our

(02:28) body so that is to protect us from becoming hypothermic um and then I got the idea that what about winter swimmers because they go into the cold water all the time so do they have more Brown fat because when you expose yourself to to code all the time we've seen rodent studies that the brown fat can increase in volume and if that if we can increase the volume of brown fat in the body then we will have more cells to increase our metabolism increase our heat in our body because when the brown fat is activated it takes

(03:03) up sugar and fats on the bloodstream and thereby we can burn some calories so that is really what researchers are doing right now there's really a Hot Topic in metabolism increasing our Brown fat did you actually did you do winter swimming or eye swimming before you do the study or did you start doing it because of your study yeah exactly it's like I really reject I don't want to go into the cold I'm comfortable I feel fine at the at the just neutral temperatures but I have to say that I was also a person

(03:43) that was really I can maybe call myself a cold because I was so scared of the cold all the time I I freeze really easily and so the thought of that was really not uh not something that appealed to me at least so going into this research I was like okay if I do this at some point I would have to try it at least so yeah that's uh so I did this I did start up the research and I did do some field research uh just observing winter swimmers how do they do it in Denmark uh noting down how how is this a good thing

(04:20) and how long do they stay in the water so it took me a year just to get like a data on how is this actually done in Praxis um but the winter swimmers were all like seeing that I was doing this study so they was they were saying well Susanna you cannot study this without trying so you have to get into the water and at some point they convinced me and I must say the first three times I was not having it it was not something I liked I know that some could some get hooked the first time and I wish I had it like that but it wasn't like that for

(05:00) me at all so but by the time of four or five times I was not scared of of the water anymore I was not really scared of getting cold like that anymore and that is when you start building up your your resilience actually so but today I like it how cold was it when you jumped in because that matters was it two Celsius or 18 Celsius or somewhere in between well so cold water cold water is 15 degrees and Below um and the reason why I say that is because we can see in the literature that um that by the time the water hits 15

(05:34) degrees and and Below we there's been some observations on people getting activation of the cold shot and also accidents so that's the the registration we have seen in in the in in records at least so 15 degrees and below is where you activate your sympathetic nervous system um by the time I went into the water it was October uh so in Denmark the the temperature in the water will be around maybe eight five yeah around that yeah but but this this year it's the water is really warm we had a really warm summer

(06:09) but usually it's around maybe eight nine ten degrees or something like that in October it could be colder but yeah I remember it was super cold at least it's through a lot of diminishing returns you know do you get the same effect at 14 degrees as you get it in two degrees or how does that work so there is probably like a bonds effect on on temperature and you can also feel on your breathing because if you go into water that is two degrees you will have a much larger activation of your sympathetic nervous system that

(06:43) that is your fight and flight system so of course you will have a more rapid increase of all the the hormones and so adrenaline noradrenaline and codisol which will make you you can say Fight for Your Life um but that would mean that you can stay in a shorter time of course in the water so you have to adjust to the the temperature as well but most important of all is just to feel how it feels for you so as soon as you you feel too uncomfortable the body will tell you now it's enough now you go up and you have

(07:18) to listen to that but building up you will have to accept that you can only stay for a certain amount of time and don't compete with anyone because people are different so some will be fine with just building up to maybe one minute or two minutes three minutes and no reason to stay in longer no matter what temperature it is I would say um and then some are just fine with just a short tip you will get the activation of the sympathetic nervous system anyways so but in the beginning you will not be able to stay for a minute that is

(07:53) also something people will have to accept that it's it's like training it's like going to the fitness center you have to build this up your cells will have to adapt so so a novice like me you're saying maybe just get in for 30 seconds and I think that takes the fair response away as well a little bit because you're you're realizing it's only for 30 seconds that your first tip will just be a few seconds you can go in and maybe count to five and then go up because I mean the next time you can count to ten and then

(08:22) to 30 and then at some point you will be able to stay in the water until the cold shock subsides and that would take you around 40 seconds one minute some people it's one and a half minutes it's a little bit different it's a little bit individual but it seems that if you can get over the code shock if you can use your breathing concentrate on your breathing getting low and light then you can relax in the water you can you can switch from sympathetic activation of your nervous system to the parasympathetic activation and when you

(08:58) can do that you can at some point rest and you will feel the switch I think it's amazing I remember the day where I could sit in the water and I I was swimming but then I was sitting and actually holding my hands above the water because I get of cool terms and I remember the first day where I actually got over the Cold Shot response and I immediately felt the calmness in my body it was it was like getting over to the other side it was amazing and it was it was a very cold day with fog on it was a lake I remember and it was just so

