What It Takes to Hold Your Breath for 24 Minutes (2017) | Hacker News Reader

What It Takes to Hold Your Breath for 24 Minutes (2017)

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83 pointsindumania45 comments

On this topic, David Blaine's TED talk about holding his breath for 17 minutes is probably the most interesting TED talk there is.

https://www.ted.com/talks/david_blaine_how_i_held_my_breath_...

Thanks for sharing - that was an incredible story. I find David Blaine fascinating because many of his magic tricks aren't tricks per se, he just does things that would be unthinkable for the average person. For instance he often takes a bite out of a wine glass and chews it up, and it seems like there must be some trick to it, except in one of his TV specials he goes to a dentist and reveals that his teeth are all worn down and messed up from eating so much glass.

This one is great: https://www.youtube.com/watch?v=oLAs11gkqKE.

Ricky Gevais: "Sorry sorry David seriously, this isn't a trick. You're just sticking a needle through your fucking arm. What are you doing? That's fucking horrible. You're a maniac. That's the worst thing I've ever seen in my life."

Why was there no blood?

I think the way the trick is done is he essentially has a healed piercing all the way through his arm. So he only had to go through the pain once and can now do the trick whenever he likes so long as he keeps the piercing open.

Likely because it's a magic trick and he didn't really poke it through his arm?

You're just guessing. He really did poke it through.

I had a look around at David Blaine poking various things into himself. I think I was probably wrong. It looks like poking a needle into a bicep is a somewhat common trick[1]. I assume he just takes the pain.

Still, I would tell everyone to be cautious believing a magician's explanation for any trick. Lying to mould people's memory of the trick is a really common technique. In one version of David Blaine's icepick through the hand[2] he says "This is the first time I let someone else choose the place" When he clearly chooses where to push the icepick through.

[1] https://vimeo.com/33462933

[2] https://www.youtube.com/watch?v=sw-l5SW5hik

I'm thinking the healed piercing thing is what it is. Basically he has something akin to a fistula (https://en.wikipedia.org/wiki/Fistula) from repeatedly poking the same spot, but the outside heals over so you can't see the hole.

Much more of it is a trick than David Blaine says so. I think Penn Jillette put it quite well: "Do you really believe a magician who last week was doing car tricks but this week is doing 'real' magic?"(paraphrased).

Remember: Magicians are allowed to lie. Sometimes it's just a simple thing like "I never touched the deck of cards" when actually they were holding them at the start of the trick. Other times it is fake explanation. "I am reading you using psychology" is a popular one with mentalists. Other people on a magicians TV show may lie too.

I don't know the particular David Blaine trick you are talking about, but I wouldn't be surprised if he does not actually chew on real glass.

> Remember: Magicians are allowed to lie

There was a magician on "Penn & Teller: Fool Us" recently who told an interesting lie. His lie was that he was doing a trick.

His "trick" involved snatching the right card out of a fast falling stream of cards, with the stream going fast enough that it seems impossible beyond the ability of a human to use counting or timing to pinpoint the right card and reach in and grab it.

In fact, he had developed the speed and skill to do just that.

Here's a page from the magician showing how he does it: https://www.kostyakimlat.com/blog/fool-us-magic-trick-reveal...

https://www.cbsnews.com/news/breath-holding-games-are-killin...

Wow. That's approaching the time for dolphins, whales and similar sea mammals.

Of course, his record is without doing any work, unlike a dolphin which is swimming.

Free divers are swimming though and their underwater time is very impressive.

In another life I spent some time training in freediving. I wasn't particularly good, but got to around 4:45 for raw breath hold, a 36m dive, and swam maybe 110m in a pool, all done under strict supervision. Fun sport but very strange, it seems to attract an odd bunch.

Doesn't the brain start to die after 10-15 minutes without oxygen? How could he possibly go that long without breathing without suffering any brain damage? I remember when David Blaine was going for the records, the biggest concern was that he would irreversibly and severely damage his brain.

Your brain still receives oxygen without you breathing.

He does start with a lung full of pure oxygen.

