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Cold Exposure Therapy & Wim Hof Breathing

The health benefits of cold water therapy with Dr. Mike T. Nelson.

Does taking a cold shower or dunking into an ice water bath seem crazy? Cold water therapy has proven health benefits for your metabolism, immune system, stress tolerance, and fat metabolism. After listening to Dr. Mike T. Nelson explain what cold exposure is good for and how to use it in this episode, you just might find yourself taking the plunge.

In This Episode

Episode Intro 00:00:44
Making Cold Therapy Accessible … 00:04:06
Temperature Stress … 00:06:51
Physiologic Flexibility … 00:08:09
Cardiovascular Benefits … 00:11:52
Brown Fat … 00:16:27
Running Experiments … 00:26:35
Stress Tolerance … 00:31:00
Immune Benefits … 000:43:25
Homeostatic Regulators … 00:50:15
How to Do This … 00:59:10
Don’t Try This at Home … 01:14:39
Physiologic Flexibility Course … 01:21:01
Episode Wrap-Up … 01:26:04

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Hey everyone. Today I spoke with Dr. Mike T. Nelson on the benefits of cold exposure therapy. This is something we discussed in the podcast years ago with Katie Bowman, but it’s resurfacing in terms of its potential importance, especially with the guru Wim Hof. If you’ve heard of him, he is the gentleman who has hiked up most of Mount Everest in just a pair of shorts and boots. Most relevant for our audience is this work of cold exposure also paired with some breathwork has shown the ability to help with immune-mediated conditions, specifically auto-immune conditions. There may also be cardiovascular benefits, potential benefits for activating brown adipose tissue and helping to metabolize body fats, and stress tolerance. But we also want to be careful because some of these things are mechanisms and we discuss the effect size of some of these.

We also discuss some tips and techniques for how to get started yourself with cold exposure therapy. Spoiler alert. I do about two to three minutes every morning in a 40-degree ice chest filled with water, and it is amazing. So we will go into this discussion now with Mike Nelson. He has fact-checked much of the science and actually built this into a broader program. In this program, he helps individuals determine what areas where we could hermetically stress someone such as diet, fasting, breath, work, cold exposure fit best into a personalized program for them. So with that, we will now go to the discussion with Dr. Mike T. Nelson.

➕ Full Podcast Transcript

Intro:

Welcome to Dr. Ruscio radio providing practical and science-based solutions to feeling your best. To stay up-to-date on the latest topics as well as all of our prior episodes, please make sure to subscribe in your podcast player. For weekly updates, DrRuscio.com. The following discussion is for educational purposes only and is not intended to diagnose or treat any disease. Please do not apply any of this information without first speaking to your doctor. Now let’s head to the show.

DrMichaelRuscio:

Hey everyone. Today I spoke with Dr. Mike T. Nelson on the benefits of cold exposure therapy. This is something we discussed in the podcast years ago with Katie Bowman, but it’s resurfacing in terms of its potential importance, especially with the guru Wim Hof. If you’ve heard of him, he is the gentleman who has hiked up most of Mount Everest in just a pair of shorts and boots. Most relevant for our audience is this work of cold exposure also paired with some breathwork has shown the ability to help with immune-mediated conditions, specifically auto-immune conditions. There may also be cardiovascular benefits, potential benefits for activating brown adipose tissue and helping to metabolize body fats, and stress tolerance. But we also want to be careful because some of these things are mechanisms and we discuss the effect size of some of these.

DrMR:

We also discuss some tips and techniques for how to get started yourself with cold exposure therapy. Spoiler alert. I do about two to three minutes every morning in a 40-degree ice chest filled with water, and it is amazing. So we will go into this discussion now with Mike Nelson. He has fact-checked much of the science and actually built this into a broader program. In this program, he helps individuals determine what areas where we could hermetically stress someone such as diet, fasting, breath, work, cold exposure fit best into a personalized program for them. So with that, we will now go to the discussion with Dr. Mike T. Nelson.

DrMR:

Hey everyone. Welcome back to another episode of Dr. Ruscio radio. I am here again with Dr. Mike T. Nelson, and we are going to be talking about cold exposure therapy. Women don’t shut off the podcast just yet. I know most women seem to detest the cold, but there is some very interesting therapeutic potential of the cold. In fact, much of this is anecdotal, at least from what I’ve seen, but Scott Carney wrote a book about Wim Hof, who pioneered cold exposure therapy, to some extent. He cites this debilitated, rheumatoid arthritis patient who had essentially failed out of all of the immunosuppressive drugs and through pretty intense breathwork and cold exposure is fully functional and on no medications from being somewhat crippled. So there is definitely an inflammatory immune application. There’s also another case study that Carney cites in his book about someone with Crohn’s disease that was to the point of no medications, no cocktail of medications, was able to suppress Crohn’s and now is in full remission. So cold exposure is a very, very interesting novel therapeutic. It is something I’ve been doing. I’ve been doing it, based on the recommendations of Mike Nelson, with this kind of home freezer chest set up. So definitely something I’m quite eager to explore here with Mike. So Mike, welcome back to the show.

DrMikeTNelson:

Yeah. Thank you very much for having me. Great to be back again.

Making Cold Therapy Accessible

DrMR:

Mike has been on the show a few times and also does my personal programming. I’ve discussed, I think it was the last time Mike was on the podcast, how I had some typical imbalances, mostly this underdevelopment of my posterior chain that was leading to some hip dysfunctions, knee pain. Mike started doing my programming and really got me balanced out. I’m no longer weak and feeble. The guys in the playground aren’t shoving me around as much. So it’s been very nice.

DrMN:

Throw sand in their face. That’s always good.

DrMR:

It’s been really nice. One of the things I picked up from Mike was a way to make cold exposure therapy more readily accessible. Mike, I really have to give you a virtual pat on the back here. Essentially if you take a freezer chest and fill it with water and put a pond filter inside of it and$ an ozone filter, you can make your own at home cryotherapy unit for $500 to $700, maybe $800, depending on the size of the chest that you get. That’s been really nice to have. There’s a lot here that we can kind of fumble into. I want to start with maybe an anecdote. Sorry, Mike, to kind of front load with all this. If you haven’t heard off Wim Hof, he’s an interesting fellow. He’s the guy who hiked most of the way up Mount Everest in just a pair of shorts and boots, no shirt. Summited Kilimanjaro, essentially in a bathing suit with shoes on, but otherwise pretty much shirtless in record time and did not need to acclimatize and also was able to bring groups of other people and enable them to do this.

DrMR:

So you may have seen some of his stunts. Scott Carney wrote a book trying to disprove and discredit Wim Hof’s work. The name of that book is What Doesn’t Kill Us. But Carney actually, through going through the process of Wim Hof’s training, came to understand and learn that there’s a deeper message. I just want to kind of lead with that. Hopefully to allow this to permeate through the conversation, which is, I think we’ve become a little bit weak when it comes to exposure to temperature extremes. This is something that Katie Bowman and I discussed in the podcast years ago. Certainly, we weren’t the first to mention this. We were just kind of reiterating this call to attention of the fact that if we’re always in this very narrow band of temperature exposure, there are certain stressors that we’re missing out on, kind of like a fasting stress.

Temperature Stress

DrMR:

We’re now learning that can be quite good for you. We all know that exercise stress can be quite good for you. What if there’s also this other type of stress that is temperature exposure that can actually allow you to heal and recover and be stronger afterwards. This is what the cold exposure therapy seems to be able to do. So I just want to lead with maybe that ancestral premise, that while it sounds weird and admittedly, it probably looks weird when I was at home walking around shirtless and 42 degrees. It did show me that while there were people driving by in cars, wearing jackets and scarves looking at me like I’m a crazy person, we have the ability to withstand those exposures and withstanding those exposures may actually give your body some exercise it really needs and isn’t otherwise getting. So Mike where do you want to launch us in? I know you are really more plugged into this from the angle of performance. I know you’ve kind of fact-checked some of the literature here. One of the things I want to do is kinda get your perspective on going into cold water tank as compared to a cryotherapy gas chamber. So where do you want to launch into the conversation?

Physiologic Flexibility

DrMN:

So obviously I did a flux diet certification on nutrition and recovery. As I was doing that, I had the thought for quite a while of metabolic flexibility. That’s what that course was based on, and flexible dieting approaches. So how well can we use fat? How well can you use carbohydrates for fuel, recovery, performance, things of that nature? Then as I started looking at that literature several years ago, I’m like I wonder if there is such a thing as physiologic flexibility. That wasn’t really a term, but kind of like you said, what other what other stressors would we have been exposed to? Especially even a few hundred years ago or longer, that we’re just not exposed to now. I think the easiest to think about is temperature differences. A couple of years after that, I ran into Mike Bledsoe who had me do some of the Wim Hof method for breathing, saw some of Wim Hof stuff and just checked into what he was doing with cold exposure and different breathing techniques.