(09:33) beautiful I have made a core memory about that and it's just it was so beautiful so Patrick one day you would have to try and just build it up a bit and then you will see that something is amazing is happening I like breathing because I've you know when you get it get the switch you get a lot of your mouth and you can just like with breeding Patrick slow breathing yeah and it's not like breath holding like if you tell somebody to hold their breath for several minutes it's too stressful you start slow the only difference is that

(10:03) controls you know temperature driven so you may not be able to do in the summer but I think there are many similarities with breeding as far as you have a little bit of an aversion to breath holding and some of those exercises that are more stressful yeah but once you get used to it slowly yeah it's not about fear I think so fear of getting into the cold fear of breath hold it's a the feeling of breath breathlessness I think a lot of my subjects and I had I did a randomized control trial um of um it was 30 subjects in this

(10:41) study it's not published yet but I trained them from never tried winter swimming before and of course I we went to me and my team we went to the sea with them and had and maybe three four five times because we we wanted to make sure that they were not stopping their winter swimming because of fear of the water because fear is not something we can use for anything so if they don't want to continue in in Winter swimming it should be because it's they're not having it they're not feeling it

(11:12) afterwards but the first few times the the reports coming back to me was that people were felt breathless and that was not a great feeling of course but that was the biggest fear not being able to breathe so what I really really encourage people to do is think about the breathing before you go into the water so calm yourself down before you go into the water takes a deep breath on the little and just just on the daddy and just to stand there for a bit relax yourself do some breathing techniques but in a relaxing way I don't encourage

(11:50) people to hyperventilate because you're already warm because you just came from home where you maybe you were running you're already warm enough you just have to calm your nervous system so you can go into the water because then the culture will activate the sympathetic nervous system but you are already in the training of lowering your breath and that you can use in the water I think just something tremendous in terms of mental health here because in terms of breathing as Daniel was saying you surrender to it now I've done

(12:20) a few ice Parts but xpt and there were four minutes in duration I just never went back to them again and so and I have we put in ice baths we put in with infrared sauna with everything here and uh yeah so shame on me but it's it's really about so what you're saying Suzanne is when people get into the water they are feeling breathless in the water yeah and this is something that they don't like so really it's about having some command over your breathing that here you're in the face of

(12:52) adversity and your breathing is getting fast which is going to happen in any situation that's stressful yes exactly and if physiological any mental stressful situation and it's really about developing the tools then to be able to take control to self-regulation whether it's in the water or whether it's in situations outside of the water so there's a lot going on and even though I have to say your book winter swimming and I'll show towards the and as well it's a beautifully crossed

(13:19) crafted book thank you and what you've included in it with photographs of real people not just Instagram people which can be very much a turn off that you're making it accessible to the normal populations the degree to which this has been practiced around the world because we had this conversation with Seth Daniel and yourself beforehand that very often we think it's only isolated say for example for Finland for Sweden for the northern countries for Denmark Etc but it's it's actually practiced worldwide

(13:48) internationally and it's not just this is not just a movement at the moment this has been practiced for decades yes there's nothing new about this no it's there's nothing new about it but I mean there's been like more you can see more research on it the last maybe 20 years and also metabolism wise which I've been studying um but also there's been a pandemic which apparently also really it really took off during the pandemic right and it really it builds into what you just said about the mental health because uh

(14:24) the lockdown didn't really do anything good for us I would say mentally so people are more stressed and they have more anxiety and and they feel more lonely I think so going going out to the water and and getting this increase in in neurotransmitters such as dopamine increase by 250 percent or even more just by a short dip actually and also in norepinephrine um and endorphins increasing to too which makes us happy it's our happiness hormones and it makes us more calm because when you submerge in the water

(15:01) you activate the parasympatic nervous system and serotonin goes up and that is what you need for the mental balance and that that is that holds on for hours after your cold sit so what people did was actually they were seeking excitement I think also maybe people go a bit bored but then they found out well this is actually making me more happy and more joyful more relaxed afterwards so in relation to mental health I think this is really interesting and when it comes to curing maybe depression and also anxiety or holding it in in Aid you

(15:36) can say um so I have seen that people use this but this is of course on on an anecdotal evidence if you can call it that or stories yeah but it has to start summer in terms of see you're seeing the observations and then time then the signs will show the the connection or at least will uncover it and but you're saying that initially when you get into the water you're activating a sympathetic response so you're feeling distressed there and then you're surrendering to it so that's transforming then from a sympathetic

