Welcome to the huberman Lab podcast, where we discuss science and science based tools for everyday life. I'm Andrew huberman, and I'm a professor of neurobiology and Ophthalmology at Stanford school of medicine.
Today. We are talking about the science of
heat and more specifically, the science of heating the verb, meaning how our body heats up from both the outside. And the inside heat is a
remarkable stimulus.
Meaning when we are in a hot environment. It has a profound effect on our
biology and heating up from the outside or as you will soon. Learn from the inside, has a profound effect
on many different
aspects of our health, including our metabolism. Both in the immediate and long-term are our cognition. Meaning, our ability to think more or less
clearly. And if you're immediately thinking that heating up, makes you less capable of thinking
You're wrong
heat applied properly. As a stimulus can engage certain neural chemical systems in your brain and body that can
allow your brain to function far better. We will talk about those data today. So we're going to talk about
the science of heat and heating both in terms of their mechanisms. And as I know many of you are interested in the tools related to the use of heat things like
sauna, how often to do, sauna. How long to be in the sauna, how hot to be in the sauna for particular go.
Goals and outcomes. We are also
going to talk about the very exciting. New signs around local heating that is
the use of heat applied to specific
areas of the body in order to heal or improve tissues at that
location that you are heating as well as your biology and health overall. In
fact, we are going to talk about one very
recently published paper. That came out in the journal cell cell is one of the three Apex journals meaning
three of the most competitive, most rigorous scientific journals.
Those are nature science and sell this particular paper
was published in cell and I will go into it in more detail later. But basically what this paper shows, is that buy locally heating up skin and fat, you can change the identity of
certain fat cells, at that location and elsewhere. We have three kinds of fat, white fat based fat, and brown fat. And as you will learn more about
soon, white fat is not very metabolically active.
It's more of a fuel.
Reserve. It's what we typically think of, as blubbery fat,
beige fat and brown, fat are rich in
mitochondria. And those
mitochondria provide a sort of furnace or heating mechanism for your entire body and increase your metabolism and the burning of
white fat. So, in other words, having more beige fat and brown fat is a good thing, and
it turns out that the proper
application of heat to
specific areas of your body, can increase the
conversion of white fat to beige fat.
In other words, turn and innocuousness.
Your Source into a metabolically active tissue that can
help you burn off more white fat. I think many people are going to be interested in this paper and the
tools that emerge from this paper. It's a fascinating set of findings that actually emerged from my understanding
of the biology of burn and people who receive intense Burns. And that is not what I'm going to recommend to you as a tool of course, but understanding a little bit
about how Burns impact
our biology and health has allowed these
earring researchers to develop new tools to combat obesity and metabolic disorders and that you can apply for basic things like fat loss. I'm pleased to announce that the huberman Lab podcast is now partnered with Momentis supplements
are motivation for partnering with Momentis is to provide people one location where they can go to access the highest quality supplements in the specific dosages, that are best supported by the
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I'm pleased to announce that I'm hosting to live events in May 20-22. The first live event will take place in, Seattle, Washington.
On May 17th. The second live event will take place in Portland, Oregon on May 18th. Both are part of a lecture series entitled, the brain-body contract during which I will talk about science, and science based tools, many of which overlap with the topics covered on the huberman Lab podcast, but most of which will not and will be completely new topics and tools, never discuss publicly before. Both Live Events will also include a question-and-answer period during which you the audience can ask me questions directly about any aspect of science or
Science based tools and I will attempt to answer them tickets for the two events again, Seattle on, May 17th. And Portland on May 18th are both available at huberman. Labs.com tour,
before we begin, I'd like to emphasize that this podcast is separate from my teaching and research roles at Stanford. It is however, part of my desire and effort to bring zero cost to Consumer information about science and science related tools to the general public in keeping with that theme. I'd like to thank the sponsors of today's
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Cam and enter the code huberman at checkout. Okay, let's talk about heat
more specifically. Let's talk about the biology of heat and heating
and the health benefits and tools related to heat and heating.
The first question that we have to answer
is how do we heat up? And the answer to that question is we heat up two ways. We heat up from the
outside? Meaning the things that we come into contact with the clothing that we put on our body whether or not there's heat in the room.
More whether or not it's cold outside or cold in a room and we heat up from the
inside. Our body has the capacity to generate more heat or to cool down meaning to turn off the heating
process and it can do that in ways that match
the external environment.
The simplest way to think about this is that we actually have two body temperatures. People would say, oh what's body temperature 98.6, that's actually not true body temperature varies between
individuals if
Varies across time of day
within individuals. And at every point across your entire life, span, you have two distinct temperatures. One is the
temperature on your skin, what scientists call your
shell and the temperature of your core. Your viscera, meaning your organs, your nervous system and your spinal
cord. And as you can imagine the temperature of your core is always higher than the temperature at your
surface. So the important thing to know is that you have a temperature at your shell and
Temperature at your core. Now, you don't
need to know exactly what those temperatures are in most cases, but it is vitally important to understand that you have those two
temperatures and that
your brain is constantly sending out signals to your body, as to whether or not it should heat up or cool down depending on the
temperature of the shell, which makes total sense. This is a lot,
like, a
thermostat in a room, which is essentially paying
attention to how cold or hot, it is. And then sending signals to the heating or cooling system.
To either heat up the environment or cool down the
environment depending on the temperature in that environment.
Your brain has neurons that send signals to other cells in your
body
and deploy, the release of chemicals in your brain and body to
heat you up when you are too cold, and too
cool you down when you are
too hot. So if you can understand that, you have to body temperatures one at your shell, the surface and one at your core inside and that your body and brain are
always trying to
balance those two temperatures in the
Way, well, then you're halfway there to understanding the biology of thermoregulation
and heating. And you'll be a
lot further along in understanding how specific tools can be used
to improve metabolism or improve cognition. For instance.
In fact later. You will learn that one way that you can heat up is by cooling, down the surface of your body. That's right. If I were to throw a cold towel ice, cold towel, onto your torso right now, and ask you, well, how do you feel you'd say? Oh, that's cold.
Cold, that's
chilly. However, because your brain is acting like a bit of a
thermostat as the surface, the shell of your body. Felt cool. It would make sense that, that thermostat would
activate biological mechanisms. That would heat up your core. Similarly. If I were to put you into a very hot environment, you'd say. Oh, wow.
It's really, really warm in here. But your brain, and your body would go
through a lot of effort to activate mechanisms to cool you
down. So anytime, we're talking about heat, meaning deliberate heat, exposure things, like sauna.
It's very important to understand, not just the
stimulus, how hot, something is, how long you're in a sauna Etc.
But the effect that has
on your shell and on your core. If you can understand that you can design protocols, that are literally perfect for your goals. And
as a final point about this, if you want to develop the best tools
leveraging heat for your biology and health and
performance. You want to
understand heat as a process as a verb as heating, not just heat.
Because there's the temperature that you are at
before you encounter the heat stimulus before, you get in the sauna, for instance, during the heat stimulus, a while. You're in the sauna
and then
afterward, everything in biology is a process. So, as you'll soon, learn that there is a specific sauna protocol that can allow you can allow anybody. In fact, to increase the
amount of growth hormone released into their brain and body. 16-fold. That's right. 16-fold. However, it involves
Shifting from a hot environment to a cool environment to a hot environment, to a cool environment over and over and over again, over a very short period of
time because it engages a switch a process that compounded Builds on itself to increase growth hormone further and further.
In fact, if you were to just get into a sauna for a very long period of time and crank up the
temperature to match the exact
temperature that was used, in that study. You would not experience those increases in growth hormone.
It really is the transition between High.
Hot and cool temperatures that engage the process of heating and reheating over and over again. So
today, you're going to learn about the use of sauna, you're going to learn about the use of other heat related
tools for health and optimization, not just for growth hormone, but also metabolic health for controlling cortisol, even to impact
mental health in positive ways. And in order to do that, you need to understand a little bit about the mechanisms of how you
heat up and how you cool down
where the cells and circuits are in the brain and body.
Those cells in circuits work. I promise to make the description of that which follows
very clear. Even if you don't have a background in
biology, and once you have that in hand along with the understanding you now have about the fact that you got a shell and a core, and you need to think about
both the shell and the core will, then you will be in the best possible position to use sauna, or hot, tub, or other
tools, even just a hot shower, as a powerful stimulus to optimize your biology. Now, the science of heat and heating and cold
and cooling for that matter.
Matter goes back well over 100 years. In fact, it's kind of amusing to me that nowadays. There's a kind of
renewed interest in the use of heat and cold and the science of
heat and cold because this was the first topic that I studied as an
undergraduate. And in fact, I did my graduate
thesis on thermal regulation and at the time, thermoregulation wasn't really
considered one of the Hot Topics in Neuroscience.
People were more focused on things like memory and Consciousness. And, of
course, those topics are still a vital interest to many people in many Laboratories.
Thermoregulation was considered more. You know, I think for the physiologist.
Now, it is not just on social media, not just in the landscape of biohackers and athletes. But in the landscape of mental
health and frankly in the general
ethos around
Health optimization, people are really interested in heat and cold. And the reason they're so interested in heat and cold, is that a lot of the science has been done, both in animal, models in mice and in humans and translates immediately to protocols that
One
can use now,
a brief warning now and another brief warning later. Anytime you're talking about heating up
your body. You need to be very cautious because
unlike cooling, down, where you have a fairly broad range of
cold temperatures that you can go into before it's damaging to tissue.
Well, you don't get to heat up the
brain and body very much before you start getting into the realm of neuron damage and
neurons in the central nervous system, the brain and spinal cord. Once they're damaged. They don't come back. So hype.
Thermae is a serious thing to avoid
later. I'll talk about ways to rapidly, protect against hyperthermia,
but I do want to give everybody a cautionary, note up front. Obviously, if you're pregnant nursing, if you're very sensitive to hot environments, you want to
stay out of saunas and things of that sort. I'm sure there are exceptions to that. You definitely have to talk to your doctor. If you're going to violate that rule.
And for everybody, you want to approach any kind of
tool related to heating very cautiously, you always have
Have the opportunity to increase the temperature later. So proceed with caution, be smart about it. I don't just say that to protect me. I say that also to protect you.
So now let's talk about what are the circuits for heating up. How does it happen? Right. Many of you have probably experienced a fever. How does that happen? What happens when you go into a cold environment and you're shivering but you put on a coat and then you feel warmer. What's really going on there. Well, there's a very basic circuit meaning neurons that exist in the skin.
