Preview Mode Links will not work in preview mode

Wild Health Podcast

Nov 21, 2018

Jody wants to talk about Saunas


"Give me a fever, and I can cure the world." quote by a famous really old doctor (Hippocrates). We've known Sauna is good for you for a long time. Ancient people have been using forever, and it's extremely popular in places like Finland.


Matt and Mike discuss how your pulse can go up by about 30% in the sauna and it's really good for your heart.

They describe THIS JAMA study of 2300 men that shows those that visited the sauna 4-7 times a week were over 60% less likely to experience sudden cardiac death and were 50% less likely to die from cardiovascular disease than those who only visited a sauna once a week.

There's a dose dependent response as well.


Matt talks about a fruit fly study that increased their lifespan on average by about 5%. That equates to 4 years for a person......but you can't apply to a person. Interesting data, though.

Sitting in a Sauna can burn about 300 calories per session. You're exercising while sitting there.


Jody says he read on the internet that a doctor says you can't detox through sauna use since the kidneys and liver are what detoxes.

Matt goes off on this topic refuting that claim and telling why he's definitely not impressed by a claim just because "a doctor" says it. Curiosity and the desire to continue learning are more important than credentials.


Matt and Mike discuss the studies showing that multiple heavy metals like BPA and phthalates have been found in sweat, suggesting that you can sweat them out. There is some controversy, but we think that you can detox from sweating in a sauna, and the downsides are so low that it's worth trying. Worst case scenario, you're getting some good relaxation.


Matt and Mike discuss the Finnish study a little more and how it decreased the risk for Alzheimer's by 65%, which could be partly from relaxation, but probably more from the microvascular effects of the increased heart rate and hyperthermic conditioning.


Mike discusses the temperatures you get to in sauna after Jody asks how high the temperature needs to be. Typically, infrared saunas should be 120-140F (49-60C) while traditional saunas must be above 150F (65.5C) to be effective.  I would say make it as hot as you can stand it. You want it to be uncomfortable enough so that your body makes the proper responses.


Mike and Matt talk about how hot exactly to get ( "if your skin is melting......that's too hot"). They describe how each of the different sauna types work to heat you up. Infrared saunas work by directing infrared rays at your body and penetrating the tissues, just like the sun.   xcept there aren't any UV rays, which are the potentially harmful part of sunlight. And dry saunas work by heating up the air, which heats up your body. So, the air temperature in an infrared sauna doesn't need to be as hot to work. It works more directly on your body. This means it also uses about 1/3rd of the energy of a dry sauna.


Matt talks about how sauna affects insulin sensitivity, which affects muscle growth, but also is really nice to know if you're diabetic.  Could be very beneficial for diabetic patients.

It also increases HGH. Studies ( H R  and H R ) have shown that growth hormone levels more than doubled after 2 20-minute sauna visits at 176F and levels hopped up 5 times with 2 15 minutes sessions at 212F! 212, is definitely too hot, though. Don't do that!

12:58 - 14:30

These studies on HGH were dose dependent. Two 1 hours sessions increased HGH levels by 16 times. We're not going to go into the pathway of growth hormone mediating IGF-1, activation of m-tor leading to protein synthesis and Fox o activation inhibiting protein degradation.   Everyone knows that basically HGH makes you swole. You look better, are stronger, and feel better with more growth hormone.

I know guys who are paying good money for HGH supplements, when it looks like they could just make themselves super hot and relax in a sauna without the risks associated with pills and injections.  Way safer, cheaper, and easier. Basically get super hot by getting super hot. 'r get super hot to get super hot.

14:30 - 16:00

Along with helping gain muscle, the heat can also help retain muscle.  A study in rodents showed that the heat-acclimated group retained 30% more muscle that the control group.  You're body is always either building muscle or breaking it down. Protein synthesis or protein degradation.  Saunas and heat stress induce production of heat shock proteins, which reduces protein degradation. So, not only does does it increase protein synthesis by increasing growth hormone like we talked about, but it stops the degradation.  There was a really cool study where they took rats, immobilized their leg, like if you got a cast, then when they remobilized and let them work the leg again and they found 30% more muscle growth when using sauna. Applicable to someone who has an injury and wants to recover more quickly.

16:00 - 17:00

Matt discusses the applicability and how it applies to humans and makes sense.  It makes sense from a simplistic standpoint as well. ven while still immobilized you can sauna and even if you can't move the extremity you get the exercise simulation benefits like we talked about earlier with increased heart rate and you get the heat shock proteins, growth hormone, increased blood flow to the leg, etc.   

It's not just muscles, though.  When Matt was training for ironmans, he didn't really want to be carrying around extra muscles for that long of a race, which was like 12 hours for someone super slow like him.  And he was obviously much more concerned with endurance. He remembers Ironman Louisville one year where the temperatures and humidity were in the 90's and there was just carnage along the race course.  If only these racers had known that a few sessions of hanging out in a sauna could dramatically affect their endurance and hyperthermic conditioning and heat tolerance in general.