(16:07) activation to relaxation response yes so okay but what what people need is a tool to do to know how to do this because the fear starts when you don't know what to do you don't know how to breathe you don't know what to do when you go into the water so I think it's really really important and that was also important for my my studies in my research when I told I guided them into the water and told them exactly before so they knew how to go into the water empty your lungs I always say so when they go in

(16:41) they should exhale because then they make capacity to breathe in more air because when you go in you will and you're not adapted you will have a invasion of your sympathetic nervous system and that will increase hyperventilation and then you will have a very high and shallow breathing you cannot get the air down but if you exhale completely before the first step in the water you will have a bigger capacity to breathe deeply so that is one thing the other thing is doing the the the light breathing before you go

(17:17) into the water so standing on the on on the beach or Jetty or before your bath or what it is you're using and just practice getting your activation of your parasympatic nervous system then it will be easier for you going into that breathing again as soon as you step in through the water we spoke a little bit earlier here before the podcast about measuring have you used any measuring devices because if you have the like myself door ring for example you can see that switch when you become calmer after and it doesn't

(17:52) happen to me every time but have you used any of that or yourself or the ones you've taught yeah so we've used a Garmin watch and the with that we can see uh the heart rate and also the um swim Strokes how many strokes did they take and we can see that how much the post actually went up and also how fast it actually declined again because what is normally said is that you have um an increase in heart rate as soon as you go into the water and you will definitely have that if you are unexperienced winter swimmer also because you are a

(18:32) bit anxious and nervous about going into the water and it's probably mostly that but because the code shock is so short you would because of the activation of the parasympathetic nervous system and the the vagus nerve you will have a decrease in the heart rate as well and that is what why you can see people sitting in water for maybe a minute two minutes three minutes and not hyperventilate that is because they have calm their nervous system to the parasympathetic vaccination so you can definitely use your your breath to to

(19:05) get into that stage and you can use that in your everyday as well so that is another thing do you but do you so you actually mostly you swim you don't sit still because there's a difference I do both I do yeah yeah I do both well it's because sometimes if I can't reach the bottom of the sea then of course I would I would have to do a swim but sometimes I just like to swim as well because then I activate my muscles and you have like two systems in your body that you that can activate the heat um that is the round fat which will be

(19:39) activated at first but at some point that will not be enough to uh to defend your your core temperature and then the muscles will of course help you but if you are swimming then the muscle will help you immediately to keep yourself warmer and actually so swimming is actually a good thing because then you will have more heat in your body but you will also have changing the temperature because of the thermal layer will be will be cold all the time so yeah of the water so it's just like we said earlier if you dig into it

(20:13) like there's a layer heat layer if you sit completely still and also if you take your hands and even your feet outside is there's a difference if you really want to get into it so but I really want to make a point there because there are some people thinking that taking your hands out of the water is like cheating and and I really don't think it is because you don't have to submerge your whole body to get the benefits of this or get your activation right or you can say it's it's not necessary

(20:45) um because we've been we have done studies not only me but other researchers as well where we see that submerging just a hand or a foot in cold water at four degrees for four minutes which is a long time but we could see immediately that there is an activation of the brown fat and we there's also studies done in fishermen where we can see that because they work with the hands in cold water all the time during cleaning the fission and stuff and what they do um but we can see that they have a code adaptation other places in the body it's

(21:19) not just the hands that they can have a long time in the cold water it's also the legs and and rest of the body so cold adaptation is not it's not necessarily the whole body of getting your head submerged you don't really have to and because I get so cold on my hands sorry um I take them up because then I can sit in the the water a longer time of course I do swim but then I take them up afterwards because then I'm able maybe to sit a little bit longer and and get my two three minutes of how long time I

(21:55) want to sit there yeah I think that's a good point to make there because some people can sit but they can't have their sometimes their feet or their hands because they have problems yes so they can still get the benefit while doing so it's these little tips and tricks that people may not necessarily really know so it's good to know that if you do it that way at least you can get the benefit even though your hands are not in the water exactly you can wear gloves as well and and also European shoes

(22:24) um I do that all the time but that's also because my my fear of touching the the ground in in the sea because I can't see it and and that's a little bit maybe just me I don't know but I I wear the shoes because then I don't have to think about that I can concentrate on my breathing and I could do a little swim because I really love that um and sit there for longer if I take my hands off and I get the benefits so yeah how how long would you normally I mean I was a individual but would you recommend