In the brain and in the body that communicate with one,
another that allow
you to heat up if you need to and
cool down. If you need to, I'm going to throw a little bit of
nomenclature, a few new words at you. You don't need to
memorize these words except for one actually need to memorize one acronym. But it's very easy. It's called the POA. If you remember POA, you be home free for the rest of the episode,
but I know that there are some afficionados out there and people interested in getting a little bit deeper mechanism and I do think it's important to understand the circuit because once you understand this,
Circuit. And the way it's structured, then you are going to be in a great
position to use the tools related to heating. So, here's how this circuit is structured. You have the shell, which is basically skin.
And within the skin, you have neurons nerve cells. Those nerve cells have channels or receptors on them. They're
called trip channels. There are some other ones as
well, which basically sense changes in heat. So, if I were to put a hot object on your hand, or your arm, or for instance, if I were to put a hot
Object on your hand or arm and then
remove that hot object.
Those neurons would respond to that. They would send electrical signals into your spinal
cord. And that's where the next station of this circuit resides in your spinal cord. You got a little
cluster of neurons exists of the top part of your spinal cord called the dorsal horn. The name again doesn't matter and those neurons specifically relay heat information up to another area of your brain. Now, here's where we get into some fancy names. It's the lateral pair of brachial area. You
Don't need to know lateral power, brachio area, but it's a relay station. The lateral pero break area, sends electrical signals to the
POA and I would like you to know POA. The POA stands for preoptic
area neurons in the preoptic
area. Basically reside over the roof of your mouth. These are neurons within the hypothalamus
and neurons in the preoptic area.
Have the
ability to send signals out to the rest of your brain and
body, to get you to heat up
and actually to
change.
Behavior, so that you heat up, that's right.
If neurons in the preoptic area
receive an electrical signal through the circuit. I just described that goes from
skin, the dorsal Horn of the spinal cord to lateral. Para.
Brachial.
They will start sending signals out to the organs of your
body and the tissues of your body to get those organs and tissues to do things and
believe it or not, your POA. Your preoptic area will actually
change the way that you think and feel
immediately for
Instance,
if something warm contacts your skin or something very hot contacts your skin. The preoptic
area will send signals out to the endothelial cells. The blood vessels
both of the brain and
body that get them to dilate right to essentially increase their
volume and their surface area. In order to cast off heat. You will also start
sweating that sweating response is initiated
not by
The hot day or the hot sun but by the preoptic area, neurons that send signals out to What's called the periphery of your body and other chemicals are released things like acetylcholine that get you to sweat.
And if you happen to be shivering
neurons, in the preoptic area, will make sure that you stop shivering.
You're probably familiar with the feeling of being somewhat
lethargic or spreading out your limbs on a hot day. Well,
that is the result of neurons. In your preoptic area, impacting your musculature
to get you to
increase your surface area. So you can
sweat off a release more heat.
So there are all these different mechanisms by which we dump heat. Some of those are purely physiological
below, our conscious control things like sweating, which you can't
Make yourself sweat on demand. Maybe you can through a set of stressful thoughts. But you can just make yourself sweat. That is autonomic. It's below your conscious control things, like vasodilation the dilation of your veins, in particular in capillaries, in particular, these
sorts of things. And of course, there are these behavioral, somewhat voluntary
aspects of dumping
Heat and the lethargy, the kind of tiredness that. We feel on a really hot
day. That's also controlled by this.
That I just described.
In fact, I just got back from a visit to a very warm place and it was remarkable
to me. How lethargic I felt in the afternoons. I just felt like a total slug. I just could not move or rally to do anything except if I waited until the evening,
even though it was later in the day, even though I hadn't
napped as the temperature in my environment, cooled off as my body temperature cooled off. I felt like I had more energy. I was actually waking up, even though I had been awake for longer.
So the relationship between temperature and
lethargy is a very intimate one if
we're warm enough, we
feel active and like, we want to move around. If we're
too warm. We feel like we need to stay put
and spread out our Limbs
and dump heat. And that brings me to a quick and kind of fun
point about how we dump Heat versus how other animals dumped eat many of you know, of course that we dump Heat by sweating
other mechanisms as well. Some
of which I described but that's our main way of dumping heat
other animals. Like dogs don't have
Have the capacity to sweat. At least not very much. So they pant right in order to dump heat
and still other animals like rodents when they get too hot they spit on their paws and they rub that spit
on the surface of their body, which might sound kind of gross in probably will get you to think twice before petting. Any of those animals are holding any of those animals again, unless that's your thing.
Now one other key thing to understand about this circuit related to heat is that the preoptic area also can send electrical signals to the
Ella a brain area that is often talked about in the context of fear, but it is really just a brain area that can activate your
sympathetic nervous system.
The sympathetic nervous system is part of your autonomic nervous system and is the one associated
with fight or flight or with the stress
response or even just the excited response, right? The sympathetic nervous system is also what gets activated when you're really
excited about something. The preoptic area has the opportunity to trigger the activation of the amygdala. Now, it
doesn't do it.
Time. But it can and it tends to do that. When you are suddenly in an environment that feels too hot that you feel is risky levels of hot.
If you ever have gotten into a sauna that was
very, very hot, maybe 210 degrees Fahrenheit. You sit there for a minute,
you'll notice that your heart rate increases and their reasons for that and we'll talk about some
of the health benefits of that in a few minutes, but it's pretty uncomfortable.
You may not feel like your skin is going to burn up but
you often will feel the impulse to
To get out, especially if you stay in there for a little while that impulse is the
consequence of this
preoptic area communicating with your amygdala saying, hey,
this environment is really hot and I'm trying to cool down and it's not really working. I'm dumping heat but I'm not able to adjust the core of my
body temperature in ways that are going to protect my neurons and
so it's a signal that you probably shouldn't stay in that environment too long. Now later, we'll talk about the advantage of pushing yourself a little bit through. Some of these very hot
environments, provided you can do it safely, but
The impulse to get yourself out of a
very hot. Environment is the
consequence of the
POA communicating, with your amygdala, and the amygdala. Then in turn activating your adrenal glands,
which are sit, right above your kidneys, the release of adrenaline. And this feeling of agitation,
like you want to move. Usually you want to move out of whatever hot environment you happen to be in. So now, you know the circuit, again, it's simple. It goes
from skin to spinal, cord one brain area to another brain area. That's the key one in this discussion, which is the
POA. The pre-op.
Take area and the preoptic area can kick
off a bunch of autonomic, subconscious
responses to heat, which make us attempt to get cooler. Things like sweating, vasodilation
Etc. And it can kick off, behavioral responses, spreading out our limbs in an attempt to dump, even more
heat feeling lethargic, so a lack of desire to run and move and it also has the opportunity to kick off a
mild or maybe not. So mild Panic
response to get us out of that hot environment if you can conceptualize that.
Circuit. Or if you can even just understand what I just said, even at a
top Contour level, you're going to be in a great position to understand the rest of the information and
the tools that follow next. I'd like to talk about the use of deliberate heat exposure, including
sauna, but other tools, as
well as a way to understand how heat and heating changes our biology. So you're going to learn to mechanism and you're going to learn some tools.
But first, I'd like to just emphasize that the use of deliberate heat exposure.
Can be a very powerful way to
improve Health and Longevity. There's a wonderful study on this that was published in 2018 that
includes a lot of data from a lot of participants in a lot of
different conditions. For instance, people. That only did sauna once verses 2 to 3 times a week versus four to seven times a week. And so on and Compares. All
those, the title of the study is sauna, bathing is associated with reduced, cardiovascular. Mortality and improves risk prediction in men and women. A prospective cohort.
Study.
This is one of several papers that clearly demonstrate that regular use of sauna or other forms of deliberate heat,
exposure can reduce. Mortality to cardiovascular events. But
also to other events, things like
stroke and other things that basically can kill us.
What I like so much about this and the related studies. And yes, I will provide a link to these in the show notes is that they involve a lot of participants. So, for instance, in this particular paper,
which was published.
Rushed in BMC medicine.
They looked at a sample of
1688 participants
who had a mean age of 63, but there was a range of Ages around 63 and of whom 51.4% were
women. The rest were men. So it's a pretty nicely varied study in terms of the populations that they looked at and
basically what they found was the more often that people do sauna the better their health is and the lower
The likelihood, they will die from some sort of cardiovascular event. Now. What do
we mean by sauna? We need to Define some of the
parameters around
sauna and I promise to provide you some alternative ways
to access some of the health benefits that were observed in this and related studies without the need to have a sauna because I do realize that a lot of people don't have access to sauna. First off the
temperature ranges that were used in this study and pretty much all the studies that I'm going to talk about unless I say otherwise are between
80 degrees Celsius. Meaning 176, degrees Fahrenheit and 100
degrees Celsius, meaning, 212 degrees Fahrenheit. So, somewhere in that range, how hot should you make the
sauna? Or the environment that you get into, should you decide to use these tools? Well, that will depend on your tolerance for
heat. How heat adapted you are. Yes,
some people are better at sweating than others and over time. We all get better at sweating mean if you go into the sauna more frequently. You become
a better.
Sweater. That's what are you wear, but the verb sweater, you get better at sweating at dumping heat through the loss of water.
So it's going to depend. I recommend starting on the lower end of the temperature scale. And if that's too hot for you that you even lower the
temperature further. Now, how
long were people exposing themselves to these hot environments, anywhere from five to 20 minutes per session? And as you'll soon, learn very brief periods. Of just five minutes of heat, exposure can be a powerful.
Stimulus. If the heat exposure is significantly. Great enough for you. Okay, 20 minutes can also be beneficial but 80 to 100 degrees Celsius. Meaning 176 degrees Fahrenheit to
212. Degrees Fahrenheit is the general range that this and most studies use
in this particular study. They compare the effects of people that did sauna once a week two or three times per week or four to seven times per
week and what they saw.
It was really remarkable. What they observed was that people who went into the sauna two or three times per week, were 27 percent less likely to
die of a cardiovascular event than people that went into the sauna, just once a week. Again, at the
temperature
levels and the duration that I talked about earlier and as you can imagine the duration of the temperature levels were related. So if people went into very hot environment that we're really uncomfortable for them. Maybe they only went in 45 minutes whereas if they were
more comfortable and Heat
It in a
given environment or their tolerance for heat was just
simply hire for whatever reason. Well then they tended to stay in longer. We can take a sort of average of this 5 to 20 minute range. And today, we're mainly going to talk about
exposures between 10 and 20 minutes at temperatures between again a degrees and 100 degree celsius, 176 degrees, Fahrenheit, or 212 degrees
Fahrenheit. So these data point to the fact that going in the sauna two or three times per week is really beneficial and can
lower mortality to cardiovascular
events.
