Welcome to Huberman Lab Essentials,
[music] where we revisit past episodes
for the most potent and actionable
science-based [music] tools for mental
health, physical health, and
performance.
[music] I'm Andrew Huberman, and I'm a
professor of neurobiology and
ophthalmology at Stanford School of
Medicine. And now for my discussion with
Dr. Susanna Søberg. Dr. Susanna Søberg,
welcome.
>> Thank you.
>> So great to have you here. For many
years, I've been interested in cold
thermogenesis, and you're bringing so
much quality information about this area
that for a long time I think was kind of
niche and is now becoming more and more
mainstream. So my first question, is
there any way that we can start to gauge
what is the best way to approach a
deliberate cold exposure
protocol? I mean, should it feel
uncomfortable?
>> If the temperature is very cold and you
feel that you also feel very cold, then
you you should stay in the water a
little bit longer. So I think it's just
you should get uncomfortable cold. So as
long as you get uncomfortable cold, it's
cold enough and you get this what we
call the cold shock. So the cold shock
is activation of your sympathetic
nervous system and these activation of
the the catecholamines.
>> Does the shock mean that I'm having
trouble controlling my breathing? Is
that a good gauge?
>> Yeah, you can say so because that's kind
of like how we define it. So you
hyperventilate, so you have a faster
breathing rate.
So that increases also because you
activate your gasping reflex if you are
new to this.
But if you are adapted, it it kind of
subsides with time with adaptation. So
what you can do is that you can train
this cold exposure and you can kind of
like get adapted to it. So you don't
have this hyperventilating response
every time you go out in the cold water.
So this is like building up your
resilience, building building up your
adaptation is going to make the shock
like subside a bit. So it's it's always
harder in the beginning, but you should
do hard things, right? You think about
cold water and cold water immersion as
something that is comfortable. It should
be hard because that's the point of it,
right? If you enjoy it, then yeah, then
I'm I'm thinking something is wrong.
It's not right. You should not enjoy it.
>> What are the differences in terms of
impact, short-term
and perhaps even long-term, between cold
showers,
cold plunge to the neck so that could be
an ice water or just very cold water,
immersion with dunking one's head and
then coming up because obviously people
have to come up for air at some point,
and then simply being outside on a cold
day in shorts and a t-shirt or something
of that sort?
>> So there are different outcomes
because there are they are very
different exposures of the cold to your
cold receptors in your skin. So the more
you can say you cover your body in the
cold, which you would do in cold water
because there are of course the
molecules are
closer to your skin, you will have a
more potent
activation of all your cold receptors in
the skin. So that one will definitely
activate your
autonomous nervous system more and rapid
compared to going out in a t-shirt in
the cold wind, just go for a walk.
But that is also something that's going
to activate your
sympathetic nervous system, meaning then
that you will have an increase in
norepinephrine
and you will activate something called
the the brown fat. So this is a healthy
kind of fat tissue that we have in our
body. And when you activate that, that's
going to increase your metabolism. So it
is kind of like our first responder in
in the body to keep our temperature up.
There are two tissues which can increase
our thermogenesis. So the brown fat,
which is like always like temperature
regulating our body, and then we have
the the muscles which will secondarily
start to shiver and that's going to
increase our
temperature in the body. But as soon as
you go into a cold shower, you will
activate your brown fat also
immediately. So it could be good also
for increasing metabolism in theory
because we haven't really any studies
showing how much does actually activate
the brown fat. So, if someone out there
wants to do a study on [laughter] that,
it would be great.
>> So, it sounds like any form of
cold
to the skin that people register as what
you call the cold shock or uncomfortable
like oh like this is kind of jarring,
activates the brown fat. Do we know what
the pathway is from cold receptors on
the skin to the brown fat? I mean, how
does the brown fat know that we're cold?
>> The cold receptors will send a signal to
our temperature regulating center in in
the brain, so hypothalamus, and that's
going to be taking in this message. And
we have so many cold receptors in the
skin, so it's going to be very fast as
you can say if you immerse the body into
cold water, this is going to be so
rapid.
