Before we discovered fire, the cold was a genuine threat to our survival.

Since then, we've continued to protect ourselves from it.

And for a good reason, the cold sucks. We've fought to get away from it over hundreds and thousands of years. We're not going back anytime soon.

So much so that we've almost made ourselves too comfy. Between seat heaters and 24/7 aircon, we can get through a cold day without ever really feeling it.

As performance wizard, PJ Nestler puts it:

"We spend so much of our time in temperature-controlled environments... making ourselves too comfortable. Then, when we have to perform in harsher conditions, we fall apart."

It's even in our culture. As Laird Hamilton puts it:

"Society teaches us that cold is bad. Everything is turned to that. Catch a cold. Coldhearted. It's in our language. These are all negative connotations, so whenever we're talking about cold, there's a negativity to it."

This isn't to say toss out your Uggies and put your 4-burner on marketplace.

But...

That some forms of deliberate cold exposure (like an ice bath or cold shower) can have some seriously positive, evidence-based effects on our performance and health.

Here's a few:

• 💪 Resilience

When we get in the cold, our sympathetic (fight or flight) nervous system kicks in screaming at us to get the f*ck out.

But if we can control our breath and teach ourselves to be calm in that situation, we're essentially training ourselves to handle real-life stressors – our ability to overcome our emotional thinking, react calmly and perform is improved. We've trained it.
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• ⚡️ Mood, energy and focus

The cold releases chemicals (like epinephrine, norepinephrine and dopamine) that make us feel good, and boost energy and focus (for hours after getting out too).
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• 💥 Boost metabolism

When we're in the cold, our body uses energy to warm us up. But this only has a short-term (and pretty insignificant effect) on metabolism.

What's cool is the long-term effect...

To understand it, we've gotta know the body has 3 types of fat – white, beige and brown.

We're all familiar with white fat. Found just under the skin and surrounding internal organs. It stores excess energy when we consume more calories than we burn.

Beige and brown fat is found deeper in the body. And it's responsible for rapidly producing heat. We're born with a heap of it, which protects us from the cold as a baby. And we gradually lose it as we get older.

Cold exposure converts white fat to beige/brown fat in the body – boosting our metabolism.

It also helps us get used to the cold over time. So if you're a cold bug, bitta autumn cold exposure could help you hate winter a little less.
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• 🦵 Physical recovery

Cold exposure after endurance and high-intensity training has been shown to reduce soreness and increase perceived recovery and future performance.

When we get in the drink, our blood vessels tighten up in response to the temp (vasoconstriction). But when we get out, they open right up (vasodilation). And blood then floods through the body giving us nutrients and flushing out the crap – boosting recovery.

But interestingly, cold can limit some of the adaptations from strength and hypertrophy training (if done within 4 hours after the session). That's because the cold can block certain hormones going to and from the muscle (which the muscle needs to repair and grow).

So, what can we do?

Most of the research has been done in ice baths. But that doesn't mean we can't get at least some of the benefits from cold showers.

If you do have access to an ice bath:

Andrew Huberman distilled all the research and suggested (for general performance and health):

11 minutes of exposure, across 2-4 sessions throughout the week e.g. 3x 4 minutes each week.

A few notes for best results:

• 🌡 The right temp is different for everyone. It should be very uncomfortable (but safe).
• 🛀 Move around (when you're still, a thermal layer builds up around your body making it warmer)
• ✋ Feet, hands and shoulders should all be under
  

If you don't have access to an ice bath:

Yep, you guessed it, cold shower. From Laird Hamilton:

"At the end of your shower in the morning, try switching the shower to cold. And hold yourself there. Feel it across yourself. Over your head. Across your skin. In a few short steps we can get our body from sleep to on and open."

It's not fun. But you feel pretty great getting out. Start short. Build it up. And breathe (it'll help).

When?

Based on how our body temperature cycles throughout the day, cold exposure before bed can make it hard to get to sleep.

So it's recommended as a morning thing. Plus, it wakes you right up. And you'll benefit from the lasting effects (energy, mood, focus etc) throughout the day ✌️