DrMN:

It made me think about what I was doing. I’m in Minnesota, and I bundle up a hundred percent to go outside. You know, most of my friends at that time had remote vehicles starters so they can start their vehicle from inside and it will run and be nice and warm by the time they run the 10 feet from the front door to the vehicle. Of course I’m doing the same thing in the summer. It gets pretty warm here, not quite as warm as Austin in the summer, by any means, but it can get pretty warm and pretty humid. I’m running from one air-conditioned place to the next. I train normally in a garage gym. I didn’t have, at the time, heated or air conditioning or any fans or anything. I realized that your body does adapt to cold as it does to heat.

DrMN:

I remember having a flashback to when I did my undergrad with Saint Scholastica in Duluth, Minnesota. My professor for anatomy and physiology was a great guy named Dr. Cizaldo. He was an interesting guy because he had this big long kind of red handlebar mustache, he had long sleeves on even in the summer. We were always like what’s with this guy? He was kind of weird, rode a Harley at a private Catholic college. We always thought he had a lot of tattoos, that’s why he wore long sleeves. This was like back in the early nineties and tattoos weren’t that common. His class was great though. I remember him saying, well, of course your body is going to adapt more to cold. You guys live in Minnesota. The first day it gets cold in fall.

DrMN:

It gets down to 40 degrees. You all run around and grab your winter coats and hats. By the end of winter, the first day it hits 40 degrees outside there are people running around in t-shirts. I was like, he’s right. So I had this flashback to that. Maybe there is something to this, you know? You had to walk outside between classes. You were kind of forced to be outside in the elements. Fast forward, I think we’ve kind of lost that more than ever. People are just scurrying around in the summer, like cockroaches, from one nice air-conditioned place to the next. I have friends who live in Arizona who are like, you’re so crazy. How do you live in Minnesota? In the winter? That’s so stupid. I’m like, you live in Arizona in the summer and you just run from one air-conditioned place to the next, I don’t really know how it’s that much different.

Cardiovascular Benefits

DrMR:

Fully agreed. The benefits of this I think are where maybe we can motivate people to expose themselves. One, it’s nice to know that you can go out either in the hot or the cold and be okay. So I think from an empowerment perspective, that’s really nice. But there are also a number of other benefits. Cardiovascular, or it may be better stated as vascular or circulatory, immune. Let’s take these one by one. So cardiovascular, vascular, circulatory, essentially when you’re hot, everything flows outward when you’re cold things shunt. In Carney’s book, I don’t know if this is actually true and I’m certainly not going to test it, but he reported that if you had your leg cut off just below the knee, there’s enough musculature in the vascularity there where you could almost shunt off all of the bleeding just through the contraction of the musculature that kind of covers the vascular system. There are some pretty strong muscles that can change how blood is flowing. Let’s start there. What thoughts do you have on this? Should we consider it cardiovascular or should it be more circulatory and what kind of benefits have you read about?

DrMN:

Yeah. In terms of closing off of blood flow, I wouldn’t do an amputation to test that model. I’ve got a Moxy set up, which is a sensor using what’s called NIRS technology. So people have all put the little PulseOx on the end of their finger and it says you’re 98 or 99% saturated. It’s the same technology, but we’re looking more at the venous side and we’re looking more at the muscle itself. So we can determine a little bit of blood flow and we can determine how well it uses oxygen. When this is on during exercise, you will see some people that can retrude enough muscle tissue under a heavy enough load that they can have a venous occlusion. So the muscle will basically squish the veins closed. And you can see some people who even have what’s called potentially arterial occlusion.

DrMN:

They can track the musculature so hard that temporarily, during that contraction, the blood flow in not just out, can be cut off. That’s not everyone. That’s probably more higher-level athletes and even different subtypes of them, but you definitely can have muscle contraction that can change those independently. Obviously, the arterials have much more of a muscular base in the wall than the veins do. If you look at temperature differences, this has been much better documented on the heat side, in terms of sauna, like what are potential mechanisms. Sauna in untrained, individuals can mirror six to eight weeks of cardiovascular training. You think about getting in a hot sauna, how much your heart rate is going to elevate. You are going to be pumping more blood because you’re trying to cool the body down. If you look at what are some of the mechanisms that may be happening, and there’s a whole bunch of different ones, but one of the main ones is upregulation of heat shock proteins.

DrMN:

One of the “organs” you could say that heat shock proteins are most regulatable or have the biggest capacity to see massive changes in is actually the vasculature. So most of that may be modified by heat shock proteins, which, just judging by the name, can respond to hot and paradoxically can respond to cold also. There’s some pretty good data on sauna, looking at vascular health as an indicator for that. Not as much on the cold side. When you get in something that’s very cold, initially you’re going to have some construction and redistribution of blood flow. Your body is going to go, Holy crap, this is cold. We don’t want to die. So let’s pull some blood away from the limbs and bring it more towards the core. When you get out, a lot of that is then going to reverse. You’re going to have a little bit more reperfusion to other areas. So we know that in terms of benefits, heat shock proteins, vascular health, probably pretty high. I would guess the cold, probably similar, although I haven’t seen that as been documented as much.

Brown Fat

DrMR:

I do want to come to immune and I’m sure our audience is quite curious on immune. Before we go there, because immune, I think at least my understanding gets a little bit skewed by the breathwork that is often done in conjunction with the cold exposure therapy or at least looking at some of the applications. One that seems to be much more clear cut is this brown adipose tissue, or just said more simply brown fat. I learned quite a bit about this from Carney’s book. Brown fat essentially serves to suck white body fat up and metabolize it, so as to produce body heat. So when people get visibly fatter, they’re not typically gaining, at least according to my understanding, brown fat. It’s white fat, that’s kind of the fat most people are thinking about when we say fat. This brown adipose tissue or brown fat is kind of like what the bear will use to burn the white fat while it’s hibernating so it maintains enough body heat during hibernation. Apparently, cold exposure will improve fat metabolism. They even discuss, I believe it was MRI findings where they used to think, early on, before they figured this out, that brown fat were actually cancerous lesions because they were so metabolically active.

DrMN:

They show up right on a CT scan.

DrMR:

So this Brown fat. So I’m trying to find as many motivation points for people as possible here. The Brown fat bit is interesting in the sense that it helps you better metabolize white fat so as to produce body heat. I don’t know if there’s been a clinical trial that’s set up parameters here. To fall in line with my own philosophy, this is an interesting mechanism but if it only leads to 0.3 pounds loss in overweight individuals, then it’s not a super successful therapy. Nonetheless, this is some of what’s being discussed regarding another benefit of cold exposure.

DrMN:

Yeah. I would say a potential benefit. What we know, at least from my interpretation on the literature, is if you have more cold exposure, we do know that brown adipose tissue is very what they call plastic, just like most things in the body, meaning it can be changed. We can see more brown adipose tissue in people who are exposed to cold versus not. I will show up a little bit brighter on your CT scans. The question then of, is it changeable enough to make any difference? I don’t know. I’m not convinced that it is yet. I mean, some of the data that I’ve seen, would suggest that you would need a lot of cold exposure to do that. Other animals can do that. You mentioned bears. I’ve been kind of reading a lot of literature on bears for the last 15 years.

DrMN:

I’ve just been fascinated by the concept of hibernation. It’s like, what does the bear do? Right. The bear eats everything in sight in the fall, gets really fat, goes to sleep all winter. Doesn’t really move. They’re just generally sleeping most of the time. The bear sticks his head out in spring, time to get up. The body composition changes are freaking amazing. The bear rarely loses much lean body mass, uses almost all body fat as a fuel during that time. To me that is fascinating. Imagine if you told some of your patients for winter, just don’t exercise. If you got a little fat before fall, it’s okay. Just sleep a lot and in spring you’ll just be leaner. Well, that’s amazing.

DrMR:

The most popular plan out there.

