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Brain damage

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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New Member
Jul 5, 2004
Do you think holding ones breath for unnatural periods of time cause any lasting long term brain damage?
The general consensus is that to suffer brain damage from a single breath-hold, you must black out, and remain unconscious for 4 minutes. As long as you don't black out, your brain still has sufficient oxygen.

However, if you do many, many breath-holds per day, to the point of just barely blacking out on each one, and you don't get enough rest or eat a good diet high in antioxidants, then you can very slowly start to incur negative side effects.

Few people can reach the point of barely blacking out, even on a single one--it would take tremendous will power and determination to do that many times per day, every day, for a while.

I have been doing breath-holding consistently for 6 years, including many 'sambas' and blackouts, and my mind is as sharp as ever, probably more sharp than ever. Your brain adapts to low energy/low oxygen states, and when this happens, your brain energy is improved, in during normal life.

In fact, there is a well done study that showed that underwater swimming for an hour or so per day, for several weeks, produced a permanent increase in I.Q.

There is a famous Japanese inventor, who holds MANY patents, who does all his inventions on the bottom of a swimming pool, with a notepad, holding his breath for 4 minutes each time.

Eric Fattah
BC, Canada
In fact, there is a well done study that showed that underwater swimming for an hour or so per day, for several weeks, produced a permanent increase in I.Q.
Is there any paper available (perhaps even online) ? There are many problems regarding the measurement of 'intelligence'. In any case, it sounds very interesting so I'd definitely like to read it...
Best regards,
The link between underwater swimming and IQ was actually posted on deeperblue, so it should be possible to search for it.

I think the hypothesis was that the carotid arteries became more 'open', improving brain blood supply, after consistent breath-held swimming.

Pipin, for example, has been measured to have very wide carotid arteries.

Eric Fattah
BC, Canada
Originally posted by efattah
There is a famous Japanese inventor, who holds MANY patents, who does all his inventions on the bottom of a swimming pool, with a notepad, holding his breath for 4 minutes each time.

That's the funniest thing I've heard all day... rofl
I can barely remember my own phone number and sometimes completely forget what I'm doing, but this hasn't happened as a result of holding my breath! I have always had a very bad memory, so it is difficult to tell if freediving has any effect - I can't imagine it getting any worse!

This makes a really bad impression when someone who doesn't know much about freediving meets me and after telling them that I hold my breath for several minutes, they ask me which station I live near, and I go "Errr... let me think...ummm" despite using the station almost every day. This really happened a few weeks ago!

I found an interesting link a while ago, as I was looking for info on the web into exactly this subject, just before I found 'Deeper Blue' (maybe this is what Eric meant):


I have come to the conclusion (correct or not, I don't know), that the really chilled out feeling I always have after my dynamic apnea efforts must at least to some degree due to the re-adjustment to an 'oxygen-rich' environment - that is, the removal of increased CO2 exposure from underwater swimming.

The theory that this guy puts forward in the above link seems to make sense to me - at the end of the day, the human body IS pretty adaptable, and I see no reason why it should not adapt in this positive way.

The main thing that I have heard of is, that rather than brain damage, you damage the smallest of the arteries in the lungs (there was a thread about this that didn't result in any 'proof' either way). Whether this really is a bad thing, I am not sure - I guess they would also heal/regrow anyway.

One thing I just thought of, though, is that if this is bad for you, it must be noticeable not only in societies where there is a lot of pearl diving (perhaps obvious), but also in synchronised swimming competitors ... they wouldn't really get exposed to any depth pressures, but hold their breaths for extended periods. Likewise, increased intelligence might also be noticeable, with large enough reference groups ...
Interesting link seagull - maybe there's hope for me! ;)

I have noticed that since I started freediving, it has become much easier for me to concentrate and sit still during lessons. I am doing a course in computer network maintenance, and it is very intensive, about 7 hours per day. Before I would have found it impossible to stay in one place for several hours and concentrate. I don't know whether this is directly because of holding my breath, or because of the mental discipline of staying still during statics.

Just found the DB thread that has the link for the IQ-article. It is http://forums.deeperblue.net/showthread.php?s=&threadid=36082 . I must say that I strongly disagree with the contents of that site (perhaps it's only the popular scientific version of an otherwise scientific article ?). There might be a positive effect of some kind due to freediving, but taking a plus of 10 points IQ as proof is irresponsible. From the Psychologist point of few, +/-10 points of "IQ" (without explaining which construct of intelligence they used and why, plus without telling which of the intelligence tests they used for their research :confused: ) is well within the margin of error of any intelligence test :head .

ok, Veronika, I have to agree with you, in essence. But then I also have to say, how can you 'summarise' human intelligence with one number ?!? Regardless of what 'construct' you use. It kind of contributes to that thing in human society that numbers amongst the things that I hate most of all - statistics. May PERHAPS serve some useful purpose somewhere, but mostly they suck ... shit. Excuse my french.

Here's a good example:

Based on statistics of who attends my local swimming pool (and yes, you deeperblueaddicts, I admit to having used this one before, but it IS a goddamn good illustration, I hope you'll agree!):

The more often you go swimming (based upon statistics of who is most often present), the fatter and older you will become - fact is, the VAST majority of people at the local swimming pool I go to are 60+ (if not 70+) and weigh AT LEAST 200 lbs.

That's statistcs for you.

And most of modern science is based, somewhere, somehow on statistics.

