Podcast: The Benefits of Cold Exposure

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Modern technology has provided us with an unprecedented amount of comfort. For example, with just a turn of a dial we can ensure that our homes are always set at a perpetual 71 degrees, even if it’s blazing hot or frigidly cold outside. But what if our quest for technology-enabled comfort has actually made us physically and mentally weaker and sicker? What if our bodies actually need discomfort to truly thrive and flourish?

My guest today explores that idea firsthand in his book What Doesn’t Kill Us: How Freezing Water, Extreme Altitude, and Environmental Conditioning Will Renew Our Lost Evolutionary Strength. His name is Scott Carney, and in this book he investigates the sometimes crazy-sounding claims of a Dutch daredevil and prophet of intentional stress exposure named Wim Hof. For a year, Scott followed Wim’s method of physical vitality that consists of daily hyperventilation breathing exercises and cold exposure to see what it would do to his physiology. And the results truly astonished him. Along the way, he interviewed scientists, researchers, and athletes who are on the forefront of exploring why embracing environmental discomfort is the missing key to our overall health.

On today’s show, Scott and I discuss Wim Hof and his claims, the health benefits of exposing ourselves to the cold, and how hyperventilating may help you do more push-ups than you ever thought possible. If you’ve enjoyed our content on the health benefits of cold showers, you’re going to love this podcast.

Show Highlights

How modern life is making humans sicker and weaker
The specific diseases in our world that are the result of modern conveniences and comfortability
How the simple technology of cooking with fire changed our biological makeup
Wim Hof, and the crazy things he’s done which baffle even scientists
Why Scott started as a sceptic of the Wim Hof methodology, and how he was ultimately “converted”
The training Scott went through to be able to withstand frigid temperatures in nothing but shorts for hours on end
What happens in our body when exposed to the cold, and its benefits
How hyperventilating can help you hold your breath longer and do more push-ups
The physiology of these various training exercises
What benefits does this training have outside of being able to do things in the cold?
How world-class athletes are using Wim’s methodology
The story of how Scott climbed Mt. Kilimanjaro at a record pace
What is brown fat? And how can it help you lose weight?
How you can start implementing Wim Hof’s method today
Getting the most out of cold showers
How to inject healthy physical stress into your life in other ways
Scott’s experience with the Tough Guy Competition

Resources/People/Articles Mentioned in Podcast

What Doesn't Kill Us book poster Scott carney.

What Doesn’t Kill Us has renewed my practice of daily cold showers. If you want to learn more about what goes on in your body when you expose yourself to the cold and the benefits that come from it, pick up a copy of Scott’s book today.

Connect With Scott Carney

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Read the Transcript

Brett McKay: Welcome to another edition of the Art of Manliness podcast. Modern technology has provided us with an unprecedented amount of comfort. For example, with the turn of a dial, we can ensure that our homes are always set at a perpetual 71 degrees even if it’s blazing hot or frigidly cold outside. What if our quest for technology enabled comfort has actually made us physically and mentally weaker and sicker? What if our bodies actually need discomfort to truly thrive and flourish? My guest today explores that idea first hand in his book “What Doesn’t Kill Us: How Freezing Water, Extreme Altitude, and Environmental Conditioning Will Renew Our Lost Evolutionary Strength.” His name is Scott Carney, he’s an anthropologist and a writer and in his latest book, he investigates the sometimes crazy sounding claims of Dutch daredevil and profit of intentional stress exposure named Wim Hoff. For years, Scott followed Wim’s method of physical vitality that consists of daily hyperventilation breathing exercises and cold exposure to see what it would do to his physiology and he results truly astonished him.

Along the way, he interviewed scientists, researchers, and athletes who were at the forefront of exploring why embracing environmental discomfort is the missing key to overall health. On Today’s show, Scott and I discuss Wim Hoff and his claims the health benefits of exposing ourselves to the cold and how hyperventilating may help you do more push ups than you ever thought possible. If you enjoyed our content on the health benefits of cold showers, you’re going to love this podcast. After the show’s over, check out the show notes at aom.is/coldexposure. Scott Carney, welcome to the show.

Scott Carney: Hey, thank you so much.

Brett McKay: All right, you wrote a book called “What Doesn’t Kill Us: How Freezing Water, Extreme Altitude, and Environmental Conditioning Will Renew Our Lost Evolutionary Strength” and it follows you as you follow the practices and methodologies of a guy named Wim Hoff. We’ll get to Wim here in a minute because he’s an interesting guy, but let’s start with the premise of this book. You start off arguing in the book that modern life is making us weaker and sicker, how so?