DrMN:

I know. I know. I always wanted to write like the hibernating bear diet, but unfortunately, humans don’t quite work that way. But other animals are able to do it. Look at ground squirrels, they go into something called torpor and they can be basically just like half dead and they come back to life in spring again. Some toads that can be like frozen solid and your thaw them out and they’re fine again. So I think it’s interesting. From a metabolic standpoint, we do know that different temperature exposures, especially to cold will actually change the kind of composition of other white fat and make it more kind of beige. What’s called browning of fat. Now, does that fat ever become what’s classified as brown adipose tissue? Probably not. At least the amount of stimulus that you would need to do that is going to be extremely excessive.

DrMN:

I think one of the main benefits is potentially better temperature regulation. That may be related to muscle. Maybe metabolism. But I think the biggest benefit is, from what I can tell, is you just have a much bigger and better sink to get rid of a mass amount of glucose. People tend to think of muscle as the main tissue that is the sink or disposal for glucose. That is correct. At the end of the day, if you take in, let’s say 80 grams of glucose from a Pop-Tart your body goes, okay, I need to get this out of the bloodstream. I want to put it wherever I possibly can. If I can jam it into glycogen and the muscles, great. If I can jam it into glycogen in the liver, great. Can I convert maybe some of that via a process called DNL (de novo lipogenesis) in the liver to fat tissue?

DrMN:

That might be a benefit too, although that rate tends to be relatively low. It appears that this kind of beige adipose tissue is not necessarily white adipose tissue, not necessarily brown adipose tissue, it’s kind of somewhere in between. It may serve as enhancing a better disposal of glucose and a buffering storers when maybe glycogen is already kind of tapped out or full. I’d love future studies to look at more metabolic health and exposure to cold temperatures, especially in populations who may not be doing a lot of exercise. I think that there may be a fair amount of metabolic benefit, I’m guessing here, with probably not a lot of time or stimulus. You think about how big a difference it is to spend even just two minutes in 50 degree water for most people. That’s a pretty massive difference that they haven’t really seen before. So I think that’s a pretty big stimulus to affect some changes in physiology.

DrMR:

First let me say that I think it is important that we are going through this exercise of not getting too over our skis with, “Oh my goodness, a novel mechanism”.

DrMN:

I wanted the brown adipose tissue to be true. That was my thought, looking at the literature. I was like look at the CT scan, look at all this brown, I can see it’s like lit up like a Christmas tree. This is gotta be a trainable thing. It’s from response to the environment. It’s got to expand in size. I just can’t find any literature that says that it does.

DrMR:

So the size isn’t changed, but there is improved activation in the cold.

DrMN:

Yes. There, you definitely do use it in the cold.

DrMR:

The other thing that it sounds like from your review of the evidence is that increased activation doesn’t lead to an appreciable amount of weight loss or have the studies not gotten that far yet? What does that look like?

DrMN:

Yeah, probably not. I mean, the studies that have tried to look at how much temperature difference affects caloric burn. So if I wanted to make an argument, I would say hey, you’ve got to do a lot more exposure to both hot and cold because we know that cold, for example, is going to take energy. It’s going to take more energy to keep you warm during that period of time. I can point to studies and say brown adipose tissue is actually more activated during that time. I can point to infants use a lot more brown adipose tissue to regulate body heat and body temperature. I could point to bears and all sorts of other animals that do it on a massive scale. However, the studies that I’ve seen, and they’ve done some interesting stuff where they’ve put people in like cold rooms, like air temperature for quite some time and measured thermic response and put like Chili vests on them and stuck them in cold water.

DrMN:

The military has been interested in this for quite a while in terms of exposure to extreme environments. Yeah, if you’re an Arctic Explorer trying to hike to the North Pole and you’re cold all the time and constantly moving, does it make a difference? Probably. Yeah. But the amount of cold you would need to be exposed to over many hours to burn like I think it was like less than a couple of hundred calories. That’s pretty crazy. So is there a physiologic mechanism there that is at play? Yup. Does it burn more calories? Absolutely. Do those calories, I think, add up to something that is going to be a meaningful change if you’re spending three minutes in cold water? Fortunately, I don’t think so. I’d probably sell a lot more courses if I said yes.

DrMR:

It’s that pesky effect size people like to leave out of the equation.

DrMN:

Yeah. The effect size, from what I’ve seen, is small. It’s not negligible. But then you add in the fact that it’s not a lot of fun being cold.

Running Experiments

DrMR:

Yeah. Well, I’m running my own experiment. I should say also it’s not that much of an experiment. I might be a little bit of a freak in the sense that when I was like seven and it would be the first snow storm of the year, I would run outside in my shorts, no socks, no shoes and run to the end of the end of the block, which is probably half a mile and back shoeless. I keep my place now at about 61 degrees. My hands and feet are a little cold, but I actually don’t mind. I kind of like it. I used to keep it a little bit warmer, maybe like 65, 67, but now I’m saying, well, I might as well push it to my tolerable low point, just to see if over the next couple months I notice any change in body fat. Way too early to tell. I’ve only been doing this now for maybe a week and a half. But yeah, it’s that effect size. I do wonder if people were to have a lower level of exposure for a longer period of time, let’s say people were keeping their houses at 62 or 63 degrees over the winter, would have an appreciable effect. Maybe, maybe not. Sounds like the data thus far suggests nothing huge, which is good. We want to be able to discuss mechanisms here on the show, but not make the error of not calling out when it’s a mechanism that doesn’t have a huge appreciable effect.

DrMN:

Yeah. The one exception that I have tried to test this out on is when is a long period of time where you may tolerate a colder temperature and not necessarily notice it, where your compliance is probably going to be a lot better. What about sleep? So I met up with the guys who do the Chili pad and the OOLER, which I have and it’s great. I talked to them. Basically the OOLER system is water that is chilled or warm to a specific temperature that goes in this mattress pad underneath your bed and allows you to sleep at a cooler temperature to help enhance sleep. I have found that definitely does help with that. So talking with them, I wanted to try to do some anecdotal experiments of, can I get this to be like super cold?

DrMN:

So I got one and I set it to the coldest setting possible. My goal was to get it so that I’d wake up shivering. Then I’ll just back it off from that temperature and see if I get any leaner during the process. The downside of that is that I’m one of these weirdos that likes having covers. I just like the weight of it. I just sleep better. So my cover content kind of skewed how cold I could get the thing to run. So when there’s no one in the bed, I can get it down to like 52 degrees. But as soon as I get in and put any amount of covers on it gets into like the upper fifties, low sixties.

DrMR:

Gotcha. So something for us to keep an eye on. There may be some benefit, the amount of which is probably fairly small,

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Stress Tolerance

DrMR:

Moving off of fat and before we go to immune impacts. Stress tolerance. This is something that I haven’t caught much of what the research literature here says. I have noticed that when I first started doing the cold exposure and also the Wim Hof breathing, I tanked pretty quickly. Then I just backed off for about a week and it came at it again.

DrMR:

Now I’m three weeks in, going significantly more intensely than I was before and I’m totally fine. This reminded me of something that I want to offer our audience to think on, which is, if you’re looking at your health as a dashboard, you’re going to have a sensor go off from time to time. That doesn’t mean anything. I think it’s important not to overly fret. I was really kind of tired for three days and I could have freaked out, wondered did I cause downregulation of hypothalamic pituitary receptors? Am I in stage three adrenal fatigue? Instead we need to just back off. Realize the sensor went off. Hit the reset button and move back from the experiment. Try it again. Notice no ill effect and in fact now, there’s a certain level of kind of energy and pep.

DrMR:

I feel like I’m doing everything right. I’m just really kind of on in every way possible. I feel like I’ve been really on for a few weeks now, whereas before I was kind of falsely concluding from that sensor buzz, that this may have been something that was damaging, deleterious or overloading my system. So, you know, sometimes on our way to the optimum plan, we’re going to hit a few speed bumps or see a few sensors buzz. We should be careful not to make any strong conclusions from that. So this would be one exposure to stress. I mean, it is quite stressful. When you get done with being in the tank for a few minutes. When you get out, you feel like you just had five cups of coffee or something akin to that, but I’m thinking that it’s helping me and would help an individual better respond to stress in their day-to-day lives. This is one of the hypotheses that Wim Hof has kind of pioneered, which is we don’t have enough exposure to these types of healthy stresses that allow our system to recover more strongly and become more stress tolerant. So those are some of the anecdotes I’ve caught, but Mike, wondering what you’re seeing regarding stress tolerance.

