The Science of Sauna & Heat Exposure Does It Really Work
00:00we humans are kind of funny because sometimes we deliberately expose ourselves to very stressful situations and today I'm referring to deliberate heat exposure specifically the sauna now saunas or deliberate heat exposure have actually been around for thousands of years but over the past few years is getting even more attention in the health and fitness World due to some of the claims that sauna use can stimulate certain health and fitness adaptations there are claims that it can Aid with detoxification recovery and even provide some remarkable cardiovascular benefits that may improve health and lifespan So today we're going to take a look at the brain and other body structures and learn how they respond to heat which will then help us to find out how much truth there is to these sauna related Health claims and of course discuss the sauna protocols you can utilize to reap some of these benefits it's clearly going to be a hot one so let's jump into this anatomical and physiological awesomeness
01:00now before we talk about any potential benefits of sauna or heat exposure we should probably understand how the body actually responds to heat pretty much all of us have a sense and understand to some level that our body wants to keep its core temperature within a fairly narrow range within about plus or minus one degree of your normal core temperature skin temperature in contrast to core temperature can actually vary much more as it rises and falls with the temperature of the surroundings and we are going to see that the skin plays an important role and all this in just a second but this process of maintaining core body temperature is known as Thermo regulation now there is some variation from personto person on what the normal core body temperature is but the average is considered to be between 98.0 to 98.6 de Fahrenheit which is about 36.7 to 37 when converted to Celsius and again the body works hard to maintain your normal core temperature and it utilizes some beautifully designed mechanisms in order to accomplish this as I mentioned just a
02:00second ago most of the time core body temperature is maintained within about plus or minus 1° of your normal but when someone exercises or is outside on a very hot day or maybe someone is deliberately exposing themselves to a sauna body temperature can rise temporarily to as high as 101° F to 104° F and this is when some of these incredible mechanisms kick in there is an awesome structure in the center of the brain called the hypothalmus that you can see here and this is in charge of maintaining m in homeostasis throughout the body and part of maintaining homeostasis is maintaining proper body temperature so as the temperature rises the hypothalamus receives input from temperature receptors also known as Thermo receptors and these Thermo receptors are located in various structures throughout the body such as the skin spinal cord and certain internal organs plus the hypothalamus itself has a large number of heat sensitive neurons and so as the hypothalamus receives this input about
03:00the temperature rising it immediately engages certain temperature regulating mechanisms and this is where the skin comes in now you might have immediately thought of sweating when I mentioned the skin and yes sweating is a major part of thermal regulation but there's also something else within the skin that occurs besides sweating which is extremely cool and yes I'm definitely going to say that pun was intended but the skin has an incredible blood supply and what happens when core temperature starts to rise is that the blood flow into the skin can be increased dramatically and this is accomplished through what is known as vasodilation which is the widening of the blood vessels meaning the diameter of the tube increases and this will therefore increase the amount of blood flow to the skin and this increased rate of flow to the skin causes heat to be conducted from the core of the body to the skin and ultimately conducted to the air cooling the body with great efficiency and when I say efficient let me give you
04:00some more context if you were to compare a fully vasoconstricted state of the skin blood vessels to a fully vasod dilated state of the skin blood vessels you would see an approximate Eightfold increase in heat conductance from the core to the skin when those blood vessels are fully vasodilated and this amount of blood flow to the skin can account for as much as 30% of the total cardiac output and cardiac output is a measure of the total volume of blood pumped out of the heart in 1 minute and keep this in mind for a little bit later when we talk about the possible cardiovascular benefits of sonuna but clearly the skin with its ability to change the rate of blood flow is an effective cooling tool for your body and as long as Skin temperature is greater than the temperature of the surroundings heat can continue to be lost or dumped to the cooler surrounding environment by this mechanism but when the temperature of the surroundings becomes greater than that of the skin the only means by which the body can continue to rid it self of
05:00heat is by adding another cooling mechanism through evaporation and so of course we need to talk a little bit about sweat and with all this talk about sweating and heat exposure it is important to have a supplement that replenishes vital nutrients and supports whole body health and this is where the sponsor of today's video comes in and that is ag1 ag1 is a daily foundational nutrition supplement backed by research studies and it's packed with multiple vitamins minerals and adaptogens it also includes prebiotics probiotics and digestive enzymes that support gut health which has led to a small pro and con for my family the pro is this has helped keep my family members bowel movements a bit more regular the con I know about the regularity of my family members bowel movements but in a recent research study ag1 doubled the levels of healthy gut bacteria these healthy bacteria help break down food alleviate bloating Aid in digestive comfort and obviously in my experience promote digestive regularity and so it's definitely nice to see that ag1 is constantly putting their formula to the test to Ure continuous Improvement