So, it will have a rapid increase in
neurotransmitters in the brain from
norepinephrine, adrenaline, cortisol,
and which is not that much, but it's but
it's still there. So, you have this
increased in norepinephrine which will
then immediately activate the brown fat.
But there's also a direct pathway from
the cold receptors in the skin to the to
the brown fat which really shows that if
because of these different pathways, it
shows that that it could be that this
tissue to keep us warm us developed in
in our evolution as humans to keep us
warm and to save us whenever the
temperature on our skin varies just a
little bit to keep us in that right
homeostatic balance so we don't get
hypothermic, but also so we don't get
hyperthermic. But because it seems that
the brown fat is also activated when we
get warmer in our skin. So, it is also
maybe a temperature regulator in our in
our body. But the pathway is different.
I think it's also
third pathway from directly from the
muscles. So, the brown fat is also
activated even though the the muscles
are starting to shiver. So, there is a
an extra pathway that way to keep our
our temperature up. So, muscles and
brown fat are working together to to
keep us warm, so we don't suffer too
much in the in the cold water.
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>> I want to ask about shiver.
Um, I've heard that shiver
causes the release of succinate, which
then activates the brown fat.
Is it known whether or not inducing
shiver is important? And when should
people shiver?
>> You shouldn't be so afraid of shivering,
I think, because the shivering as long
as you don't get too hypothermic, so if
you don't if you don't sit in the cold
water for too long, something called the
after drop is when your core temperature
decreases even after you get out of the
cold water. And it always does that your
body because it
as soon as you get into the cold water,
all the
your blood vessels is going to constrict
because you need to keep your blood in
your core and and keep your vital organs
warm. So as soon as you get up that
those blood vessel will open again and
the warm blood will flow out and get
colder and then flow back again into the
core and that's going to decrease the
temperature in your core of course.
>> Years ago, Wim Hof, I heard him talk
about the drop and I've heard colleagues
of mine talk about the drop, but that's
the first time I've ever heard it
explained clearly. Let me make sure I
understand this. So
I get into cold water, obviously I'm
cold
vessels constrict to keep blood near the
center of my body, keep me alive. I get
out. The warming up of my body allows
those vessels and capillaries to dilate
again. The blood goes out to the
surface, but the surface is still cold
and so that blood is cooled and then my
core body temperature drops and that's
what you're referring to as the drop and
that's what induces shiver.
>> Exactly.
>> Great. And then am I right in thinking
that then the shiver activates brown fat
which then warms me up again?
>> Yes.
>> Got it.
>> That's why you should end on the cold.
It's training. It's training for your
for all your cells. It's training for
your muscles. It's training of your
metabolism and that's going to increase
your what's called the insulin
sensitivity. So if you can like
in your mind get used to the thought of
shivering is just like when you go
exercising in the training center and
get that feeling of like oh this is
tough, now it hurts a little bit. Yeah,
it's going to hurt because that's what
shivering also does, but it's just a
different way of training your cells in
your body. It's going to create what is
healthy stress. It's called hormesis in
the cells and the more you expose your
your muscle cells or your brown fat
cells to these kind of like healthy
stresses, exercise, cold and heat
exposure
it's going to make them better at like
activating and also at keeping you
healthy. So as long as the the cells get
exposed to this
it's going to keep them on its toes you
can say, because it becomes more robust
um increasing these
heat shock proteins and cold shock
proteins in the cells to um make you uh
more robust for the next time. And that
is also what happens when you go to the
training center. And I keep like drawing
that parallel because pop people today
know more about windmill, more about
exercise and what that's uh is is going
to do to your muscle cells. But the same
kind of like training is also what you
do when you go out and and into the cold
water and submerge into cold water
because that is just your cold training
center, you can say that. And and also
your heat training center going into the
sauna because the cells are getting
stronger with hormetic stress. So it's
the same process, just different
practice.