DrMN:

In the formal literature, there’s not a ton looking at it from the angle of stress tolerance. Anyone who’s done it, we know that it’s an acute, very much on the more sympathetic side, stressor. Stick your head in cold water, take a cold shower, jump in a cold Lake. Everyone will pretty much agree across the board that’s definitely a sympathetic stressor. The good part is that it’s generally relatively short-lived because usually your body’s first response is to get me the heck out of there. So you get out and you can look at it with heart rate variability. That’s probably primarily what I do the next day. HRV is very good at telling us status of our autonomic nervous system. Are we becoming more parasympathetic, rest and digest or more sympathetic kind of fight or flight area, but that is a totality of all the other stressors during the day.

DrMN:

So similar to what you found, I found if I was too aggressive with cold, especially at first, my HRV would start to become a little bit on the sympathetic side, meaning that I’ve probably pushed my stressors a little bit too hard. So I found for myself if I back off and I’ll use the gauge of how fast can I get control of my breathing. So what I’m training my body then is the stressor may be the same, say it’s 50 degree water for two minutes, but can I do lower kind of slower nasal breathing during that time? So the first time you get in, I may only do 30 seconds, get control of my breathing, get out. I’ll do that for a few days. Then maybe that feels easier. Okay. 45 seconds. Right. Just like training. I do a little bit more of the stressor once I feel like I can get a better control over that.

DrMN:

So that’s way of progressively adding more stress, just like you would with training. If you’re into running, just like you would run a little bit farther. We know that your body is always going to adapt. It’s just, what is that response look like? So I’m a bigger fan of eustress over distress. Eustress is stress you can generally recover from faster. So if I do cold water each day, I probably don’t want to push it too hard because I want to come back and be able to do it again the next day. And then over time, you know, do a little bit colder water and a little bit longer time. In terms of the literature, there’s not much in terms of stress tolerance. We do know that people do get better at adaptation to cold water.

DrMN:

Now, what exactly is that? Is it really an upregulation of metabolic rate? Probably not. Is it more on the psychology side of, you know what to expect? So your body is a little bit better at handling it. Probably. As part of that, even as weird as it sounds, your physiologic response to it. So if I get into cold water and I’m just basically hyperventilating and yelling for 30 seconds versus I get in and I have a nice response, I can breathe through my nose. I can take long breaths, you know, physiologically. That’s also going to be a different response to my body. So I think that’s part of it too. What I’ve noticed is I haven’t noticed a huge change. Like I’ve been doing it for about a year now. I haven’t noticed a massive change in heart rate variability.

DrMN:

I have noticed that cold tolerance doesn’t take too long to get better at and does appear to go away pretty fast. If you don’t do it for a couple of days, a couple of weeks, it definitely feels colder going into the same temperature. I have noticed if I’m in more of a caloric deficit, my tolerance to cold is definitely different. I noticed that with the Oohler in terms of sleeping temperatures and getting into cold water. I think one of the main benefits that’s not talked about as much is controlling your physiologic state in the face of a stressor, right? So the main reason I started doing cold was to determine if I can do something that’s hard every day, but in such a controlled fashion that I can come back and do it again the next day? You can do this exercise.

DrMN:

You can do it with a lot of things, but at some point with exercise, I may start out stripping my ability to recover from it. With cold, I don’t know what your experience is, but I never get super excited, even a year later, to get into cold water. I can trick myself and be like, “Oh, it’s going to feel so much better when I’m done and I’ll have a sense of accomplishment. I’ve made it this far”. I can do that kind of cognitive work around. But the limbic part of my brain is always like, Hey, you’re dumb. This is cold water. You don’t want to do this. This is a stupid idea.

DrMR:

Yeah, generally. Except for when it was summertime in Austin, then I just kind of had dreams of being in a cave of ice. I think it’s a great point that you make. I also want to share quickly my personal experience with exercise. I noticed a remarkable, and I really noticed this when we started working together on my training because I had a consistent plan and program. When someone is putting this together for you, it’s very easy to see when you do hit an exercise or when you miss one. Whereas before I was just kind of rolling with it from day today. So it was harder for me to see when I was compliant and when I wasn’t. Now I’m even to the point where there are some days where I’ll workout at lunch and then I’ll just go for a run in the evening.

DrMR:

I’m just like I wouldn’t mind getting a little bit of a bit of activity in. A year ago that run would have been a run that I would have dreaded. It seemed so hard. It is amazing with just continued effort and slowly ramping up of the volume, how much more people can do. Yeah, it is same thing with the cold exposure. Definitely, at first it was much more difficult, but now I don’t get that crazy response. I think it helps for me that I go face down and I hold my breath. So that kind of helps attenuate some of that response, but clearly it’s a quick adaptation on the way up. Also, I have noticed when I took a maybe a week and a half off, it felt like I reset back to zero. Also that after three days, my tolerance seemed to jump up pretty quickly.

DrMN:

When I was reading the literature, I saw the stories of a plane that goes down in cold water or someone falls out of a boat in very cold water and you would see mortality rates would be 10, 20, 25% within a few minutes. I was like, what the heck is going on with that? Because even if you went in completely naked, you’re not going to get cold enough in a minute that you’re going to die of hypothermia, no matter how cold the water is. Now, again, I don’t recommend that people do this, but from a physiologic response, you’re not going to get hypothermia within a minute. But what would happen is people would feel the cold water hit their face, especially if they had no prior experience with it and they would panic. They would panic and they would go face down in the water and they would literally inhale water.

DrMN:

They found that people were drowning before they would have hypothermia. So I think it’s worth pointing that out. Just because the risk of hypothermia is a real possibility, you have more time than you realize. But if you’ve ever stuck your face in the cold water in a controlled environment, it doesn’t feel like that the first time. It feels horrible. It’s hard to regain your senses within any short period of time. Over time, when you have practice, just like any other fear exposure therapy, or whatever words you wanna use for it, you get better at it and you can handle it and you have more experience. It’s not nearly as physiologic and psychologically frightening.

DrMR:

Yep. One of the things Carney mentions in his book is that the trigeminal nerve, which kind of wraps around the eyes, the nose, that’s probably what’s eliciting that response. I’ve noticed that getting my head under it takes it to a whole other level of stimuli. I feel even more of this kind of mental clarity and freshness when I get out having my head under, as opposed to not having my head under. So even though it’s a bit more to kind of get over the reactionary hump, I feel like the benefits on the other side are definitely worth it.

DrMN:

Yeah. There’s some hypothetical stuff on that in terms of, are you stimulating the trigeminal nerve because of the location of where it is in the face. It is a good indicator of environmental cold exposure. Some people will recommend just doing a face plunge if you can’t do a full body exposure. There may be some truth to that. I haven’t been able to find any literature that says yay or nay on that, but it definitely does feel different that’s for sure. Yeah.

Immune Benefits

DrMR:

Some people go and they get cryotherapy done on their face for aesthetic purposes. So, I mean, you’re really kind of getting that here as a “twofer”. Now, the immune aspect is one that I think is a little bit more, at least from my purview, convoluted. Oftentimes people are doing breathwork when they’re doing the cold exposure. If they’re in that kind of a Wim Hof camp, that is. Definitely, some pretty interesting stuff that I opened with regarding immune system benefits. There’s an interesting phrase that Kearney uses, I’m not sure if it’s him or if he’s quoting someone else, but he says if the body doesn’t have something to fight, it fights itself. We’ve discussed this on the podcast before about the microbiome and no exposure to dirt and bugs and so the immune system has nothing to push again.

DrMR:

So it just starts attacking its own tissue. That may extend more broadly to where, if there’s not a stressor that the body is having to push against, in this case, the elements, then the body can attack itself. A lot of this is anecdote, although I haven’t looked robustly at this. That being said, Wim Hof has been able to replicate some of his findings or what’s been observed in him in others that he’s taught. So it’s beyond anecdote. I mean, it’s not quite the clinical trial, for at least for immune, but it’s something. Mike, what thoughts you have on the immune aspect of this, and can you parse wherever possible between breathwork alone versus cold alone? I know they’re oftentimes done together.

DrMN:

Yeah. So what we do know is that contrary to popular belief, acute stress does actually ramp up the immune system. So a lot of times we hear that, Oh, all this stress is bad for our immune system. That’s kind of true, but that has to do with chronic poor resolution of different stressors. If you go back and think of just ancestral terms, you’re running through the forest or whatever, and you get cut by some weird twig or something like that. You probably want, in that acute case, your immune system to be ramped up a little bit to handle whatever thing is going on, or the lion chasing you or things of that nature. Anecdotally you hear of people who had a very high period of stress, they do okay, then they have three days to relax and they get super sick.