(22:55) somebody to be in until they're calm their breathing or uh because you said in Excel before you go in and breathe light what do you kind of tell them when you're in the water um do you have any certain protocol for people who are their breath of course um and and try to calm themselves down by do a a deep inhalation and try to do it slow as well so deep and light and slow actually so by doing that they will get the activation of the parasympathetic nervous system quicklier um and they also of course they will

(23:39) have a best dilation as well which will mean in the beginning it will be like a struggle between getting cold adapted and also opening your veins so you will actually quickly get called by the parasympathetic activation but at some point you will be able to basically constrict that well in your skin that you will not get that cold by by activating your parasympatic activation with slow breathing so it's like there's also a building up and a switch the way the body needs to to get um yeah so you're kind of you're kind of

(24:16) saying listen to your body yeah it's it's not always an easy one because you could say to yourself and I'm going to be macho here so I'm going to keep on saying to myself I should stay in longer and longer and longer and then one over does it and sometimes extremes sometimes I feel with people with with breathing they can push you to the extremes that there's different personality types and I can understand that the individuals who were the long breath holds are also the ones that are going to jump into the water as well so

(24:43) how would you know if you're overdoing it would you would you know by your shivering afterwards that it takes you so long to get back to normal temperature or yeah I know Daniel's looking at Aura ring and things like that but say for a normal individual how would they know yeah so that's that's a really good question and I think that the that that is right if you feel if you feel bad in the water and you'll start shivering that is the your definitely your last cue to get off you should not shiver in

(25:13) the water because then you know your temperature has decreased too much um and I think that I I did like a um a small uh table in my in my book where it says exactly what is happening what can you feel when the temperature reaches 30 36 degrees that is decreasing one degree in your core and also what happens at 35 degrees and when it reaches 35 you will have the shivering and you should not have that that is absolutely no reason to go there so when you feel a little bit like the tingle in your skin has gone away and

(25:50) you feel like a cold shiver towards your core it's like a feeling it's something you can feel then it's definitely time to get up because one thing you need to know is when you are in the water that is not when you are the coldest in your core you will have what is called the after drop when you have been in the water so when you get up from the water the the blood vessels will dilate and the the blood in your core will of course go to your tissues and your skin and that will decrease the temperature of the blood

(26:24) and that goes back to your core and then the the temperature receptors will will of course pick that up sensor signal to the temperature regulating Center in the brain and then it it feel well now we're getting even colder so when you get up from your cold dip you will have a decrease in your temperature in the cold even after that so don't stay until you absolutely feel this is getting too much don't push it there's absolutely also no reason because we see the health benefits happening within a few minutes

(26:54) and after that it plateaus so there's no reason to stay longer and this is everything to do with hermesis as well I don't know if we should talk about that but yeah why not I think it's talking about but I think Patrick that it goes back if you do the link to breath holds like the diaphragm if you do breathal your diaphragm will start Contracting more and more if your experience it will take longer same with if you're in the cold like you feel these Downs After whatever a minute and then after a minute there

(27:25) when when they come more and more often just like you know like the contractions of the diaphragm it's kind of telling you you're stressing the system so at least for me so you have these subjective measures as well yeah that would experience I would say yeah but also when you are a new winter swimmer or a coach Dipper you will have shivering afterwards and the Shivering is not in itself anything dangerous but it's just the muscle warming you up which is a good thing uh but if you if you experience that many times or all

(27:58) the time actually then you would know maybe just stay in for a short amount of time because then you will learn the body will learn to heat itself up but not to extremes because I mean then it doesn't feel that great to to feel that shivering for hours afterwards so you have to adjust it to yourself it's all about body composition and it's about your yeah it's it's really difficult to like say this is how you should do and this is just the protocol you cannot do that but we can set up some some you can

(28:30) say advice around how how much you should do but as far as the literature goes it there's you shouldn't stay in the water for 10 minutes 15 minutes which some very competitive people would do in pushing it to the extremes there was no reason too so how would you tell somebody to now is the perfect time to start or maybe a month ago but how would you tell them to kind of build the Habit if and if it is in the middle of the winter how do you have a like a general like just go down to the knee if for 30 seconds so you

(29:06) have a certain like uh protocol or adaptation for somebody who's a complete beginner well it's completely beginner I would say start after summer um or just continue your summer swimming into the winter because then your your the season the temperature in nature and and weather will just do the conditions for you so if you can swim in the summer and you just continue that then it will be much easier for you to adapt to the temperature decreasing um um just slowly because then you don't have to get the immediate cold shock if