Fact, the benefits were even greater for people that were going into the sauna for 27 times per week. Those people were
50%, less likely to die of a cardiovascular event compared to people that went into the sonnet just once a week. So
these are really impressive and frankly, encouraging studies. Certainly, they caught my eye and encouraged me to start using deliberate heat exposure on a regular basis. What's particularly nice about this study? And the related study that again, is linked in the show notes, is that they looked
at a number of potentially confounding variables. Things like whether or not people smokes things like whether or not people were overweight whether or not they tended to
exercise or not exercise and
they were able to separate out those variables. So the percentages that I described earlier 27 percent
less likely to die of a cardiovascular event for those that when the sauna two to three times a week and fifty percent less likely to die of a cardiovascular event for those that went
into the sauna four times per week as compared to just once a week, those effects really do seem to be the consequence.
Of the saint exposure and not some other effect that's correlated with Saint exposure. Like going to the
gym where people are working
out seven times a week and then also happen to get into the sauna
or quitting smoking. Right
about the same time. They adopt a sauna protocol these sorts of things and now there have been additional analyses of the use of sauna for improving health or I should say for offsetting
mortality that have found that it's not just reductions in cardiovascular events, but
so-called all-cause mortality. This is
Kind of medical geek speak for saying, How likely are you or somebody to die
from a cardiovascular
event, but maybe also from some other event, some other health related event, like cancer or something of that
sort. And in every case regular exposure to sauna starting at about two or three times per week,
all the way up to seven times per week. Greatly improves,
meaning statistically significant improvements in longevity, in the sense that they
people are less likely to
I of cardiovascular events and other things that kill us. So, I and many other people who are interested, not just in our own health, but in educating about health
related, tools to the general public, find this really exciting but knowing what we
know about how heat impacts our
biology, it probably shouldn't surprise us that this sauna type
exposure or deliberate heat. Exposure has these incredible effects. So before we
get into the biological mechanisms of
how heat can have all these impressive,
Civ
health effects.
I want to just talk about the use of sauna as a
tool and emphasize that you don't have to use a sauna. In order to get these benefits. It is simply
a matter of making sure that your shell and your core
heat up properly a bit. Not too much, not too little but the heat those up and no you do not need to carry a thermometer around or place a thermometer into your core, you know, in laboratory studies and in humans.
You really want to know someone's core temperature. Basically, you try and put the thermal probe as close to the core as you can. So typically that's done, rectally, or a mouth thermometer or even up the nose. You don't need to do any of that. All right. This
isn't a laboratory study. There's there are ways to
create a hot environment such that you heat up
your shell in your core safely without
having to measure your core temperature. All along, if you want to do that, be my guest, but I'm not going to provide a protocol.
So the question is, how are you heating
up your environment? And I
I realize that there are
dry saunas. There are
steam saunas. There are infrared saunas. There are
hot tubs and there are simply rooms that you crank up the heat. Okay. There are also ways in which you can increase your shell in your core temperature. By moving around a lot and doing that, wearing a lot of clothing. There's nothing special about
any one of these approaches are protocols.
It's just so happens. That sauna is one of the more
convenient ways to do this. And so,
Only for the studies that I've talked about, not
just the ones I reference before. But all the studies that I research
looking at this episode. It makes sense why they would use sauna because it's
very hard for instance to create conditions, where you have five people go out
jogging wearing heavy sweaters and hats, will hats on the middle of summer. It's very hard to
set up those conditions in a way, that's controlled for everybody. Whereas it's pretty straightforward to have a sauna where you have one or several people just get into that one. Uniformly, hot environment. That's me.
Much easier study to
run. So, just to be clear.
The temperature range is important. You want to get between 80 and 100 degrees Celsius. Now, you know, the conversion to Fahrenheit. You could however, immerse yourself in a hot tub or hot water bath up to your neck. That's another way to approach it.
If you didn't have access to either of those, you could also put on
a hoodie or
wool hat and a hoodie, or you could do like the wrestlers do
and you could
She buy one of these plastic suits. They're literally called Plastics that wrestlers are other athletes, that wish to drop water weight will wear and then go jogging that all of those will increase your shell in your core body temperature, right? Especially if you do it on a hot day, but of course, be careful hydrate and don't overheat. Don't become excessively hyperthermic because you can get heat stroke and you can potentially die.
But if you're going to use sauna often, I get the question. How hot should the
sauna be will now, you know, how long should you be in there 5 to 20 minutes per session, although I will
Talk in a minute about ways to optimize hormone output in particular, growth hormone output, by doing for very brief sessions. So maybe not a continuous session. We'll get into that in a few
minutes. And of course, you have to ask yourself wets on a dry sauna, you know, what doesn't
matter. Use what you prefer? Many people ask me. What about infrared? Sauna?
We have an entire episode. All about the use of light and
low level light therapy, including infrared light. It does have certain benefits for skin and other organs and tissues of the body. If
Used properly my understanding or at least my assessment of most infrared saunas out. There is that they don't get hot enough. They don't get up to that, 80 to 100 degrees Celsius
range. Some do most don't. So what you end up with is a situation where you've got a red light, low level, light
therapy stimulus and you've got a sauna that's
not quite hot enough and there are a lot of ideas and claims about how
they work together in order to get you improved benefits.
I personally am of The Stance based on the literature, that I've
read that, you want to get into those ranges of 80 to 100 degrees Celsius. Before you start considering whether or not, you're also going to include red light therapies
etcetera. So there's nothing special about red light
sauna. It's really the temperature of the song that you happen to get into.
So which tool right? Which sauna which stimulus
do you run in wearing Plastics in a hoodie? And a wool hat. You get into a sonnet that's
going to depend a lot on your
circumstances, your budget and what you have access.
S2 on a regular basis, this is a lot like our discussion about the use of
cold. Most of the studies have looked at
immersion in cold water, up to the neck because that's a very controlled situation that you can do in a laboratory. They have not explored cold showers as much. So there's just less data or walking around in a cold environment, but we'll talk a
little bit about those data because
as you'll soon, learn when you talk about cold, you're actually talking about heating as well. So what kind of mechanisms are activated in your brain and body that allow for
the various health benefits of sauna or other forms of deliberate heating. Well, we talked about reduce risk of cardiovascular event related mortality and all cause mortality as you'll
soon learn. There are also tremendous
benefits in terms of increases in growth hormone, reductions and cortisol, Etc. I will detail those. So what happens when you get into a hot environment? What are the mechanisms that allow for the various health effects of that? Well,
Or she'll your skin
senses that and through the circuit that I described earlier activates
neurons in the POA, the preoptic area, which
in turn activates mechanisms in your autonomic nervous system, like
vasodilation. So blood flow increases plasma volume of your blood increases and stroke volume, the volume of blood that is mobilized with each beat of your heart. Also increases
and your heart rate increases to anywhere between 100 to
150
beats per minute that General constellation of affects looks a lot like cardiovascular exercise. And in fact
for all intents and purposes. It really is cardiovascular exercise except that there isn't the mobilization in the loading of
joints and Limbs and things of that sort. And of course there are additional benefits of cardiovascular exercise that relate to
impact on the ground. Improvements in bone density, etc. Etc. But basically your heart starts beating more blood.
Circulating
your vascular changes shape, literally to accommodate those increases
in heart rate and blood volume and
you're busy. Getting a cardiovascular workout in
that hot environment. Even if you're just sitting down,
another set of positive
effects related to being in these hot environments are hormone
effects shifts in the output of hormones. Both from where your adrenals and possibly from the testes and ovaries and even within the brain, one of the more striking.
Samples of that comes from a study that was published in 2021. The title of the study is endocrine effects of repeated hot thermal stress and Coldwater
immersion in young adult men. And indeed, the study was, in this case, just done on men. I'll just briefly describe the protocol, they used,
they had these men attend for sauna sessions of 12 minutes each. So,
again, well within that range of 5 to 20 minutes, 12 minutes,
the temperature of those saunas was 90 to 91 degrees.
So I'll just quickly do the calculation, admittedly not in my head. That's
194° Fahrenheit. And they did that four times afterwards. They had a six minute cooldown break, during which they did, get into some
cool water or cold water of about 10 degrees, which is 10, degrees. Celsius is 50 degrees Fahrenheit.
And then they measured hormones
at various times throughout this study before during. And after they look to testosterone, they looked at
Hea, which is in the Androgen pathway, they looked at prolactin and they looked at
cortisol, the significant effects of the protocol that I just described were on cortisol, a
so-called stress hormone so-called because when we are very stressed for long periods of time, cortisol levels tend to increase dramatically,
but I should point out that a increase in cortisol each day, right about the time of
waking and specifically right about the time of waking is actually beneficial for our alertness and our energy. So having
some
Using cortisol, every 24 hours is a good thing. Provided happens early in the day. Late day increases in, cortisol are associated with depression. That's been shown by studies at Stanford, and elsewhere.
The major effect of this study is a significant decrease. In cortisol
output in these subjects.
I think this is really interesting and important because many people suffer from acute, meaning immediate and long-term stress and are looking for ways to control their stress. Controlling your cortisol is tricky.
In the episode on stress. I talked about supplements, such as ashwagandha that can be used to limit cortisol. But you have to be careful, not to use ashwagandha for extended periods of time, meaning for longer than 2 weeks, because you can get into other issues.
I talked about breathwork protocols, that can
allow you to clamp or reduce the stress response in real time again, see that episode for those. But many people are overworked their overstressed there for one reason or another, they're subjected to many to many stressors or their level of stress resilience.
In
high enough to keep their
cortisol levels clamped at a healthy level.
So, the protocol I described of 12 minute
exposure to 90 degree environment. That's again, 90 degrees Celsius,
followed by a six minute cooldown break in, Cool Water, 50 degrees or so. That's pretty cold. I can imagine that. You could also just take a
cool shower or cold, shower
afterwards. That had a very significant effect on lowering cortisol. So there you have a tool. It's not a completely
zero cost tool because you need to heat the water.
You need to have access to hot and cold water. At least hot and cold contrast of some sort, but
it's fairly minimal cost at for most people. Especially if you start getting
creative about maybe taking a 12 minute jog, wearing a
lot of clothing. If it's hot out then getting into a cool shower, you might not get the same extreme or significant reduction in cortisol. That was observed here with these very specific protocols, but it's likely that you would get a similar result. Overall. Now I mentioned, they did look at these other hormones and I'll just tell you that they did not see.
Significant shifts in testosterone prolactin DHEA, Etc. Using this protocol, as you'll
soon, see, there are other sauna
protocols that can impact those other hormones.
So if you're seeking to use sauna to reduce stress, I think this is a very interesting and potentially useful
research back protocol. And again, we will provide a link to the paper if you'd like to read more about the data, so that is one set of biological effects on cortisol.
And the related protocol. What about some of the other benefits of sauna? Well, we'll talk
Talk about those but I want to talk about those in the
context of the underlying mechanisms
because if you understanding those underlying mechanisms, you can really
tailor your sauna protocols, for your particular needs.
