I also try to challenge myself

to do things that doctors say are not possible.

I was buried alive in New York City in a coffin,

buried alive in a coffin in April, 1999, for a week.

I lived there with nothing but water.

And it ended up being so much fun

that I decided I could pursue doing more of these things.

The next one is I froze myself in a block of ice

for three days and three nights in New York City.

That one was way more difficult than I had expected.

The one after that, I stood on top of a hundred-foot pillar

for 36 hours.

I began to hallucinate so hard

that the buildings that were behind me started to look like big animal heads.

So, next I went to London.

In London I lived in a glass box for 44 days

with nothing but water.

It was, for me, one of the most difficult things I'd ever done,

but it was also the most beautiful.

There was so many skeptics, especially the press in London,

that they started flying cheeseburgers on helicopters around my box to tempt me.

(Laughter)

So, I felt very validated

when the New England Journal of Medicine actually used the research for science.

My next pursuit was I wanted to see how long I could go without breathing,

like how long I could survive with nothing, not even air.

I didn't realize that it would become the most amazing journey of my life.

As a young magician,

I was obsessed with Houdini and his underwater challenges.

So, I began, early on, competing against the other kids,

seeing how long I could stay underwater while they went up and down to breathe,

you know, five times, while I stayed under on one breath.

By the time I was a teenager,

I was able to hold my breath for three minutes and 30 seconds.

I would later find out that was Houdini's personal record.

In 1987 I heard of a story

about a boy that fell through ice and was trapped under a river.

He was underneath, not breathing for 45 minutes.

When the rescue workers came,

they resuscitated him and there was no brain damage.

His core temperature had dropped to 77 degrees.

As a magician, I think everything is possible.

And I think if something is done by one person,

it can be done by others.

I started to think,

if the boy could survive without breathing for that long,

there must be a way that I could do it.

So, I met with a top neurosurgeon.

And I asked him, how long is it possible to go without breathing,

like how long could I go without air?

And he said to me that anything over six minutes

you have a serious risk of hypoxic brain damage.

So, I took that as a challenge, basically.

(Laughter)

My first try, I figured that I could do something similar,

and I created a water tank,

and I filled it with ice and freezing cold water.

And I stayed inside of that water tank

hoping my core temperature would start to drop.

And I was shivering.

In my first attempt to hold my breath, I couldn't even last a minute.

So, I realized that was completely not going to work.

I went to talk to a doctor friend --

and I asked him, "How could I do that?"

"I want to hold my breath for a really long time. How could it be done?"

And he said, "David, you're a magician,

create the illusion of not breathing, it will be much easier."

(Laughter)

So, he came up with this idea of creating a rebreather,

with a CO2 scrubber,

which was basically a tube from Home Depot,

with a balloon duct-taped to it,

that he thought we could put inside of me,

and somehow be able to circulate the air and rebreathe

with this thing in me.

This is a little hard to watch.

But this is that attempt.

So, that clearly wasn't going to work.

(Laughter)

Then I actually started thinking about liquid breathing.

There is a chemical that's called perflubron.

And it's so high in oxygen levels that in theory you could breathe it.

So, I got my hands on that chemical,

filled the sink up with it, and stuck my face in the sink

and tried to breathe that in, which was really impossible.

It's basically like trying to breathe, as a doctor said,

while having an elephant standing on your chest.

So, that idea disappeared.

Then I started thinking,

would it be possible to hook up a heart/lung bypass machine

and have a surgery where it was a tube going into my artery,

and then appear to not breathe while they were oxygenating my blood?

Which was another insane idea, obviously.

Then I thought about the craziest idea of all the ideas:

to actually do it.

(Laughter)

To actually try to hold my breath past the point

that doctors would consider you brain dead.

So, I started researching into pearl divers.

You know, because they go down for four minutes on one breath.

And when I was researching pearl divers, I found the world of free-diving.

It was the most amazing thing that I ever discovered, pretty much.

There is many different aspects to free-diving.

There is depth records, where people go as deep as they can.

And then there is static apnea.

That's holding your breath as long as you can

in one place without moving.

That was the one that I studied.

The first thing that I learned is when you're holding your breath,

you should never move at all; that wastes energy.

And that depletes oxygen,

and it builds up CO2 in your blood.

So, I learned never to move.

And I learned how to slow my heart rate down.

I had to remain perfectly still and just relax

and think that I wasn't in my body, and just control that.

And then I learned how to purge.

Purging is basically hyperventilating.

You blow in and out --

(Breathing loudly)

You do that, you get lightheaded, you get tingling.

And you're really ridding your body of CO2.

So, when you hold your breath, it's infinitely easier.

Then I learned that you have to take a huge breath,

and just hold and relax and never let any air out,

and just hold and relax through all the pain.

Every morning, this is for months,

I would wake up and the first thing that I would do

is I would hold my breath

for, out of 52 minutes, I would hold my breath for 44 minutes.