(29:41) you start in December or January when winter is at its peak so it's easier for yourself to start in in the summer it's also more safe because there's also of course some safety around this so people with heart diseases or high blood pressure not treated um that is people I usually tell not to do winter swimming or they should do go to the doctor and talk to them about it because it is really difficult to to say that everybody can just start winter swimming because as I told you before the conflict of The sympathetic and the

(30:19) parasympatic nervous system one raises the heart rate and blood pressure and the other one brings it down and that makes the conflict to the heart and you can almost if you tried winter swimming and dipping you can remember that the heart is like oh it's like struggling the first few seconds of it and if you have a heart problems I would I would say you should be careful about that but starting out from Summer would definitely be less stressful for your cardiovascular system and in terms of when we're looking at

(30:51) breathing exercise people with anxiety we have to go really really gentle because especially when we give them air hunger because that air hunger compartment with stress response is there anybody would say predisposition towards anxiety or panic disorder that they have to go even easier than somebody without those issues or do you see do you see that difference or not um I haven't really trained a group of people with an anxiety or um or or depression as such um so I cannot really talk about that on a scientific level but my observation is

(31:28) that that people with anxiety and depression are doing winter swimming and and they start out slow but I would say it's it's it would be the same for everybody because it's it's all individual you have to to you have to feel it yourself how much can I do but relaxing before you go in having anxiety or not having a slow breath before you go in and exhale completely will help you in the water but nobody everybody will have an increase in their heart rate in in the first few seconds and everybody will have an activation from

(32:05) the cold shock so having an anxiety could trigger even more anxiety with blowing in so they maybe have to take it even more slow is my recently sure sure yeah so what about uh as far dipping the face in cold water or even submerged uh are there any benefits from that or should you or should you not do it what what are you what's your experience the face can be very cold water in your face because that is also giving you at this energy boost and also no adrenaline release from from your nervous system but I mean you don't

(32:47) have to dunk your head under the water to get the benefits of dipping in cold water so I usually say that we don't have to there's also a safety around it um because when you submerge your body up to your neck you will have studies show that you have a decrease of blood flow to the brain of 30 or even more so dunking your head even more that will increase that shock and you have the risk of of course hitting your head or drowning and you don't really need that so so for safety I always say there's no

(33:25) need to and for health benefits there's also no need to but sometimes when I'm out in the sea and we have really clean water here so I take some water and just splice it in my face is because then I get that refreshing feeling afterwards because it's also very much calming your yourself but it's also because it activates the parasympathetic nerves of the vagal nerve by putting cold water in your face so that could be nice too is this is a mammalian reflex as well if you yes get the get the heart rate down

(34:00) so there's uh maybe it's not something you do the first day but it's interesting uh to maybe to maybe use as well so just wanted to get your input on that yeah yeah yeah it's very interesting in terms of the reduced blood flow to the brain so I'm assuming that's this is the body is conserving energy and the heart rate is really slowing down bradycardia as Daniel was talking about yeah but it's really positives as a result of reducing blood flow to the brain like that because for example when we're

(34:34) doing retrolling we would advise never lower your blood oxygen saturation to below 50 because this is when you can have a reduction of blood flow to the brain but if you hold your breath until you drop to about eight percent you can actually have an increase of blood flow to the brain so I'm kind of surprised with the cold that it would actually cause a reduction of blood flow and you would think that the body is going to look after the brain and the heart so that the there's peripheral circulation is going to constrict and this blood is

(35:00) diverted dense the more essential organs to maintain survival so that's not the case now I'm surprised as well I I must say that that is maybe why that those studies actually also performed in Denmark I was quite surprised when I saw it I was like this this is really interesting because I would think that the brain must be very vital for us to uh to to to increase the blood flow and and people always say that oh when you go into the cold water you have an increase in blood flow to the brain but it's quite opposite apparently and these

(35:31) studies were they were performed in a laboratory where they had this um a big to what they put people in and for exactly 30 seconds and then took them up again and at zero degrees so it was really really cool as well so Celsius um but what is important here I think is that that is why we should be a bit cautious around dunking the head in in the water and also going alone because the low blood flow to the brain can cause people to to faint yeah water as well so yeah I always say never never go alone but I think Patrick and Senna maybe it's