Scott Carney: If you think about where our species came from, you know, homosapien sapien, we are about 200,000 years old. That’s when we evolved from our previous ancestor which was pretty similar to us. In that time, we endured all the variations that nature could throw at us. Even in the equatorial regions of Africa, the temperature swing between night and day could be 50 degrees. Then we left Africa, we crossed the Alps with a whisper of modern technology. We went through Asia, made it to Australia, and the New World and all of this was with nothing to really help us. Some fur skin, some sailboats, some basic stuff and to do it, we had to rely on our amazing innate biology to resist the elements, to resist these variations. If you went back in time, it would be a terrible idea to challenge one of your ancestors to an arm wrestling match or a foot race, they would crush you. One of the reasons for this is that now we live in this cocoon of technological comfort where our need for that, we can call homeostasis, this place where the environment meets every biological need has made our bodies not have to do any work.

Because of that, we don’t experience the natural variations that our biology developed in. We live in a perpetual summer of 72 degrees and it doesn’t matter what the outdoor temperature is like. We have antiseptic environments where we’ve scrubbed out the bacteria and the things that attack us and this makes the underlying biology that we have, that wants to resist it, that where change was constant, it makes that biology under-utilized. In some cases, it turns inwards and attacks itself leading to autoimmune illnesses but also we’re not able to … We look outside at a snowstorm and we consider that extreme weather and we’re like “Hell no, I don’t want to go out there” but our species can do that. What this process of the book was doing was exposing myself to some extreme temperatures and some extreme environments and unlocking that hidden biology that everyone of us has inside.

Brett McKay: Right and besides the autoimmune diseases, what are some of the other diseases of civilization that have come from constant comfort?

Scott Carney: Oh my God, there’s so many. There’s osteoporosis is one, diabetes, obesity, poor sleep cycles because of the constant electric lighting that we have. Oh, my favorite and one that I come back to in the book all the time is just since the 1990s, do you remember that time period? I don’t know how old you are, you probably remember the 90s.

Brett McKay: Yeah, I’m 34, yeah, 34.

Scott Carney: Okay, fantastic. Do you remember that when you moved to a new city and you were like “Hey, this is a cool place, I want to go explore and find my way across town.” You had to take out this ancient piece of technology that had a picture of the city on it and the streets and their names of the streets. You had to navigate your way across the city by using this map. I think that’s how you pronounce it, I haven’t seen one in a while. By using that map, you learned innately how to navigate the city. Nowadays, when I move to a new place, I have a GPS and I rely on it for every turn as I go through and I’ve lost this innate ability that humans have to tell direction. That’s just happened in our lifetime.

Brett McKay: Yeah, it’s nuts. You also talk about some of the other changes thanks to technology. A lot of these diseases of civilization have come with technology, it’s not just digital technology but even rudimentary technology like cooking with fire. That made our jaws weaker, right?

Scott Carney: Yeah, well, fire’s a really interesting case because it’s an old technology, right? That goes possible all the way back to homo erectus which is our ancestors’, ancestors’, ancestor. What happened when we invented fire was that we could instead of this chimp-like primate or ancestor, which would have to chew cellulose and vegetables and things. You have to chew a hell of a lot to get out the nutrition and they had really big guts because of that because you had to have more digestive tract. Your jaws were super powerful, think of a chimps’ jaws, that’s some serious tooth action. As we invented fire, what that did is it outsourced the ability of our bodies to essentially, you digest food outside of your body and by cooking something, it becomes essentially, more nutritious and you have to chew it less.

Overtime, fire made our jaws smaller, made our guts smaller, that led us to be able to walk around upright in a convoluted evolutionary path for the way we searched for food. It also gave us more time to instead of chewing all the time, right, we actually had time to use our brains to do other things. Fire’s one of these technologies that evolved slowly with us and actually, we had it and it changed our physiology. We are impossible to separate from fire, our bodies could not exist without fire. What I’m looking at in the book is more these modern technologies like heating and all of these conveniences that we have now where our bodies haven’t had a chance to adapt slowly like they did to fire. It was dropped on us and if we’ve been around for 200,000 years that we’re talking 150 years, that’s a blink of an evolutionary eye. That stuff, our body hasn’t caught up to the new environment that we inhabit and that is doing crazy things to us.

Brett McKay: Right, the mismatch is causing these problems?

Scott Carney: Exactly.

Brett McKay: Okay. Let’s talk about Wim Hoff. I’ve heard of Wim Hoff, he seems like possibly a mad man, crazy guy, charlatan but he’s doing some crazy things to counter these diseases of civilization where he’s purposefully exposing himself to extreme cold, extreme conditions, and he’s surviving. Can you talk about some of the crazy things that he has done that baffle people that he’s able to do this?

