FreeDiving and Brain Damage?

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FreeDiving and Brain Damage?

Postby Drip » Wed Jun 16, 2010 12:11 am

QUESTION: Does FreeDiving (Apnea) cause long term Brain Damage :?:
- the lack of constant oxygen to the brain/the brain going long periods without oxygen/the brain getting used to less oxygen than normal (think of Sherpas in high altitudes)...
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Re: FreeDiving and Brain Damage?

Postby Andy » Wed Jun 16, 2010 11:19 am

Short answer: No.

Part of the physiological response to breath holding is the body to reduce blood flow to muscles etc, and direct it to the bits that need the oxygen.

That's how I understand it, at least. It's not quite that simple - but it's a good starting point.
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Re: FreeDiving and Brain Damage?

Postby Drip » Wed Jun 16, 2010 1:54 pm

Andy wrote:Part of the physiological response to breath holding is the body to reduce blood flow to muscles etc, and direct it to the bits that need the oxygen.

I remember reading/hearing that somewhere now.
But I can't help but bring up the Epilogue from the book Deep Descent by Kevin F. McMurray (re Diving the Andrea Doria) and the peice where Dive Guru Billy Deans states...

Deans believes that in deep diving you are "insulting the brain," loading the vital organ with high doses of nitrogen and high partial pressures of oxygen. The brain is sensitive to that, given that it doesn't regenerate cells.
Deans finds that he often loses a word or phrase, short term memory - neurological damage that he attributes to his deep diving. There is not a lot of medical information on the effects of diving, according to Deans, because it is a relatively new phenomenon. Until the death of Jacques Cousteau, most of the pioneers of scuba were still alive. But the "neurological deficit" has to have some permanent effect, and the continuing damage to your body can age you prematurely.
Deans explained, "The powerful oxidisers produced by the hight patial pressure of oxygen grab electrons. One of the first places it happens is in the DNA code. These mutants damage the DNA, which cannot replicate themselves, and cause aging. They can also produce cancer cells." He posed an important question: "How can a 25-year diving career not cause damage, and how much damage do you want to chance?"

...it is this that makes me wonder about the effects upon FreeDiving, especially beyond the conventional 30 metre mark where the weight of the water just keeps pushing you downward. A FreeDiver that is again coming up against the pressure, the added nitrogen and for those who do it constantly without a break (the break being symbolic of a good breathing spell between dives). I think of those women who have dived in Nippon for ages - they seem such simple folk ...possibly simple minded too?
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Re: FreeDiving and Brain Damage?

Postby long john » Wed Jun 16, 2010 6:40 pm

http://www.the-aps.org/press/releases/09/33.htm
If you can't be bothered reading this,and let's face it, who can?, then.... maybe. The article is not so much about the depths involved, rather the long term effects of oxygen starvation. It does seem logical enough to assume that getting that hypoxic that often can't be good for you but there's no real data to back that up. Hence this article is full of potentially's and possiblys without really coming up with much. It will be interesting to see, given that this current batch of super divers are pushing so far beyond what the generation before achieved (10 years ago the constant weight record (down and back up with fins and weightbelt) was about 80m and now it's over 120m) whether there'll be problems. Personally, I think not.
I checked some of those other videos on youtube under 'Bluehole'-all those poor barstards getting narced off their pips and sinking into the abyss. That one of the guy filming his own death was just awful. What a terrible, terrible thing.
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Re: FreeDiving and Brain Damage?

Postby binklebonk » Wed Jun 16, 2010 8:25 pm

long john wrote:I checked some of those other videos on youtube under 'Bluehole'-all those poor barstards getting narced off their pips and sinking into the abyss. That one of the guy filming his own death was just awful. What a terrible, terrible thing.


And you'll still get folk bragging about 80m on a single tank. I'm thankful I'm not surrounded by divers who see diving as an extension of their "machismo".

The video of Yuri Lipskis' fatal dive is an interesting thing indeed. I too find it distressing but at the same time (as Kurt Vonnegut would say) "So it goes".


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Re: FreeDiving and Brain Damage?