>> What are some of the other things that
happen at the level of metabolism and
brown fat in let's say the hours and um
day after deliberate cold exposure?
>> Yeah, so
what happens is that you you get adapted
a little bit every time you go. So you
will like exercise get a little bit
stronger. So every time you go into the
cold water, for every time you will be
more exposed to it, you will you feel
more comfortable in the cold. So you
were going to you're going to build your
adaptation, which happens on a metabolic
level, which is going to be the brown
fat. So you have more activation of your
brown fat. The mitochondria in the the
brown fat cells are going to be um you
have more of those and they will be more
efficient at heating you up because it
expects the body expects you to to do
this again, so you are prepared. The
capillaries in your skin is also
will also become better at like
constricting. So you will have a better
shield of your body to uh prepare you
for the next time. Your stress response
will also be subsided a bit, so you will
have a less increase of your
catecholamines because of this
activation of your brown fat or your
muscles. You have an increase in
in in your metabolism, which will then
make your insulin sensitivity better.
And this is shown in in studies. For
example, there was this interesting
study I found just before I started my
PhD, which was from
et al. from 2016 where they measured
insulin sensitivity in middle-aged men
and women during one winter swimming
season. During these four or five months
they were winter swimming, they saw that
they had a lower blood pressure after
the season, and they had a lower heart
rate, and they also saw that they have a
better insulin sensitivity. And I think
that is very interesting because if you
can have a better insulin sensitivity,
you can prevent lifestyle diseases and
with lower blood pressure, which is a
very strong outcome also for telling how
much inflammation you have in the body.
And because it didn't measure brown fat,
I figured that it could be that was the
missing link, that was the one of the
explanations to why we see this less
inflammation in the body. So the longer
outcomes or the long-term outcomes could
be that you lower your blood pressure
and have a lower heart rate,
you also
have
better insulin sensitivity and better
glucose balance, but that was shown that
is shown in my study.
>> Is it the case that as we're just moving
around, I've heard of NEAT, non-exercise
induced thermogenesis, so if we're just
moving around
that we are activating brown fat or does
there need to be this stressor? Does
there need to be shiver and a cold
stimulus or a heat stimulus to activate
the brown fat?
>> So cold is the the most potent stressor
activator of our brown fat because it's
our temperature regulating organ in our
body, so first responder to that. So
actually just exposing yourself or a
hand actually just to cold water. So
studies have shown
that if you just put your hand in cold
water, not that you're going to going to
do that all day or or every day or
anything, it's not it's it's not
something you have to do, but it just
shows that you can activate your brown
fat just by getting a temperature change
on your skin. People who works outside
or move a lot or get in and out of like
changing the temperature of their body
all the time, they will have more brown
fat. And uh activating that is going to
keep your metabolism higher and your
insulin sensitivity. A study has also
shown this. So the brown fat can be
activated as soon as you just change
your temperature in the skin. So going
outside in a t-shirt, wearing cooling
vests, also studies have shown this for
10 days, it's going to also grow your
your brown fat. So you can get more
brown fat if you expose yourself to the
cold. You don't have to start in a cold
shower, you don't have to start in a
cold plunge if you're not really ready
for that yet, but just exposing yourself
to the cold wind has also shown to
activate your brown fat. Or if you don't
want to be like in this
awake state,
then you can also just sleep in the cold
and you won't notice it that much maybe,
but studies have shown that if you sleep
in 19° Celsius, um then you will
activate your brown fat and you will
grow your brown fat, so you have more of
it. So this very nice studies um
from Hansen et al from 2017
showed that
a group of subjects who slept in a room
at 24° and then they made this PET CT
scanning to see how much brown fat do
they have from the beginning, so what we
call baseline. Then they measured again
after a month of sleeping in 19° and
they saw, I think it's remarkable, just
one month at 19° sleeping there, they
had a duvet on and they were still had
clothes on when they were sleeping.