(36:12) got something to do with the temperature there's a big difference between zero and 15 Celsius there's a big difference between going down to 80 on this oxygen saturation of 50 same as training it's a big difference between jogging for one hour or going all out for 20 seconds so the intensity of the temperature the intensity of breath hold matters is you can't you can't in my opinion you can't just say well if you're in 15 for 20 minutes it's not the same it's very very cold it's same with training that's why

(36:40) you get a different effect and maybe that is the reason down to a certain point you get increased but below that it goes into a different year and for me that makes it wouldn't make sense not known but I I know from experience this it's like when people say burning calories it's very different doing low intensity high intensity on the shock of your body and and different gears come come into play so maybe there's something again it could be something gradually there happening of course so the warmer the water is the the more

(37:15) blood flow you will have in your brain when you go into the water but I think that because that is really hard for people to distinguish when should I then dunk my head and not dunk my head I just say that there's no reason to there is absolutely nothing showing that this is gonna do anything good for you so yeah so but I think that 15 degrees and below is very cold and and also it's relative there's also something relative to this so if your skin is very warm you will you can get a cold shock and at a higher degree but if

(37:52) you are a bit cold already then the cold shop will be less so and some people are just warmer than other people so it's weird so so this thing is going to matter then if you're going from a hot sauna into the cold spot and then back into the hot sun again so what's the difference between that then a normal temperature the atmospheric temperature going into the the water sorry once again so say you're you're going from a hot sauna yeah you're feeling really really harsh yeah and now you're jumping into a call back and

(38:24) you're going from one extreme right down to the Other Extreme yeah so that's going to increase your culture of course uh because you yeah the relative difference is is quite big at this moment when you come straight from the very hot sauna um and that is also why I think it's not really that important if it's 15 degrees or it's 12 degrees but there's a difference in 15 and zero of course but if you just look at the relative difference then you will have a code shock response no matter what so yeah

(38:54) again the blood flow to the brain will decrease you do that as well what is there a difference between doing just going down doing a cold exposure versus doing sauna first cold and then so on again or the the various combinations ending with a sauna have you noticed a difference in what happens with people when they mix it or versus just doing cold exposure so that I'll tell you but what I did in my research was um based on all the observations that I did and also what is happening in your metabolism I would say that because of

(39:34) my hypothesis saying that the code will activate your metabolism I said that a my protocol should be that people should start in the cold to decrease the skin temperature and then they go into the sauna and back to the cold back to the sauna and then they end on cold because if you end on cold then you force your body to reheat itself and that will will of course take energy and the energy comes from activating your brown fat and activating your muscles eventually when you get home you will maybe start shivering a

(40:04) bit um and that is really good for your health so if you don't overdo it or do it extremely then it's good it's really good for you um so I learned the hard way that it's not it's not necessarily good to go from cold to heat cold to heat when the contrast is 90 Celsius too quickly it actually I have to be very careful about that so yeah I hope always say that people should just stand on stand on the bridge or just wait a bit to cool down in the wind so they have what we talked about so the cold shock responds to

(40:36) going submerging yourself will be a little bit less so it should of course be uh done carefully but also never alone so that is also for safety really important but luckily Patrick you you got a a mile or two down to the ocean from your phone you have ways so envious sir I can I can see it it's a bit I can almost see Galway Bay but it's a little bit uh overcast at the minute and we have we have an infrared sauna down there as well so there's no excuses you should have definitely try oh it's probably totally so I'm feeling so

(41:13) guilty have this podcast you know I'm sitting here and I'm saying no contribution whatsoever to make we'll do a repeat podcast in a few weeks past we will see what uh no other choice um Susanna for somebody who wouldn't be familiar with brown fat and um what's the benefits and what's the comparisons and do some people naturally have more Brown fat than others yeah and what's the whole aspect in terms of weight loss and things like that um so the brown fat is a very remarkable tissue that we have in our body nobody

(41:47) really knows about it it's it's really something new that we started researching and um but we have known about it since uh the I think it was the 1500 or something there was this research of finding Brown fat in the this uh this animal and so that the it's a hibernating animal and the and so that it was activated with cold but then the researchers found that it was also in in animals that was not in hibernation so and then they got confused and they put down the reason didn't want to look at it again because

(42:24) it was very confusing but what the brown fat does and we found out a little bit later was that it when it's activated the cold it increases the metabolism by taking in a sugar and fat from the bloodstream and then it releases heat as you can say the product um and it's activated immediately as soon as the skin gets cold um so that is because of norepinephrine release so when we're cold it activates norepinephrine from the brain and the brown fat which is located very close to the central nervous system so in humans