Postby Drip » Thu Jun 17, 2010 3:25 pm

Interesting Link LJ,
I personally conclude then that as long as one doesn't 'saturate' oneself with the effect caused by FreeDiving and gives the Brain time to return to normal, then all is well. I'm sure the body (brain) can learn to adapt to the deeper limits that modern FreeDivers are taking as well. So I guess possible Brain Damage and Adaption are walking hand in hand and its a matter of just being well balanced and well paced.

binklebonk wrote:And you'll still get folk bragging about 80m on a single tank. I'm thankful I'm not surrounded by divers who see diving as an extension of their "machismo".

The video of Yuri Lipskis' fatal dive is an interesting thing indeed. I too find it distressing but at the same time (as Kurt Vonnegut would say) "So it goes".


One of the few good things about modern times: If you die horribly on television, you will not have died in vain. You will have entertained us.......
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I've met a few of those Air heroes. I also think such stuff will become more common upon Television ...even now a Father admits he pushed his daughter into a Round-the-World Sail for Media money. She ended up capsizing in the Southern Ocean during the time of the year that it is not wise to be there. The pressure to make the Media timeslot was more important than his daughter's life. With the Media handing out bickie$ for anything they can get their hands on, don't be surprised that poor people will be desperately trying to do anything to make a buck. I blame the Media factor for the death of Dave Shaw in South Africa - a pity he didn't realise how much a danger this would be to him. Divers who run to the Media for $250,000 to tell how they were left behind by Dive Boat Operators. Etc, etc.
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Re: FreeDiving and Brain Damage?

Postby Mullins » Tue Jul 06, 2010 2:50 pm

Yes, I think gradual long-term adaptation is an important factor. Just as we get steadily better at storing and using oxygen, there are probably protective adaptations that help prevent hypoxia, hyperoxia and hypercapnia from doing real damage. Of course these would be less noticeable because they aren't expressed in performance terms.

A key feature of the physiological stresses that go with freediving is that they are transient. A 100m dive would take around 3:30, and only a small amount of that time (maybe 30s) would be spent severely hypoxic. Even then, cerebral O2 saturation stays fairly high (>50%) as the brain is given priority over everything else. As far as nitrogen loading goes, I don't think we have time to accummulate much. If we did, our rapid ascent rates (peaking at 1.8m/s for me) would mean we'd get bent every time. As it stands, DCS is only an outside chance as long as we stick to 1 dive per day. And as for hyperoxia - I think we would spend little time with ppO2 above 1atm, if any, since oxygen is being consumed on the way down. Much like breathing pure oxygen on the surface for a couple of minutes, which is something people do quite regularly.

It seems to me that SCUBA diving, with the durations involved, the N2 uptake and the greatly varying partial pressures of all the other relevant gasses along the way, is a very different kettle of fish. I certainly wouldn't want to SCUBA dive as deep as I can freedive, would consider it way too risky. Nutcases!
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Re: FreeDiving and Brain Damage?

Postby Phantom Menace » Wed Jul 07, 2010 12:47 am

Mullins wrote: I certainly wouldn't want to SCUBA dive as deep as I can freedive, would consider it way too risky. Nutcases!


Dave - not many people dive (free or scuba) to the depths you hit though ...

The whole area of free-diving physiology, response to pressure, etc. is interesting. Is there a book you could point me at that would provide an overview?
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Re: FreeDiving and Brain Damage?

Postby Tony » Wed Jul 07, 2010 3:30 am

binklebonk wrote:
long john wrote:I checked some of those other videos on youtube under 'Bluehole'-all those poor barstards getting narced off their pips and sinking into the abyss. That one of the guy filming his own death was just awful. What a terrible, terrible thing.


And you'll still get folk bragging about 80m on a single tank. I'm thankful I'm not surrounded by divers who see diving as an extension of their "machismo".

The video of Yuri Lipskis' fatal dive is an interesting thing indeed. I too find it distressing but at the same time (as Kurt Vonnegut would say) "So it goes".


One of the few good things about modern times: If you die horribly on television, you will not have died in vain. You will have entertained us.......
Kurt Vonnegut


That 80m?? Are you for real Binkie?? Thats nuts!!
You know the speed of light. So what is the speed of dark?
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Re: FreeDiving and Brain Damage?

Postby binklebonk » Wed Jul 07, 2010 9:09 am

Yup Tony there are nutty folk out there..