>> So they're under a cover, under a duvet?
>> under a duvet, yeah, yeah. The subjects
were sleeping at 19° for 1 month had
increased his insulin sensitivity. The
next month they slept at 24°, they
measured this again and then [laughter]
they had decreased actually a little bit
and then they slept at the 27°, so quite
warm room actually for for the fourth
month and they saw even less activation
of the brown fat and also insulin
sensitivity. So it seems that you expose
yourself and pretty rapidly the brown
fat will respond to this because it's so
sensitive to norepinephrine, right? So,
if you keep exposing yourself to a
little bit of cold, you also get a
little bit adapted to it, but that's
because the brown fat um has grown these
more mitochondria in the cells. So,
these small energy fat breaks that's
going to activate the cells and that's
going to take up glucose and fat from
the fatty acids from the bloodstream to
keep uh the thermogenesis up. And that's
going to clear up some sugar and it's
going to clear so in the in the
bloodstream and some some fat as well.
So, the brown fat can in that way
decrease uh our unhealthy fat, which is
the white fat.
Um and the white fat is what we don't
want too much of, but we still need
some, of course. It's our energy
storage, so it's very important that
it's there. We just don't need uh a lot
of it. So, on our thighs and also around
our inner organs, that's where it's it's
located. So, if we can have activation
of the brown fat just by going out in
the cold and just by sleeping in a cold
room or if you are have courage for it,
you can go out and expose yourself in a
cold plunge. Cold showers is also going
to do the trick. So, you can do
different variations of this. Just
exposing yourself to various
temperatures is going to activate the
brown fat because it was involved to
keep us in a perfect homeostatic balance
regarding temperature. So, to keep us
alive.
>> I would just get a clarification around
this 19° Celsius um room that they're
sleeping in. So, they're under a
comforter, a duvet, and um and you
mentioned they had clothes on. Uh the
room is 19° Celsius, but the temperature
underneath their blanket might not be
19° Celsius. So, presumably it's the
cold on their face that's activating the
increase in brown fat. Is that a
reasonable uh expectation?
>> I think so, yeah, because it's you have
so many uh co-receptors in your face as
so it's actually it's enough and it I
think it corresponds very well with the
studies showing that you can activate
the brown fat just by putting a hand
into a a bucket of cold water.
And I did this experiment myself in in
my studies just to see how well did they
respond to cold water. So it was a 4°
Celsius cold water for 4 minutes and
then I just measured blood pressure and
heart rate to see do they have like an
activation of this. I actually also
measured the brown fat during this
cold exposure for 4 minutes with an
infrared thermography camera. Usually
you cannot really see activation of your
brown fat because it's located centrally
in your around your central nervous
system and the biggest depot, as you
mentioned before, is up here under the
the clavicular bones, very close to the
skin surface. And because it's so close
to the skin surface, I could measure it
with this very expensive camera. We
measured the brown fat with this
and and I could see that after a few
minutes that the activation was there
and increase in temperature
arose from that activation, just 4
minutes. So it's very rapid and I'm also
measured in my study how deep was the
brown fat under your skin. So it's very
close to the surface, which also shows
that it it needs to be there to heat you
up and heat heat your inner organs.
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>> I'd like to talk about your study. It
explored not just cold, but sauna and
the co-use of cold and sauna as a way to
probe metabolism and brown fat and other
markers as well. If you could tell us
about your study, what you did, and what
you discovered.
>> When I started this research in 2016, I
wanted to see if we can do like some
kind of activity so we can have people
move also, go and do something, do
something together or whatever. And and
and the cold
made us think about well, what about
winter swimming? So we were just
thinking, okay, winter swimmers um must
in theory activate the brown fat, right?