Scott Carney: He holds all sorts of crazy records for mostly having to do with his body being in extreme cold things. I actually first heard about him when I was a foreign correspondent for Wired magazine in India. There’s a little, small snippet in the paper of this guy who was climbing Mount Everest in just a pair of shorts, bare chest, climbing up Mount Everest. He made it up 3/4 of the way and at the time, I was like this guy is insane and not only insane, he’s disrespectful to the power of nature. He’s run barefoot marathons in the Arctic, across snow. He’s run marathons through the, I think, it’s the Kalahari Desert with no water. He’s held the record for swimming underneath sea ice in distance. He has done these things, which really are super human. He’s stayed in an ice bath for, I believe, 90 minutes and his body temperature while they were testing him actually rose while he was in the bath. Usually a person who’s not trained just dunked into this ice, might die from anywhere between 15 and 45 minutes. He does things that are super human and you are right to say he sounds like a mad man because he’s absolutely a mad man because only a mad man would do this. He’s also a prophet because he is showing that what the human body is able to do if conditioned consciously and correctly into these environments.

When I first heard of him, I’m an investigative journalist, I’m an anthropologist and I had written several books and articles at that point about the dangers of intensive meditation and in particular, the types of spiritual practices that offer you super powers. In 2005, I was leading an abroad program in Northern India, I was an anthropologist getting my PhD at the time. One of my students, the best, the brightest, the smartest student in the program, at the end of the silent meditation treat, as we’re contemplating enlightenment, contemplating Nirvana, she climbs up to the roof of the retreat center and jumps to her death committing suicide on the last day of the retreat. As the person who is in charge of her, of the students, I had to read her journal. I was involved with the police investigation and it was a horrible thing but in her journal, the last words in it were “I am a bodhisattva” which means “I am enlightened, that I am going to be essentially an angel and all I need to do is leave my body to attain that state.”

This was the cautionary experience that led me down to write another book about intensive meditation where people literally get so caught up in this idea of spiritual transcendence and becoming supernatural almost that they lose touch with reality. A lot of people die and it’s a story that’s not really talked about very much. With all of this in mind, when I hear about Wim Hoff, and this is in 2011, 2012, I am certain that he is one of these guru charlatans who wants to tell people that he can give them super powers, take all their money as he does it, and then potentially get people killed. I wanted to get in front of that and show people that the attainment of superpowers is not a great idea.

Brett McKay: Yeah, but if he is claiming that some superpowers, he claims that with meditation and breathing and exposure, you can on demand increase your metabolism so you warm yourself up or on demand, you can increase your immunity system so you can fight diseases. He is making those claims.

Scott Carney: Damn right and I think I was absolutely right to go out there and try to debunk this guy because they are huge and they’re things that you should be absolutely skeptical of. As an anthropologist, as an investigative journalist who has a certain set of ethics that I abide by, when I went out to see him on a commission that eventually ran in Playboy magazine. My intention was to debunk him but by doing it through his method. By saying, look, I’m going to learn your method and I’m going to watch it fall apart. I’m going to watch these students be mindless followers of your method and you basically taking advantage of them and then I’m going to see you put us into a dangerous situation that I’ll be able to tell the tragic story of Wim Hoff. It turns out that when I did the method, that when I actually did his breathing method and his environmental exposure routines that things in my own physiology started changing very rapidly. I was living in Los Angeles at the time, so we’re talking perpetual summer there and I fly to Poland in the middle of the Winter that stopped Napoleon’s army. It’s the Winter that ground Hitler’s Blitzkrieg to a halt and within a couple of days, I’m standing outside in the middle of this frigid cold in nothing but shorts with my bare feet in the snow and I’m burning up.

I can stay out in the snow for an hour like this. We do these things, I sit on the banks of a river and all of the snow melts around me because my body is running so hot. Then I climb up a mountain in Poland, it was actually a ski slope called Sniezka, and we spend about eight hours on this mountain. It’s about two degrees fahrenheit outside and I make it to the top and I’m hot the entire way, I’m sweating and I’m in shorts and boots. It’s amazing, it was eye-opening, and it happened so rapidly that there was nothing I could do but say that Hoff is onto something. He may make some grandiose claims that surpass this shock and awe at that point, but it was enough for me to realize that I had to examine this guy on fair terms and really delve deeply into the ideas that he’s putting forward that we can unlock hidden human potential. These aren’t superpowers, these are human powers that we all have. I think that’s the crux of it, right? We don’t have superpowers, we have normal, human abilities that we have suppressed.

Brett McKay: What does his method look like? Part of it is getting exposed to the cold. What else is involved?

Scott Carney: There’s two basic parts of the method and you can learn the Wim Hoff method in 15 or 20 minutes, it’s not very difficult because it involves putting yourself in situations where the environment creates a predictable biological response. In the cold, one of the things would be, the first thing that happens when you jump into the snow is you tense up or you take a cold shower, you tense up. Eventually you’ll start shivering and this is your body trying to fight that stimulus. What Wim teaches is that you get into that situation and instead of tensing up, you relax, you let that cold in. By suppressing that tensing moment and suppressing the shiver, you actually are having a significant impact on your sympathetic nervous system. These are your fight or flight responses. By modulating that, you actually start gaining control over how your sympathetic nervous system works. Because our bodies have evolved to adapt quickly, you get this control super fast, it doesn’t take very long to accumulate that. When you jump into ice water or something, you don’t shiver, you suppress that and your body figures out a different way to heat itself up. At first, it does it weakly but overtime, it’s able to ramp up the engine and keep you warm in those environments.

