- [Narrator] It's not just you.
Everyone seems to be cold plunging
or watching other people do it.
[cold plunger whooping]
We're going to have cold plunger Josh Cameron
film the process. [ice breaking]
This is what is happening in his body.
[water splashing]
First, the cold shock,
where the cold might just take our breath away.
- As soon as you step into the water
you will activate your hyperventilation
[Josh hyperventilating] [water splashing]
and that is because you are not adapted yet.
- [Narrator] His body goes into fight or flight mode
from the cold shock.
- Every cell in your body is gonna be affected
by this stressor,
which is very potent for you.
- [Narrator] Micro-stress might feel painful in the moment,
but it has long-term benefits.
- That will help your overall health
by increasing your metabolism
and it will help on your muscles,
on your fat storage,
and it will help on your mental balance.
- [Narrator] The skin sends signals to the brain
once the body starts to get cold.
- The temperature regulating center sense that,
"Wow, this is an emergency."
It will immediately increase noradrenaline in the body
to activate our fight and flight system.
We will have a huge increase by 2.5-fold of noradrenaline
within a few minutes.
- [Narrator] Noradrenaline acts on what's called brown fat,
a type of fat tissue that keeps you warm
by breaking down glucose and fat molecules in the body.
- It not only activate the brown fat,
it also makes sure that our blood vessels contract
to our arms and legs
so we can keep the warm blood in the center of our body,
because that's gonna save our vital organs.
- [Narrator] Activating this brown fat
has long-term benefits.
- [Narrator] Scientists saw
that if you can increase your metabolism
by activating the brown fat,
this could actually be a way
to prevent lifestyle diseases such as type 2 diabetes.
The longer time you stay in the water,
the more heat you lose,
and then you have an activation of the muscles.
- [Narrator] And the first muscles that start to shiver,
they're located in your chest and legs.
- Pectoralis major, which is the breast muscle,
and also the femoralis,
which is the big muscle on your thigh.
And when you feel the muscles are shivering,
it's time to actually get up.
You have reaped all the benefits that you need.
- [Narrator] The more times you cold plunge,
the more benefits the body gets.
This includes an increase in dopamine.
- This dopamine increase from cold immersion
is just as high as nicotine or cocaine.
- Let's go baby.
- So this is definitely the most natural high you could get.
Dopamine gives you drive and motivation.
You'll have an increase
of 2.5-fold above baseline of dopamine.
That's not gonna subside just immediately
as soon as you go up.
That will last for hours afterwards.
- [Narrator] An increase in serotonin.
- So after three times, after four times,
you also activate your vagus tone.
That will give you a sense of mental balance
because it increases serotonin in the the brain.
That is not something you get
from cold showers, for example.
You get that from submerging into cold water.
- [Narrator] And an increase in oxytocin.
- We have seen that from mice studies,
they have an increase in oxytocin.
And oxytocin is our love drug, natural drug in our brain,
that is increased every time we fall in love,
or we have sex,
or we eat chocolate,
touch and stuff like that.
- [Narrator] You don't necessarily
need to dunk your entire body [water splashing]
into cold water
to reap the benefits.
- I found this very interesting study from Canada
from a scientists group.
They have calculated how much heat you lose
submerging your body into cold water up to the neck
versus how much heat you lose from also dunking your head.
Submerging up to the neck,
you would lose 11% of heat from the head.
But if you also then do a head dunk,
you will increase that heat loss by 36%.
- [Narrator] In fact, dunking your hands
can be just as beneficial.
- I found this very interesting study in fishermen.
They work in very cold water
with their hands submerged many hours.
Scientists found they were cold-adapted,
so the cold adaptation doesn't just come
from exposing your full body up to the neck.
You can also expose parts of your body
and you will get a systemic effect.
- [Narrator] Finally, the after drop.
- You will actually be colder when you get up.
All your muscles will start to shiver
because when you're in the water,
your body is completely trying to shut out the cold
but when you get up,
the blood vessels will dilate
and the warm blood from your core
will flowed out to your fingers
and your cold tissue in your muscles.
In your core, you have receptors
which will send, then, a signal to the brain telling you,
"Oh, now the blood has become much colder."
That is a decrease in temperature in your core
and your muscles would then start to shiver even more
because now you got colder.
That is completely normal and just keep moving afterwards.
Just don't sit on your couch.
This principle is called this Soeberg Principle
and it's named by a professor from Stanford University.
- [Narrator] Cold plunging is a practice
with a long history with the Egyptians.
- This first civilization,
they built the seas and the rivers
and thermal sources around them.
In Egyptian times,
the water was used for hygienic and clinical purposes
- [Narrator] And with the Greeks.
- Hippocrates said
that because of the imbalances that we have,
the fluids in the body can get stuck
and that imbalance can be restored
going into cold water and warm water.
- [Narrator] But researching what happens in the body
and the potential benefits of the cold is recent.
- The Titanic actually sunk in April the 15th in 1912
and that was a big disaster,
but this is in history the first time we really know
how much time the body can be in cold water
before it gets hypothermic.
From that on, people were thinking,
"Whoa, cold water could actually be really dangerous."
It didn't really get any better
when we jump right on to World War II,
where Nazi experiments were performed
in the concentration camps in Dachau
to investigate how long a human body could be cooled
before they died.
It has taken decades before scientists started again,
investigating human physiology and cold water.
In the sixties and seventies,
we begin, again, to see studies where we can see
what happens when you put people into cold water.
- [Narrator] Cold plunging weekly
can have many long-term benefits.
- Another long-term benefits of going into the cold water
is the increase in metabolism.
Just by 11 minutes per week divided on two to three days,
you will have an increase in thermogenesis in the body
so you'll get warmer,
you will get a increased insulin sensitivity,
and you will have a better glucose balance,
meaning that you will easier
get rid of the glucose in your bloodstream
when you are adapted to cold water.
- [Narrator] The same study
by Dr. Soeberg and her colleagues
suggests adding warmth.
- We also saw that going into a sauna,
57 minutes divided on two to three days,
10 to 15 minutes at a time,
you can also increase your metabolism
and you will lower your core temperature
which is a good thing,
because then you have a higher threshold
for getting hypothermic as well.
[water splashing]
The long-term benefits of cold plunging seems to be
that you will have
a better temperature regulation in your body.
You will become a warmer person physically.
Apparently, also emotionally.
That could explain the culture
that is also in the winter swimming clubs,
that people get this gratitude
because they have, maybe, this large increase in oxytocin.
I think it explains why we see
that kind of friendly atmosphere there.
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