But we kind of didn't really know with
was this kind of stressor too much, too
little, or what will happen actually. I
read the literature. I understood in
theory what happens when you go into
cold water, but I completely understood
it when I first tried it. It was really
uncomfortable just doing it, but
afterwards, as soon as I got up, I felt
fantastic. And we went into the sauna,
and I did three rounds because I just
loved it. I loved the feeling afterwards
because you have all these neurons going
in your brain, and you feel more
positive, you feel I feel invigorated,
had so much energy, and that like I I
could totally see why people would do
this to get energy throughout the day
because I definitely had that. I didn't
have to do three dips to to get that. I
think one would be enough. I wanted to
study the lowest dose you can say, the
lowest amount that we can get away with,
but still see health benefits. So I
recruited winter to who have been
swimming for two to three seasons and
they stayed only in the water for one to
two minutes. So the cold subsides very
quickly and you would get this
activation of your rest and digest
system, which is your parasympathetic
nervous system. So the the other branch
of your
nervous nervous system.
And you get that activation because you
submerge into cold water and when you do
that you have an activation of your
diving response and you slow down your
your oxygen consumption in your body and
that is because the body tries to
preserve
oxygen so you will not get hypothermic
too fast. So it's kind of like a
survival system in your body.
So this survival system is very
important for us of course. So that
would be activated and because of that
you will after maybe one minute or so. I
I can't be precise on that because maybe
also varies a bit in in humans. So one
to two minutes you will have full
activation of the sympathetic nervous
system but also the parasympathetic
nervous system. So they do this two to
three times per week and for each time
they go each day they go they take three
rounds of so three dips and two sauna
sessions. So they start in the cold and
they end in the cold water.
>> What is the temperature of the sauna?
>> About 80° Celsius.
>> Then how long are they in the sauna?
>> So they stayed there for 10 to 15
minutes so depending on if they went two
times per week or three times per week.
>> And we will talk about why it's
important to end on cold the so-called
Soburg principle. How cold was the water
in this particular given average because
I realize it's outdoor winter swimming
so it's going to vary.
>> It's a very uncontrolled environment to
do this kind of study in but I wanted to
do something that was also very close to
something people can do for free going
out in nature and use that and also have
the nature like it's a very healthy
impact on us. It lowers our stress
stress level as well. So it's within the
spectrum of very cold water I would say
from around 15 15° Celsius and and down.
But it was actually not colder than like
two to four degrees like in in on
average when it it was the coldest. So
it doesn't have to be that cold to be
good enough and and enough to activate
our metabolism.
>> So what did you discover in terms of
changes in brown fat, insulin resistance
or insulin sensitivity rather and um
metabolism?
>> So what we we saw uh was we had these
kind of different measures uh to see
what to try and unravel what what's
actually going on when they are already
adapted to the cold water compared to a
control group who was
matched uh on on various parameters. We
did see that the winter swimmers had an
increased insulin sensitivity. They
produced less insulin uh on all the
experimental days. So besides from just
cooling them and measuring the brown fat
on each of these cooling days or two
cooling days and one thermal comfortable
day, right? So I wanted to measure
insulin when they were just they were
fasting, meaning that they hadn't eaten
in
uh eight hours before the study day. Um
and they were completely length still,
not moving just in a bed.
Um and we measured insulin uh during the
experimental day just to see
how what level are they on. And we could
see that the the
the winter swimmer had lower production
of insulin.
And they also when they had an glucose
drink, so we give them that to see if
they to test before we enroll them in
studies to see if they have diabetes for
example and not knowing for example that
that wouldn't that would like ruin maybe
the the study. So we test for that and
see if they have like a normal curve. So
what we did see in that was that the
winter swimmers had a faster glucose
clearance in the bloodstream. So after
two hours uh we could see that they had
a lower level and it went the curve went
down faster than in the control group.
>> So despite having lower insulin release,
they have better blood glucose
clearance, which is really what you want
what we all seek, right? You don't
Excessive insulin is bad, insulin being
a more or less a chaperone for blood
glucose. How much cold exposure do
people need? How much heat exposure do
people need in order to extract these
benefits?