The other part of the method is a breathing method and you don’t need to do it at the same time, you don’t have to do this in the cold water or something, you do this, it could by hours in the day, it’s fine. Where you hyperventilate, not panic-y hyperventilations but deep, rapid breaths, it would sound something like this. You do about 30 of those and then at the end of that, you let all of the air out of your lungs and then you hold your breath for as long as you can. Usually I’ll do a minute at first and then you do another hyperventilation round and then you hold your breath again. Then all of a sudden, instead of a minute of holding my breath, I can hold it for two minutes, do another round and then I’m holding it for three minutes. It’s really a very fast increase. What you’re trying to do is suppress this response and modulate this response, this need for gasping, and once you get that, that’s another para sympathetic response.

You’re getting control of both sides of this autonomic nervous system by doing these two sorts of exercises. At the end of that, then what you do is you do a third round of hyperventilation and you let all of the air out of your lungs, you start doing push ups, immediately go into doing your normal push up routine of whatever you do. When I first had started this, doing this practice, I could do about 20 push ups. You know, I’m not an athlete, I’m a dude, a journalist, I’m a writer, I could do 20 push ups. When I did this breathing method at Wims house, I could do 40 and I wasn’t breathing and I had no air in my lungs, it was amazing. Now I do it every morning, I do 50 push ups breathless, the most I’ve ever hit was 80 and it’s a really surprising thing and maybe that’s the a-ha moment where I decided that Wim was really onto something because you don’t double the amount of exercises you can do with a breathing method, that’s not how I thought the world worked.

Brett McKay: Besides following Wim, you actually go and talk to scientists who have been researching some of the things that Wim’s been doing. With the breathing thing, why is it that you’re able to do more push ups by doing this hyperventilating exercise and holding your breath? What’s going on there?

Scott Carney: The first thing that’s happening is you’re blowing off carbon dioxide from your lungs. The way your body detects that it needs to breath air, it’s running out of breath, it detects the buildup of CO2, it can’t actually detect oxygen. That’s the way that the body’s biology works. When you hyperventilate, you blow off all of that CO2 and then you’re moving that gas point later, as you’re holding your breath, that respiration has to basically fill up your lungs again with CO2 or the bloodstream has to accumulate CO2. That’s like, okay, great we got CO2 and we need to breathe. You’re tricking your body’s normal respiratory method by blowing off all that CO2 and pushing yourself into a physical place where you can do more push ups.

The reason why this is interesting rather than it’s a hack that’s okay, you tricked your body, is that you still did the push ups, right? Your body actually had that ability to do this and its warning signals were actually far too conservative. Your body has this, you know, the world we grew up in which is homeostatic, which is comfortable, we set off our alarm bells for where we’re reaching our limits super duper early. If you start doing these things where you’re pushing yourself in this hypoxic or low oxygen environment, all of the sudden, your body starts to learn that it actually has more ability and will see the little bit more control into your system, sorry, into your mind.

Brett McKay: Yeah, what’s the benefit of that besides doing more push ups? How else does that translate into performance in other areas?

Scott Carney: There’s lots of ways that this happens. It increases your ability to breathe in general, which puts more oxygen in your bloodstream, gives you more available energy. I think the most interesting way that I’ve seen people use it, a guy names Brian MacKenzie and this legendary surfer Laird Hamilton, who both get a chapter in the book. What they’re doing, Brian MacKenzie’s one of the founders of high intensity interval training, or HIIT workouts. The idea for HIIT workouts is that if you train at the absolute maximum exertion, athletes would call the VO2 max, or if you’re trying to train for a marathon, instead of logging more and more miles every week, you do these sprints but at your absolute highest level. Then you actually are pushing your body much better and much more efficiently to run marathons elsewhere. Shorter workouts, shorter high intensity workouts are more efficient. When that mixes with the Wim Hoff method, if you’re now prepping yourself to push past what your limits are, it’s going at 100%, if you can trick your body it’s like 104% or 107%. Then your high intensity interval workouts are even more power packed and you get that much more benefit for these longer endurance races. It’s awesome, you see these top tier athletes doing this method now.

Brett McKay: This only works for endurance. You wouldn’t be able to do this and them pull a deadlift ER, right?

Scott Carney: No, actually, that’s a good question, how does it affect strength? This is probably a little bit outside of my knowledge about it because I’m not a big weightlifter but I would say that if you can suddenly do more reps than you could usually do in training, then wouldn’t that make you a stronger person in general? If all of a sudden I could do 20 push ups, I was usually doing 20 push ups and now I can do 40 in my workouts, isn’t that 20 more push ups than I could usually do, doesn’t that affect my ability to get stronger?