That seems like a poor idea.

https://en.wikipedia.org/wiki/Oxygen_toxicity

oxygen toxicity at sea level (1 atmosphere of pressure) would require a 140% oxygen mixture - it's only when you go to higher pressure environments (eg 10m underwater = 2 atm) that it becomes an issue (at 2atm, 70% oxygen is toxic; at 4atm, 35% oxygen is toxic, etc - regular air is 21% oxygen, which becomes toxic around 7atm aka 60m underwater)

You’re generally on the right track, just off slightly. In the scuba diving world 1.4atm partial pressure of Oxygen is generally considered the maximum safe partial pressure when working (ie swimming). 1.5 atm for rest. This makes the depth limit for regular air to be 216 feet. Though there are a lot of divers who dove deeper than that befor trimix became so common.

Watch the TED talk linked elsewhere in the thread, there are many, many things he talks about doing that are also poor ideas.

Brains cells start dying in less than 5 minutes without oxygen.

Yes, and the trick is to supersaturate your blood & tissues with vastly greater amounts of O2 than normal, and also to reduce your oxygen consumption rate.

Of course, even with these preparations, freedivers have died and some have shown some damage.

Also, humans cannot detect O2 levels, we detect CO2 levels. When you supersaturate your blood with O2, you're also purging CO2 levels. This can result in you holding your breath beyond the point where your O2 levels drop below the blackout threshold, which is typically a fatal experience if you're underwater when it happens.

Your brain starts to die without any oxygen, but not breathing is not the same as not giving your brain any O2.

Your blood cells buffer amount of O2 for use and CO2 ready for removal, which is how an untrained person is able to hold their breath and not die. When you stop breathing, consumption of O2 continues until CO2 builds up to a threshold point, triggering a desperate need to breathe (humans cannot actually detect O2 levels). If you try and hold your breath for too long, either the buildup of CO2 will cause the need to breathe, or lack of O2 will cause blackout and the autonomous nervous system to take over and resume normal breathing. While I am not a doctor, I don't see how it's possible to deprive your brain of enough O2 to damage it and not lose consciousness.

It's possible to train long breath holding in two ways: increasing O2 stores and increasing efficiency.

Hyperventilating can result in you purposefully purging extra CO2 and over oxygenating your blood. This will let you hold your breath for a very long time, I can comfortably go from a 30s hold to a 2m hold by pre-hyperventilating (see: Wim Hof Method). It also adds the risk of letting O2 levels drop before CO2 rises, causing blackout, which is basically one of the things that kills free divers. DO NOT DO THIS IN OR NEAR WATER, BLACKING OUT IN ANY AMOUNT OF WATER KILLS.

The other thing is that our systems that consume O2 can be made much much more efficient. Training probably helps, but there are some autonomous systems capable of reducing O2 consumption that all of us carry around. The mammalian diving reflex appears to automatically cut O2 consumption and limit max heart rate once your face is under water, for example.

tl:dr:

You carry extra O2, and you can increase how much on purpose. The rate you use O2 isn't fixed, and if you run out of O2 you black out and start breathing normally (which kills you if your underwater).

I read that some free divers advised against hyperventilating. Instead they suggested to train to control urges to breathe despite rising CO2 in blood. This is much more difficult, but this way one keeps a solid indicator of dangerously low oxygen level.

That makes sense. I wonder if they do anything to add extra O2, or if that carries too high a risk of blackout due to low CO2 levels. I clearly am not a free diver.

Either way, the all caps warning stands. And even experienced free divers black out on occasion, so be careful out there.

That's very cool but it's definitely a stunt, breathing pure O2 is definitely not normal.

I'm more impressed by spearos going down for several minutes, swimming hard, doing work, fighting a fish on a line and coming back up. I can manage 1:30 with that kind of activity but I have met folks who can go several minutes.

I'm very curious: once you've practiced for a bit, are you still having a gigantic fight with your brain/lungs to take a breath, or is that "put off" until, in your case, 1:30?

Not GP, but have trained freediving and used to spearfish almost daily.

There is usually an easy period until the desire to breath starts, from 1 to 2 minutes in. The next minute or so is tricky, you get contractions as your body tries to breathe. After that you start to slowly zone out, but you're no longer in pain. Eventually the world closes in around you.