(43:03) at least it's up here under the superclavicular bones and down the spine um and a little bit around the kidneys a little bit around the heart which also makes sense um so when it's activated it keeps our vital organs warm and it happens within like minute seconds actually I could tell from my studies doing um measuring with an infrared thermography a camera I could see the activation immediately but what it does is that when it's activated it takes up sugar and and the fat from the bloodstream as fuel to keep

(43:40) it activated and keep us warm from the inside um and some people have more than others which we started looking into by 2000 by the Millennium actually and we saw that some people have more and that is apparently the the younger you are and when you reach around 40 50 years old we can see a decrease also at the same time when we see that obesity goes up so we don't really know if obesity is happening because you have a reduction in your brown fat or the brown fat or the Obesity is making the brown fat shrink

(44:20) so we don't really know which way it really goes but there is so much research in this showing also that the brown fat is very dependent on insulin like the muscles so if you are insulin resistant which these subjects are people are and you will have a difficulty activating the brown fat um so it could be that if you were you have a you are above Noble BMI you will have less uh of the brown fat and if you are younger and normal BMI you have more are we see in babies babies have a lot of brown fat and before the Millennium

(45:06) we thought that well the brown fat is only for babies because um they have a lot and we can see it on on the back of them um so they have that because they cannot shiver in the muscles in the first I don't know six months or something like that so they need the brown fat to keep themselves warm and then it it vanishes a bit it shrinks with age but we can activate the brown fat and keep it alive you can say and use it for increasing our metabolism if we go into some kind of code and I know that I took the model of uh winter

(45:44) swimming but studies also show that if you sleep in a courtroom at 19 degrees for a month studies show that these subjects increase the amount of brown fat it's not that big but it's like increase the amount of brown fat that they have they got um more um um when you say they got a lower a higher insulin sensitivity and also a faster you can say blood sugar and um a reduction in the bloodstream and when the same subjects then slept in the in a room at 24 degrees and the later months at 27 degrees they saw that the amount

(46:29) of round fat is stringed again so it's definitely something that we can build the brown fat if we go into the cold or sleep in the code or go in the cold wind because when when we do that we activate it and then we will increase the amount of mitochondria in the cells and also we can maybe Brown some of the the white fat cells into what we call Base fat cells now we have the whole color scale of Base brown and white fat cells so but they are very distinguished the white fat cell and the brown fat cell because

(47:03) the brown fat cell has lots of mitochondria and can you could say you can use the white fat as fuel but the white fat is not that easily activated and we know that also from exercise it's really hard to get to get it activated and get rid of it or empty the white fat cells but we can do that with the cold because the brown fat is going to use it as fuel we want more of it it's so cool so it's almost as if it's going back to basics like your ancestors would have been exposing themselves to colder

(47:37) environments and we now were so Comfort creatures yeah that we don't do that so does dishonor have the opposite of factors that are super question it's not a stupid question it's a really good question and I love it because now we've been talking about the brown fat as a tissue that is only activated by the cone but actually it's also activated by heat so you can maybe look at yeah because you also have an increase in norepinephrine but it's so I think we should look at the brown fat as

(48:06) like at temperature balance and organ in our body it's just trying to make you survive it doesn't really want anything else it it has to use fuel to heat you up and keep you warm but if you get too warm it activates so you can dilate your vessels and get rid of your heat so it's also so that's music this is absolutely music for my ears because I was in disorder this morning yeah and yesterday morning and all those mornings yeah so now you're saying I don't even need to post the cold all I have to

(48:41) I think so because my studies actually show that you also but it makes sense going into the heat because it shows that you will have an increase in insulin sensitivity and also you will get a faster rid of the sugar in your bloodstream but doing the contrast therapy shows exactly the same which my studies showed I published last year so doing both you will you will have an increase in mitochondria for going into the cold but when you go into the heat the heat will help you use those mitochondria in an efficient way so they

(49:15) they kind of like implementation or complement each other yeah exactly that's so cool yeah what about afterwards have you what have you seen in subjects or yourself as well uh once you're one once you come up what you know what happens in your body uh physically and what how long does the dopamine effect lasts and so on because I guess for most people they want they want the after effects so what what happens when once you get up so the effects of the higher release of norepinephrine and dopamine and the

(49:56) serotonin lasts for hours afterwards I believe it's it could be two hours up to four hours after you dip so that is also when people report fact they say I feel really really good in hours after my winter swim or my sound sauna and it really makes sense when it comes to what the literature shows regarding dopamine and norepinephrine so I think it's really something where we can put on the new transmitters afterwards but also warming the body afterwards you get this really comforting warm in your body it