One of the more dramatic and important
effects of going into a hot environment for some period
of time. Is the activation of so called heat shock
proteins. Hsps heat, shock proteins are a protective mechanism in your brain and body
to rescue proteins. That would otherwise, Miss.
Old. And what I mean by this? Well,
most of you are familiar with the fact that you have protein in the kitchen, like a steak, or a piece of chicken or a piece of fish and you heat it up. It changes its texture, right? Raw meat is different than cooked
meat to be quite blunt about it.
Heat changes the quality of proteins, not, just in terms of how they taste, but the way in which they are configured, change the right down to the molecular
level.
When your body goes through changes in temperature
each day, and we'll talk about those changes.
But in response to hot
environments or cold environments, heat shock proteins are
deployed to go and rescue and prevent the changes in proteins. That would be detrimental to your health. So at least in the short term activating heat. Shock proteins is a good thing. You don't want
heat shock proteins to be activated for long periods of time because that gets to be
problematic for other reasons, but these heat shock proteins of which there are many varieties.
He's
basically have the job of traveling in your brain and body and making sure that cells that contain proteins that are
misfolding because they got heated up too much.
Don't miss fold and they also serve a protective mechanism. Making sure that proteins within the cells of your brain and body, don't fold in the wrong
ways. Again. I'm describing this in very general
terms, but it's well established in animal models and in humans that sauna exposure of the sort that I
Described earlier activates these heat shock proteins. There's some interesting studies that were carried out in animal models. That really nicely mechanistically
support the role of heat shock proteins in some of the benefits of deliberate heat exposure. Some of these studies were done in flies. Some of meaning drosophila fruit flies because
they're a great model organism because you can delete jeans or a jeans easily. Other Studies have been done in mice and now there are also
studies being carried out in humans and I will talk about those
one of the more dramatic.
Examples that's always touted in this field
of deliberate heat exposure. As it relates to longevity is that if they
expose these flies, these fruit flies to 70 minutes of a heat stimulus that would obviously didn't kill them, but activated heat, shock proteins, it could extend their life by 15% in a heat shock
dependent way.
Meaning if they made flies, that didn't have these heat shock
proteins. Well, then they didn't see this extension in
life. And
this is one of the reason to use model organisms is
not an experiment that you could do in people.
However, there have been interesting studies done in humans examining some of the downstream molecular
Pathways of deliberate, heat exposure
that point to the mechanisms by which deliberate heat exposure can help protect against different forms of mortality, improve health overall and possibly and I want to highlight
possibly, possibly extend Life.
One such mechanism involves a genetic program involving a
Molecule called Fox 03.
Fox 03 is a very interesting molecule because it's involved in
DNA repair, Pathways.
DNA repair is part of the process of remaining healthy, you know, we'd all like to think that were born. And based on the jeans. We have we are healthy, healthy healthy. Then eventually we age and then we die. But from the time were born until the time we die. There's a constant repair of our proteins, in our cells, in a modification of the genes that are being expressed.
Rest, you know, puberty being the most
dramatic example, right? You see a kid
before puberty? And after viewing looks like a different kid. Sounds like a different kid. Things like a different kid. In
fact, basically is a different human being, right? It's not just
the hormones. It's that hormones themselves
have the capacity to
turn on and turn off
certain genes, literally converting certain tissues and cells in the brain and body to do entirely different things. So it's not just the
sprouting of new
aspects of our biology is literally the conversion of different brain centers from one function to another
There.
That's puberty, will do a whole episode about puberty. We actually did an episode on sexual development, that talks a little bit about those mechanisms.
But the point is that throughout our entire lifespan genes are being turned on genes are being turned off,
genes are being turned on genes are being turned off and DNA. The stuff of genes gets damaged in that process.
Fox 03. Sits Upstream in a pathway related to
DNA repair and again, clearing of the senescent cells.
Sana exposure in particular, Saint exposure, two to three times or ideally, for 27 times per
week in that. 80 to
100 degree celsius range has been shown to upregulate levels of fox 03.
Fox 03 in turn up, regulates Pathways related to DNA repair and clearing out of the senescent or dead cells, which is known to be important for various aspects, of maintaining cognition,
and other aspects
of maintaining health.
So these are the likely biological mechanisms for the improvements in lifespan or I rather I should say. These are the biological mechanisms that apparently offset some of the cardiovascular risk and other forms of mortality that were described
earlier. One, especially interesting thing about Fox 03. There are individuals out there that have either additional copies of fox 03 or who have versions of fox 03
We that are hyperactive. So to speak. Those people tend to be two point seven times more likely to live to 100 years of age or longer. So these are people that were just naturally, unfortunately, for them endowed with more, Fox 03, more clearance of senescent
cells, more DNA, repair, etc. For the rest of us, at least, you know, to my knowledge. I don't have the one of these Health promoting, foxo three mutations. Remember, mutations can be beneficial or they can.
After mental, this if your goal is to live longer is a beneficial mutation.
Well, if you
don't have these foxo three mutations that allow you to be a centenarian at 2.7 Times Higher likelihood than other people delivered. Heat exposure is one way that you can increase Fox 03. Activity, at this point in time, meaning when looking at the research out
there. It isn't clear, what the optimal sauna protocol is
going to be specifically to increase Fox 03, and that's probably because there isn't
Not one,
there is no sauna protocol designed specifically to reduce cortisol or specifically to increase Fox 03 or
specifically to activate heat shock proteins. Any deliberate heat exposure is likely to impact all of those mechanisms. Again, I encourage you to use this guide of 80 to 100 degrees
Celsius, as your kind of bookends, for
what you can tolerate, and where you want to start. And eventually
transition to in terms of deliberate heat exposure.
And I would encourage you to use that 5 to 20 minutes per session
for the sauna, as your Rough Guide of how long to remain in the sauna. Now, there was a study published just this last year that was mainly focused on deliberate cold exposure. I detailed this quite extensively in the episode on
cold. This is the beautiful work of Susanna. So Berg and that study looked at deliberate cold exposure, but also saw an exposure, and that study found that 57. Yes.
57 minutes per week
of Saint exposure
in conjunction with 11 minutes per week. Total of deliberate cold. Exposure was the threshold for getting improvements in
metabolism and increases in brown fat. This very active fat tissue that improves mitochondrial function and thermogenesis mean heating of the body, will talk more about Brown fat later. Why do I mention this? Well, for those of you
that are interested in increasing metabolism, it does.
To be most beneficial to do that. 11 minutes per week of cold
exposure, again, divided up across two or more sessions. So it's not 11 minutes
all at once, but shorter sessions and to get 57 minutes minimum per week
of Saint exposure, again, in the temperature, ranges that I've talked about here. And again, it's not 57 minutes in the sauna, all at once, that's 57
minutes total per
week as the minimum threshold. So you might divide that into three
sections of 20 minutes. And again,
again, I don't think 57 is the magic number.
It could be 60. It could be
64. It probably could be 55. Remember your biological systems are not counting things
off minute by minute, second by, second least, not in most cases. So, for those of you that are
interested in improving metabolism, check out the episode on cold, or just take the so Berg protocol, as I call it, which is 11 minutes, total per week of uncomfortably cold, but safe, cold exposure. So, uncomfortably cold means you really,
really want to get out of the shower or the
Of the or the ice bath, or whatever
environment, but you can stay in 11 minutes, total per week, divided across a couple sessions and then 57 minutes per week or so of deliberate heat exposure again, uncomfortably, but uncomfortably
hot scuse me, but safe to stay in. Probably divided up across three or more sessions.
Okay, so we've talked about the use of sauna to decrease cortisol. We've talked about the use of Saint and to increase heat shock proteins. We've talked about the use of sauna to increase Foxhole.
03. Now, I'd like to talk about the use of sauna to increase growth hormone. Growth. Hormone is a hormone that we all
naturally secrete from our pituitary, which also resides near the roof of our mouth,
the signal for the pituitary to release growth,
hormone arrives, from neurons that exist in the
hypothalamus. So growth hormone, releasing
hormones believe or not. That's what they're called
stimulate. The release of growth hormone from
the anterior pituitary gland into
General circulation. And then growth hormone impacts
metabolism and growth of cells and tissues of the body. It is responsible for tissue repair
as well and the growth spurt that everyone experiences during puberty is the consequence of growth hormone. When I'm about to describe is a study that found
dramatic, really dramatic. I should say
increases in growth
hormone, but I
also want to emphasize that these increases in growth hormone were not of the
sort that are
Of dim puberty or an infant's becoming adolescents or adolescents growing into teenagers,
those levels of growth hormone that are associated with those massive Transformations. Excuse me, of body, morphology of shape are far greater than the
sorts that I'm talking about here. And
yet, as all of us age, when we go from adolescence to your teenage years and then into young adulthood, but then starting in our early 30s or so, the amount of growth
hormone that we secrete is greatly diminished.
Finished.
Normally we would release growth hormone every
night after we go to sleep in particular in the early part of the night, when our sleep is comprised mostly of slow-wave sleep
as we age less growth hormone
is released. During that slow-wave sleep.
There are various things that can promote the release of growth hormone, and we will talk about some of those
other things. In a moment, things. Like low, blood. Sugar turns out is a stimulus for
growth.
Oh, mon release. And I don't mean
hypoglycemia of the sort that makes you dizzy and want to pass out. That's bad. I mean, not having high levels of glucose and Insulin in your bloodstream. This is one of the reasons why many people are drawn to intermittent fasting or even prolonged fasting. It's because of the reported increases in growth hormone. I'll touch on those briefly, but if you
want to learn more about those and what their real impact is and the extent of growth hormone,
check out the episode I did on fasting. You can find that at huberman lab.com
certain forms of
Exercise have also been shown to stimulate growth hormone
release and in a few moments. I'll talk about how exercise and fasting can be combined or how heat can be combined with exercise or certain patterns of food intake to further, increase growth hormone. But before I do that, I want to review some of the data and one study in particular, that discovered certain forms of deliberate, heat exposure. Using sauna, can stimulate very large increases in growth hormone output which for people in their 30s, 40s and Beyond could be very useful. And may also
Oh, be useful for people who are just trying to stimulate the release of more growth hormone in order to for
instance, recover from exercise or stimulate fat loss or muscle growth or repair of a particular
injury. The title of this paper is endocrine effects of repeated sauna bathing. And this is a paper that was published in 1986, which is some years ago, but nonetheless serves as a basis for a lot of other studies that followed. So, let me describe what they did in the study.