DrMN:

We know acutely the immune system does get a little bit better, more ramped up from that. Now we can drive that to a poor outcome by just chronically staying in that state all the time and that’s not beneficial. That has the reverse effect. So it’s kind of like a bi-phasic response. When you do what’s typically Wim Hof breathing technique, which is like a supra ventilation. You’re kind of inhaling and exhaling very fast. That is an acute stressor. You think about if you didn’t know any different and you see someone breathing really hard, you would assume they probably just did a lot of hard, heavy exercise. That can acutely increase the immune system. That was the one study they did and I don’t remember if it was published in PNS or somewhere else, but I think they put in an endotoxin, wasn’t it?

DrMN:

Then Wim Hof did his breathing technique with the people and they found that their immune system was able to fend off this invader. Cold water probably has a very similar effect. I would say immune changes based on cold water, most of the literature would probably say, yeah, I think that that kind of makes sense. There’s movements in that direction. Does all the literature perfectly match that? Not quite, but nothing’s really perfect anyway. The caveat that makes it harder to study is what may be an acute stressor for one person may not be an acute stressor for someone else. It may be a chronic stressor for somebody else. So if you think about how you’re going to set up a study, you’re going to say, for recovery, a lot of times they would use 50 degree Fahrenheit water for 12 to 15 minutes or sometimes 10 minutes. But if someone’s more acclimated to that, that may have a different physiologic response than somebody else. So I would say in general, acute effects on the immune system from cold water, I think is probably beneficial. There’s some early literature that does support that.

DrMR:

With the study that you’re referring to I believe the finding was most people will have this unnecessary, but very strong reaction against the endotoxin. Wim Hof was able to suppress their reaction so that the immune system didn’t have this kind of unnecessary but strong response. That kind of ties into some of the findings, again mostly anecdote, that he’s able to help people or the technique is with auto-immune conditions. This does pose a question, which is, does this stress lead to immunosuppression that may also increase risk for infection? We see this with some obviously immunosuppressive drugs. They may help something like RA or inflammatory bowel disease on the one hand, but they increased risk of infection on the other. That also may be a false dichotomy that I’m painting there because I believe that if we looked hard enough, we could probably make a case that certain things like sleep and/or improved diet quality would improve both autoimmune conditions and would not increase risk of infection or would allow one to better fight off infection.

DrMR:

So it may not be that there’s always kind of this teeter-totter in the immune system. But that is one question I have, which is, you know, do these people who are doing the cold exposure and the breathwork therapy, see this global immune benefit? I would assume they are, because it does seem that these foundational pillars, so to speak, diet, sleep, stress if addressed the right way, don’t seem to have this trade-off where some drugs will help one thing, but cause another problem. I’ll remain open there to whatever the data says, but it is interesting. That, that acute versus chronic, and maybe to our earlier line of inquiry, it’s more so about having the right amount of load so that no one over exceeds their capacity to say buffer. I guess maybe this would be considered a pseudo hormetic stress for the immune system, as long as the load wasn’t too excessive.

Homeostatic Regulators

DrMN:

Yeah. How I think of it from a conceptual framework and obviously I’m biased because I did a whole course on physiologic flexibility. So someone has nutrition and exercise down pretty good or maybe they’ve got some other weird stuff we can’t quite figure out, what are other points of intervention in our physiology that we know? We know they probably need to be stressed. We know they can adapt. We know they are probably not getting the stressors that they used to get. So you can look at things that the body has to hold within a very tight window or else you’re dead. So if I think the body is survival based or hardwired to do everything possible to survive, especially acutely, I refer to them as homeostatic regulators. Things we have to regulate to keep homeostasis or a nice even point. Body temperature is the big one, right?

DrMN:

98.6. It’s actually a little bit less than that. We can’t regulate much more than a few degrees, either direction in terms of core body temperature, or you’re going to be in a world of hurt or die from heat stroke or die from being too cold. However, with training, we can put people in very hot environments for short periods of time. We can put people in very cold environments for short periods of time and they can get better at buffering and those changes in temperature. Another one would be pH. Your body has to operate within a very fine range of pH or else everything’s going to go wrong. We also know we can do crazy stuff like you’ve done before. We can put you on a two rower and have you go as hard as you possibly can for three minutes.

DrMN:

Your body is going to create a ton of lactate and a ton of hydrogen ions. You’re literally going to be dumping acid into your muscles, but over time and with training and your body gets better at adapting to that. We can do that at rest with using different types of breathing techniques. If you go back to the Wim Hof breathing technique, what you’re doing when you’re doing a super ventilation or a hyperventilation technique, you are actually driving and exhaling more carbon dioxide. So carbon dioxide, when it’s in the body forms carbonic acid. It’s acidic. So if I am getting rid of more CO2 and I’m not doing any exercise, I’m just at rest, then the body temporarily does become a little bit more alkaline. That’s a temporary effect. That’s not a permanent effect. So there may be some change there in terms of homeostatic regulators. The last two would probably be blood glucose and then, like we mentioned, carbon dioxide and oxygen. So I think if you can do things to safely edge out of your comfort zone, just a little bit more of that eustress model in those four areas, and assuming you’ve got the basics under wraps, that’s the next area to be a more resilient, better functioning human, and to be able to handle more random acute stressors from life.

DrMR:

Gotcha. And then a theoretical gain for multiple systems of the of the body, including the immune system. Would you agree?

DrMN:

Yeah, that’d be my guess because the immune system is just so tied in to everything else. Unfortunately we’re running the opposite of that experiment now for most people. We’re removing a lot of those stressors. A lot of people don’t do high-intensity exercise. People don’t do different breathing techniques. They don’t have much exposure to hot. They don’t have much exposure to cold. They’re pretty poor at handling high spikes of blood glucose or long periods without blood glucose such as fasting. So we’re kind of running the opposite experiment. I would say that the general public level, at least in the US, it’s not super favorable and you drop those humans into an area of caloric surplus and sleep deficit and it’s not good.

DrMR:

Yeah. It’s not going good so far. All right. So let’s go into some how-tos. Maybe actually before we go into the how-tos, but as a springboard to that, have you looked at the cryotherapy chamber, gas chambers versus an ice bath or a water bath? I’ve done both. My strong preference is for getting in the water as compared to getting into the gas chamber. It’s not to disparage the cryotherapy chambers. I like what they’re doing. Personal preference clearly is the water. I’m just wondering if there’s been any comparison there and what the consensus is.

DrMN:

There’s been a little comparison. There isn’t nearly as much data on the “blast your skin with super cold nitrogen” approach just because it’s a newer-ish technology. It wasn’t really that available before. I’ve done both. From what I can tell, looking at the literature, I think the cold water probably has more benefits. Now that could just be because there just isn’t much data on the air kind of cryo version. The mechanisms are quite different. I found like the cryo, the air version, wasn’t really that bad. I was expecting it to be quite a bit worse, but it wasn’t too bad. But if we look at what’s going on. If we put someone in water, let’s go back to thermodynamics. We know you’re going to draw away more heat faster than you are air.

DrMN:

Now we can make up for that difference, like we can with the air cryo, by making the air a lot, lot colder. So we can make that more of a temperature difference, but we’re still dealing with the medium of air, which for thermal conduction, is not very good. You’re relying on convection at that point. If we go into the physiology just a little bit, the air version, definitely, I think you get a sensation that it feels good because you’re lighting up more of those sympathetic nerve endings that are more on the end of your skin. So if you touch your skin, it’s very sensitive for good reason. So in the air version, we know you’re not getting much deep tissue cooling, really at all. But you are getting a pretty big effect from the nervous system and just kind of being able to survive something that feels very, very cold because you’re lighting up all those nerve endings on the end of the skin.

DrMN:

When you get in cold water. I think a lot of it depends on the temperature too. So recently, before we got on here, I had mine set to 34, 35 degrees for a while. I had been in South Padre, Texas kiteboarding for a while. Hadn’t been used to it. Got in the first day and it was just God, awful horrible. It was really bad. When I got out after just 30 seconds, I didn’t have that kind of colder sensation that I’ve gotten from doing just 45 degrees for like four or five minutes. More than likely because I’m getting more of that acute lighting up those nerve endings. I’m not in long enough to see much of a heat transfer effect. Similar to when I did my master’s thesis, I actually worked on with what the military now calls a ray gun or active denial system. It is literally a big microwave transmitter they mounted to the back of a truck. It puts out frequency in the gigahertz range. So super, super high frequency. When you go high frequency on a microwave, you get very low penetration. So what it does is it lights up all those sympathetic nerve endings on your skin, feels like your skin is being burnt by a light bulb, but there’s no deep tissue necrosis or cell death or heating of it. I think sometimes by just interacting with that skin environment, you’re getting not as much heat transfer and probably more of just a nervous system effect. I would love to see more of a metabolic study comparing cold water immersion compared to just the air version. My gut feeling is that the more metabolic benefits, especially the “beige-ing” of fat and just the ability to handle glucose and fuels will probably show up more with the cold water immersion in the water than it would just from the air.

