The Neuroscience of Cold Showers 🧠

Curious about the hype around "Cold Showers?" (10min Read)

TL;DR Summary

• The Evolutionary Science of Cold Showers

• “Hormesis” = If it doesn’t kill you, it makes you stronger.

• The Benefits

  • Cardiovascular

  • Immune

  • Metabolism

  • Nervous System

• Do it Now! & Challenge your friends

Cold Exposure

I get asked to provide the “Neuroscience” of things a lot. One of the most common is around cold showers or cold exposure.

As I researched more, I realized more people need to know about some of the crazy benefits of these practices!

For those of you who don’t know what I’m talking about, there are people on this planet, who choose to take cold showers instead of hot ones.

I’m one of those people, and by the end of this blog, I hope you’ll consider them too!

If it’s not a cold shower, it may be a cold plunge, or some kind of ice bath instead, which is where the “cold exposure” term comes from!

Tony Robbins is one of the first people I heard referencing this type of practice, his routine is jumping into a mini pool that’s just above freezing temperature!

You may have also heard of “The Iceman” otherwise known as Wim Hof. He’s one of the best-studied humans in history for the things he’s been able to do around cold exposure.

Some of his achievements include:

• Running a half marathon above the Arctic Circle, barefoot only wearing shorts.

• Swimming underneath ice for 66 meters.

• Climbing the highest mountains in the world while wearing only shorts.

So, what is all the hype about? Let’s find out!

200k Years Ago

Before we dive into the details, let’s talk about what’s going on here big picture.

To do that, let’s go back 200,000 years to when our ancestors roamed the earth.

Unlike today, they didn’t have air conditioning or heating, in fact, they barely even had clothes to protect them from the environment.

This means they were exposed to extreme conditions like the cold constantly!

This put them in a constant state of “hormesis” which basically means, “What doesn’t kill you, makes you stronger.”

When we are in a state of hormesis, our body has to adapt and renew itself, it’s how we survive evolutionarily, and it still works today!

Most of us are more familiar with hormesis than we think. If you’ve ever lifted weights or ran, you know that putting your muscles & body under “stress” makes you stronger over time.

The same is true for cold exposure, the only exception is that it’s not just your muscles!

Having to adapt to extreme temperatures is like a workout for your entire central nervous system, cardiovascular system, endocrine system (hormones), and immune system all at once.

And instead of just strength gains, you get a whole host of “hormetic effects” and benefits.

Now, let’s dive a little deeper into what some of these benefits are.

The Benefits of Cold Exposure & Hormesis

Cold exposure is one of the best-studied forms of hormesis.

And it’s become abundantly clear over the years, that there is almost no better way to put our bodies into hormesis!

The benefits hit almost every single system of our bodies, and today, we’re going to cover some specific ones: The Cardiovascular System, the Immune System, the Metabolism & finally, my favorite, the Nervous System.

The Cardiovascular System

The Cardiovascular System is the body system that is responsible for our blood circulation, which helps get nutrients to our cells, clears out waste from our body, and gets our immune cells to the areas that they are needed most.

It transports these things using its engine, the heart, through our arteries, veins, and capillaries.

These highways inside our body would span about 100k miles if we took them out of us!

An important thing to note is that while the heart is the main driver in pumping our blood, there are also millions of micro-muscles along these vessels.

For most of us, these extra muscles grow weak over time because we don’t use them enough, making our heart’s job much harder!

Cold exposure shocks these micro-muscles the same way weight training shocks your muscles!

Overtime, this causes the heart rate of someone who has a deliberate cold exposure practice to decrease by 20-30 beats per minute.

This is because as you strengthen those micro-muscles, your heart doesn’t have to work as hard to pump blood around your system!

This also makes your Cardiocasular System much more efficient, meaning it can deliver nutrients more effectively, clear our systems more efficiently, and pump our immune cells to the places they need to be faster!

The Immune System

This brings us to the Immune System, which as I just mentioned is traveling through our blood!

With the heart & vascular system in hyperdrive from the cold exposure, the Immune System is now seeing the downstream benefits & effects.

The most important of which is increasing our overall immunity to pathogens and decreasing our inflammation levels.

If you don’t know, Chronic Inflammatory Diseases has been recognized as the most significant cause of death in the world today accounting for more than 50% of total deaths worldwide!

And yes, in moderation inflammation can be hugely beneficial like when you get a bug bite and the area swells to block the poison from traveling anywhere else in the body but when inflammation becomes chronic it can lead to:

• Arthritis

• Cancer

• Diabetes

• Alzheimer’s

• Non-alcoholic fatty liver disease

• Mental illness

That’s why lowering inflammation is a huge part of living a healthy life and with that vascular system on overdrive more blood is getting to more places efficiently.

Meaning more nutrients are being delivered to where they need to be, and more waste can leave the area which includes unneeded inflammatory cells like cytokines, which are responsible for causing inflammation.