(50:31) feels like I think it feels like just after I've been training I get this really relaxing feeling in my body like I've used it in a really really good way I get the same feeling from using the contrast therapy going into the cold and heat um so I think it it's it pretty much does the same um you can say homies is in the cells but it's the cells are um trained to become stronger and that is also what you do when you go for a run or you go training so it's exercise for your body when you use the cold and

(51:08) the Heat um it's really interesting and I was reading this writing a book about the viral reflex that you're going to have to strengthen it so you've got a very strong influence on the autonomic nervous system to make one more resilient true that how does the process work though in terms of strengthening the barrel reflex it's something as well I I never get my head around the intra relationship between the vagus nerve and the viral reflex and are connected and how that's influencing their heart rate

(51:37) variability but in terms of the cold because I'm conscious just in terms of time we're nearly drawn to a close but uh yeah the bar the barrel reflex is an interesting phenomenon because if we can strengthen that we can improve the autonomic nervous system and we can bring everything into balance yeah in terms of people with mental and physical issues so the code goes Way Beyond it's applicable so to pretty much everybody which any sort of issue is if that's the case yeah it seems like that I mean again

(52:07) going back to people with heart problems or a high blood pressure there is of course some precautions there um but I think that people should people are different of course and they if they do it on on if they don't follow like a certain protocol but they have to like feel how it how it does yeah how it is for themselves it's not really something that you can just say that everybody should do it in the same way but people increase their resilience in different ways and also what you are talking about the mental

(52:43) health it's going to be different protocol for people but there are some studies showing how much you you could do to get the health benefits yeah but the the question about the baroreceptors and well I think we need more research on exactly that and also regarding the breathing and the code that could be really interesting so it's going further yeah it's what actually different breathing techniques when applied in terms of what's doing to the autonomic nervous system yeah it's really cool

(53:12) um I'll just crunch sorry Daniel no I just had a final question when you said that it would have been interesting because you said you know you go down and you go in normally to a winter swim a fairly relaxed but if you came from a hard workout like two minutes before like earlier football team or whatever yeah then you're so then your heart rate is already Ram up and of course your body heat is but that's a little bit different at least for me do you have any thoughts on that like you come in to

(53:42) from a different angle if you have a really really tough workout and go straight in uh or different I wouldn't recommend that you go straight in uh I've seen people just jumping in I mean young people and maybe that is more okay but I think I actually think that people should be a bit cautious around that because as we talked about the relative difference it also in in skin temperature because they are really hot at this point um and also already have a high a heart rate so maybe spend some time just standing there lowering your heart rate

(54:16) and getting into that State of Mind where you're thinking now I'm going into the cold and the purpose of that is actually to lower my my breathing and to activate my parasympathetic nervous system and not to just get the the excitement of the cold water that means it could be that people just want that and then that that's fine too but if you if you want to like get that mental balanced feeling afterwards um and also use um yeah use the benefits of the the chemicals in the brain I think that people should try and build up the

(54:53) resilience and and get in calm in the water and then they will have really good after a feeling of the neurotransmitters afterwards so I don't think that people should jump into the water definitely not if they are very hot from a from a run or a training or something like that just getting a little bit chilled on on the bridge it would be good yeah yeah so in terms of bringing it to a close um I'd just like to show Susanna's book and you see the cover of it here it's called winter swimming and the one thing

(55:27) I love about this book is aside from the fact that it's really well put together and it's very informative There's real people who are not just talking about Instagram and these sculpted bodies that's typically when we see a photograph nowadays we don't see real people we've actually a guy who's totally naked there yes so no and um yeah so I would I think this is a great resource for anybody who wants to delve into this a little bit more where would people get your book Susanna uh so

(55:59) people can get my book on Amazon um and uh you can just type in Amazon and just my name and then it will pop up but also on Instagram I have a link in my bio where you can click and you can have multiple choices for where to to get the Google as well what's your Instagram uh it's my name Susanna super with an OE so ESU s a n n a and s-o-e-p-e-r-g excellent well it's been an absolutely pleasure talking to you it was great meeting you back two months ago and I think Daniel this is a great conversation all things cold many many

(56:36) more questions but I mean uh you know I pressed for time so I'm conscious of that so we'll we'll do repeat when when you feel comfortable Patrick doing the uh the call bar so well no pressure no pressure thanks very much guys thank you for having me it was fun nice stuff good stuff good bye-bye


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