Brett McKay: Possibly. You also talk about deep sea divers. This technique, deep sea divers actually don’t like doing this, even though it allows them to hold their breath longer, they don’t do this. We had James Nester on the podcast a while ago-

Scott Carney: Oh, he’s awesome, by the way. Yeah, I love him.

Brett McKay: This is something you don’t want to do because this could actually kill you if you’re trying to hold your breath underwater.

Scott Carney: Yes. A big caution to anyone listening to this, it would seem that free diving and the Wim Hoff method go together like peas and carrots because you’re able to blow off CO2, you’re able to hold your breath longer, and therefore if you were going to dive 300 feet underwater, that’s a useful ability. The issue is, what they call shallow water blackouts. Because you’re tricking your body by blowing off CO2, you don’t always know when that gasp reflex is going to kick in. I have passed out doing this push up method. When I did 80 push ups, I mentioned earlier, I hit 80 and boom, I went out like a light, banged my head on the floor and that was unfortunate. If I was doing that and free diving, I would’ve passed out and my autonomic reflex would be to gasp and this is why 300 free divers died in the last few years. If you are doing this on dry land, the worse thing that’s going to happen is you’re going to fall down. You do it underwater, you’re going to drown.

Brett McKay: Right. I’m imagining this breathing technique also is what allows Wim and which allowed yourself, we’ll talk about more detail later on, but to climb Mount Kilimanjaro at a record pace, right? Instead of doing the usual acclimation, you’re doing it slowly, you’re able to get up in two days.

Scott Carney: Yeah, I mean, faster than two days. We actually summited Kilimanjaro in 28 hours. I will say, that is not the record. The records I just shy of 7 hours by this crazy endurance athlete, Kilian Jornet. What he did is he actually acclimated his body at high altitude first, ran down to the bottom of the mountain. When you’re at high altitude, you’re generating more red blood cells so you can move more oxygen through your system. He went down to the bottom, then sprinted up to the top and I got nothing on Kilian, right? I would never assume that however, what we did is we did it without acclimation. We went up from the base of Kilimanjaro to the top and we did it in 28 hours and it usually takes five days to acclimate your body to that altitude.

We had spoken to the US military and environmental scientists and they predicted that 70% of our group, I think we had 28 people, would come down with acute mountain sickness or AMS. Which is a debilitating and possibly fatal condition of being at high altitude. When we did it, we only had two people come down with AMS, which was unheard of. We talked to some mountaineers in Holland, the mountaineering club of Holland said that all of us would die on the mountain. We hiked up right to the top and then we did it at this mind boggling pace. I did this mostly shirtless too.

Brett McKay: I guess it was thanks to the breathing technique?

Scott Carney: Right. What we were doing is the entire way up, we were doing that Wim Hoff breathing. 28 hours which took more mental focus than I knew I had to do but we were breathing rapidly because we were trying to consciously account for the decreased oxygen by increasing our respiration and it worked. This is a technique that people can use as they go up mountains now. If you’re getting down to acute mountain sickness, this is one way that I think that we can combat that which is fantastic, you don’t need Diamox. If you’re getting AMS, by all means, descend quickly because that’s the medically right thing to do but you can prevent this from even coming on with this breathing method. That is really cool.

Brett McKay: Let’s circle back to the cold exposure. I’m a big fan of cold showers, we’ve written about it on the site before, a lot of our listeners are probably practitioners of cold showers. What’s the science behind cold exposure? What happens to our bodies when we expose ourselves to cold?

Scott Carney: The cold does a whole bunch of things to our autonomic nervous system that we don’t usually have. The most obvious and the most interesting, I feel, is something called vasoconstriction. Our body is full of all these arteries and veins and we’ve got enough of this, if you lined all of those arteries and veins end to end, we’d be going across the states two times. It’s a huge circulatory network and along all of the veins, the veins are what return blood to the heart, are muscles. These muscles sit there but they’re potentially so strong that if someone were to cut my leg off below the knee, those veins would constrict to stop the flow of blood out of my body. This is why soldiers are able to survive these debilitating wounds, we have this autonomic system that will stem blood loss. The other use for it and the more common use for vasoconstriction is to shunt blood to the core if you get cold, sacrifice the extremities to keep your core warm. For the vast majority of us who live at this constant 72 degrees, we never, ever activate those muscles so those muscles get weak and that weakness leads to all sorts of circulatory diseases.