17:00 - 20:00

They discuss the study that shows increased endurance H R . It showed that a 30 minute sauna session 2 times per week for 3 weeks after workout increased time to exhaustion by 32%.  Now, that's a crazy number, and I don't want you thinking that means you can decrease your 5k time by 32%. The way they did the study they got this number, but in real terms what it equates to is about a 2% improvement in a 5k, which honestly is still massive.  If your PR is 20min for a 5k, then this suggests this very simple 2 wk intervention could decrease that time to 19:36. If you're a runner you realize how much intense training would have to be done to decrease your PR by 24s. This is incredible. Honestly, it's so incredible, I had a hard time believing it initially, especially since this was only done in 6 athletes.  However, it's more believable because they actually showed the physiologic mechanism of why. Blood plasma volume increased by 7.1%. RBCs and total volume were also increased. So, you kind of get the blood doping effects of P', which you've probably heard about from tour de france riders, without injecting and actually cheating. It's just 'like' cheating, but completely legal.  I love anything that basically makes you a better human to the same level as cheating without the risks. That's not the only mechanism, though. It's been proven that muscle glycogen use is decreased, meaning longer time until you hit the wall, less lactate accumulation, and better thermoregulatory control, basically you sweat more and sooner. In the end, if you're trying to get faster or more endurance, then this is totally worth doing.

20:00 - 24:40

Matt discusses the studies on depression. Studies have shown that sauna use releases dynorphins (the opposite of endorphins) which are what create feelings of discomfort.  An increase in dynorphins actually increases endorphin receptors. Your body is kind of trying to compensate is one way to look at this.

Specifically, dynorphins bind to kappa opioid receptors and upregulate mu opioid receptors.  The point is, you don't just feel good right afterwards, but the increase receptors for endorphins mean you're more sensitive to the great feeling of endorphins later as well. You're primed to be pumped and happy.

There was a pretty amazing study in JAMA Psychiatry.  A randomized, placebo controlled trial looking at this showed that 1 session significantly decreased depressive symptoms, and the really cool thing is that it persisted 6 wks.  Maybe longer, but that's when they quit tracking. Now, I TOTALLY didn't believe this when I first read the headline. Absolutely no way that one session of sauna decreased depressive symptoms for at least 6 weeks, maybe longer.  Didn't pass the sniff test, and as a doctor and science geek I was mad at JAMA for publishing this crap and I dug into the article with an angry disposition. So, I was pretty shocked after I read it. It's not a huge study. But it's really well done, and I owed the authors and JAMA a mental apology.  My first thought was that 'well, you can't blind this stuff. People know they're getting the intervention. It's all placebo. But they did a pretty good job. First, they whittled it down from over 300 to about 30 participants and specifically eliminated folks who seemed to be good placebo responders.  Then they did apply some heat, just not intervention heat to the control subjects and about 3/4ths of the controls thought they had gotten the intervention afterwards, so those controls should have a placebo response if that was the case, making the results less significant. But there was still a really significant result.  I'm totally impressed.

24:40 - 27:30

Mike discusses how Sauna can make you more pretty, boost your immune system, makes you smarter, and makes you prettier.

Now remember, you're not getting the UV rays which age skin with the infrared saunas. So, don't confuse this as being the same as sunlight.  It seems from research on this, and just makes sense, that you can increase the rate that you turn over skin cells and get rid of dead cells by sweating.  You also clear pores of dirt and bacteria and flush out wastes. AND you increase capillary circulation. So, you should get a more healthful, young looking glow, which I can tell by your unkempt beard is super important to you.

One study showed that you can potentially decrease your colds by 30% by using a sauna.  Not a huge study, though, with 50 people over 6 months, but we think we have a mechanism, which makes it more plausible.  That mechanism is by increasing WBC's, lymphocytes, neutrophils, and basophils, which suggests a stimulated immune system.  This was in a 2013 study in the Journal of Human Kinetics.

As for sleeping better, it makes sense, but not very much science on this one.

It makes you smarter: It's been shown to increase BDNF, which increases neurogenesis and enhances learning, long term memory, and neuronal plasticity.  This BDNF increase is also one of the reasons that ketones from a ketogenic diet make you more mentally sharp and potentially helps with neurodegenerative disorders, and also part of the reason exercise makes you smarter. It's good stuff.  A really big reason to do sauna. Probably enough in and of itself if none of the other benefits applied.

27:30 - 31:30

Matt and Mike discuss what type of sauna they recommend:

Well, we have absolutely no affiliation with any type of sauna company but we have opinions. We already talked about the differences. Your core body temperature, which is what is going to give you the benefits we've talked about should get just as high with either.  The air temperature will be lower in the infrared, but you should get a similar internal temperature rise. Infrared are traditionally smaller, take less energy, and pose less of a fire hazard, so I think that's why they tend to be more popular now.