When spearfishing you're typically fairly conservative and never get past the first easy section.

Huh, so that uncomfortableness thing actually lengthens with time. Interesting.

</completely_naive> :)

Adds learning how to hold breath safely to todo list (Todo list falls over)

What blows my mind is the guys that actually perform activities diving while holding their breathe for similarly long durations.

Learning to control your body in idle circumstances is impressive in a meditative sense, but how people manage comparable durations while physically active is a different thing entirely.

Some people seem to have _evolved_ to be able to hold their breath (over 12 minutes) and work.

Look for the "sea nomads", there have been articles about them recently, a recent (2016) research ( https://www.cell.com/cell/fulltext/S0092-8674(18)30386-6 ) suggests that their ability could be because they evolved a larger spleen (which helps with red blood cells).

I thought it was interesting that there are also sea nomad children who are able to see clearly underwater: http://www.bbc.com/future/story/20160229-the-sea-nomad-child...

Although that skill didn't evolve. It's just something kids can do with practice, and the ability is lost as we age and our lenses become less flexible.

They measured a difference in spleen size between the "sea nomads" and some neighboring group of farmers.

However, all the news stories neglected to mention that the sea nomads still had smaller spleens than average humans overall.

PSA: Trying to hold your breath for a long time is dangerous, especially if you hyperventilate first. People die this way.

The hyperventilation thing is because your brain needs oxygen to live, but your impulse to breathe is driven by carbon dioxide saturation. When you hyperventilate, you get rid of a ton of carbon dioxide, and you can get into a situation where you don't have enough CO2 buildup to trigger the signal to breathe, but you have so little oxygen that your brain is dying.

Personally, not something I'd like to mess with.

It's more than that. Hemoglobin will preferentially release Oxygen in low pH (acidic) conditions and take up Oxygen in high pH (alkaline) conditions. CO2 in the blood increases acidity, so the result of this behavior is that hemoglobin will release Oxygen in parts of the body where CO2 concentrations are higher and will pick up Oxygen in areas where CO2 concentrations are very low. If you hyperventilate then you remove CO2 from your blood, reducing its ability to deliver Oxygen to tissues due to reduced acidity. This conditions, called hypocapnia, leads to vasoconstriction of blood vessels in the brain, which can cause even lower Oxygen uptake in the brain, as well as bronchoconstriction. This can cause you to blackout and can, in combination with the mechanism you've described, result in decreased ventilation when breathing resumes.

CO2 levels rise to unhealthy levels (700ppm) within a few hours of a typical bedroom if you keep the doors and windows closed. Its also why Submarines have CO2 scrubbers.

Do you have any source for this? A bedroom isn't sealed shut like a submarine would be?

I have a CO2 monitor, and I can confirm that it goes up at least that fast in my home. I can't speak for submarines or healthy levels. I've been wondering for a while why environmental rhetoric only talks about the global rise in CO2 in terms that make people think it's just an atmospheric phenomenon rather than notably changing what they're breathing. It looks like we've nearly doubled the CO2 we're breathing in the past couple centuries, not including our more sealed up lifestyle.

>only talks about the global rise in CO2 in terms that make people think

Because the levels in the global rise are negligible in comparison to what is dangerous for breathing. Here's a hint, if you think you've spotted something blindingly obvious in a field scrutinized by hundreds of thousands of scientists, you're probably making a mistake.

Reminds me of all the bugs in the java compiler I used to find when I first started learning the language and writing Hello World apps.

Thanks for the hint. The thought that the health effects of a waste product from the most profitable of industries may have gone under-reported is indeed preposterous.

Here's a study showing reduced cognitive performance at various CO2 levels in the ranges we're talking about.

https://ehp.niehs.nih.gov/1104789/

I've seen multiple people black out and have blacked out myself under water ... twice? (while training freediving). It comes on slowly and is far easier to do than you'd think.

If you do any of this without supervision it's just a matter of time until you die.

I call BS. His entire head was not submerged. He simply found a way to breathe through his ears.

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