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Does Cold Water Exposure Really Have Scientific Backing with Dr. Mark Harper

Hey everybody, what's up? It's Chase. Welcome to another episode of The Chase Jarvis LIVE Show here on CreativeLive. You know, that show where I sit down with amazing humans. I unpack their brain with the goal of helping you live your dreams. Today's guest is Dr. Mark Harper. Now Dr. Harper, like many people that have been on this show and you've heard out there in popular culture are advocates for cold water immersion. Now, before you can skip onto the next video say I don't want anything to do with cold water. If you knew that cold water could alleviate not just chronic pain and arthritis, but anxiety, depression, PTSD, migraines, and more, would you stick around? The least of which, the top performers in the world, most of them have some experience with cold water immersion. Dr. Mark Harper does a fantastic job of introducing you, if it's new to you, this concept, and if you are a practitioner already, will add some context to why it's actually helpful and share some amazing stories...

. So I'm gonna get outta the way. Yours truly, Dr. Mark Harper, all about cold water. (lively music) We love you. Dr. Mark Harper, thank you very much for being on the show today. Really appreciate you joining us. It's a real pleasure. I look forward to it. Well, the reason that you're on the show is because as this audience knows, I am very obsessed with the benefits of cold water. I first became a accustomed to it probably a decade ago with some polar plunges on New Year's day with friends. And it has become a big part of my life. And we are excited to have you on the show for lots of reasons. Not the least, of which is your new book called "Chill: The Cold Water Swim Cure." But more importantly, the idea of cold water as medically, scientifically proven to be beneficial to our health. So without further ado, and if you would, please tell us a little bit about your backstory, aside from just the cold water bit, just orient us and the audience here listening today around who you are, where you spend your time and energy, what you care about. And then we'll get into some of the specifics. Yeah, well, I guess I came to cold water swimming through two routes, really. The first was skiing, in fact. And that was 'cause I decided, it's part of my medical career, part of my medical training, instead of going straight through the whole process, I decided to take six months off, go and work in the French ski resort. Nothing medical just as a holiday rec, do loads of skiing. And just before I left the director of the training program rang me and said, "We're advertising the next level of jobs. I think you should apply it." "Ernie, I'm really flattered, but I'm gonna take six months off and go skiing." He said, "It's not gonna advance your career very much." Ironically, nothing's had a greater effect on my whole career than taking those six months off. He's a really nice guy. There's another lesson in there that I definitely wanna talk about, but sorry for interrupting. I think this is fascinating. You said, I'm outta here. I'm going to France to ski obviously, in cold weather. And sorry, to keep going. Yeah, so anyway, so I mean, he's a really nice guy. He did it in a nicest possible way. And the night before we went, it was the days when you still had sponsored, drug companies sponsored you for an evening out. And he came up to me. We both had our fair share and he came up to me the end of the evening and said, "I think you should organize a meeting in a ski resort." An anesthetic meeting in a ski resort. So I said okay. I don't think he really thought I would, but the next year, we started running an annual conference in the ski resort. And it's still running. Given two years of COVID, it's still going 20 odd years later. But the reason why that had the effect was the first year, I had to give a talk and I thought, well, what do I talk about? And I thought, ah, hypothermia. That seems like a reasonable thing to think about. It's appropriate in altitude and things like that. And so I just gave a talk. I picked up some of the literature on hypothermia 'cause this is it. When you swim and when you have an operation, you tend to get cold. Your body thermoregulation closes down. And becoming hypothermic is always bad for you. If you go in the water and become hyperthermic, I think is a really important point. That's actually bad for you. Exposing yourself to the cold, good. But will come onto that. And anyway, after that, I started doing research into it eventually. And that's where my PhD comes from is stopping people getting cold during their operation because that reduces the number of complications they suffer. But as part of this, as I was doing my research into this, I kept coming across articles from someone I'm sure you've heard of, Professor Mike Tipton from Portsmouth. He's done all the cold adaptation stuff. I mean he's a great guy, great researcher. And it was all about cold adaptation. So I'll come back to that. Because in the meantime, I've always swum. I've always been a pool swimmer. Trained competitively, I still swim in the pool with the club, three, 4,000 meters, two or three times a week. But one summer, as usual, the pool shut down, I was complaining to a really old friend of mine, ah, there's no swimming in the pool and it's a bit boring. He said, "Ah, go swimming in the sea. The club's got a sea swimming section." I didn't even realize they did have. I thought, well when did they swim? Seven o'clock. Well, yeah when, but what days? "Well, all year." So I was as shocked as everyone else at this point. And anyway, I intended to start swimming for, just swim for those two weeks in Brighton, bit in the ocean. And then nearly 20 years later, here I am still doing it. But then as part of that, that first swim I had, the day after I chatted to Jasper. I remember I had my swim, I walked up the beach. I thought, ah, this feels good. And it wasn't cold. I mean, it was probably 20 degrees centigrade. It was at 68 Fahrenheit. So not really cold. And so to come back to the hypothermia, the perioperative hypothermia thing, I came back and said, well, what I'm reading about here is that getting into cold water is a stress. And that stress is having the same effect on the body as operations have. 