They used an 80 degree celsius environment. So that's 176 degrees Fahrenheit and they had subjects do this sauna for 30 minutes four times
per day. So that's two hours total in one day,
30 minutes in the sauna, a
period of cool down rest, 30 minutes in this on again, cool down. Rest a third and a fourth time. Okay. So two hours total in this 80 °C environment, so
that's a lot but what they observed was
really quite significant, so
They had subjects do this protocol and I should mention, they had both male and female subjects in the study
and the entire study lasted a week. They did this
two hours of sauna exposure on day. One day, three and day, seven of that week,
and they measured a lot of different hormones. Cortisol fibroids stimulating hormone, thyroid hormone itself, luteinizing, hormone and follicle-stimulating hormone, which are hormones, that essentially Drive the production of other hormones. We
won't get into that.
Too deeply. But if you'd like to learn about FSH follicle stimulating hormone and luteinizing hormone. Please see the episode on optimizing testosterone and estrogen at huberman, lab.com. They
looked at prolactin and they looked at growth hormone. I'll just cut to the Chase and tell you the effects on growth hormone.
In subjects that did this to
our a day. 80 °C protocol experienced, 16 fold increases in growth hormone. So they measure growth hormone before the sauna and after the sauna and growth hormone levels went up 16-fold, which is obviously an
enormous
end. It turns out statistically significant effect. Now,
one important caveat here, remember earlier, when I talked about,
People who did sauna once a week versus two to three times a week versus four to seven times a week. And the more often people did sauna, the less likely they were to die of cardiovascular events or other things of that sort.
Well, in this case, the effects of
Saint exposure on growth hormone actually went down
the more often that people did this deliberate heat exposure.
So, as I mentioned, they did this
to our day divided, into 30 minute sessions protocol on day one, day, three and day, seven.
A week and what they found was on day one. There was a
16 fold increase in growth hormone
on day three. However, there was still a significant effect on growth hormone as compared to before sauna. But that effect was basically cut by two-thirds.
Okay. So now instead of getting
16 fold increase,
it was more like a three or four fold
increase, which is still a huge increase, but not as great. As the
increase observed on day one.
And then, on day seven there, tended to
Ba Tu may be a three-fold
increase, but not as great as the one observed on day one.
What does this mean? And why does this happen?
Well, the
reason this happens is because heat just like cold is a
shock or a stressor to the system
in the context of cold. If you get into a very cold, ice bath, for instance, a 5 degree ice bath, even for 20 seconds. It's known to increase norepinephrine, two hundred percent. It can
double the amount of norepinephrine that you suddenly release into your brain and body, which actually can have some
Facts, I'll talk about those in a little
bit. But if you were to do that every day, you will become cold-adapted this circuit that compares the shell and core of your body,
would adjust in ways that it could either predict
that cold stimulus or more likely to create some thermogenic mechanisms in
preparation for that cold exposure.
This is why, for instance, people that use deliberate cold exposure to try and
increase lipolysis. The burning of fat, oftentimes will get
Results for a while, but then if they're
doing it a lot, a lot. They
stopped getting those effects.
I talked a lot about avoiding cold
adaptation. If that's your goal in the episode on
cold, but similar, mechanisms are at play here. So, we have to imagine that when the subjects got into this on on day, one, Whatever Pathways when from measurement of temperature at the Shell to changes in temperature at the core led to these big increases in growth hormone, which is
basically a way of just describing the result. I already told you
before but the fact that that result diminished over time.
Either means that the circuit was not as efficient in communicating that shift in temperature or that that shift in temperature was of less impact because the downstream effectors were
not engaged to the same extent because it wasn't as much of a shock and I think the latter explanation is far more likely. This is
very much akin to weight
training or cardiovascular exercise. Where if
you run up a hill very fast, for instance, in your lungs are burning and your heaving and breathing hard on the
first day. That's a very painful thing. But if you do it every day,
Or every other day provide, you allow yourself to recover pretty
soon. You're running up that hill and
you're not breathing as hard. There isn't much burning in your muscles, etc. Etc.
Your body adapts. So one of the key things to understand about the use of deliberate heat, exposure is if you're going to use it in order to try and Trigger massive increases in growth hormone, you're going to need to be careful about not doing it more than let's say once a
week. Now. I'm extrapolating from this study. Maybe once every 10 days would be even better. But if you start
getting heated,
Updated. It's very unlikely
that you're going to get these massive increases in
growth hormone. So I don't mean to be discouraging of using deliberate heat exposure to
access growth hormone increases. But if that's your
specific goal or your main goal, then, I think it's reasonable to say that you don't want to do deliberate heat exposure. At least not of the sort that I described here more than once a week or maybe even once every 10 days and that you would want a time that two other events in your life,
maybe hard workouts or if you're trying to push through.
You a fat loss
barrier or simply in order to access growth hormone at Peak levels. Maybe three times per
month or four times per month.
If you start doing deliberate heat exposure, more often, you'll still get increases in growth hormone, but they are not going to be
nearly as large as the increases in growth hormone that you're going to experience. If you shock your system, with the Libre, deliberate heat, exposure. Every once in a while,
an important way to frame, this is actually in the context of cold, and while you
might say, wait, this is an episode on heat and Heat?
Not cold. You really can't have a conversation about heat and heating without talking about cold. Because
as I mentioned earlier if you cool the outside of your body, the shell you're actually heating up your body. In fact, the circuits that control heating of the body and that control cooling of the Body, for instance, the activation of things like shiver or fat loss in response to cold and shiver. Those are also controlled by the preoptic area of the hypothalamus.
So we can take a step back and start to think about what it would take to design the
Animal protocol
for deliberate heat exposure by
looking at cold. And here's what I mean. There have been beautiful studies showing that if people get into a very cold
body of water, 4
degrees Celsius for 20 seconds, as I mentioned earlier, that will cause the a
200 to 300 percent increase in nor epinephrine.
Norepinephrine is also called more adrenaline and norepinephrine and other so-called catecholamines, like dopamine increased dramatically in this
very brief, cold water
exposure, and those increases in
Epinephrine and dopamine are known to have long-lasting effects that generally to improvements in mood,
focus and alertness. They're pretty significant.
However, they aren't significant enough to increase metabolism
to a very high degree. Whereas
other Studies have shown that if people
go outside in 16, °C weather
with a proper amount but fairly minimum amount of clothing. You can experience even greater increases in norepinephrine,
but the
time that's
Required in order to experience. Those increases
is six hours at, for instance, 16 degrees Celsius.
So if you have six hours a day to be out there in the cold, or if you can turn the air conditioning
on in an environment, make it very, very cold
fine. But basically what I'm describing is that you can sort of bookend, the
parameters that you can use, you can use a
very brief exposure to
cold, or to heat in order to stimulate heat shock proteins, growth hormone etcetera, or you can use longer exposure in less intense versions of heat and cold.
You really have to
What's going to work for you
and what you can do safely? And
if you're confused about where to start, please use the parameters that I described earlier. First of all, check with your
doctor, as always, make sure that you're somebody who can do deliberate cold or heat exposure safely, but that 80
to 100 degrees Celsius, meaning 176 degrees
Fahrenheit to 212 degrees Fahrenheit that keep repeating over and over because I know somebody's going to ask even though I repeat it over and over which is fine. I'm delighted to keep. Keep saying it and to respond if someone asks again, well,
those
Ears are going to get a bookend, what you should do in terms
of the intensity of the heat stimulus.
How long? Well, we heard earlier 5 to 20 minutes, why not start with 5 and then ramp it up to 10 or 15 and then if you're feeling really bold and you really want to crank out growth hormone. Well, then you could do that 30-minute four times in one day stimulus, every once in a while. So you have to really figure out what you're using heat exposure for this is one of the reasons why when
people say is it better to get in a wet Saint or dry
sauna, what's the optimal
temperature? Is it better to
Hot shower, a hot bath or a hot tub to be completely honest. It depends on what you're going to be able to do
regularly whether or not you want to do it regularly and what your specific goals are. So the
purpose of this episode is really the army with the underlying mechanisms and army with the general parameters that are going to
allow you to access the results that you're seeking
for what it's worth. I personally use a
protocol and I've been using a protocol for a long time that involves trying meaning. I can push this most weeks not all
trying to get into a sauna for three 20-minute sessions.
Every week
I use a dry sauna. So it's not a steam room.
If I don't have access to it. I might take a hot bath or something of
that sort. But in general,
I just stick to doing the sauna three times a week and I generally will do that either after a
workout, either a cardiovascular
workout or a weight workout, or I will do it later in the evening. Why later in the evening? Well, it has to do with the Circadian shifts in
temperature that we all experience talked a lot about this in the Circadian episodes and the episodes related to
sleep.
But in a nutshell, here's how it works. Every early morning about two hours before your typical. Wake up time.
Your body temperature is at its all-time lowest. Okay, we call that your temperature minimum
right about waking your
body temperature increases. In fact, an increase in body temperature is part of the reason you wake up at all, unless of course you're setting an alarm.
Increases in body temperature are going to be one of the major things that wakes up your brain and body
body. Temperature will tend to continue to increase through the morning. You'll get that
increase in cortisol. That's in
a healthy increase in cortisol, body temperature will increase into the afternoon and then
we'll start to drop in the later afternoon.
This General Contour can be
shifted by whether or not you exercise. How often you eat because of the so-called thermogenic effects of food. That is every time you eat. There's a slight increase in body temperature metabolism, but it's not really that
Significant to throw off this General Contour in Rhythm
but toward the afternoon around 4:00 5:00, most days. Depending on time of year, your body temperature will Peak and then it will start to drop. And as your body temperature, drops by one, to three degrees in here.
I'm referring to your core body temperature. Not your shell body temperature, you will start to get
sleepy and to transition into sleep and to maintain sleep throughout the night.
Your body temperature will remain low until you hit that temperature minimum and they'll start to come up again.
Okay, what that means is
Is that when you decide to do
sauna or cold exposure for that matter, is going to be
important. Why? Well, as I mentioned earlier, if you were to make the surface of your body cold at least in the
immediate period, after that, your body temperature will increase.
So for those of you that are challenging getting to sleep and are still working on your sleep. Remember sleep at the
foundation, of all mental and physical health, and Optimal Performance. You should try to get really quality sleep of sufficient duration, at least 80% of nights. That's should be an ongoing goal throughout your life.
Been for a huge number of reasons.
Watch the master sleep episode. If you'd like to hear more of those reasons in the mechanisms to make sure that you do
that. But in any event,
cold exposure, late in the evening will start to increase your body temperature again, and that can make it hard for some people to fall asleep. Now, if you're very, very tired because you've been working hard or training hard or both throughout the day, might not throw off your sleep so much. I've gone through bouts where I'm just so. So, busy from morning till night. That the only time I can get into the ice bath of the cold showers late in the evening, and I have no trouble sleeping after that.
However, if you have trouble sleeping, I would recommend doing the cold exposure, early in the day to match that
natural heating that natural increase in body temperature that occurs across the 24-hour. So called circadian rhythm.
Similarly, if you're going to use deliberate heat exposure.