It's a topic with lots of scope for argument, do a quick search on some of the other forums if your interested in seeing some "interesting" arguments as to why it's "fine" or "safe" according to some.. :roll:
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Re: FreeDiving and Brain Damage?

Postby Drip » Wed Jul 07, 2010 9:44 am

binklebonk wrote:Yup Tony there are nutty folk out there..

It's a topic with lots of scope for argument, do a quick search on some of the other forums if your interested in seeing some "interesting" arguments as to why it's "fine" or "safe" according to some..


Totally agree. Definately have to be brain damaged to be diving way down there (not bounce diving) upon a single air tank. The only danger I incorporate in my Diving is unzipping attractive (female) dive buddies as a married man. :twisted: Luckily I've returned again another day to continue my diving, happy to say.

Because Champion Free/Apnea Divers can bounce dive way beyond 80metres, when diving down to say, 50m ...do they have the luxury to 'swim about' for a minute or two and can this give them 'nitrogen loading' and enhance the possibility of DCI etc ??
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Re: FreeDiving and Brain Damage?

Postby Mullins » Wed Jul 07, 2010 10:37 am

I've done 45 second bottom times at 60m, but that was still less than a 3:00 total dive time. I think the greatest DCS risk is on our deepest competition dives (around 120m), which take about 4:00. The risk is there and some have been bent, but it's rare. The thing is, nobody would bother to push recreational dives that hard and get, say 2:00 bottom time in 80m because although it's possible it wouldn't be much fun.

Repeat dives are a different matter. If I'm doing deep weight-assisted spearfishing dives in that 60m range, I limit myself to just a few every day. This is because we don't have any deco tables, so we have to err on the side of caution. I do know people who've been badly bent doing this kind of thing. Herbert Nitsch hopped in somewhere in the Med, did about a dozen 40m dives at 3:00 each with brief surface intervals, then needed to be carted off to a deco chamber.
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Re: FreeDiving and Brain Damage?

Postby binklebonk » Wed Jul 07, 2010 10:51 am

Mullins wrote:I've done 45 second bottom times at 60m, but that was still less than a 3:00 total dive time. I think the greatest DCS risk is on our deepest competition dives (around 120m), which take about 4:00. The risk is there and some have been bent, but it's rare. The thing is, nobody would bother to push recreational dives that hard and get, say 2:00 bottom time in 80m because although it's possible it wouldn't be much fun.
So how comparable is the narcosis that you get during breathhold compared to a tank dive? I've always assumed that it would be substantially less and therefore more manageable?
Drip wrote:
binklebonk wrote:Yup Tony there are nutty folk out there..

It's a topic with lots of scope for argument, do a quick search on some of the other forums if your interested in seeing some "interesting" arguments as to why it's "fine" or "safe" according to some..


Totally agree. Definately have to be brain damaged to be diving way down there (not bounce diving) upon a single air tank.
So do you see bounce dives to 80 on a single as well reasoned behaviour?
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Re: FreeDiving and Brain Damage?

Postby Mullins » Wed Jul 07, 2010 1:25 pm

Haven't been tank diving, so I can't compare. I expect that for the same depth, narcosis on SCUBA (air) would be more severe because of the longer duration. I normally only feel narced past about 80m, for example. But I get some severe effects below 100m - bright visual distortion, numb face, metallic taste, poor coordination and shaking. I think these effects are mostly caused by CO2 rather than N2, as they get worse for a time on the ascent (when we're producing more CO2) and can linger even back at the surface. They're made much worse by a fast descent, which is a bit counter-intuitive.
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Re: FreeDiving and Brain Damage?

Postby binklebonk » Wed Jul 07, 2010 2:47 pm

Mullins wrote: I normally only feel narced past about 80m, for example. But I get some severe effects below 100m - bright visual distortion, numb face, metallic taste, poor coordination and shaking...


I've heard, as an example of how narked you can feel really deep on a freedive, that the guy in that youtube vid http://www.youtube.com/watch?v=-8qCIu3q7E4 who gets rescued by the safety diver actually thought that he was ascending already..

I had thought that he was just being as mellow about the whole situation as possible to give himself the greatest chance of survival but to hear that he was unaware of the problem is scary... :shock:
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