Getting into the snow, getting into cold water is like lifting weights for your circulatory system. It’s the easiest thing to do to turn a cold shower and then they flex and you go warm and you relax and you go cold and they flex again. Even somebody with chiseled abs, is a total gym rat, could have this totally weak circulatory system. That’s the first thing that the cold does. Another thing that it does is it modulate insulin production and insulin resistance is the condition that leads to diabetes. The cold will also make you lose weight so fast. If you think about, you’re at the gym and you have a little bit of a ponch and you want to lose weight, it’s pretty hard to do that through running and exercise, right? You can but it takes a lot of focus effort. Your body would generally prefer to burn muscle and other tissues before it goes after your fat content.

The reason for that is that fat has an evolutionary purpose to actually heat your body and we have a tissue that we’re born with called brown adipose tissue or brown fat that every infant, human, who’s not premature has. That’s because when you’re that small, you’re just born, you don’t have a musculature or digestive system to heat your body the normal way, you know that adults. Every time you move, you generate heat, every time your digestive system moves, it generates heat. This is how we maintain it to a 98.6 body temperature, this is how we thermo regulate. Infants, who are also very small, which means they have a high surface area to mass ratio, lose heat very quickly. The strategies that infants use to survive is this brown adipose tissue which they have a lot of and what it does is it sucks white fat from their body and directly metabolizes it for heat energy. It produces a lot of heat and this is how all of us got through our earliest years.

As we get older, we’re able to heat ourselves in various other ways and scientists thought that most adults didn’t have any BAT until 2007 when, I won’t get into all of the whole story of how they found it but a researcher named Aaron Cypess over at Harvard discovered that adults actually do have it and the reason that they didn’t realize it before is because you only keep it around after childhood and you only develop more if you’re constantly exposed to cold. The response and the reason you get BAT is that you’re cold and your body’s like okay, I don’t want to shiver myself warm all the time, I’m going to use my metabolism, and that sucks out your white fat. This white fat is energy that we have but it’s not for caloric energy to move our muscles, it’s caloric energy to heat our bodies. That’s one of the things that’s an evolutionary mismatch with how we live today.

Brett McKay: You actually lost seven pounds of fat after your first trip to Poland with Wim, correct?

Scott Carney: Isn’t that nuts, right? Me hanging out in the snow, eating Polish food, which I will remind you is mostly sausage and pierogies, oily, fatty, carb-y food, I lost seven pounds of fat while hanging out with him.

Brett McKay: Let’s say someone’s listening to this. That sounds awesome, I want to give my circulatory system a workout but I always want to get this brown fat so I can start losing white fat. What do you need to do? How long do you need to expose yourself to cold for you to start developing this ability?

Scott Carney: Everyone’s physiology is a little bit different, I can’t give an exact response and actually, still research is ongoing. I can say that I was able to keep my body warm through this metabolic process very well after three days of going out in the snow for as long as I could manage. I need to be clear that you need to be in control in the snow. If you start shivering uncontrollably or start getting frostbite, you’re doing this wrong, you’re pushing past your limits. Humans are designed, we evolve to adapt rapidly. Our ancestors who passed on their genes, didn’t see an oncoming snow storm and say “I’ll get ready for it next month,” they were like “Our bodies have to be ready now.” You build it up extremely rapidly. One test in a lab in Holland showed that they put 12 diabetic men, overweight, diabetic men, I think they were mostly in their 50s and they put them in a cold room for about 51 degrees for three hours a day for three weeks. At the end of that time, and they were wearing shorts and a shirt I believe, at the end of that time, being cold decreased their insulin sensitivity by 54% which is a dramatic improvement for their diabetes.

You do this quick and all you need to do is get cold. Start with cold showers, that’s the easiest way to do it. Start with your hot shower and take your Scottish shower that starts hot and goes cold. Then when you’re in that environment, the most important thing is to relax. You don’t want to warm yourself by that muscle action, which may help you lose weight but it’s not going to help you get this metabolic activity. You consciously, you take a deep breath and you say “Okay, I’m cold and it’ll be all right” and this is the signal to your nervous system to start building up metabolic changes in your body. Another very easy way to do things, that I do a lot, if it’s Winter, which it is now, go for a run outside in a pair of shorts. Maybe wear a hat and gloves if it’s super cold out and you’re worried about your extremities but go shirtless or if you’re a woman, wear a sports bra. Go with as much of your skin as possible out to the cold and go for a three mile run or five mile run, something like that.

Come back and what’s going to happen is because you’re moving your muscles a lot, you’re actually generating a tremendous amount of heat. If you run in the winter now and you’re wearing fleece, you’re probably sweating under all that stuff. This is a great way to do this method because your skin is actually getting that signal for the cold, your skin will be cold to the touch but your core will be warm. Those neural signals for saying get ready for Winter are coming into your body and that’s going to be one great way to start building up this metabolic change.

Brett McKay: For the cold showers, is there a time length you should shoot for? Five minutes under the cold or does it matter?