>> Yeah, so when we then calculated the
numbers together, we could see that this
was ended up being 11 minutes uh in
total per week. Uh so not in one
session, of course, but they had two to
three visits to the water and the sauna
per week. So
when we divide that out, it corresponds
to being in cold water one to two
minutes at a time, but also in the sauna
10 to 15 minutes at a time. And I think
this is very like um also similar to
what we see in other studies, and I
think it fits very well with what we
call the hormetic stress or healthy
stress that you expose the cells to this
kind of like potent very uh stressful
situation uh where they increase heat
shock proteins in the cells and that
will repair the cells. It shows that you
don't have to expose yourself very much
to the heat or very much actually to the
cold to get this healthy uh benefits uh
from going into cold, going to heat and
have healthy benefits on your
cardiovascular system. So I think this
is very important also message to to to
get out that you don't have to go
extreme, you don't have to uh swim for a
half an hour in the cold water. You can
go in the water for one to two minutes
um per session, but go up to 11 minutes
per week in total. And for the sauna, my
study showed uh 57 minutes in total per
week. And if we also then divide it out
on these two to three days and two
sessions each day correspond to 10 to 15
minutes. So it's a low threshold, but I
think it's it's good to have that to
maybe we can aim for that if if people
need to have something to to aim for.
And I think and I think it's really good
to have that because then you you don't
have then you don't overdo it. And if
you overdo it, you exhaust the cells and
that will increase your risk of
cardiovascular disease also.
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>> So in addition to looking at regulation
of blood sugar,
brown fat,
metabolism, and so on,
were there any markers that you examined
in the deliberate cold exposure group as
compared to controls um that revealed to
you that deliberate cold exposure could
have additional benefits um say for uh
immune system function um or for any
function for that matter?
>> Yeah, so for um
we looked at inflammation. Of course, we
measured the outcome of blood pressure
and so on, but we also measured the IL-6
in the study just to see also an
inflammatory and inflammatory marker. So
IL-6 went up and it also follows with
the IL-10. So that is like also very
known in the literature. So we measured
that and I think it's very important to
to think about the cold exposure and the
heat exposure as something that then
lowers the inflammation in the body. And
if we can do that, we will have an open
door for
preventing lifestyle diseases, right? So
for
type two diabetes, but actually also for
some mental diseases as well, so as
known as depression and anxiety and also
Alzheimer's disease, which are all
associated
in research, also newer research showing
that
that inflammation increases the risk of
depression and anxiety and Alzheimer's
disease, neurological diseases. So if we
can decrease inflammation in the body,
we will decrease our modern lifestyle
diseases, but also these increasing
mental diseases that we see in these
modern lifestyle times. I think it's
very interesting that we can go out in
nature and we can use these natural
stressors and it I don't want to have it
sound very romantic or anything. It's
just it's just exposure to temperature
actually, just to cold or to heat that
is going to tweak our body into a
natural state again and and reset it
where the the homeostasis, the balance
has is lost a bit.
So
the body is going to repair itself in
that way and I think it's beautiful that
we can do that just by changing the
temperature of our body. And although
people are very scared of doing this
because in our times we have been away
from cold, away from heat
temperature
for some for decades now
since we isolated our houses better and
we are more sedentary. We also sit more
indoor. We don't move as much. So this
very
modern sedentary lifestyle has made us
more temperature comfortable, just
neutral. So no no wonder I mean that
obesity is increasing. We don't expose
ourselves to the natural stresses that
we did earlier on
in in our involvement, but up until
maybe the '70s, the '60s where we
started having more like a comfortable
lifestyles, right? And obesity increases
in the in the eighties. We can see that
from statistics. So I think that if we
can take in cold and heat, it all
increases the hermetic stress in the
body. So it's doesn't have to be
other than natural stresses to the body
which then could keep us in that natural
balance again.
>> Could we talk about what I refer to as
the Soburg principle, which is to end on
cold in order to force your body to heat
itself back up and thereby
increase metabolism further still?