'Cause although you get an anesthetic and hopefully, I give you an anesthetic, so you don't feel anything and you don't have any pain during the operation. Your body still reacts as if it's a massive stress. A really big stress on the body. And what I also found from Mike's work was that it was reducing, if you got used to swimming in cold water, it actually reduced this stress response. Now we need a stress response, but we don't want too much of it. We want to keep it in the good physiological zone, not the bad pathological zone. And that's what happens when you have an operation. And so I thought, well, if you reduce that by cold water swimming, perhaps you can reduce the stress of surgery by cold water swimming and thereby, reduce number of complications. So sadly, I haven't actually done the study, but I wrote a paper and published a paper outlining my theory. And that's where it kind of came together. That's kind of the backstory. Well, it seems to me, I'm just gonna summarize, you're a doctor interested in the effects and preventing the negative effects of the body losing temperature regulation during surgery. It gets very cold, there's harmful stuff. And yet when you personally swam and you realize this is a stressor, it's a low weight stressor, but that low weight stressor, not dissimilar maybe to like doing bicep curls every day can over time, make you stronger and more resilient. Is that a fair summary? Completely. It's exactly the same as doing exercise. You're exercising your cold tolerance. Yeah, whatever. Okay. What I find fascinating is now all of the downstream benefits that is becoming known based on your research, the research of your colleague in Portmouth. Other folks like Wim Hof who've also been on the show and have popularized this extreme cold water. Let's go now to your own experience. Let's go back to swimming in the sea. You got out. It's like mild by cold water concepts. Maybe would you say it's about 68 degrees Fahrenheit or something, 70. But that's still very cold relative to a body that's 98.6. So you get out, you feel a buzz. You say, gosh, there's something to this. Take us then from, hey, maybe there's something to this, to your own experience. And what does the research start to say about this cold exposure over time, sustained low level stress, how does it help us? Well, I think the kinda the next stage in the process of the development of my thought was, well came a few years later when I was sitting in the pub, actually. Again, this is another thing, like you go skiing, something comes out of it. You go and sit in the pub, read the paper. And I was reading the newspaper, nothing scientific. And I read this article, which said that depression, it said that depression is perhaps an allergic reaction and that a lot of depression was related to inflammation. Now, the kind of the main way in which the cold adaptation works has these positive effects or certainly, I was thinking about with surgery was in reducing the levels of information. Again, like stress, it's something we need. It's our body's first line of defense against injury and infection, but we don't want too much of it. And we want it when it's needed, not the whole time. When we have it the whole time, it's bad for you. So I thought, well, first of all, we've got cold water swimming and we know cold water adaptation, and we know that reduces inflammation. Then I know how good I feel after I've had a swim and I'm not even depressed. So maybe we could use cold water swimming to treat depression. And then that is where Mike comes in again. So I hadn't met him at this point. But by a series of events, I ended up meeting him a couple of months later. And I put this theory to him and he said, "You know what? I think that's a really good theory." And a couple of months after that, he was contacted by the one of our British TV doctors, Chris van Tulleken and he said, "Look, I'm doing this program called the doctor who gave up drugs. Is there anything we can use cold water swimming to treat?" And he said, "Well funny you should say that. 'Cause I've just met this guy who has a theory that it could be used to treat depression." And so from that, we did this BBC television program and we found this rather amazing young woman, Sarah, 24 years old. Been on antidepressant since she was 16. Father committed suicide. Brother died of a drug overdose. She was a single mom, but she really didn't want to see her daughter grow up, seeing her mom take pills to sort herself out. So yeah, we took her to Mike's lab, adapted her to the cold, took her for a swim the next day. And then Chris followed her up and within a few months, she was off the pills. And when I last had contact with her, which was just before Christmas, several years later, she's still off the pills and still swimming. All right. So I'd like to separate the swimming part from the cold water exposure because theoretically, exercise is also good for relieving depression. It releases some chemicals that we like. There's some endorphins when we exercise. I wanna focus if we can specifically on cold. I think that story is incredible. I'm gonna share just for 30 seconds here, my personal experience with it. And I'm wondering if you can sort of connect the dots what Sarah, someone who was clinically depressed at the time and my experience. And I think there's some fabric there but I'm gonna ask you to do that work. And maybe even, I still am hanging