How To Do This

DrMR:

Yeah. Certainly, that’s been my lived experience. It’s a whole other ball game when you’re actually getting into the water. Let’s give people some protocol and usage guides. One of the simple things that people can start with. Turn your shower all the way to cold. So when I go home to visit family in the Northeast and it’s December, that is awesome. It is cold and I’ll be in there for a minute or two and you know, your skin will feel a little bit numb. When you get out, take it with a grain of salt and you have to build up to it a little bit, but you will feel fantastic. In the summertime in Austin, I was praying for the cold water to get colder.

DrMR:

I’m going to guess at my parents’ place in December in Massachusetts, it was probably close to 45 degrees. It’s cold. I don’t know that for a fact, I’m just guesstimating and I’m guessing in Austin in the summer, the water maybe gets low sixties. There’s a noticeable difference, but if you have nothing else, you don’t need to go out and buy a freezer chest. You can just start off with maybe a minute or two on warm, do whatever washing you gotta do in the shower and then just do the last 30 seconds or so as cold as a shower will go. The first 10 seconds is definitely the worst, you have to push through that. Then on the other side of that, it’s not so jolting, it’s actually not too bad. If you can let that cold kind of permeate you, I think you’ll find when you shut the water off, you feel zestful, refreshing, clean, clear, very bright bright-eyed so to speak. So that’s one easy way to start. Then there’s the chamber. Mike, before we go to the chamber, any simple on-ramp guides for people with cold exposure.

DrMN:

Yeah. I tell people the same thing. Wim Hof popularized this. I was telling people to start at just 10 seconds, just turn it to cold and count backwards from 10. Most people can probably do that and then just expand from there to 20 seconds, 30 seconds. Usually what you find is the first exposure is, by far, the worst. So once you get through the first 10 seconds, it’s not too bad. From a behavioral standpoint I find telling someone, go take your shower and at the end, just do two minutes of cold water” they never comply. So I start with 10 seconds.

DrMN:

Just 10 seconds. You can do 10 seconds. So just the more on the psychology side of making it small enough that they can’t really talk themselves out of it.

DrMR:

Agreed. Just to reiterate for people, let’s say you do it for 40 seconds. The whole 40 seconds will not feel the same way. The first 10 is far worse. The body isn’t used to this exposure. So it’s a little bit uncomfortable at first, but on the other side of that, there is this nice result. As you said earlier, Mike, one of the things you do is talk yourself into it saying “I’m going to feel so great after”. You will feel great after for 10, 20, 30 minutes. So just get through that 10 seconds. Then on the other side, there will be 30 minutes of mental clarity and energy. I oftentimes laugh actually when I’m doing it.

DrMR:

So it’s probably worth it. Then there’s the tank set up, which far and away, is my favorite. One of my favorite things to do is go in the sauna, I’ll be in there for maybe 15 minutes or so, and then I go into the freezer tank and I go face down and I hold my breath. Completely submerged, hold my breath. What’s really cool about this is you’re in there and you can hear your heart beating because when it’s quiet and you can hear your heartbeat. When you first get in coming out of the sauna, your heart rate is going to be elevated. But then as you’re in there for 30 seconds or a minute kind of underneath the water, the heart rate slows. You almost feel like you’re just frozen in time.

DrMR:

It’s a really cool phenomenon just to kind of witness and you can actually stay under water for a decent amount of time because the heart rate is so slow and you’re using less oxygen, at least I think you are. So that’s been a really cool thing just to kind of see and hear and feel that circulatory shift. Mike, what do you recommend people do with the tank? By the way, Mike was nice enough to send me his instructions. Michael we took your instructions and made them into a Google doc and if it’s cool with you, we’ll share it with the audience.

DrMN:

Yeah, of course.

DrMR:

I don’t mean to put you on the spot here. So Mike sent me his instructions for how he made his setup, which is essentially a pond filter for macroparticles and an Ozonator for microparticles, bacteria, fungus, etc. It’s an amazing setup. He also has an external thermostat. So you can set it at whatever temperature that you want. So we’ll link for that. If someone wants to just buy a freezer on Amazon, you’re looking at between five and $700. Other equipment, I think $100-$200. It’s not pennies, but it’s also not exorbitant. For what I’ve gotten out of it, it’s been a great investment. What do you recommend people do if they’re going to take the leap into tankville?

DrMN:

My recommendations for people,once they have something set up, I’m a bigger fan of daily exposure and just making it easier. I started at just 50 degrees people. People I’ve worked with, some of them start at 55, 60 degrees. So at face value, you’re like, wait a minute. That’s not that cold. Your reference point a lot of times is air temperature. The air temperature, not that big of a deal. Even, water temperature, if you’ve been in water for many hours at 70 degrees, it can be cold. You can run into issues sometimes because you’re losing that amount of heat. As a recommendation, I usually tell people, 50, 55 degrees get in for 30 seconds, get out. What I like people to do is see how fast you can control your breathing.

DrMN:

As you inhale through your nose and exhale through your mouth or inhale through your nose, exhale through your nose, it’s going to be a little bit more calming. I do like people to get out before they paradoxically start feeling too good. There’s some negative things that can happen to you after the fact. I grew up in Minnesota. I always remember my parents telling me, okay, if you go outside and your feet get cold and then they get warm again, you need to come inside right away. That doesn’t make any sense. Then when it actually happened to me once. It’s like your body is telling you your feet are cold. Your feet are cold. And you aren’t listening. You didn’t randomly find some fire in the snowbank. Your body just starts shutting down sensation because you’re starting to freeze your feet.

DrMN:

So similar idea, kind of a landmark. I tell people, get out before you start to shiver. I don’t think that there is much benefit to shivering in there. Plus you’re running more of a risk with cold. There’s a lot bigger safety margin than with hot. If you get into something like a hot tub that’s too hot, you can burn yourself instantly. With cold you have a much bigger kind of safety area. It’s going to be several minutes before you’re going to run into issues even in very, very cold water. The other part that I do that helps is I actually have a thin pair of neoprene booties that I’ll put on. Part of that is just to keep crap out of the tank, so I don’t have to clean it as much, because I’m lazy.

DrMN:

The other part is if you have some even thin layer on your feet or your feet and your hands out, you can get more of a whole body effect and it doesn’t feel quite as bad. So I tell people if you can do that, that’s even better. If not, don’t worry about it. The feet don’t seem to be as bad as the hands for most people. So having your hands outside of the water makes it a little bit more tolerable. At first I’m all about finding anything I can do to make it somewhat tolerable, because it’s going to suck. I want someone to do it just a little bit more each day. So you may start at just 50 degrees for 30 seconds. Usually I’ll have people not put their head in. One, because the size of the tank may not allow it.

DrMN:

You can get out and then stick your head in if you want. The other part is if you can put your head under water, you’ll get something called the mammalian dive reflex where your heart rate will actually get quite a bit lower. The caveat is that I would not do any breathing techniques and stick my face under water. You can end up with a shallow water blackouts, which have happened to people. Unfortunately, people have died from that. Wim Hof at an incident where he basically almost died from that happening. So just be super careful with that. Especially if you’re trying to combine some super ventilatory method where you’re purposely off-gassing a lot of CO2 and you’re sticking your head under water.

DrMN:

In general, I tell people, just sit in the tank, keep your head out, keep your hands out, control your breathing as fast as you can. If you want to use a watch or something to time it just so you know where you’re at. I think that’s good. If you still want the exposure of cold water, I’ll have people get out and just stick your head in the water once you’re outside of the tub. So you’re not sitting in it. From there you can get as fancy as you want. My bias is I think people get a little bit too aggressive, pushing the adaptations. I don’t think you need to. If you think about you spent most of your time being 70 ish degrees going into water that’s 50 degrees that that’s going to be enough to get your body to adapt in the direction you want it to go.

DrMN:

I don’t think you need to get super, super aggressive with it. Last thing and another game I play is trying to get out before I start to feel too good. I know that sounds weird because when you get in, like you said, the first two seconds are by far the worst and then it starts to get easier. Then it’s easy to kind of fall into this trap of “oh, I’ll just stay in a lot longer, it doesn’t feel so bad”. My bias is I’m probably more on the cautious side of, get out before that. You can always go again the next day. I don’t think there’s any reason to go super hard and super long. There’s no Olympics. There’s just no competition. I think if you push it a little bit too hard, even if you stay in the safe zone again, your stressor now is starting to get to the point where you may be outstripping your recovery capacity.