>> Yes. So when you when you end on the
cold, you you force your body to heat up
by itself and that will require that you
activate you keep your brown fat
activated and also your muscles, which
is a good thing. It's a good
collaboration to keep your thermogenesis
up. And that's like an an exercise even
when you go home. So in that way, you
don't have to think about your cold
exposure dipping in in your plunge
or open sea or what it is as just
an exercise that you do for one to two
minutes and then it's over. If you
end on the cold, you have an exercise
for your body going on for hours
afterwards. And that's not only on your
metabolism, but it's also going to keep
your neurotransmitters activated as well
and increase that because your body is
still cold. So you need that
those neurotransmitters to activate the
brown fat as well. So that's going to
make your brown fat cells more efficient
and also your muscle cells more
efficient, so increasing mitochondria in
the cells,
which will then generate heat very fast.
So if you have done this for a few
times, so maybe three, four, five times,
you will notice a switch where you like
feel that you get easily warmer and you
can keep yourself warmer. And that is
also what we shown in in my study is
that the the winter swimmers were
physically
warmer on the skin compared to the
control group. So they they
>> When they are out of the cold?
>> When they are out
>> the cold, just relaxing, and we tested
this in in on the days where they were
sleeping in the lab. So we could see
that they had
a more activation of the brown fat, a
higher temperature. So probably because
they also lose heat.
They have a higher heat loss to the body
compared to the control group because
they have a more vascular skin
because of the contrast of cold and
heat. So they lose heat faster from the
body during their day. But is that a bad
thing? No, probably not because that's
going to keep your brown fat and your
muscles a little bit activated. So you
will have to
it has to work to keep you warm.
>> Let's say somebody only had two days a
week
to do deliberate cold exposure. Maybe
they don't have access to a sauna, maybe
they do. Would you suggest that they get
in for one or two minutes, then get out,
then get back in for another couple of
minutes, then get out and call that four
you know, four or five minutes
to try and get to that 11 minutes total
per week?
>> Yeah, absolutely. I think the the
changes in temperature is what is
strengthening your your cells in the
body. So if you can do the short amount
of exposure and then get out and get
back in, that is going to
you can say
strengthen your cells because you are
challenging them to to adapt to
changing temperatures.
>> That's really what I keep hearing coming
through in as you explain these data and
all these beautiful studies, yours and
others,
is that it's not really about getting
cold. It's about going from warm to cold
and from cold to warm.
I think if people can internalize that
idea that they're going to have a lot
more flexibility, a lot more fun, and
and get a lot more benefit as opposed to
thinking, okay, I need to get into X
degrees of water for X amount of time on
X number of days, you know, in a very
rigid way.
>> all the time. How much and how cold? And
and I mean, it's it's just like well
because we also don't have studies
showing exactly if you just keep five
degrees in your water and you do that
for a month, then what happens? We maybe
the future we will know much more about
this and I'm I'm sure it's going to come
and I really hope so, but
I just think by logically changing that
temperature up and down up and down and
you also do that in your water, it
doesn't really it's not that important
what temperature you you have your water
then then just keep changing it going up
and down it could be all up to 12
degrees Celsius. You're going to
activate your brown fat anyways. I mean
12 19 degrees
cold air is enough to activate your
brown fat. So maybe we don't have to go
as cold as I think many people think
and putting ice even all the time you
don't have to. It's not I don't think
it's necessary to to expose yourself to
that cold
temperature all the time
but vary it a bit.
>> Well, listen I I want to really thank
you for coming here today to talk about
your work
and the incredible direction that it
points to because I think that
you know
no one study is definitive, but your
study really again stands as a landmark
in the landscape of exploring deliberate
cold exposure and heat. So first of all,
I just want to thank you for doing the
work that you've done and for the work
that you continue to do which includes
coming here today to to share knowledge
with me and our audience. So thank you
ever so much.
>> I'm very grateful for being here.
>> [music]