onto that bit you said earlier in the broadcast with, like you got out of the cold water and you like, wow, I feel great. I'm not depressed, but I feel great. So again, my early experiences were on New Year's day. After a night of partying with friends, we have a tradition in my family with a bunch of friends to go to some islands off the coast of Washington to Seattle here. It's very cold, cold water. It's the middle of the winter. Everyone's kind of hung over from staying up late the night before you get in, you get out, you're instantly wide awake. There's all kinds of good chemistry falling through your body. And I did that a couple times over the course of a number of years. And then I started doing it, not on New Year's. And it wasn't just, these are times where then I wasn't hungover. Or for example, I hadn't stayed up all night and I felt the same or better. And there is this electric feeling. A feeling that's equivalent to like, better than caffeine, all natural. And my body actually felt warm after getting out. There's like this flush feeling after getting out. And I then started experimenting and saying, if this is something that's reproducible just in my little beach town here, started looking into the research, realized that it was actually a thing. And then made it a daily practice and incorporated cold showers when I wasn't there up at the shore, up at the beach. And lo and behold, while the shower couldn't get quite as cold as the sea up in that part of the world, which is less than 50 degrees Fahrenheit almost year round. So it's quite cold. I, I wouldn't say became addicted, but it was very clear to me that the chemistry that my own body was producing as a result of this. I noticed after some time that I stopped getting sick. I went multiple years without catching a cold. I overall felt there was at a very difficult work time. There was a ton of work working 60, 70, 80 hours a week. That the pressure pressure and the stressors from that seemed to moderate or dissipate. Now, this is my personal experience. The early chapters of your book, one is called My Cold Water Epiphanies. And the second is The Felt Experience of Cold Water. So I'm clearly in this camp. Can you explain to us, you just told this beautiful story about cold water being an antiseptic, if you will, to Sarah's depression. Tell everybody who's listening what I was experiencing. What's the neurochemistry that's going on? Why did I feel better? And how could perhaps they adopt a similar practice that would yield similar benefits? Well, it's a big question. I'll try and stay focused. See what I can. So at the very basic level or the basic physiological level, start with that. So what you do, when you put your body into cold water, you are exposing yourself to stress. You're setting off this massive sympathetic reaction. The fight flight response is totally engaged as you go into the water. And water is very cold if you know what I mean. And I'll talk about a bit about the physics. I mean, the physics of water is fascinating. It's got a really high what we call specific heat capacity. So it's got this ability to just draw cold out of you, and this is why you get into, well, I suppose, you think of it the other way, if you put your hand into 100 degree water. It's, oh my God. Yeah, boiling point. That's dreadful. You put your hand in an oven, which is a 200 degrees Fahrenheit. It's just no bother at all. So it's a big thermal stress is what you're getting from the water and that sets off this big sympathetic reaction. And what you get with that is you get things like, we're not really sure. There's a lot of speculation about what is released and what isn't released but I think that the big headline one for me are that the adrenaline and the noradrenaline that are set off and that you get big dose of this. And this is essentially, it's what you get from cocaine. You get a bit dopamine, bit of all kinds of stuff, but that is, yeah, cocaine sets off your adrenaline and noradrenaline. It's interesting. When we started the swimming with Chris, the TV swimming. So he hadn't done it before and he sort of joined in. And he said to me after the first time, "God, if this was a drug, they'd make it illegal." And that kind of sums it up, doesn't it? And I think that's the big thing about it. And you just get the high, and I think you touched upon it. It's a natural high as well. Your body has control over this. It's not gonna overdo it. And what it has is these feedback mechanisms, which mean that it brings it back to a workable level. So I think that's the really basic physiology and yeah, why you feel so good. There's also, I think there's stuff that we can't really explain. And certainly for me, you talk about the working the long hours and I totally get where you're coming from with that. So there's a fantastic story. You're probably aware of it. Jill Bolte Taylor, who's a neuroscientist who had a stroke and she's done a 25 million plus TED talk about this and a book called "My Stroke of Insight" I think it is. And what she describes, so she had this stroke and she woke up one day and she realized she was having a stroke. But she didn't care. She said, I'm having this. And yeah, she just didn't care. And what it was, and this was actually interesting is with the area she was researching, what it was, that stroke, she had a big bleed on the left-hand side of her brain. Now the left-hand side of your brain is the one that is our sense of self. It's our worries. It's our fear. It's all that chatter. And it was pushing on that. So that side of the brain wasn't working. The right-hand side of her brain still was, and that's our sense of empathy, our sense of being one with the world and just general love of stuff. And so that's what she had. And since then, she's gone on to, her motivation for getting her six years of recovery after that, her motivation was I want to help people take a step to the right. And you don't just need to use cold water. You can use meditation. There are all kinds of other things, breathing techniques. But certainly what I find is, cycle 10 miles to work. And just before I get to work, there's a little lake. And I get there. My head's full of chatter. I'm hot, I'm sweaty, I'm all that. I get into the lake. And then, I come out minutes later, it's not a long swim and minutes later and I am at one with the world. I can feel this. This is empathy. It's like, oh, this feels so good. And that's kind of, apart from the buzz, that's this taking a step to the right. And recently, I was just reflecting on this. And I think what has happened over time is that has shifted me completely. 