06:00another thing I love about ag1 is that it has a comprehensive formula and instead of needing to add more supplements I get everything I need in one easy scoop so if you're interested Right Now ag1 is offering a surprise limited edition gift on top of the welcome kit when you subscribe it won't last long so go to drink a1.com human anatomy or scan the QR code to get started thanks again for ag1 for sponsoring today's video and now back to sweating and saunas to initiate sweating the hypothal will send nerve impulses through autonomic Pathways down through the spinal cord and then through sympathetic nerves to the sweat glands that are located in the skin pretty much everywhere throughout the body this will activate the sweat glands causing them to produce sweat that will eventually make it to the surface of the skin and as the sweat evaporates this will cool the body now that likely isn't shocking to you as we've all known that sweat helps to cool the body down but there are some fun facts about sweat that you might not know a person that is unacclimatized or unadapted which would
07:00be someone that doesn't exercise often or isn't exposed much to hot and humid environments this person would seldom be able to produce more than about one liter of sweat per hour however when that person exposes themselves to a hot environment from anywhere from 1 to 6 weeks and or starts to consistently exercise the sweat glands will adapt and begin to sweat more profusely often increasing maximum sweat production to as much as two and sometimes even as high as three lers per hour an evaporation of this much sweat can remove heat from the body at a rate more than 10 times the normal basil rate of heat production and this increased ability of the sweat glands to produce more sweat comes from changes of the cells in the sweat gland as well as an increase in the size of the sweat gland something else that also changes with sweat is the amount of salt in the sweat someone that is unacclimatized when they first are exposed to those hot
08:00environments Andor intense exercise and they start to sweat profusely they could potentially lose as much as 15 to 30 gram of salt per hour but after about 4 to 6 weeks of acclimatization or adaptation the loss may only be as low as 3 to 5 grams per day so from a practical exercise perspective the a climatized or adapted person is holding on to their electrolytes more effectively so now that we know how the body responds to heat are there any major benefits to deliberately exposing the body to heat like in the form of a sauna now I'm sure most of you know what a sauna is and have even been in one before but if you haven't it is essentially a small room or space designed to expose your body to what you could kind of think of as a more dry heat typically reaching temperatures between 140° F to as high as 212° F but as we'll see in just a minute the average temperature that people are seeing many of the benefits of sauna are in the mid 170s now now clearly this is
09:00going to stimulate the mechanisms of vasodilation and sweat that we just talked about but what are the specific health benefits of doing this and are these benefits significant enough for you to even include the sauna in your routine well often people will say the SAA can improve circulation enhance detoxification provide relief to sore muscles and some are now saying that it has cardiovascular benefits potentially reducing the risk of heart attack and other cardiovascular related diseases so let's go through some of these claims and let's start with detoxification and I'm going to try to not get on too much of a soap box here but the claim is that the sauna could detoxify the body due to sweating out waste products and it is true that certain waste products are found in the sweat such as Ura uric acid ammonia lactic acid and even certain heavy metals however this does not come close to what the liver and the kidneys can do for detoxifying the body those organs do the heavy lifting when it
10:00comes to detoxification and the waste products found in the sweat are only found in small amounts and so if the body gets elevated levels of some of these waste products it's not like the body's like uhoh activate all the sweat glands and this person who is not even hot or working out starts sweating profusely just to get rid of the waste products we know this doesn't happen because again the liver in the kidneys will handle this the primary function of sweat is to cool the body but yes a small small amount of waste products can come out with the sweat so you could consider this a little extra additional benefit of sweating profusely in the saom but one thing that excessive sweating in a sauna could potentially be beneficial for is let's say we had an athlete that was training for an athletic event and they were going to go run a half marathon or a marathon in a very hot and humid environment but they live in a more cold or more moderate environment where they're conducting most of their training they could spend some time in a sauna in the weeks leading up to that race in way to kind of pre- acclimate or heat adapt