And this hyperdrive also increases your levels of white blood cells (WBC) dramatically, which are the cells that make up your Immune System and are responsible for trapping pathogens as they enter your body.

With more White Blood Cells flowing through your body, your immunity spikes, meaning you get sick less often, and when you do get sick, it is for a shorter amount of time because more of these cells are there to stop the invading pathogens, toxins, and bacteria much faster.

The Metabolism

The next area cold exposure benefits is your metabolism.

A cold exposure practice can increase your metabolism by 350%… Yes, 350%.

Your metabolism is a measurement of how well you break down and use glucose for energy.

Cold exposure boosts your metabolism dramatically in a couple of ways:

• Increasing brown fat (good fat)

• Decreasing white fat (bad fat)

• Increasing insulin sensitivity

Brown fat is created when we are cold and helps us warm up our bodies to keep our internal organs warmer.

It’s called brown fat because it has more mitochondria inside of it, making it appear darker.

Mitochondria are what power our cells, they use the glucose in our blood to create the energy that allows us to live.

Cold exposure causes our bodies to turn their white fat, which is the type we are all most familiar with, into brown fat to keep us warmer more effectively.

Having more brown fat also increases our insulin sensitivity because, with more mitochondria, we uptake glucose more efficiently.

Adipose is a fancy word for “fat”

This decreases our risk for diabetes and insulin resistance!

The Nervous System

Finally, the Nervous System is one of the largest beneficiaries of cold exposure and is the main driver of all of the positive effects given by the other systems we just covered.

Some of the most notable benefits are:

• A 530% increase in Norepinephrine

• A 250% increase in Dopamine

• Decreases in cortisol

• Increased goal-directed behavior & focus

• Decreased anxiety, depression, & stress

• Increased mood

The start of these benefits begins with our Fight-Flight or Freeze system.

This is the portion of our Nervous system responsible for the 530% increase in Norepinephrine.

When we are deliberately exposed to the cold, it causes our brain and body to release this chemical into our blood!

This is probably the most important benefit of deliberate cold exposure because Norepinephrine is the main driver of most of the benefits we’ve talked about so far!

Norepinephrine

For example, Norepinephrine released into our white fat cells triggers the production of mitochondria, which is how white fat turns into brown fat!

In relation to Mental Health, Norepinepherine release triggers the release of Dopamine, which is why we see that 230% increase in Dopamine.

These two neurochemicals (Norepinepherine & Dopamine) along with Seratonin are the main neurochemicals connected to Depression, Anxiety, ADHD, and many more.

People who struggle with these types of Mental Health issues have lower levels of all of these chemicals.

So when you hear people say cold exposure helps with Mental Health, they aren’t lying! Norepinephrine release is paired with the release of both Dopamine and Seratonin.

Not only does cold exposure help increase these chemicals more effectively than any other traditional treatment, but the effects have also even been shown to last longer!

Finally, Norepinephrine & Dopamine hone our focus, literally increasing our “goal-directed behavior” which is a fancy way to say it increases your motivation & drive towards your goals.

What doesn’t kill you…

Knowing what you know now about hormesis & cold exposure, I hope you’re interested in adding some level of deliberate cold exposure into your routine!

For those of you who are, I figured adding in some tips and tricks on just that would be helpful.

First of all, you don’t need to jump into a cold lake as your first attempt to add some kind of cold exposure practice into your life.

There are various options, for example, you could start by splashing cold water on your face, even this small act has some of the beneficial effects we’ve covered today.

A lot of the people I work with also start by taking a hot shower, but at the end, turning the water to cold for 30 seconds, and then warming it back up again!

As you progress, you can start to take the cold for longer, eventually shifting to a full-on cold shower instead of a warm shower.

Other people prefer plunges into ice bathes or mini pools like Tony Robbins.

Extremists like Wim Hof jump into frozen lakes or take a swim in the Arctic ocean.

Finally, as this type of practice is hitting the mainstream, there are even cryotherapy chambers/machines, however, this option is not always the most cost-effective way to install this practice into your life.

Commonly Asked Questions:

• How cold?

  • Everyone has a different tolerance, but Dr. Andrew Huberman's rule of thumb is that you should be saying, “Whoa, I would really like to get out of this, but I can survive.”

• How long?

  • The benefits start with as little as 30 seconds and top out at around 10 minutes.

• Can I do this every day?

  • Yes, I highly recommend it.

• Is this dangerous?

  • The danger level is very low. Going from never trying it to jumping into the Arctic ocean with no training could lead to some problems, but for the average person, this is a very low danger

The Challenge

I hope you enjoyed today’s blog, if you did, act on it.

One of the easiest ways to start a cold exposure practice is with a buddy.

Forward this email to a couple of your friends who you believe would benefit from cold exposure, and challenge them to start a 21-Day Challenge with you!

If you’re feeling extra brave, record yourself doing yours and @ me on Social Media (@mindbrainbodylab)! I would love to see it.

Please keep it PG and wear a swimsuit!

Thank you for tuning in, and as always, live Heroically! 👍🏻