'Cause I find, I thought, I was reflecting. Actually, I've never been a particularly highly stressed person, but I'm even less stressed these days. And I can go, I can put up with whatever and it doesn't really phase me out. Obviously, I have emotions and I have good days and bad days and all that, but yeah, life is just a bit calmer. Maybe having done it for years. I'm speculating, but it just describes for me, I'd be interested to know what you thought. It just describes for me what happens. Yeah, well, part of when I got your book, again, for those who are interested, it's called "Transformative Guide to Renew Your Body and Mind. "Chill: The Cold Water Swim Cure." And when I first picked it up, I'm looking and some of the stories in there, they mirror, I haven't had, knock on wood, serious health concerns prior to my exposure. But a lot of, you go through, there are treatments, for example, for chronic pain. And I think this is worth listening to now very closely. If you find yourself suffering from any of these maladies, then Mark's book is gonna be helpful to you. Chronic pain in any way, migraines, fibromyalgia with which is just overall body pain that is very difficult to diagnose where it comes from and why. Any autoimmune diseases, trauma, or post-traumatic stress disorder, depression, mental health challenges. So if any of those things fall in your camp, your own human experience. I have had some of those. I had a PTSD experience. It was I think too premature and too long ago, rather for me to ascertain whether or not the cold water helped treat it. But when I'm looking at this book and I'm reading, there are phrases that I've got captured here. I feel happy. These are reports from individuals. I feel happy, I feel strong, I feel whole. This helps me feel grounded and strong. I'm alert, alive, have a sense of euphoria and achievement. Now you see, that one. Because what gets me about that one that's from Martin, is the guy with fibromyalgia. And what strikes me every time I read that is, you don't get that from a pill. You take a pill, you say, I've got this real sense of achievement. I've taken the pill. But you get it from swimming in the cold water. Yeah, one more. It just feels like heaven. I'm recovering myself in the sea. So I think the connection between these maladies and the reports that they share after experiencing cold water, this is why I'm maybe freakishly passionate about it. And not dissimilar to you, I didn't find myself, the reason I started cold water therapy was not because I was suffering. It was because I completely stumbled into it. And yet, the benefits I can undoubtedly say that my life is better. Now I got a text. A friend of mine I've been trying to talk into cold water. And he said, "Took my first cold water shower today. And wow, I feel incredible." And I love receiving those messages. There's something that I wanna shift our attention to now real quick, which is this idea of achievement that you mentioned from was it Martin, who was the guy with fibromyalgia? I have recognized that there is not one time where I am, prior to getting in 48 or 50 degree water. And now, I have an actual cold plunge at my house here, it operates, its sole purpose in life is to make me cold. And it sits right next to a hot tub whose sole purpose is to make me warm. And I contrast those. Which increases the effect. But there's not one time where I'm just about to get in that icy called water where I say, oh, I can't wait. This is gonna be so good. I'm usually like, okay, here we go again. And what I recognize, and this is probably similar to Martin's feelings of achievement is that it's not a negotiation. I am just doing this because I have done it enough to know that there are benefits. It's sort of like going to the gym. And when I get out, I 100% of the time, feel something, feel euphoria, feel a connection, feel that I've done something. And I haven't negotiated. This is where self-confidence comes from. If you make promises to yourself and you repeatedly keep those promises, this is an example. So now, I can't think of not doing it. And what I believe. And I'd like to hear your comment on this. this is the punchline to my rambling here is I have become comfortable being uncomfortable. And now I find that of a vector that's more easily reconciled in other areas of my life. If I'm going into an uncomfortable conversation at work or an experience where I know it's gonna be slightly unpleasant, whether that's medical or surgical, or I am better at those moments in life, which as you indicated earlier, you have an overall more, pun intended, you're more chill. So sharing my own story. And I'm wondering if you can, is there any mechanism to what I'm asking about or is it all sort of anecdotal and just experiential? This connection, these feelings of feeling like heaven, a euphoria achievement of putting yourself in an uncomfortable situation to get more comfortable overall? Well, again, there's a lot to unpack. Yeah, to unpack, on purpose, Mark. So well, basic biological mechanisms, I don't think we can go down there, but what we can say is, there's lots of stuff. As you said earlier, exercise is good