So, basically what that means is I would purge,

I'd breathe really hard for a minute.

And I would hold, immediately after, for five and a half minutes.

Then I would breathe again for a minute, purging as hard as I can,

then immediately after that I would hold again for five and a half minutes.

I would repeat this process eight times in a row.

Out of 52 minutes, you're only breathing for eight minutes.

At the end of that you're completely fried, your brain.

You feel like you're walking around in a daze.

And you have these awful headaches.

Basically, I'm not the best person to talk to when I'm doing that stuff.

I started learning about the world-record holder.

His name is Tom Sietas.

And this guy is perfectly built for holding his breath.

He's six foot four. He's 160 pounds.

And his total lung capacity is twice the size of an average person.

I'm six foot one, and fat.

We'll say big-boned.

(Laughter)

I had to drop 50 pounds in three months.

So, everything that I put into my body, I considered as medicine.

Every bit of food was exactly what it was for its nutritional value.

I ate really small controlled portions throughout the day.

And I started to really adapt my body.

[Individual results may vary]

(Laughter)

The thinner I was, the longer I was able to hold my breath.

And by eating so well and training so hard,

my resting heart-rate dropped to 38 beats per minute.

Which is lower than most Olympic athletes.

In four months of training,

I was able to hold my breath for over seven minutes.

I wanted to try holding my breath everywhere.

I wanted to try it in the most extreme situations

to see if I could slow my heart rate down under duress.

(Laughter)

I decided that I was going to break the world record

live on prime-time television.

The world record was eight minutes and 58 seconds,

held by Tom Sietas, that guy with the whale lungs I told you about.

I assumed that I could put a water tank at Lincoln Center

and if I stayed there a week not eating,

I would get comfortable in that situation and I would slow my metabolism,

which I was sure would help me hold my breath

longer than I had been able to do it.

I was completely wrong.

I entered the sphere a week before the scheduled air date.

And I thought everything seemed to be on track.

Two days before my big breath-hold attempt, for the record,

the producers of my television special

thought that just watching somebody holding their breath, and almost drowning,

is too boring for television.

(Laughter)

So, I had to add handcuffs, while holding my breath, to escape from.

This was a critical mistake.

Because of the movement, I was wasting oxygen.

And by seven minutes I had gone into these awful convulsions.

By 7:08, I started to black out.

And by seven minutes and 30 seconds,

they had to pull my body out and bring me back.

I had failed on every level.

(Laughter)

So, naturally, the only way out of the slump that I could think of was,

I decided to call Oprah.

(Laughter)

I told her that I wanted to up the ante

and hold my breath longer than any human being ever had.

This was a different record.

This was a pure O2 static apnea record

that Guinness had set the world record at 13 minutes.

So, basically you breathe pure O2 first, oxygenating your body, flushing out CO2,

and you are able to hold much longer.

I realized that my real competition was the beaver.

(Laughter)

(Laughter ends)

In January of '08,

Oprah gave me four months to prepare and train.

So, I would sleep in a hypoxic tent every night.

A hypoxic tent is a tent that simulates altitude at 15,000 feet.

So, it's like base camp, Everest.

What that does is, you start building up the red bloodcell count in your body,

which helps you carry oxygen better.

Every morning, again, after getting out of that tent,

your brain is completely wiped out.

My first attempt on pure O2, I was able to go up to 15 minutes.

So, it was a pretty big success.

The neurosurgeon pulled me out of the water

because in his mind, at 15 minutes your brain is done, you're brain dead.

So, he pulled me up, and I was fine.

There was one person there that was definitely not impressed.

It was my ex-girlfriend.

While I was breaking the record underwater for the first time,

she was sifting through my Blackberry, checking all my messages.

(Laughter)

My brother had a picture of it. It is really --

(Laughter)

(Laughter ends)

I then announced that I was going to go for Sietas' record, publicly.

And what he did in response, is he went on Regis and Kelly,

and broke his old record.

Then his main competitor went out and broke his record.

So, he suddenly pushed the record up to 16 minutes and 32 seconds.

Which was three minutes longer than I had prepared.

It was longer than the record.

I wanted to get the Science Times to document this.

I wanted to get them to do a piece on it.

So, I did what any person

seriously pursuing scientific advancement would do.

I walked into the New York Times offices and did card tricks to everybody.

(Laughter)

So, I don't know if it was the magic or the lure of the Cayman Islands,

but John Tierney flew down

and did a piece on the seriousness of breath-holding.

While he was there, I tried to impress him, of course.

And I did a dive down to 160 feet,

which is basically the height of a 16 story building,

and as I was coming up, I blacked out underwater,

which is really dangerous; that's how you drown.

Luckily, Kirk had seen me and he swam over and pulled me up.

So, I started full focus.

I completely trained to get my breath-hold time up