You'd be wise to do that later in the
day. You'd be wise to do it later in the day. Because
when you get into a warm environment, sure, the surface of your body, the shell
heats up, the core of your body heats up,
but then it also activates cooling mechanisms through the
preoptic area and when you get out of that hot environments on our otherwise
your body will continue to cool down and so many people find that they do
sauna in the later half of the day or even just before sleep and then take a
A shower afterwards. Then they find it easier to fall asleep and that makes sense because their body temperature is dropping. And in fact, if your goal is to really promote the maximum amount of growth hormone release. That's also going to be the best time of day to do it. Especially if you haven't eaten in the two hours before sleep. Okay. So if you're really going for
growth hormone release, you're really trying to optimize sleep. And the two
things are actually linked because of the release of growth hormone that happens from the pituitary in the early night's sleep.
Well, then you would be wise to do your sauna. Maybe.
Once or maybe twice a week in the evening or at night time than taking a warm or cool
shower, just briefly, just enough to kind of rinse off all the sweat from the
sauna and then get ready for sleep. And to do that, not necessarily fasted, but to try and keep
your levels of glucose and Insulin, somewhat low in your bloodstream. The
reason I say that is that having elevated blood glucose and or insulin tends to blonde to reduce growth
hormone release. And that's
true for any number of different.
Including
exercise and including sauna. So there's a really nice study on this that I can point you to is this study that was published in the journal
stress. Literally. That's the name of the journal. I love it. When journals have these names like, pain or stress. I find that somewhat amusing for reasons. That escape me, but nonetheless, amuse me.
The title of this study is growth hormone response to different consecutive stress, stimuli in healthy men. Is there any difference? And I don't want to go into all the details of the study because it's pretty extensive and complicated but basically what they did,
Is that they had people do sauna and then gave them a drug or a condition of having low, not
dangerously low, but low blood sugar
or they had them in a condition where they had low blood sugar and then did sauna or they had them do an exercise protocol that led them to increase growth hormone and then have them do low blocher basically mixing and matching the various stimuli that could increase growth hormone and what they found was very straightforward. What they found was that doing sauna once
And then waiting some period of time. And then later that day doing sauna, again, they didn't see the same increase in growth hormone both times
first. They got a big increase in growth hormone, and then less if they did. So on again, if
they had people do exercise and then sauna what they found was exercise could stimulate growth hormone, but then following it with sauna did not allow you to get twice as much
growth hormone
in general. Anytime you release growth hormone. You reduce the likelihood that you're going to release
growth.
Own again, later that
day. And this partially explains that earlier, study, where people did this growth hormone promoting protocol on day one, but then, on day 3, that NC quite as big, an effect on a seven, they didn't see quite as big effect. All it basically boils down to is that if you really want to crank out the most amount of growth hormone in response to sauna, do it fast it or at least not having ingested any food in the
two or three hours before you don't have to be deep into a fast and the whole notion of what breaks a fast is, kind of an interesting conversation, because it's
Textual right will a sip of coffee break your fast.
Well, maybe probably not will one grain of sugar and break your fast. No!
Will a,
you know, an entire candy bar break your fast. Yes, it has to do
with where your blood glucose is. When you ingest that particular food, item, not so much what that food item is per se, but the
bottom line here is if you want to crank out the most amount of growth hormone, get wait a couple of hours after eating before getting into the sauna, or maybe do it before dinner and then prepare dinner. Do the sauna before dinner. That is then prepared.
Pear dinner then eat dinner and then make sure that you
wait a few hours before going to
sleep. You're going to have to arrange your schedule accordingly. I know, most people can't arrange their schedule perfectly just to get growth hormone increases nor do I think people should approach Health protocols, that way. I think for 90% of people ninety percent of the time just getting into the sauna once
or twice or three times a week is going to be beneficial for the number of reasons that I described
earlier and you don't want to obsess too much
about the exact conditions you need.
Order to get the greatest effect out of that sort of treatment. These are just some additional tweaks, related to food intake and
low-level hypoglycemia
and exercise that if you wanted to leverage, you could. So if decreases in body temperature, tend to Aid, the transition to sleep, and getting out of a hot sauna tends to promote decreases in body temperature. It makes sense why you would want to put your sauna exposure or other deliberate. Heat, exposure in the second half of your day and maybe even right before sleep. Now, regardless of what time of day you do so on.
Now or how frequently you do it, you're going to want to hydrate. After going in the sauna.
When you go in the sauna you lose water and when you lose water,
you need to replace it. Why? Well, you need water for all your cells, but you also need
electrolytes. So make sure that you're replacing the water
that you lose in the sauna. Now, there's no
exact formula of how much water to
drink and whether or not you need electrolytes in that water or not. It's going to depend on how much you sweat. Meaning how heat adapted you are. It's going to depend on how much salt. You tend to excrete in your sweat, huge
amount of variation.
And but in general, one way to approach, this would be to make sure that you drink, at least 16 ounces of water
for every 10 minutes that you happen to be in the sauna. You could do that
before and during and after you could do it during and
after or you could do it after.
Now. There are other
reasons to do deliberate heat exposure that have
nothing to do with cardiovascular effects. Nothing to do with growth hormone or anything of that sort. But rather have
to do with improvements in mood and mental
health. In fact, the data related to
To sauna and other forms of deliberate, heat, exposure, improving mood are very impressive, both at the mechanistic level. And in terms of the long-term consequences that people
experience, first of all, we need to ask, how is it that deliberate heat exposure can improve our mood and well-being?
Well, it turns out that it improves mood and well-being, but it also improves
our capacity to feel good in response to things, that would ordinarily. Make us feel somewhat good.
Now, this is not a situation where,
You're
going to be walking around grinning ear-to-ear in response
to nothing at all. Simply because you went in a sauna.
What I'm talking about is the upregulation of Pathways meaning, chemical
Pathways in your brain and body that allow you to experience pleasure in all its
fullness. So here's how this whole
delivery heat exposure. Sauna mood thing works.
Many of you have probably heard of endorphins endorphins are a category of molecules that are made naturally in your brain and body and that are released in response to
Two different forms of
stressors. That's right. In response to stressors. So if ever you've
gone out on a long run and at some point that run you feel like you're aching and your joints hurt or maybe you have shin splints and you push through that part of the reason that you experience a lack of pain at some point. Usually, or you experience a Euphoria during or after that exercise is the exercise
induced effects on
endorphin release or rather to be more specific. I should say the
exercise-induced.
Consequences on the stress system which in turn trigger the release of endorphins.
In other words, when we experience short-term or acute stress,
the endorphin system is activated.
Now, the endorphin system is not just about feeling good,
believe it or not. It's also about feeling bad. And there are
two general categories of endorphins. The first are the ones that you
normally hear about endorphins things that bind for instance to receptors, like the Mew
opioid receptor. Opioids are not
just Peru.
Brad
compounds or unfortunately, drugs of abuse which they are right? We have this opioid crisis in the United States and elsewhere, which is a very serious and tragic thing.
But we make
endogenous opioids, we make endorphins that naturally act as pain relievers, and that make us feel mildly euphoric. We also make endorphins such as dine orphan. That's dyn 0, R Phi, n Dine orphan,
that actually make us
feel worse.
In response to
stressors.
When we get into a hot sauna, or a hot environment of any
kind, dine, orphans are liberated in the brain and body. And I should mention that dine, orphans
are made by many neurons in many different areas of the
brain. You might think, well, why would I want that? Why would I want to release dine orphan into my brain and body? Well, first of
all, when you get into an
uncomfortably hot situation, uncomfortably hot scenario. Oh my gosh, this is sounding
terrible and it deliberately hot environment that you are using to try.
Trigger some sort of biological or psychological benefit. I should say
the discomfort that you feel the desire to get out of than that environment is in part, the consequence of the release of down
orphan. It's
also the consequence of the activation of that sympathetic nervous system. Remember, the preoptic area can communicate
with the amygdala and Trigger that kind of fight or flight mode. I want to get out of the sauna. This is really, really hot.
But dine orphan is also
liberated from a certain number of neurons.
Dine orphan binds.
To What's called the Kappa
receptor. The Kappa receptor
binds dine orphan, and triggers Pathways in
the brain and body that lead to agitation to stress and
believe it or not, to a general sense of pain. This is why you want to
get out of the hot sauna and remember if it's unsafe levels of hot than you should get out of that sauna or other hot
environment. But if you're working in a range or you're exposing yourself to a
range of heat, that's uncomfortable, but safe to be in dine orphan will be
liberated.
From these neurons bind to the Kappa receptor. And as a downstream consequence of that, there will be an increase in The receptors that bind the other endorphins, the endorphins that make you feel soothed
that make you feel happy and that make you feel mild
Euphoria. So, they've been a number of studies showing that
initially deliberate heat, exposure bison, or otherwise causes the release of down orphan. In fact, I
think it's fair to say that every time we get into a hot environment that's uncomfortable or a cold environment.
That's uncomfortable. Dine orphan is likely released and binding to the Kappa receptor.
But over time, that binding of down, orphan of the Kappa receptor
leads to Downstream
changes in the way that the feel-good endorphins things like endorphin, binding to the MU opioid receptor, and there are still
other feel-good endorphins. So to speak that system becomes much much more efficient,
such that people feel an elevation in their
Baseline level of
mood. And when a good or happy event comes along, they feel a heightened level
of happiness, or Joy, or aw.
Improve mood in response to that.
This is not unlike the effects of caffeine on the dopamine receptor that I've
described previously. And for those either aren't familiar with
it. Many of you drink caffeine and love it. Part of the reason you love it is because of the release of certain neurochemicals, like norepinephrine, Etc. The energy that it gives you maybe the taste, I would hope as well, but caffeine
ingestion also causes increases in dopamine receptor concentration and efficacy. In other words. It allows The receptors for dopamine.
To work better so that for a given amount of dopamine release, you experience more pleasure and motivation. This is a similar mechanism but within the Endorphin
pathway, so what does it mean? It means that a little bit of discomfort as a consequence of deliberate heat exposure, while in the short term,
doesn't feel good by definition. It
is activating Pathways that are
allowing the feel-good molecules and neural circuitry. Is that exist in your brain and body to increase their efficiency placing you in.
Better position to be joyful in response to the events of life.
I confess. I'm very excited about the data
on deliberate, heat, exposure and improvements in the chemical systems that underlie, good mood and just to
underscore this further. The dine orphan system is not
unique to heat induced stress. In fact, there are beautiful, studies and reviews out there about the role of
down, orphan in stress and depression in stress and
alcoholism just as a
A brief aside. And in the future, we will do a whole episode on alcohol and
alcoholism, but turns out that chronic alcohol use and alcoholism causes changes in dopamine receptors.