for you. We know getting out in nature is good for you. Getting all these things. You've just got a pony pill, a package of benefits. And it's stressful. So post-traumatic stress, and people talk about post-traumatic stress and yes, it's a real thing, but people don't focus so much on post-traumatic growth and that's kind of what you are getting I think, by going in the sea. That's quite a good analogy to the effect. Every time you go in, you come out and you've achieved it. And a lot of these people who've come to our courses have another repeated thing that comes back is this is in fact Sarah said, "Oh, this is probably the hardest thing I've ever done in my life." It is, it's a challenge. It is a brutal challenge. And the fact that when you still go in and I'm absolutely the same. I go in, it's a real challenge to get in when it's middle of winter, the rain's coming down and it's cold, ugh. Dark. But I know that when I come out the other side, I'm gonna feel so good and that's what gets me in. And then every day I've achieved that at the beginning. And then I get those great effects coming out. Hmm. Your book mostly focuses on the sea and swimming, understandably. I am assuming, I have experienced this personally, but I am hoping to hear from you, the doctor, that while you don't get all of the benefits from taking a cold shower, because A, not everybody lives on the sea, and B, not everybody has 20 minutes to go for a swim or whatever, but can you confirm that after taking a normal shower and standing under the coldest water that you can create in your own house environment for say, three minutes on the back of your neck, your head, your face chest, that there is an at least a similar analogous, maybe slightly less, but there's a benefit there as well? Yes, I can confirm that. So what you get from... The stress response that you get is down to two things. It's one, the absolute temperature of the water and two, it's the rate of cooling. So the thing about a shower is it's not quite as cold as the water, but it is colder than you. So the water's not quite as cold. It might be it's cold depending on where your shower is coming from, but that's one thing, but it's still enough to have an effect. And the other is the rate of cooling because if you get into a bath of the same temperature, for example, that will have a more rapid cooling effect, 'cause you're exposing your whole body rather than just kind of intermittently. So it doesn't cool you as rapidly, but yes, it does have an effect. And there's one interesting study which showed that people who took cold showers took less days off work sick than those colleagues who didn't. Yeah, there's a page, one of my reference here, and I'm asking you to confirm this is on page of your book again called "Chill" is the getting started, you cite an experimenter or an experience where you took a group of high school students to Norway. And the beginning of their cold water immersion activity, as a preparation, you invited them to dunk their faces and hands, I think, into ice water. And I think this is, if you were curious about this as someone who has not done this before, this is an interesting experience, sorry, experiment. This is not new in pop culture. You're splashing cold water on your face, you feel more awake. But but doing that same action, splashing cold water, or putting your face in an ice bath, or you're head in an ice bath, that you just make in the sink with some cubes of ice and cold water that you can experience it at a small lightweight level, and then you can extrapolate in your mind. Okay, what if I did that, what's the next level up from that? And even these basic activities you cite here in the study on page 80 of, putting your hands in cold water, putting your face into an ice bath, those interventions by themselves, kickstarted the participants' parasympathetic and sympathetic nervous systems. Yeah, that's the theory. It's a bit difficult to tell. It's not that scientific, but it does have an effect. And I think you kind of bring up another important point here because when you put your hand in the water, that is sympathetic, that is the stress response. And that's the response you get all over your body except for your face. Now you put your face, so we've talked a lot about the sympathetic response and how you attenuate that by regular cold water swimming. But what you also get by putting your face in, is it stimulates the diving reflex. And this is a parasympathetic response. So the rest and digest. So it boosts your levels of happy, relaxing hormones and reduces inflammation directly by, it all goes through the via vagus nerve into the body. And it's interesting also you should mention three minutes is your thing. And that's kinda what I recommend. The reason being that if you say I'm gonna be in for three minutes, chances are, it's not gonna be dangerous. And it will get you past that initial phase. You first get into the water and it's that, ah. And we are still getting that years into the practice. But once you've got past that and you sort of, ah, yeah, now I can concentrate a bit. And you get past the hyperventilation and things like this. So that three minutes works quite well. So you just gotta stay in long enough that you get past that really bad bit. And then I also say, yeah, put your face in the water three times. And again, don't just put it in and take it out. Put it in, wait for the worst to go past, it's a few seconds. And then bring your face out. Yeah. I'm obsessed also with sort of minimum effective dose. Like where do you get the 80-20 results. And sure, I might get, what that be? Incremental benefits beyond three minutes, but I get 80% of the benefit with three minutes that I would with 20 minutes. So that's good enough for me mostly because I wanna do this every day or have made it a part of my lifestyle in the shower. And I don't want to take a 20-minute