Scott Carney: Longer equals better in this case but with any new practice, you have the benefit of the law of diminishing returns. This happens really for any exercise routine, any meditation routine, anything new that you do is you learn the most in the introduction to this. If you can get into the shower and relax and stay there for 30 seconds after you’re relaxed, you have gotten a huge benefit into your system. After you stay there longer, you’ll still get benefits but the curve bends a little bit after that. I would say a minimum, shoot for a minute because really it’s not going to kill you, it’s going to be fine. If you could do five, that’s great. Some people work this up for a long, long time but the goal is to subdue your panic response and relax and that is a signal to your body that you have to have mental control instead of this autonomic control and that’s the first step. Then you do more stuff, you’ll find that it gets easier and the really cool thing, when you’re in the cold, you release all of these awesome, feel good hormones, norepinephrine, epinephrine, adrenaline, cortisol. They all start releasing in your system and you get out of that cold shower and you feel awesome. That becomes this addictive and really fun thing.

Brett McKay: Besides the cold exposure, that’s what your book’s primarily about, are there any other ways we can eject stress in our lives so we can become stronger?

Scott Carney: Sure. I find the cold to be a safe way to do it because you obviously can kill yourself with extreme cold but it’s easier to warm up your body if you get a little too cold than it is to cool down your body if you get a little too hot. That doesn’t mean you can’t do the same basic training with the other extreme. You have to be a lot more careful in pushing your limits. The breathing method, the cold, you can use heat, you can use altitude, a lot of this stuff is things that people have known for a while. The reason why the Olympic Training Center in America is up in Colorado is because we’re at 5000 feet and that’s an environmental stimulus and you don’t even realize it, you get the passive benefit of being at high altitude.

I write in the book, there’s this concept that I have called the wedge which is where any environmental stimulus that comes into your body that has a predictable, biological response, that if that stimulus and that response, if you have any control over that response, that is a moment of where you can train. I talk about this in the book because you can say a sneeze is a great example of this. You know if you start to have to sneeze and you say I don’t want to sneeze right now, you can actually delay that. You can say “Okay, I’m going to resist this sneezing reflex that I have.” That is growing this ability that you have to master your autonomic nervous system. I don’t know if you should never sneeze in your life, this is not necessarily useless, sneezing is a great thing to do but it’s one of the fundamental ways that humans learn and you could maybe learn to hold your pee for a long time or delay an orgasm. There’s lots of predictable biological responses that you can start to master. The body is the limit there, whatever you can think of.

Brett McKay: Part of your experiment with Wim Hoff’s method, besides the hike up Mount Kilimanjaro, you also did the Tough Guy. We’ve had Scott Keneally on the podcast to talk about the Sufferfest and the Tough Guy.

Scott Carney: He’s running that right now, I’m so jealous.

Brett McKay: It’s cold here in Oklahoma, I can’t imagine what it is over there. It’s the original obstacle course race, it’s in the dead of Winter in England. This guy named Mouse makes these guys go through ice cold water, brutal stuff and you did this Tough Guy. Not only did you do it, you did it in a pair of shorts and a pair of shoes, that’s it. Can you tell us about your experience doing the Tough Guy while following Wim Hoff’s method?

Scott Carney: Yeah, I am not an endurance athlete, I didn’t expect to want to win this or anything. People win tough guy in an hour and a half but it’s a 12 or 15 miles race but mostly obstacles where you’re jumping over walls and into icy water and then you’re all muddy and then you’re climbing under barbed wire and there’s electrical shocks. All these typical, what we now think of as typical obstacle course things. The main obstacle in Tough Guy is the cold and people will run this basically wearing wetsuits, covered in neoprene because the year before I did it, there were 300 people who ended up in the emergency room with hypothermia.

I wanted to run this in shorts, I had shorts, shoes, I may have had gloves because I wanted to be able to climb up those obstacles efficiently. I completed the course in about three and a half hours which is definitely nothing special but in this frigid, frigid weather, and I was warm. I was actually elated the whole time I was doing it. It was this total high because whereas everyone else was shivering and really fighting this one challenge, my body responded to it with releasing adrenaline and epinephrine and making me feel great. Everyone who I met on the course was like “Why are you smiling, my friend?” It was an awesome whole body, pleasurable experience to me and I think because I’d been doing this Wim Hoff training for at that point regularly for about six months, the challenge that other peoples’ bodies were failing at, I had no issue with, I thought it was great.

Brett McKay: Yeah, I think it’s interesting, this whole obstacle course, racing phenomenon, this interest in what Wim Hoff and what he’s doing, it seems like there is an underground revolt going against the diseases of civilization. Are there any other subcultures you came across during the research of your book where you found people purposely injecting environmental stress in their life to become healthier and stronger?