That make it
very difficult for people to achieve pleasure through
things other than alcohol and even alcohol. That's kind of the, you know, really diabolical nature of addiction, which is the thing that initially brings pleasure eventually is just required to maintain Baseline levels of dopamine. And I've talked before and dr. Anna Lemke when she was a guest.
On this podcast, talk to you about the pleasure plane balance that exist within the dopamine system as beautifully described in her book, dopamine Nation, by the way, excellent book. I recommend to all people addicts or not. Well,
in that context of Pleasure and Pain, it's very clear. What the pleasure molecule is. It's
actually a molecule more related to motivation and that's dopamine the pain molecule. However,
appears to be dine orphan. And the fact that dine orphan is
Is dysregulated in stress and depression, and
alcoholism. And the relationship between dine orphan and dopamine is something that we should all take very seriously. And
for that reason, I'm very excited about the fact that deliberate heat exposure, can Leverage The dine orphan system. In a short term in, a cute way that allows mood to
improve after the sauna exposure. So for those of you that don't like heat
exposure, keep in mind that a lot of The observed positive
effects on our
Relate to metabolism cardiovascular function, but also mental health
and along those lines. There is a wonderful study again, published in
2018. I don't know why I guess 2018 was a big year for delivery heat exposure studies.
The, the title of this study is sauna bathing and
risk of psychotic disorders. And this was a prospective cohort. Study again, will provide a link to this study.
It's a really interesting study that explored the relationship between mental health. So people
Suffering from various forms of
psychosis, schizophrenia and other forms of
psychosis and use of sauna. So, essentially, what this study did is they looked at a
very large number of subjects, more than 2,000 subjects
who had no history of psychotic disorders. They were classified into three groups based on their
frequency of sauna use either once
a week, two to three
times per week or four to seven times per week. This should call to mind that earlier study on all risk mortality and cardiovascular event risk.
They explored the hazard ratio for psychosis specifically meaning. How likely it was that people would develop psychotic symptoms or full-blown psychotic illness
according to their frequency of sauna session. So again, this isn't causal. This is
correlative and according to the data in this study. What they concluded is that there was a strong and inverse
independent association between frequent sauna bathing and the future risk of psychotic disorders in this population. This does not
Not mean that going to a sauna seven times per week is going to prevent people from becoming schizophrenic necessarily, or from having a psychotic episode
necessarily end, of course, frequent
sauna use will be related
to other health promoting activities. But in this study, as in the previous study, they went to Great Lengths in order to try and limit those so
called confounding variables.
Now, of course, this is just one study. And again, it's correlative not causal, but based on the large number of subjects, they included plus the
Rigor of the statistical analysis. We're starting to see a general picture that using the sorts of sauna protocols that have described throughout this
episode, right, 5 to 20 minutes or so
done 127 times per week is associated with a general Improvement in cardiovascular health, a general Improvement in mental health, and it really points to the fact that yes sauna done, acutely for three or four times a day, 30 minutes.
Each session separated by a cooling may be getting into cold bath. Sure that can potently increase growth hormone. But done on a more regular basis can reduce cortisol, improve heart, health, improve mental health, and for that reason. And the fact that for most people, it is conceivable to come up with a way that you could get into deliberate heat exposure for a minimum of
cost. Right? It's a hot bath or if you had to resort to, you know, bundling up and going for a jog, this sort of thing, or if you have access to it, a sauna of some sort.
That we're really talking about a stimulus to initiate a large number of different biological
Cascades that Wick out to improve multiple aspects of brain and body health.
So up until now, I've been talking about whole
body heating. So, for instance, putting your whole body into the sauna, which of course, is what most people do or getting into a hot tub or hot bath up to your neck
or in the cases, where we were talking about deliberate cold exposure, as a means to increase core body, temperature and metabolism.
Getting into an
ice bath or cold water of some sort up to your neck or into a cold shower, Etc. Now, I'd like to talk about deliberately heating or cooling specific parts of the body, meaning,
certain surface
areas of your body, as a means to get effects on those particular areas, as well as at the whole body
level numerous times throughout this episode. I've talked about the dangers of overheating. So what should you do? If you think you or someone else is hyperthermic, it's too hot. Well, if you understand just a
Little bit about the cooling and heating systems of your shell and core. There are some terrific tools that you can use in order to
cool off your core quickly. And remember, the core consists of the nervous system, the spinal cord in the viscera, which are really the organs. You're trying to protect. So being able to cool
off the core of your body, quickly can be very
beneficial and in some cases. It could even save your life.
There is a way to more quickly, heat or cool, the body and that's
through specific elements of your shell meaning.
A particular skin surfaces. I've talked
extensively about this in the episode on cold. It was also covered in the episode with my guest.
Dr. Craig Heller from the biology department at Stanford.
It relates to the so-called glabrous skin
surfaces on the upper half of our
face Palms of our hands and the bottoms of our feet. And for those of you that heard this before, I encourage you to continue to listen nonetheless because today I'm going to talk about specifically how to heat the body or cool. The body
through these glabrous skin surface.
Very briefly. The mechanism is
as follows. The palms of our hands, the bombs of our feet in the upper half of our
face.
/ lie, specific types
of vasculature
meaning specific types of veins
and arteries that don't have capillaries between them. And as a consequence
heat and cold can move very quickly from the palms of the hands, the bottoms of the feet in the
upper half of our face and change our core body temperature.
There's a name for these particular vascular structures. They're called a VA s or arteriovenous. Anastomoses, basically.
Eames and arteries, interacting directly without
capillaries in between,
which allows cooling of blood or heating of blood much more quickly than as
possible, by applying cold or heat Elsewhere on the body where capillaries intervene between veins and arteries.
These a VA s arteriovenous. Anastomoses can be leveraged to cool off your core
body temperature very quickly. The key thing is to
get the palms of your hands, the bottoms of your feet, and the upper half of your face in contact, with a cold surface.
Or fluid that is cold enough to
cool the blood and the core of your body
but not so cold that it constricts, the
veins just below the palms of your hands, bottoms of your feet or the upper half of your face. So not placing ice packs
necessarily, but may be placing
cool. Towels on the bottoms of the feet, the palms of the hands and the upper half of the face and as they warm up, replacing those with other cool towels. The exact temperature will depend on how hot you happen to be. I can't.
That without knowing your particular circumstances. If you'd like
to learn more about how to cool off your core very quickly, and some of the details and some of the technologies that are being developed to do that. Please see the
episode idea with Craig Heller or the episode on cold. If you
don't want to go to those episodes, here's a good procedure that you could use. You could grab, for instance, a package of frozen broccoli or frozen blueberries. If someone is really, really warm, make
sure they take off their shoes and socks, get their feet. On top of those ideally, get some into their hands, as well. Get some cool.
Isis and get them onto people's face. You
could, of course, also put a cool compress
on the back of the neck, on the top of the head. That would be an especially good idea.
If someone were
hyperthermic because of the way that cooling of the brain occurs under conditions of hyperthermia,
but the key Point here is that just putting
cold compresses or cold materials onto. Somebody's torso is not going to be as efficient as cooling. Those glabrous skin surfaces the bottoms of the feet, the palms of the hands and the upper half of their face. Similarly or I supposed to be more accurate as
Say conversely. There are times when it is desirable to heat the core of the body.
And once again, just simply throwing a hot towel over.
Somebody is not going to be the most efficient way. If someone is hypothermia occurs too cold,
it is not a problem to cover them with a blanket.
But ideally what you do is you use some
warm object or warm fluid to warm the bottoms of their feet, their hands and the
upper half of their face, of course not.
So warm that you burn those skin surfaces.
This is actually been examined in studies from the Heller. Lab turns out that for instance to get people out of anesthesia. It is beneficial to warm their core body temperature. And of course there is fever
which you should know is an Adaptive response while fever is uncomfortable. And in fact, often involves a mismatch between our perception of our shell and a perception of our core temperature.
In other words. There are times when our
body temperature is really high. We have a fever, and yet, we're shivering were
cold, and that's because, under,
In the fever, the immune system liberates, certain
molecules that impact and
in some ways intentionally disrupt, the preoptic area, the
POA, and the way it normally
functions, so that it can override peripheral signals and simply try and heat the body and
kill whatever pathogen has infected the body.
So, for those of you that think about fever is always
a bad thing, it's not now, of course, we don't want our core body. Temperature to go so high that tissues of the brain and body are
Damaged. This is one reason why if a fever ever goes, you know,
above 103. You need to start
getting a little bit worried 104, you know, there are times when you need to call an ambulance or go to a hospital. You really need to employ cooling methods of the sort that I talked about before to prevent hypothermia, of course safe ranges for body temperature, vary between infants and adults. You can look those up online depending on the person's age. What is a safe range? What is not? But
keep in mind that if you are taking compounds pills to reduce your fever. You're actually short.
Circuiting the protective mechanism for burning up the pathogen and that's because
most pathogens bacteria and viruses don't survive. Well at high temperatures, in fact, in Laboratories, if we want to preserve a virus for use, we put it into a freezer. If we want to kill a virus, we want we heat inoculate
it. So in many ways fever is
your natural form of heat, inoculation designed to kill pathogens of various kinds.
Now, last but certainly not least. I want to refer to the study that I described at the very beginning of this episode involving
What's called local hyperthermia, in order to trigger a number of biological
processes in
fat tissue, in order to convert white fat to beige
fat, which is the metabolically active form of fat,
many of you, or at least some of you should be familiar
with the fact that deliberate cold exposure
can increase Brown
fat stores. These mitochondrial dense fat stores that can in turn allow a person to feel more comfortable in cold temperatures, water, or
otherwise and increase core.
ISM, I talked about this in the episode on
cold, but very briefly, the general protocol again is to get 11 minutes total per week of uncomfortable yet safe,
deliberate cold exposure, either through
ice bath, cold shower, cold it immersion up to the neck or some other form of cold
exposure that triggers increases in brown fat. That's been beautifully shown by. Dr. Suzanne
us oberg and that increase in brown fat in turn increases core metabolism and one's ability to feel
comfortable in court.
Temperatures. This was a study done
in humans, and there's now a evidence from
animal models to support that. This is a general phenomenon that I think most people could use and benefit from
Local hyperthermia is a distinctly different phenomenon. It involves heating a particular surface of the body, as a way to convert the white fat at that location to beige fat, which in turn leads to more systemic increases in thermogenesis and
increases in metabolism and believe it or not in Fat Loss.
Now, the study that I'm referring to is a very recent study that was published again in this terrific Apex
Journal cell. So I'll press journal. And again, one of the three top journals nature.