shower. (laughs) I wanna take a four-minute shower. One minute where I clean myself and then the next three minutes where I'm standing under cold water. And I think there's another piece of your work here. You talked a little bit about, in the Sarah stuff, you've talked about doing it with your son. The idea of sort of planning for this. And I'm speaking now to people who are, they're still with us, whatever we're 40 minutes in 30 something minutes into our conversation here and like, okay, I'm still intrigued. We've tried to provide some, if the first phase is splashing waters, do you feel any more alive or better? Second is maybe a cold shower. Clean yourself for a minute, then stand and there for as long as you can. Breathe through the things that you talked about. Third is like, getting into either cold bath or the sea, which is cold. I think the kicker is a commitment to doing it more than once. Yeah, without doubt. Yeah, I'm wondering if you can talk about how people ought to think about at least, when you decide that you're going to do this, I'm going to take, say, I'm gonna do this every day for a week and see if I feel the same, worse or better. So would you tell me what you found in the research and what you recommend? Well, what you can do, so it takes about six immersions to get yourself to full adaptation. So you've got two things here. You've got the adaptation, which is a long-term effect, and you've got the parasympathetic stimulation, sticking your face in the water, which is every time you go in, you'll get the benefit. And of course, every time you go in, you'll come out feeling great. So there we go. But the studies where they're using adaptation is before, we've been looking into it for its health benefits. They used about six immersions to adapt someone to cold water. You can actually do that over the course of a day, as long as you warm up in between times. Typically, they did them over a week or six weeks. I think yeah, as you say, it's really important to commit to it. And I would say on that basis, six times. Commit to six times you don't need to do it every day for a week. Once a week, I have found works really well. And that's what our studies, the studies here where we've been using it as an intervention. They were eight weeks, but they were every week. In fact, we had one group which was twice a week and the rest of the groups were once a week. We didn't see any difference. And so that commitment is really important because the first time you go in is gonna be really hard and you might probably come out feeling good, but yeah, it's gonna be bad. The second time, that's the worst. You kind of, well, I've done it the first time you were psyched up and this time, it's just bad. It's just painful. Yeah, it's just awful. And yeah, that's what I found with my son. The second time he did it, he's like, "I'm never doing it again." But the lure of extra screen time on the Sunday was too much for him or any screen time on the Sunday. And then the third time, then you start getting into it. Then you kind of really get it. And so if you commit to six times and you commit to do it with someone else again, the studies, the feedback we had from the studies was that people didn't want to let other people down. And that sense of community was really important in getting them to come back every time. And there's another benefit for cold. Yeah, you can do it in a shower. You can do it in your bath. And yeah, absolutely. But if you start be becoming part of community as well, I mean, that's another benefit. We know reducing social isolation is massive health benefit. This idea of doing it with a couple other folks is also, there's an accountability effect. You don't wanna let anybody else down and you wanna show up and even just sharing the stories, whether this is with a peer or a partner or spouse or whatever, that's benefit enough, but you cite the benefits of community. And also, you are clear in your work that if you can get into a cold body of water, that is in nature, that there are added benefits. You cited some of them earlier, just the feeling of one and connecting with nature. And there's a little bit more of a natural feel, not required, but we're looking for people or we're looking for the things to share for people who wanna go the extra mile. Yeah, and it helps you. If you've got that prospect, that helps going out. You see, we know it has further benefits, but it's like the diet. The diet that's good for you is the diet you can stick to. And the exercise, the exercise you can do is the one you can stick to. And if you've got an exercise where you're out in nature, and you're doing it with friends, and when you come out, you have a real laugh, everyone's laughing and sharing a hot drink and stuff like that. That is the exercise you're going to stick with. Great. And I think it's fair to inject in here now. There is a difference between what we're talking about and inducing hypothermia, staying in cold water for 30 minutes, swimming. These are not activities, I can't say that, I'm not a doctor. You can say that. But what we're coaching here and what your book is about is this repeated exposure to cold water as a benefit. And we wanna distinguish this from again, making yourself hypothermic over a long period of time. Uncontrollable shivering, doing so without others. And these are fortunately, there's not too many experiences of people giving themselves that in their own shower or their own bathtub, and it's much safer. But just put that out there. We're not talking about hardcore hypothermia. That would be way beyond the minimum effective dose. That would be essentially an overdose of what we're talking about. Yeah, exactly. Yeah, totally. You go to the gym, you work out, you damage, you have microdamage to your muscles, that's how your muscles grow. But if you pull a muscle, you've damaged it, it's the same. And