DrMR:

Several grade points starting with the last one. More doesn’t seem to equal better. I’ve learned that. What I look for is if on the back end of that, if I’m shivering, this is partially known as after drop. If I’m really cold for like 30 minutes after then I know I pushed it too hard.

DrMR:

To your point, it’s easy to kind of stay in there once you’ve acclimated a bit. Be on the lookout for those other things that tell you you’ve pushed past that sweet spot. Then definitely I think it’s always worth repeating this since the cold exposure is oftentimes paired with the Wim Hof breathing, you shouldn’t be hyperventilating and then going into water or hyperventilating in the water. I’m sure most people who’ve tried the Wim Hof breathing method, when they’re doing the extended breath-holds, you can pass out. I think more commonly you have these kind of pseudo pass-outs where I will be staring at the clock, trying to go as long as I can and then all of a sudden 20 seconds have passed and I didn’t even realize it. I’ve breathed in and I’m in my body saying “did I just breathe in?” and I can tell in my lungs that I did breathe in, but I didn’t even realize that I did.

DrMR:

You don’t want to be doing that in a freezer full of water. Definitely be careful not to pair those two.

DrMN:

If you’re doing Wim Hof technique, I know some of the, let’s say early proponents of it had some crazy videos. They’re like “you’re now breathing really fast, you’re hyper oxygenating your body”. No, you are not. You are actually depleting your body of oxygen, which is why, if you’re not careful, you will pass out because your body is like I’m not getting enough oxygen. I know that I need this function. So I’m basically cutting you off. So if you were doing that standing or even sitting, and especially if you’re not experienced with it, you can have some bad stuff happen. So lay down, be in a safe area, don’t do it in the water. If you pass out, when you’re laying down, there’s nowhere to go. You’re already at the lowest level. You’re going to be okay.

DrRuscioResources:

Hi everyone. This is Dr. Ruscio. In case you need help, I wanted to quickly make you aware of what resources are available to you. If you go to drruscio.com/Resources, you will see a few links you can click through for more. Firstly, there is the clinic, which I’m immensely proud of. The fact that we deliver, cost-effective, simple, but highly efficacious, functional medicine. There’s also my book, Healthy Gut, Healthy You, which has been proven to allow those who’ve been unable to improve their health, even after seeing numerous doctors, be able to help them finally feel better. There’s also our store where there’s a number of products like our Elemental Heal line, our probiotic line, and other gut supportive and health supportive supplements. We now offer health coaching. So if you’ve read the book or listened to a podcast like this one, or are reading about a product and you need some help with how or when to use, or how to integrate with diet, we now offer health coaching to help you along your way. And then finally, if you are a clinician, there is our clinicians newsletter, the Future of Functional Medicine Review. I’m very proud to say, we’ve now had doctors who’ve read that newsletter, find challenging cases in their practices, apply what we teach in the newsletter and be able to help these patients who were otherwise considered challenging cases. Everything for these resources can be accessed through drruscio.com/Resources. Alrighty, back to the show.

Don’t Try This at Home

DrMR:

Well, Mike, now I have you here, I’m going to kind of share with the audience how dumb I can be. I figured I should probably ask you this question because one of the things that I’ve been experimenting with, and this is a “don’t try this at home” type thing. We all have weird stuff that we do, pushing the envelope with some of this. So when I was home, I was walking from my parents to my brother’s house.

DrMR:

It’s about a 10 minute walk and it was 40-42 degrees. I was just in shorts and no shirt and I also started doing some of the Wim Hof breathing while I was walking. I was being careful because as part of the Wim Hof breathing, you’ll do a breath-hold. I don’t believe that the Wim Hof protocol advocates for while you’re braving cold exposure, like when they’re doing these Kilimanjaro hikes, I don’t believe they’re doing any breath-holds. I think they’re just doing the hyperventilations to a degree. There’s also some sort of occipital ridge area they focus on to try to ignite the inner fire, so to speak. I don’t believe they advocate for a breath-hold, but me being an idiot thinking, well, maybe I can increase some of my lung and endurance capacity by improving CO2 tolerance.

DrMR:

I’ll just do a full exhale with extended hold while I’m walking. I did get lightheaded. So what I would do is make sure I’m not doing a breath-hold while I’m crossing the street, because if I pass out in the middle of the road, game over. So I would only do it in areas that were safe. If I was coming to the end of the breath-hold, I’d kind of just take a knee so if I did pass out, I’d just fall. Outside of any situational risk is there anything that’s overly detrimental about doing something like that? Just to share one evidence point, I know Laird Hamilton is doing some of this where they’re doing these exercises while holding their breath. That’s partially where I got the idea. So I’m not, I’m not a complete moron, but just wondering, you know, anything I should know about doing that.

DrMN:

If you talk to Laird, he’ll be like, yeah, I knew guys who are doing this in our pool and they get what he calls floppy, which means they passed out under underwater and obviously they’re supervised and they’ve done this a lot. So they bring him back to the surface and they’re fine, you know, but doing that under somebody’s supervision, like that is a completely different world compared to something going to do by yourself in your backyard. I’m not super convinced that the Wim Hof techniques, in terms of a super ventilation and then a breath-hold, is the best idea for CO2 tolerance. My bias, and I don’t have any data to base this on, is that I think it might be the opposite.

DrMN:

If we think back, we’re laying down, we’re safe. We’re not walking across the street. We’re not even walking. We’re just laying down in our backyard. We’re in a safe place. We’re going to hyperventilate really fast. So inhale, exhale. You know, if you talk to Wim, he doesn’t care, nose, mouth, whatever orifice you want, doesn’t matter. I personally will do inhale through my nose, exhale through my mouth. So I do that for 20, 30, 40, 50 breaths. You can do either a hard exhale or not. Then you’re going to do a breath-hold. See how long you can hold your breath. So when I am super ventilating breathing really, really fast, I am exhaling a lot of carbon dioxide. So that will temporarily make my blood more alkaline.

DrMN:

When you are holding your breath, your body is still running metabolism. So when it’s running metabolism, you’re building up a by-product of CO2. CO2 is not really a waste product. It’s a by-product. You can hold your breath much longer doing that Wim Hof type method, because you have just gotten rid of a lot more CO2. So you actually have made the blood temporarily a little bit more alkaline. So now it’s starting to become a little bit more acidic. You’ve driven off more of that CO2. So you change those chemoceptors and you can hold your breath a little bit longer. If you want to do the longest breath-hold possible and you’re not near water. Freedivers have known this for quite a while. The caveat is, I think that may be useful from expanding both ends of where you’re going and then switching back and forth.

DrMN:

So a high, high rate of ventilation, then almost no ventilation, and then go back and forth. So I think there may be some benefit to that in terms of training the physiologic system from both ends. However, if you said, I want to increase my CO2 tolerance, I don’t know if the hyperventilation beforehand is sort of putting you into an artificial state that you wouldn’t normally have. So I’m a bigger fan of nasal breathing on a rower, nasal breathing on a bike. Beyond that, Anders Olson has recommended this, you can do like a hypo volumetric walking. So you’re going to inhale and exhale through your nose and just start to make the exhale a little bit longer and a little bit longer. That is hard, but it’s probably not enough of a stressor to make you pass out. I didn’t change the gain of that CO2 sensor yet by hyperventilating beforehand.

DrMN:

So I think that’s where I would probably differentiate a little bit. If I was really going after CO2 tolerance, I would do a lot of nasal breathing. I would slow inhale and exhale. You’ll actually see your heart rate will drop when you do that. Then I would probably play around with breathing normal and then exhale, and then see how long you can kind of hold your breath, that type of thing, which is more kind of what a lot of free divers, have done in terms of their dry line training.

DrMN:

Physiologic Flexibility Course

DrMR:

So I got some stuff here to play with. We didn’t necessarily try to coordinate this, but you have the physiological flexibility course, which ironically ties in so nicely with the theme of this call. Would you tell people a little bit more about that and obviously in light of this conversation and with how important it is to be not only metabolically, but also physiologically flexible. I think this is a really timely course. Tell us a little bit more.

