Three, two, one

and hold.

(gentle music)

If you're like most people, you can probably

hold your breath for 30 seconds, maybe a minute,

before you start to feel the urge to breathe,

but the truth is most healthy people can actually

hold their breath quite a bit longer than that,

some people can hold it a lot longer,

the current world record is 11 minutes 33 seconds

and as if that weren't ridiculous enough,

some competitions allow athletes to breathe pure oxygen,

before their breath holds.

In 2016, Spanish free diver, Aleix Segura

used this technique to go 24 minutes and three seconds

without breathing, how is that possible?

To find out, I spoke with professional free divers

and researchers, who study their physiology,

I also took a crash course

in proper breath holding technique.

When I started, I could hold my breath for about a minute,

but by the end I was holding it way longer,

than I ever would have expected,

but before we get to that,

let's talk about some of the science behind breath holding

and why the professionals

are so much better at it than the rest of us.

The reason why some people

are better at holding their breath for a long time

would be partly genetics and partly because of training.

That's Peter Lindholm,

he's a physician researcher

at Sweden's Karolinska Institute.

He's been studying the physiology

of elite breath hold divers for more than two decades.

He says that a lot of them are just physically gifted,

take lung size for example,

the average human has a total lung capacity

of between four and six liters,

but many of the world's top free divers

have lung capacities of 10 liters or more.

This isn't necessarily something that they've trained,

they were just born with big lungs.

On top of this, many professional free divers

use the muscles of their mouth and throat

to overfill their lungs with air,

this is called lung packing

and the x-ray footage you see here

shows an elite free diver using the technique

to expand his lungs several liters

beyond their normal capacity.

Lindholm also says a lot of elite breath holders

have relatively slow metabolisms

and relatively large blood volumes, which makes sense,

your blood and your lungs hold oxygen

and your body consumes it,

the slower you churn through your oxygen supply,

the longer you can go on a breathful of air,

before succumbing to unconsciousness,

but when it comes to breath holding,

lung size is only part of the equation,

even more important is a physiological response

called the mammalian diving reflex.

When you hold your breath,

it actually causes your heart rate to slow down,

this reduces your body's oxygen consumption,

[Peter] And what that does is it reduces

the blood flow to your legs and your arms,

so blood is pumped preferentially to the brain,

which means that the oxygen that's in the blood

and oxygen stores in the lungs

is used by the brain and not consumed by your muscles.

And cold water actually amplifies the response.

Exposing your face to cold water

activates your trigeminal nerves,

what are your trigeminal nerves?

Take your fingers and you pinch your cheek and you feel it?

You have your trigeminal nerves to thank,

they're responsible for sensation in your face,

but they also connect to the part of your nervous system,

that regulates your heart.

It's not totally clear how or why this response evolved

and it's found in a lot of animals,

but for some reason, when your trigeminal nerves get chilly,

they tell your autonomic nervous system

to tell your heart to slow things down

and as it turns out, slowing down is probably

the single most important thing you can do,

when you're working with a limited supply of oxygen.

I don't try to focus too hard,

this is also a sport where you can't really just push it,

like you can you know, get in, do a run

and really pump yourself and go do it,

this is something completely the opposite,

you have to be really, really relaxed.

Serbian free diver, Lena Balta

is a 16-time national record holder.

She showed us some of the techniques she uses

to calm herself before a dive,

the most important is a series of slow,

controlled inhalations called a breathe out.

These help her relax and purge her lungs of carbon dioxide.

(gentle music)

When she's ready to go, she takes a series of sharp inhales,

using the muscles of her diaphragm to fill her lungs,

before topping them off with some lung packing.

(gentle music)

These techniques take time and practice to perfect,

which is important, because when done incorrectly,

they can be pretty harmful or even deadly,

purging too hard before a dive can cause you to black out,

which is not something you wanna do in the water

and it's exactly why divers not only compete,

but practice in the company of spotters

and lung packing, it can actually tear

the tissues in your lungs,

but Lindholm says that with just a few hours

of supervision and instruction,

most people can actually learn

to hold their breath well over two minutes.

So I gave it a shot.

Just of the CO two but also any physical--

[Robbie] Brian Stanley is a free diving instructor

at Bamboo Reef Dive Shop in San Francisco.

He had me start by holding my breath on land

with my face in a bowl of cold water.

I lasted about a minute,

but thanks to the mammalian dive response,

my heart rate dropped from 74 to 51.

After your heart spiked up to 74. (laughs)

[Robbie] Next, Brian had me move outside

to the pool deck to hold my breath, while lying down.

The idea here was to help my body relax,

this time I held my breath for just over two minutes.

Next, Brian taught me some basic breathe up techniques,

to use my diaphragm to fill my lungs

and to focus on relaxing.

And what this will do is it will help

to relax your muscles, reduce any stress

or tension that you have in the body

and then get that heart rate lower,

which is key for starting your free dive.

[Robbie] As I held my breath, he calmly instructed me

to relax every part of my body, beginning with my toes,

progressing up to my head

and then going back down to my feet.

If you've ever taken a yoga class,

it felt surprisingly similar to that.

Before I knew it,

I had held my breath for just over three minutes.

Finally, Brian had me put on a wetsuit and get in the pool,

where we did some more breathing exercises

and finally had me lie face down

and hold my breath for as long as possible.

Now, there's a few things going on here,

for starters, being in the pool did a lot

to relieve tension throughout my body,

I found it much easier to relax, while bobbing in the water,

than I did when I was on the pool deck

and the wetsuit made me super buoyant,

which helped me relax even further.

Nobody knows for sure, but the mustache probably helped too.

After two minutes in the water,

Brian started having me signal with my finger

every few seconds to let him know I was okay.

We'll say this again, please never attempt this

without professional supervision

and before I knew it, I'd lasted three minutes

and then three minutes and 30 seconds,

then three minutes and 45 seconds.

There you go, nice and slow, bring your feet in.

(gentle music)

(breathing noisily)

Hold.

(breathing heavily)

Catch your breath.

(laughs) That was so cool.

How long was that Four 16.

Four 16!

That's insane! Four minutes 16 seconds.

That's awesome.

(laughing)

Four 16.

[Brian] Oh yeah, nice.

Oh, that's so cool. Hey, nice job, man.

Thanks man. (slapping hands)

(laughing)

That was great, thank you so much.

Yeah.