hypothermia is the body's equivalent of damaging a muscle. It's really interesting. One of the studies we did, we looked at people people having colds over a winter, and we compared cold swimmers and their partners and pool swimmers and their partners. And there was a difference between cold swimmers and their partners. The cold swimmers had less upper respiratory tract infections. But what was really interesting was that if you looked at the graph of incidents and severity, there were a few of the cold swimmers. The ones who, all the cold swimmers who were in that little bit longer, I think the time was 15 minutes. I mean, of course, it's totally variable on what the temperature is. There were two or three of them who actually were worse. And if you'd taken them out and just did the ones who were less than 15 minutes, that effect would have been more pronounced. Of course there were two or three who were very hardy souls who could stand more than 15 minutes. But I can't emphasize enough how important it is not to stay in too long. That dose, that 80% you get after three minutes, you're right. You probably stay in much more than four, five minutes when it's sub 30, well sub 40 or whatever. You start doing yourself damage. It's about dipping. It's not about a lot of exercise. And you think about it in terms of exercise, you're probably doing enough just walking, like we do in Brighton, just walking down to the beach. Studies are shown that walking up three flights of stairs every day is enough to show a measurable decrease in cardiovascular risk. So you really don't need to do much exercise. Hmm. Yeah. Again, I was just floored at some of the research in your book around the benefits of folks who, chronic migraines, people who have reported suffering up to 28 migraines in a month, debilitating. And there's millions of people, disproportionately women as I understand also, who suffer from that affliction. And your experience is that you can improve that condition with cold water. We've already listed fibromyalgia. We've listed anxiety and depression. I'm wondering because I haven't cited any statistics from your work here. If you can talk a little bit more specifically about, we are in a different world. We are now based largely on the fact of how fast information moves. And we are getting all of this information. We are biologically as a species wired for a negative bias. So we're paying attention disproportionately to negative messaging. We're getting those messages tens of thousands of times a day, which is our neurology and biology. We're not necessarily meant it. It's not in a stretch to say that as a culture, we are more stressed out, more anxiety-ridden than even times where there were saber-toothed tigers that were out there aiming to kill us. And we have a similar response in our body. So knowing that anxiety and stress are, this is anecdotal, but let's just say at an all time high. Can you talk about specifically, 'cause I believe this speaks to the largest number of people. If you are overstressed at work at home, the combination of working through the pandemic, living at home and working and all of the things, these minor stressors. Talk to us about what you saw in people who suffered from sort of those afflictions and the benefits of cold water. Well, so the only study or the strongest study that we've done is the one on depression and anxiety. And we took people clinically diagnosed depression and anxiety took them, as I said, eight sessions, Sarah. This is Sarah. So Sarah was the first one. Sarah was that pilot as it were. And so I said, I was really worried. I said to Chris, I said, "Look, what happens if this doesn't work?" Before we started her off on it. Because then that blows my whole theory out of the water. Beautiful research career disappears immediately. He said, "Don't worry. It always works on TV." So that was it. But what we need to do after that of course is take it a bit further. And what we did next in terms of depression, anxiety was run these courses. And these were people with clinical depression and they weren't on TV. And what we found was that remarkable results, really. 70, 80% of them were cured. So not just a bit better. I mean, if you look at the results for Prozac, SSRI tablets like this. Possibly 40, 50%, if you're lucky, show a response, but they're not clinically cured. I mean, cure is a bit a strong word, but they were in the normal range after the course. And what was even better was that three months later, we followed them up three months later, there was still over 50% remained in that cured zone. So yeah, it's a really powerful thing. Yeah, if it was a drug, no one would believe you. Yeah if you show- Let's restate this. SSRIs, serotonin, something- Selective serotonin reuptake inhibitors. Inhibitors, there you go. Yeah, that's right. Were 50%, I wouldn't even call them effective. 50% had a response. Exactly. And cold water exposure was 70 to 80% reported not just a response, but wellness. Yeah, exactly. Yeah, and these people with serious depression, but they were clinically diagnosed depression and anxiety. So for those folks at listening right now, and again, whether you're walking on a path or you're sitting in traffic on a subway, wherever you listen or watch this show, I want you to groc that data for a second. That is serious. And imagine, and for those who suffer with it, I have managed about a depression in my life as a part of that PTSD from a medical condition that I had. And so knowing that there are benefits there is heartfelt to me and earnest and exciting. And hopefully you're hearing this and if you're suffering from any of that, that this is one course, this is not the only course of action you should be taking. And also imagine if you don't suffer from that. You can imagine that there are still dramatic benefits. If you are entering this procedure or these ideas or experiencing or experimenting with this, you don't suffer from that stuff. Imagine the upside. It is powerful. And you're listening to two people here, Mark and Chase. You guys are probably so sick of me talking about cold water. But I just encourage you to just think about that study for a second and how powerful that is. And I think there's another really interesting thing came out of that study. 