DrMN:

Like I said, I was always thinking of, Hey, you got your basics down, right? This could be just people who exercise. This could be high end athletes. Exercise is good. Your training is good. Sleep is good. You’re pretty good with all the basics, like what is the next level? If you look at all these different recovery metrics and breathing techniques and cold water and hot water and increased circulation and this and that, I’ve always thinking, okay, so what is the main leverage within the body? I think it’s the homeostatic regulators, right? So things your body has to hold constant, no matter what. Temperature, pH, CO2/O2 levels, probably blood glucose. So I think those would be kind of the four areas. Then within that, we know you can do a fair amount of training.

DrMN:

Like we talked about, and you can get exposure to cold, you can exposure to hot, you can do breathing techniques to change pH locally. You can do what I call the “two pop tart test” and see, can you buffer 80 grams of glucose, without exercise or with exercise. You go through periods of time, like 19 to 24 hours of fasting where your blood glucose is going to go down. Can you use other fuels effectively? You do nasal breathing for more aerobic based development. How is your aerobic base? Is your VO2, like the bottom 10% of the population. The rest of your life is going to be pretty hard. So how do all those things tie together? Because what I saw was, especially in the fitness world, there’s lots of cool techniques, there’s lots of cool courses. There’s a lot of stuff on just breathing alone now, but I didn’t see anything that kind of ties all of it together with any sort of physiologic rationale. Um, and then beyond that, like, what does the current literature say?

DrMN:

I could probably sell a lot more courses if I said, “Hey, just get in the cold water, like two hours a day, you’re going to burn fat, like crazy” You know, you can eat pizza every night. That’s unethical, but it would probably sell. So what does the literature say about each one of those? Then what is the bigger picture of how they all relate together? Then what are the individual action steps you would do for each one? So if you want to get into cold water, you know, where do you start? You want to get into certain breathing techniques, where do you start? I think the other part that’s not talked about a lot is based on your goals for training or life, like where should you start?

DrMN:

I just listed off eight different interventions of categories you could do. There are probably a bazillion ones in each one. Out of all of those, where would you start? So my bias, I think starting with temperature is probably the best one. We have the most data. It’s something people are probably not exposed to at all now. Because they’re not exposed to it hardly at all you don’t need much time to do it. You can start with a 10-30 second cold shower and you don’t need a lot. Ironically on the heat side, exercise is a really good way to produce internal heat, heat shock proteins, all that stuff. You can go beyond that and do like Laird and stick your Airdyne bike in the sauna and exercise in there, which is batshit crazy. But if you’re Laird Hamilton and you’ve been doing this stuff for two decades, it kind of makes sense to be on that end of the spectrum. How do all those things relate and then are there things you shouldn’t do? Right. So if your goal is, I want to add as much hypertrophy (or muscle mass) as humanly possible.

DrMN:

Then yeah, getting in 45 degree water for 15 minutes immediately after training is probably not a good idea. There’s like two or three studies now that have shown that. Again, is the effect size massive? No, but it doesn’t appear to have that effect on aerobic exercise. There’s some data on aerobic exercise that heat exposure after may further exacerbate the positive adaptations of exercise by completely different mechanisms. Even aerobic exercise with exposure to cold may up regulate a PGC-1alpha. So we may see benefits thereby completely different mechanisms. We then pair these things together so that you’re kind of pulling the system in the same direction, not pushing it on two opposite ends. Pushing it one direction with hypertrophy work and then kind of kicking yourself in the foot going in the other direction.

Episode Wrap-Up

DrMR:

Awesome. I think it is a great idea to be looking at all these different stress categories that one could try to optimize for and give people a overarching structure for how to apply them. It makes a ton of sense, and further to your point how one of these things comes into Vogue, right now we’re kind of voguing on cold exposure and breathing, but we should look at this in the context of the broader programming of the individual so that we don’t just excessively weigh the importance of what’s in Vogue at the expense of what may be better for the individual. Where can people go to learn more about that and/or learn more about you?

DrMN:

So right now the best place is probably through the Flex Diet? So go to flexdiet.com. There’ll be a little button there on the top where you can get on the wait list and that’ll put you actually on the list for both potential courses, the Flex Diet certification and the physiologic flexibility certification. You’ll get the newsletter that has all the updates daily from it. That would be the best place to go.

DrMR:

Awesome. Check out Mike’s work. I train with Mike. I really value his approach. So he definitely has my stamp of approval and of appreciation. Mike, thanks so much for what you’re doing. I really appreciate it and you for taking the time to have a chill talk with us today.

DrMN:

Yeah. I like the chill talk. Thank you so much for having me come on here again. I really appreciate it. And thanks for sharing all of your experience.

Outro:

Thank you for listening to Dr. Ruscio radio today. Check us out on iTunes and leave a review. Visit Dr. Ruscio.com to ask a question for an upcoming podcast, post comments for today’s show and sign up to receive weekly updates.

➕ DIY Cold Water Immersion Freezer

Chest Freezer

First – obtain a chest freezer. The size of the freezer depends on the size of the individual and how comfortably you want to fit inside. For example, a larger human would benefit from a freezer with a range from 16 – 18 cubic feet.

Location of the freezer is important. Some types of freezer aren’t built for certain environments where the compressor is rated. Additionally, do not place it where chances of water leaking can cause major damage.

Sealing

Freezers are not designed to hold water, so it needs to be sealed properly.

Caulk all the sides, seams, and don’t forget to seal the bottom.

Be sure to pay special attention to the corners to ensure full coverage.

Let it cure/fully set before adding the water.

*Helpful tip*

Be careful when stepping inside the freezer to prevent denting and other interior damage.

Adding Water

Use a durable drain plug inside the freezer to hold the water. You can seal the default plug that comes with the freezer but that may make it more difficult to drain the water later on.

Test the water retention to ensure there is no leakage, a couple of inches of water at a time.

Be sure to not fill it all the way. The water level should be at least 6 inches from the top to allow the water to rise as you enter the freezer.

When using a hose, attaching a water filter is definitely an added benefit. Be sure to secure it in place using duct tape or another method to prevent it from moving. Slowly turn on the water as the pressure will build up inside the filter.

*Helpful tip*

Add some ice BEFORE filling the freezer with water to help to cool the water faster. About 3-5 18 lb bags of ice.

Temperature Control

The freezer should be able to hold the water at a cool temperature on its own. DO NOT leave the freezer on as it may risk overheating. Best is to run it in 30-40 minute intervals throughout the day or before getting inside the freezer.

Getting a device to control the temperature will help avoid the manual labor it takes to keep the water cool. One such item is an Inkbird timer which is set up to run by temperature with a probe that goes into water.

*Helpful tip*

Lower the temperature incrementally to lessen power usage.

Cleaning Water

The water should be changed regularly, about every 4-6 weeks. Additionally, you can get devices to help keep the water clean and lessen frequency of changing out the water. 

One such device is an ozone generator that has an attachment for purifying water. Another device would be a water pump that is typically used for small ponds to keep the water circulating.

Having these devices helps to maintain the water and easily manage the temperature and cleanliness. An optimal setup would have the freezer plugged into Inkbird, and then the Inkbird is plugged into a power source. A splitter is attached to the Inkbird where the pump and freezer are connected, which only turns them on when the temperature drops.

Guidelines

Here are some useful guidelines to follow when using this cold water immersion freezer.

  • Be sure to have everything unplugged before getting into it
  • Don’t spend too much time in the water
  • Start at 50° F for 5 minutes
  • Don’t be in a constant state of shivering 
  • Water booties are helpful for keeping water clean and feet warm

Item List

Inkbird WiFi ITC-308 Digital Temperature Controller
https://amzn.to/2XUSjQa 

Invincible Marine 3/4-Inch Brass Snap Plug
https://amzn.to/35YbDQJ 

Beckett Corporation 500 GPH Submersible Pond Water Pump Kit
https://amzn.to/3p7f92U 

Camco 40043 TastePure RV/Marine Water Filter
https://amzn.to/2Nnm9e5 

GE Sealants & Adhesives GE012A All Purpose Silicone 1 Sealant
https://amzn.to/2M6a7VK 

Ozone Generator Air Purifier
https://amzn.to/3iwxjbO 

Aquarium Clean Light Submersible Waterproof Lamp
https://amzn.to/3nZRIaf 

Mike Nelson’s Resources

Mike Nelson’s Podcast
https://flexdiet-podcast.s3.amazonaws.com/podcast-freezer.mp3

Mike Nelson’s Freezer Video 1
https://youtu.be/uLgJ21WC9R4

Mike Nelson’s Early Freezer Setup 2
https://youtu.be/kLdt7v5Cskk


Sponsored Resources

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Discussion

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