And seller the three top journals
top, because they're the most competitive but also generally not always but generally the most stringent in terms of the
review process papers that make it into these three journals. Generally are very, very high quality and certainly enough people see them that if they're not of high quality, they get shot down pretty quickly in a short amount of time, whereas papers and other journals can sometimes last a long time before they're ever replicated
Etc. The title of this paper is local hyperthermia therapy, induces Browning of white
fat and treats.
City. This was a study that was performed on mice and humans in the same
study. What the study involved was heating of a local patch of skin to 41 degrees Celsius, which is
105 point. Eight degrees Fahrenheit, but not
damaging the skin. Okay. So the, the methods of heating did not involved placing something on the skin that would damage. It. In fact, in the study on the mice. They use this kind of clever molecular chicanery in order to do it. And in humans, they used
Thermocouple that would allow
them to heat the skin up just locally in particular locations. On the body that I'll talk about in a moment.
They refer to this process as
lht or local heat therapy. The reason they did this is worth considering
it's long been known from clinical data. And in fact from bit of research data that people that experienced burn on a small War. Unfortunately in some circumstances a
significant portion.
One of their body
experience, overall decreases in body fat and increases in
metabolism that can last many years. Now, of
course is not reasonable nor would one ever
want to induce burn in order to induce fat loss,
but the observed increases in metabolism
and fat loss in response to
skin surface burn couldn't be explained by
reductions in activity related to the burn for instance.
And in fact, there are molecular pathways.
Related to something called, you see p 1 which is uncoupling protein
one. I talked about this also in the cold
episode, but don't worry. If you didn't see that episode, if you choose not to you see, P1 has the ability to increase mitochondrial function in ways that increase core body
temperature overall, in particular, in beige and brown fat, which are these fat cells that exist
generally along our spine, and in particular, in the upper part of our
back and around our neck and clavicles and they're responsible for activating.
As sort of a candle,
or I should say, the, the
fuel, where the fat of a candle that can be burned up to
manufacture heat in the body. So,
if you normally think about
fating, you think about blubbery fat, you're thinking about white fat, which again is just a storage site, beige fat and brown fat exists. It just a few locations, mainly internally around our spinal cord and our
clavicles and those fat stores are responsible for
generating heat in our body. So they are very metabolically active form of fat.
That
small children have a lot of
brown fat and beige fat
in particular, because very young children. Can't
shiver number of you probably didn't know that, but very young children can't shiver. So they need some way to generate heat in order to make sure that they stay alive. If they were ever to get cold. This is also probably, the reason why little kids can run around on a cold day outside without their shirt on. And they don't even seem to notice residents are freezing cold as we get older, the amount of beige and brown fat tends to either
reduce or Shrink.
Or disappear entirely. It's still debated, which happens, but we know that white fat can be converted to this more
metabolically active form of beige
fat, by deliberate cold exposure,
according to the protocol. I talked about earlier
and now, it seems based on this new study that local heating of skin tissue can also
induce, you see P1 and the effects of UCP one on increasing mitochondria. And in fact that
local hyperthermia for
81 degrees Celsius, that is hundred
five point. Eight degrees Fahrenheit can actually induce the conversion of white fat to beige fat. Now. That's pretty interesting, and I can already predict the way. This is probably going to go in the kind of wellness and biohacking and Longevity communities. I'm sure that pretty soon. They're going to be
people putting heating pads on different fat pads of theirs on their body trying to reduce or at least convert the white fat into beige fat and who knows? Maybe that'll work there. Have not been many controlled studies of this yet. This is the first at least to my knowledge.
Of such studies looking at this in non burn conditions. Nonetheless, the data are mechanistically even more interesting than this whole business. About you see p 1 and here's
why
local hyperthermia using the protocol that I described before resulted in the increase of a promoter, which is a essentially a mechanism by which certain genes regulate their activity. This is a DNA binding of something called hsf one. We don't have
To go too deep into the mechanism here or the nomenclature. But HS F stands for heat, shock Factor 1 and
HS f, 1 binding to a particular location in the genome allowed for a different molecule with a very long name.
I'll just tell it to you for fun. But you can just let the numbers and letters stream by. It's not important h n RN P A2, B1 shortened to A2 B1, which frankly is not that short to begin with a to b. 1 is still a name that should be meaningless to
most everybody. But here's what's really cool A2, B1 is directly involved in glucose and lipid metabolism.
Some and regulates the genes that control
glucose and lipid metabolism.
So, here we have a situation where local heating of skin, converted a metabolically sluggish or inactive cell type, the white fat
cell into
the metabolically charging.
So to speak
beige fat cell, which in turn led to systemic meaning body-wide
increases in metabolism through to mechanism. One mechanism,
is this increase in, you see P1, which for those of you that want to know, you see p 1
an causes shifts in the way that potential energy is pushed from the protons through the mitochondria, basically more
mitochondrial function, which means more ATP, which means cells are more active AKA increase metabolism
and increases in things like heat, shock Factor 1 and
A2 B1, which are involved in lipid and glucose metabolism and
regulation. So I want to be very clear. This study does not say that spot reduction is
possible with local heating of tissue. I just can see it now that once this paper gets
Out into the Press, people are going to say, oh heating up. A certain patch of skin is going to burn fat or convert fat to some other cell type at that location. Sorry, that's not the way it
works.
They did observe increases in beige fat cells at certain locations in the body, but those increases in beige fat occurred where beige
fat cells always reside around the
spine the upper
neck, the clavicles and so on
this is exciting because it provides yet another potential mechanism in
Mission
to deliberate cold
exposure, to increase beige fat,
meaning the metabolically active form of fat cell.
It also nicely
provides a mechanism or at least a potential mechanism for
the observation that burn either small patch of skin being burned or again. Sadly, large patches of skin being burned leading to these very extreme and very long
lasting increases in body, fat loss and metabolism.
If anything should you do with this information? Well, first of all, I want to very much caution people about putting anything so
hot that it can damage the surface of your skin onto your skin. That would be a terrible idea.
However, I do predict a time not too far from now where people will start to explore the use of local skin heating as a means
to increase the conversion of
white to beige fat and in turn for beige fat stores.
To increase
metabolism overall and maybe even improve glucose metabolism and
thermogenesis. If you'd like, more details about this study, we will provide a link to it in the show notes caption. I should mention that the study least a portion of the study that was focused on
humans involved, roughly
equal numbers of males. And females the subject, followed their normal daily schedule
including timing composition of meals, they
say arrest in active hours, etc. Etc. The local hyperthermia therapy was done in the following way. Here. I'm paraphrasing.
From their methods section, subjects were seated in upright posture. They were wearing a standard test robe with the head and neck, and shoulders unclothed, and 1 meter away from a thermal imaging camera, which could basically measure the temperature at their skin surface, to make sure that it remained constant across subjects. And yet safe the supraclavicular fat deposits. Meaning the upper shoulders, and upper back area were exposed to this thermal Source again 41 degrees for 20 minutes.
Okay, so is 41 degrees for 20 minutes and their core temperatures and skin
temperatures were monitored before. And after this local hyperthermic therapy.
The subjects were exposed to this local hyperthermia. Therapy. Three days per week separated by a day, Monday, Wednesday and Friday, so they had weekends off for five weeks total
after which their data were collected
and the study has a number of other really interesting features that are sure to lead to increased understanding of both mechanism and new protocols such as
Of the genes and
proteins that are activated Downstream of this local hyperthermia therapy. I
find these data incredibly interesting in part because of the ways that local hyperthermia therapy mimics, deliberate, cold, exposure therapy, same Downstream mechanisms, you see P1, and some of the other pathways are involved and all of that points to a somewhat new. But certainly an important concept, many of you have probably heard of hormesis, which is the subjecting of oneself or others. I suppose to enough stress to
induce an ad.
Updation of some kind. So hormesis is the reason why
if you get into cold water repeatedly at first, it's very
painful psychologically. And over time you get used to it. You never get completely used to it. But you get more used to
it. Hormesis is also used to describe the adaptation to
cardiovascular exercise or two.
The hard rep sets of resistance training and the
growth of muscles are the strengthening of muscles or the Improvement in cardiovascular function, turned Durance exercise and so
forth. Hormesis is a somewhat common term nowadays if you haven't heard it,
You
heard it?
In this paper, they describe what is called my toe. Hormesis, which is in essence the fact that any number of different stressful stimuli provided they activate, you see P1,
and some of these other Pathways that I just described like hsf
one. Can induce changes in the
mitochondria that lead to increases in metabolism.
So it shouldn't surprise us that cold and heat can both lead to increases in metabolism and
conversion of white fat to beige fat.
It shouldn't surprise us because both pathways,
Or stress local hyperthermia is stress
burn. Certainly is stress. Sauna is a form of stress, deliberate. Cold, exposure is a form of stress. Exercise is a form of stress and the adaptation to those stressors is not infinite all of those protocols, any protocol for that matter
is going to be effective because it's going to converge on an existing, internal biological mechanism. So there's no unique mechanism for each protocol. Each protocol that I've talked about today whether or not
Five minutes or 20 minutes or four times in a day or three times per week or seven times per week is tickling or pushing or stomping if you will
on a given pathway and really activating it to a milder to severe degree.
What I've tried to do today is to illustrate the general mechanisms by which heat in particular can activate, certain biological Pathways, so that you can devise protocols that are
going to be optimal for you and your needs. So just to briefly recap.
If you want to get the greatest growth hormone increases do sauna or other deliberate, heat exposure, fairly seldom. Probably no more than once per week. Maybe even less and do it a lot that day. Just make sure that you break it up into
multiple sessions in the study. I described really, they did four sessions 30 minutes each, but that was just once a week.
If you're interested in the cardiovascular
benefits and the potential longevity benefits of sauna. Well, then it's clear that doing it, three to four, maybe even seven times per week, is going to be
Have
beneficial than doing it just one or three times per week. It
stands to reason that for those of you interested in the general health effects of sauna
about an hour per week, broken up into three sessions makes the most sense based on my read of the data. And again that range of 80 to 100 degrees. Celsius is going to be your guide.
And in terms of the mental health benefits, it seems that getting a little bit uncomfortable
in that heat environments on our
otherwise provide, it safe is going to be the best way to access those mental health effects.
By way of increasing dine orphan, which as you recall will, then increase the ability of endorphin to have its positive effects on mood. After you get out of the sauna or other deliberate, heat exposure.
And in terms of timing, after a workout of any kind morning or afternoon, or if you're not doing it after a workout certainly in the later, part of the day
is going to be most beneficial as it relates to sleep. But of course, there's a caveat there, which I mentioned again, which is that
for those of you that have no trouble sleeping because
Exhausted or you're just one of these phenomenal sleepers. Well, then do it any time of day or night. But for most people doing it later in the day, is going to be more beneficial because of the posts
on a cooling
effect and the relationship between cooling by a degree or more as a way to enter sleep.
Thank you for joining me today for my discussion about the science
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