Like, try drawing a graph from just 2 points of data. You can make it look like anything you want. But lots of people do this, AND pass it off successfully as "valid scientific research"
When you took your measurements of the ages and weights of attendees at your pool, did you also find out how often they attended? The correlation you draw would be invalid unless you could show that the people who attended more often tended to be older and gain weight.

Next, you might want to modify your experiment to take into account temporal factors, since you claim that a certain change will take place over time. That is, you should determine the rates at which pool attendees' age and weight change. For this to be a valid experiment, you'd need a control group -- a bunch of people who don't go to the pool, so you can also measure the rates of change of age and weight, and do a comparison.

Lastly, you'll want to recall that science is not just based on statistics, but also proper interpretation of statistics. One of the statements that always gets drilled into students' heads is that "correlation is not causation" -- i.e., just because you've noticed a pattern, doesn't mean that going to the pool *causes* being old and fat.

I do agree with you that statistics is easily and often misused. For example, I recently noticed a newspaper headline stating that British Columbia residents are more likely to be in a car accident in the lower mainland area of British Columbia (where Vancouver is) than elsewhere in British Columbia, while the simple fact is, you're much more likely to *be* in the lower mainlaind area than elsewhere. Or an article I read that claimed that nearly 50% of all people suffering from a certain disease were women. Often, people throw in some (possibly true) statistics in order to win some believers, when in fact those statistics are fairly useless and misleading. However, if used properly (appropriate controls, samples, etc.), statistics can be a powerful and useful tool, and science (while not, as you say, inevitably based on it) has had a lot of success with it over the years.
Ironically, it is no joke. Serious studies have been done, I've heard several times--the more you swim, the more likely you are to put on lots of fat later in life. Something to do with adaptation to the water. I mean look at the whales and seals, they have tons of fat, so it shouldn't be surprising.

In fact, one weight loss 'success author,' strongly recommends against swimming for cardio because of that very reason.

Eric Fattah
BC, Canada
In fact, there is a well done study that showed that underwater swimming for an hour or so per day, for several weeks, produced a permanent increase in I.Q.

This claim assumes that:
1. Intelligence is well defined.
2. IQ is measure of intelligence.
3. High correlation necessarily means direct link between two phenomena.

I think you would struggle to justify any of the points.

The wonders of correlation technique seem to be limitless, especially when applied to linguistic concepts. :duh

I think we should stay at questioning physical damage to the neurones rather than stating wild claims that do not mean much. :)
how can you 'summarise' human intelligence with one number ?!?
Exactly thit is one of my points :) . Leaving all the problems of psychological tests aside, no one even knows how to define "Intelligence", as octupus already mentioned. (Actually, a lot of numbers based on different constructs can be transformed to "IQ" points. So even the unit iitself doesn't tell which of the constructs was used. Which leads me to the point that the article mentioned has no references whatsoever :confused: ). Cumulating a pofile of talents and shortcomings (right word ? not a native speaker, sorry) and taking the average to call it "intelligence" does make just as much sense as saying a person who lost one leg can run well "on average".

The study has a lot of shortcomings IMHO.

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Does it refer to people that are still active swimmers ? If not, I could imagine it might just be a matter of not adapting a high calorie uptake after quitting ?
Just thoughts.

My friend says that he definitely notices that his memory is worse on days when he has done a lot of freediving, and that several others have noticed the same.

Eric, do you have references to this? I would be interested to read about the studies you're talking about.

I think whales and seals and such creatures have fatty deposits for reasons unrelated to their cardiovascular activity. For one thing, since they have lost their hair through evolution, they needed to replace their insulation somehow. Also, I could see fat, appropriately placed in various areas of the body, as ameliorating some buoyancy and streamlining issues. Lastly, they probably rely on fat for energy more than we do; perhaps carbohydrates are less available in the ocean than on land.

While it seems to me that in aquatic mammals, fat distribution might be genetic, I also wouldn't be surprised if an active youth, followed by a sedentary lifestyle later in years, could lead to a rapid buildup of fat and loss of muscle tissue.

I find the original question very intresting.

Can freediving cause negative long term effects?
Of course there is a positive effect that comes from training. BUT could repeated states of low oxygen harm the brain.
AS Eric says; the real and obvious bad effects comes the second you become unconcious because of hypoxia. If you dont get oxygen in that very second I believe there is a price to pay.

I have noticed that my general concentration has degenarated and that I on occasions have a "worse memory" than I use to. And this worries me.

In general freediving has made me more fit than ever and I have a greater ability to feel and analyze things that happens in my body - a greater awareness (probably also due to training I have done besides freediving for the benefit of Freediving).

The negative effects I have mentioned I cannot say is because of LMC and BO, but who knows.

I was part of a study trying to find out if Static breathholding caused the same effects as hypoxi at stroke e t c - there was a measured effect but not at all anywhere close to a stroke.

I hope the bad effects comes from age and from my increasing awareness of mind and body. That is I didnt notice it before, but now I do.

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For me, freediving has mostly been a good thing, because before I was disastrously unfit, and now I go to the gym once a week and do static and dynamic training in the pool twice a week. And of course, lots of dry statics! (This probably doesn't do much good in the fitness department, but.....)

I have also met lots of great people - I can honestly say that freedivers are the nicest group of people I've ever met.

Sometimes I push myself too hard and don't know my limits, but on the whole I really enjoy training, even if it is nowhere near a PB.

I really hope that it doesn't have any effects on my memory and concentration - I want to keep the little bit I have!

The memory span of a goldfish is supposed to be 3 seconds - hopefully this is not a result of staying in the water for too long, otherwise.....

I like goldfish.....I wish I had some.....

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