That, and the fact that they take less time to heat.  About 15 minutes compared to 30-40 minutes with traditional.  And even before they're fully heated up, you're still getting benefit from the infrared rays penetrating your body and heating you up. If 140 degrees combined with the infrared penetration isn't enough for you, there's a great hack for increasing the temperature even higher that Ben Greenfield describes really well.  We'll link to his site in the show notes. In fact, if you really want to learn more about this after listening to this and digging into the articles we'll link to both Ben and Rhonda Patrick, who have discussed sauna use and hyperthermic conditioning a lot on their sites and podcasts. A lot of my initial knowledge I gleaned about hyperthermic conditioning came from hearing them talk about it and then digging into the literature once they peaked my interest.

In general, either are fine. It kind of depends on your preferences.  I would caution you very strongly against using wet steam rooms, though.  It's fine at your house if you're controlling the water source, but do not use them in gyms or hotels where you don't know where the water is coming from.  Normal tap water has chlorine in it that is released into the air when you evaporate the water and you're inhaling that or any other impurities in the water.

Well, that goes for traditional saunas as well.  The overheating phone incident I mentioned earlier was in a sauna in an airbnb we rented. And I knew they had a sauna, so on the way there I stopped and bought a gallon of distilled water that I could use on the rocks when I needed to.  With all the benefits of hyperthermic conditioning, it would be a shame to negate all those by inhaling chlorine gas.

31:30 - 32:30

Matt and Mike discuss  MFs briefly:

So,  MFs probably deserve their own podcast, which we'll do.   But if you google around before you listen to us talk about it on the podcast and decide that they are harmful enough to worry about, then yes, there are low and zero  MF products out there. Personally, I am very concerned about them and think we're harmed way more than we realize by MF's, which by the way Jody, stand for electromagnetic fields. I hate to be alarmist, but I'm definitely doing everything I can to mitigate their risks to myself and my family. The infrared sauna I bought is a zero  MF version that definitely costs more, but I thought it was worth it. You can find plenty of good options for that.

32:30 - 36:50

Matt and Mike discuss how long you should stay in:

Well, it depends on your goals and how much time you have.  First off, don't be stupid and fall asleep in one for hours at a time.  That's called cooking, not suana'ing. Most of the protocols in the studies we talked about are for 20-30 minutes, but you can definitely go longer. 

The depression study got their participants up to a pretty high core body temperature for about an hour.  So, if you're using this to clinically treat something like depression then maybe longer than if you're doing it just to relax or increase endurance or muscle growth. 'f course, in most studies there was a dose dependent effect.  Remember the HGH study and the massive increase with higher temperatures and longer duration. Similar to high intensity exercise, fasting, and just about anything else you do for performance optimization, there is a higher risk for badness as you push the envelope.  Longer durations mean you definitely need to be more cognizant about how much fluid you drink, replacing your electrolytes, etc. If you really want to get crazy, which sometimes I do, you can workout in the sauna. Be careful, though. Recently I did a high intensity workout consisting of 50 lb 1 arm kettlebell swings, burpees, and goblet squats in a full on infrared sauna and I nearly killed myself.  Went way deep into a pain hole that I could not climb out of for a few days. Similar to a feeling I had one time when I got lost on a long run without water in 100 degree heat. Days of recovery.

You have to be careful as you're working your way up to more intense sauna. Be careful as you start.

36:50 - 38:30

Let's test this:

Jody, you don't have a sauna, but they do have an infrared sauna at the castle that you can use at least a few times per week.  So, let's do this. Try to use it at least 3-4 times per week for 2 months for a full hour. Let's go hard with this. If you workout beforehand, then limit it to 40 minutes, and if you workout in the sauna, then limit it to 20-30 minutes.  Don't fry yourself. Let's get your blood drawn and measure as much as we can and also have you do some exercise tolerance tests. We'll do a modified bruce protocol on the treadmill and a test of max deadlifts at 10 reps and overhead press at 10 reps before and after.  We'll also measure your body composition and weight. Lean muscle mass and body fat percentage. I want to get a good overall view of your health before and after. Try not to workout more or change your diet in any way, though. This is obviously completely unscientific, but we'll control as much as we can.

We're tempted to have you do some stuff around measuring overall well-being, happiness, and sleep as well, but that seems too complicated and too prone to placebo anyway.  The other stuff can definitely be influenced by placebo, but probably not quite as much as subjective scores. Actually, sleep tracking would be cool as well since you can passively measure that with an aura ring.  Add that to the list.

38:30 - end

Matt describes some experiments he's been doing in the shower, sauna, and working out in the sauna. He can increase his core temperature to 101.1 in the shower, but all the way up to 102.2 with an intense workout in the sauna. His core temperature does not increase just sitting in the sauna. This is probably due to his thermoregulatory system being pretty efficient in general.