Scott Carney: Sure. I like the obstacle course race industry because it’s so contained and obvious. It’s like you’re a weekend warrior and you go out there and you get a little suffering because hey, not only does it look good on Facebook, it actually feels really cool to take on a challenge, to do something out of your ordinary routine. In some sense, every exercise routine that anyone takes on, Crossfit or surfing where you hang out in the water for a hell of a long period of time, all of that is bucking your nose at this comfortable life that you could live in your office the whole time everyday. I have mad respect for anyone who can go out there and go grab a little bit of suffering and say “Actually, that suffering is actually making me stronger and then I start to enjoy it.”

Maybe you’ve seen this viral video going around of kids in Siberia dumping ice water on themselves. This is where there’s this school, it’s like an elementary or even a preschool and they have this video of these kids running outside into the Siberian Winter, pouring ice water on themselves, rolling in the snow for five minutes and then going back inside. The teachers at the school say that it has prevented all their kids from getting sick. Which is crazy, no one would do that in America. We are so coddled in this country, this is the country where a free range child, the parents of that kid end up having child protective services called on them. It’s so funny but I think there’s a lot of people out there who want to get back to nature and there’s a whole ancestral health movement, bare foot running, Paleo diet people, all of these people are pushing on this idea that technology isn’t all that it’s cracked up to be and maybe comfort hides it’s own type of suffering.

Brett McKay: Before you started Wim Hoff’s method for a year, you got your physiology test, you went through some medical tests. How did your physiology change after you followed his methodology?

Scott Carney: I went to the Boulder Sports and Recreation Center over at the University of Colorado Boulder where this physiologist first measured me before I was doing the method regularly. I had actually consciously stopped doing it for about a month in the middle of the Summer and he measured me on a stress test which is basically getting me to my VO2 max and seeing how my body processed energy. I was a pretty ordinary dude, definitely nothing special, he actually laughed at how not special I was. Which meant that I burn mostly carbohydrates during my exercise and then eventually started burning fat at the very end. Which is the exact opposite of what you want to be if you’re an endurance athlete.

At the end of the training course, after I’d climbed Kili, after I’d done all these things, where I hadn’t changed my daily workout routine anymore than doing the breathing exercises and cold exposure. At the end of all of that, that’s 15 minutes a day, it’s really not that much time. He examined my physiology again and I had suddenly switched to a primarily fat burning person and I was able to do additional stages on his VO2 max test. He was actually really surprised by these results because I hadn’t actually changed my cardio routine that much. I was doing three runs a week or something like that. He was like as if I had added seven hours of exercise to my routine every week and he thought it was really, really cool. I was pretty happy with those results.

Brett McKay: You went into this investigation as a skeptic, are you a believer now or are there some aspects of Wim’s claims where you’re like I don’t know about that but are there some aspects where you’re like yeah, I’m down with that?

Scott Carney: Certainly, I’m always going to be a skeptic of claims that are too big and I think Wim is the doorway into something really beautiful and really wonderful about our physiology but sometimes he’ll say things that are impossible to prove or dangerous to prove. He’ll sometimes say “I can cure cancer, cure AIDs” and I don’t know about that. I’ll wait for the evidence to roll in for that. What I will say is he has certainly opened my eyes to a different way of looking at our body and the environment. We used to think that health, general health relied on two things, diet and exercise. The energy you put into your body and what you expend through physical exertion. What this has taught me is that there’s actually a third pillar and the environment you inhabit is just as important as those two other things. That alone seems to have a whole cascade of other effects on health in general. It’s changed my life, it’s changed my perspective on things forever I would think.

Brett McKay: Scott, this has been a great conversation. Where can people learn more about your book and your work?

Scott Carney: I have the book which is called “What Doesn’t Kill Us: How Freezing Water, Extreme Altitude, and Environmental Conditioning Will Renew Our Lost Evolutionary Strength,” it is on all the places that you might find a book. Bookstores and Amazon and all those places. There’s an audio book so if you really liked listening to my voice now, you can do 10 hours of it on Audible and iBooks. Also, I have Facebook, I got the Twitter, I’ve got email, I’ve got my own website which is scottcarney.com. All the things, Google is your friend for finding me.

Brett McKay: Scott Carney, thank you so much for your time, it’s been a pleasure.

Scott Carney: Awesome, this has been a lot of fun, thanks.

Brett McKay: My guest here was Scott Carney, he’s the author of the book “What Doesn’t Kill Us,” it’s available on Amazon.com and bookstores everywhere. You can also find out more information about Scott’s work at scottcarney.com. Also, check out our show notes at aom.is/coldexposure where you can find links to resources and delve deeper into this topic. That wraps up another edition of the Art of Manliness podcast, for more manly tips and advice, make sure to check out the Art of Manliness website at artofmanliness.com. This show is recorded on clearcast.io if you’re a podcaster who are looking for a solution for better sounding, remote podcast interviews, check it out at clearcast.io, something I developed. As always, we appreciate your support and until next time, this is Brett McKay telling you to stay manly.