11:00themselves to that environment that they're going to be racing in because remember we saw that the sweat glands can modify and change from heat exposure but let's actually talk about another claimed benefit from sauna use that actually is quite interesting and this includes the potential cardiovascular benefits from the sauna there are studies that have compared sauna use and aerobic exercise and they did find some comparable improvements in the both groups there have also been studies comparing people that exercised alone versus people that exercise and use sauna directly after exercising and those that exercised plus used the sauna had even greater cardiovascular fitness with improved measurements in V2 Max there are also other studies that show correlations with a reduction in the risk of death from cardiovascular disease with frequent son use one in particular that I'll reference and I'll link in the description showed that after following up with these individuals 15 years later they had a significantly lower risk of cardiovascular death with sauna use of
12:00four to seven times per week now how could the sauna result in these cardiovascular benefits and before you abandon your cardio routine for just using the sauna we'll also discuss some of the limitations of this first exposing the body to these high temperatures for about 20 minutes as the 19 to 20 minute Mark was kind of The Sweet Spot in many of these studies but this exposure for 20 minutes would somewhat mimic the body's physiological responses to mild to aerobic exercise if you remember earlier I mentioned that 30% of the cardiac output would go to the complete vasod dialation of the blood vessels in the skin and this will result in an increased heart rate plus being exposed to that much heat does induce a bit of a stress response which also influences heart rate and many people in the sauna can see that their overall heart rate could get into the 120s and therefore close to the heart rate someone would experience when participating in moderate aerobic exercise and we know that after consistently doing aerobic exercise we
13:00see those health benefits of improved cardiovascular fitness with improved V2 Max improved resting heart rate improvements in blood pressure and this overall risk reduction in cardiovascular disease and so again in a way frequent exposure to the sauna is mimicking mild to moderate cardiovascular exercise and for the studies where they compared the group that participated in only aerobic exercise versus the group that did the same aerobic exercise plus use sauna directly afterwards essentially what was explaining the further improvements in cardiovascular fitness in V2 Max was that the exercise plus SAA group was again in a way extending the workout or that cardiovascular stimulus for another 20 minutes but there are limitations to this if you were to say just like sit in a sauna for your cardio and do nothing else you could see some improvements in your cardiovascular health and fitness however this won't do much for you at the local level and what I mean by that
14:00is at the skeletal muscle level if you're running cycling doing a stair Master rowing swimming or some other form of cardio you're also going to be working in benefiting your skeletal muscles and this will stimulate adaptations such as increased mitochondrial density within the fibers increase capillarization to the fibers and improvements in strength depending on the level of intensity so obviously exercise is still going to be superior to the sauna alone but you could get some extra benefits by going into the Sona directly afterwards I kind of think of it as a form of heat intensive active recovery you still continue to stimulate your cardiovascular system for 20 extra minutes or so you still continue to get that increased blood flow but you are discontinuing the strain on your muscles connective tissues and Joints this is also something that someone could consider doing if they had some sort of injury or disability that didn't allow them to participate in traditional cardio training so what are some of the effective protocols for the sauna that you could incorporate into your routine
15:00well ideally you would want to build up to about 175 degrees with about 10 to 20% humidity for 20 minutes 3 to four times a week now some of the studies did have people do this four to seven times a week but seven times is kind of a lot and you can still get many of these benefits doing it three to four times a week also notice that I said build up you will get heat adapted the more you do this but it is always wise to start low and go slow meaning you could start at a lower time and or lower temperature and build up from there you obviously also want to be well hydrated before and after so use common sense but again you can always build up by starting at the lower end first and then building up and the last thing that I think is important to mention with all this is that a lot of the health and fitness channels out there myself included we sometimes get excited about these little Health protocols we tend to get all excited about cold plunging or sauna or some new research study and so I do want to be very clear about something even though
16:00we talked about some of the potential benefits of sauna today I don't want people to get the impression that this is the number one thing or number one priority on your health list it's still the big four that need to be taken care of first and that is a consistent and wellth thought out exercise program balanced diet sleep and Stress Management then once you've got a handle on those start adding these little extras for some potential additional benefits so thank you for watching today's video and supporting the channel I've got some cool other videos linked here about sweating and cardiovascular exercise and of course I'll see you soon