'Cause a couple of the guys I talk about in the book more than that. So come back to Martin, for example, with his fibromyalgia. He went along because of his anxiety. He was chronically anxious. This fibromyalgia made him more anxious. He didn't go along for his fibromyalgia. He just thought, well, I'll give it a go. And what he noticed coincidentally was that fibromyalgia got better. And it was the same with Beth who had the migraine. She did something separate. I mean, there's a wonderful film of it. She just thought I gotta do something. Here I am in bed 28 days a month with headaches. With migraines, not headaches, migraines. I've gotta do something. Let's just get out in nature or perhaps we could go swim in the sea. It was no intention of helping her migraine, which is why she went out. But then she started noticing that it had an effect. So these aren't people that we've tried to cure even had any expectation of it having an effect on their symptoms who seem to have really reaps and benefit. And so while we can't say we haven't got the studies to prove that it works, I think that's quite a powerful indicator that there's something to it. Yeah. And one of the other things that I think is worth remarking, again, I'm gonna hear the title, "Chill: The Cold Water Swim Cure - a Transformative Guide to Renew Your Body and Mind." It's excellent. It tells some great stories. It cites some of these studies that we're talking about. It's very consumable. And one of my favorite things about A, your book and B, this practice in general is it is virtually available to everyone. If you are able to listen to this podcast or watch this video recording, you have access to cold water. I'm not saying you have to live on the ocean. But whether it's a city park, a lake or you are near the sea, or you have a bathtub, a shower or a sink. The relative ubiquity of the access to this thing is one of the things that this is a core value of the show. Creating access to experts, to ideas, but also, it's so available to you right now. So I'm gonna stop convincing people. I think I've gone maybe gone too far. But I wanna thank you personally for writing the book. I think it's very powerful, very timely. As we shared earlier, the rate of an anxiety and whatnot is incredibly high. Before we let you go. 'Cause you've been very gracious in hearing my long stories and these very complicated, multifaceted questions that I'm asking. Is there anything else that we haven't covered that you want us to know about cold water immersion as something that's beneficial to virtually everyone? I think what I'm looking at now and what I'm quite excited about is its effect. I suppose it's putting it into the context of lifestyle medicine. And this is the way where, drugs are great. Yeah, I couldn't do my job as an anesthesiologist without really, really good drugs. I use really good and really strong drugs every day and they are fantastic. But there is what we've kind of lost if you look back into the history of medicine, we found drugs and they were really good. But you look back and in my own town of Brighton, there was this guy, Richard Russell, who was using this therapy in the 18th century. He describes very clearly the kind of effects, we are seeing now. But the drugs came along and we kinda forgot about this thing. And I think we need to remember it again. And this is what lifestyle medicine is about. It's about reducing the need for substances. Yeah, you get that. You get your natural high from the sea or from the cold water. You want better sleep. You want community. You want exercise. You want being out in nature. And on top of that, the one thing I don't think we get from a cold water swimming is the nutritional benefits. 'Cause eating well is another thing. Bit of cake afterwards, that probably doesn't count. But currently coffee, which is what I tend to have afterwards is good for you. At the moment, the theory is coffee's good for you. So I think it's really good to look at it in these terms. It's as a part of an overall package and it probably won't cure all your ills, but it can certainly help them. And there are things like, we've had the pandemic. And one of the other things we've done is take healthcare workers out and run courses for them. They have been really struggling under the pandemic. And just getting them into the sea and allowing them to do that. Our feedback again has been similar to all the other things. The other course we run. These are people who are not clinically depressed. They're just having a hard time. They want to make their lives better. They want to feel better. And they do feel better as a consequence of getting into that cold water. And that to me is this umbrella of lifestyle medicine. Amazing. Dr. Mark Harper, thank you so much for sharing your experiences with us. Your new book, "Chill: The Cold Water Swim Cure." Grateful to have you on the show. I would love to stay in touch and check in with you as you continue this research. And I'm always happy to be a subject. I'm a willing participant in any and all of this stuff. If you need someone to put themselves under cold water stress, I just continue to see the benefits. I'm grateful for your time and everyone out here in our community, I think will rally behind you and your new book. Congrats again, and thank you for being a guest. Thank you very much. It's been an absolute pleasure. Awesome. For everybody out there in the world from Dr. Mark and yours truly, we both bid you a good day and thank you. (upbeat music)