Long term effect of repetitive apnea

[melarvie]

I have a close friend, an anesthesiologist, who is aware that I enjoy freediving. He thinks that breatholding on a repetitive basis is bad for the brain over the long term. I asked him if he had read some paper documenting this, but he could not relate a reference, saying instead, "it's just not natural."

I was wondering if any one out there is aware of any evidence supporting, or discrediting his position. I know there are many freedivers with many years of apnea under their respective belts, so I wouldn't imagine that it is a problem, but thought I'd still ask.

I don't post much, but I read the message boards frequently and have found this site to be an incredible resource. Many thanks to the staff.

[scott]

Thanks Melarvie for asking the question as to the long-term effects of breatholding. I don't have the answer and look forward to reading the replies; but since my wife asks me this question all the time, I thought I would post my thanks for you asking it.

I too post seldom but read often and have learned a great deal on these forums. Thanks to all.

Scott

[efattah]

There are two very different types of breath-holding:
1. Breath-hold diving (at depth & pressure)
2. Breath-holding at the surface (either in a pool or on dry land--at atmospheric pressure)

These are totally different, so if someone tells you 'breath-holding is bad for you' ask them which one they mean.

Most people who argue that 'breath-holding is bad for you' claim that 'you are starving your brain of oxygen.' Actually, when breath-holding at depth, you have TOO MUCH OXYGEN, not too little. Only in the last 3 or 4 seconds of the dive (during the last 15 feet of the ascent) does your O2 drop below normal levels. For 90% of the dive, you have too much oxygen--essentially you are treating yourself to free 'hyperbaric oxygen therapy.' So if someone tells you that freediving is bad for you, ask them if hyperbaric oxygen therapy is good for you, and if they say yes, then tell them that they are contradicting themselves. Extreme deep divers can even black-out from too much oxygen at depth (hyperoxia).

The question of atmospheric pressure apnea is different. In this case, there is the possibility of extended hypoxia. Normally, a doctor will become concerned about a patient when the patient's SaO2 (hemoglobin saturation) drops below 80%. If that concern is valid, then a breath-holder enters the 'concern region' after 3 to 5 minutes of apnea, depending on the person (i.e. some people may hit SaO2=80% after 3 minutes, others may take 5 minutes).

However, that's not the whole story. Many champion athletes such as olympic triathlon champion Simon Whitfield use IHT (interval hypoxic training). They breathe through a mask which momentarily 'hypoxicates' them by dropping their SaO2 to 70-75% (the 'concern zone' as a doctor would put it). One to two hours of cyclic hypoxia causes the body to increase natural antioxidant production, and EPO levels increase (thus creating more red blood cells). The end result is a better, stronger, healthier athlete, proven by the success of people who use IHT.

I asked an IHT specialist if a person could achieve the same results without paying $15K for an IHT machine. By just holding your breath! He answered: "YES!--BUT IT IS NOT COMFORTABLE!"

So, those should be enough arguments to convince people that apnea is not bad for you, unless you push yourself to near blackout at atmospheric pressure many times per day.

Remember that brain damage does not begin after 4 minutes of apnea, but more likely 4 minutes after blackout.

Eric Fattah
BC, Canada

[Stephan Whelan]

When I first saw this question I thought to myself...

"Gee...good question, I suppose i'm going to have to hunt down some expert to answer this question for our visitors!"

And once again I have been proved that the sheer quality of people browsing the forums and answering questions is of the uttermost level.

Thanks for the comprehensive answer Eric - you've proved your skill is beyond just being a top level Freediver!

[Cliff Etzel]

Eric - First of all, I and the rest of the deeperblue.net staff want to extend our congratulations on your recent record!

Secondly, Your response on this topic was very enlightening and gave a lot of information that I know I or anyone else who had these concerns and questions could not have found very easily on the net.

I also want to say thanks for imparting your expertise in the freedive section of the forums. You have made a great contribution by being a part of them.

[melarvie]

Wow!

Thank you so much for your thoughtful reply, Eric. My congratulations as well on your recent record. Judging from your intelligent post it is apparent that prolonged apnea is indeed not harmful, and probably, beneficial. I've been barely breathing since I read it.

I'm soon to be forty and have always been what you might call a "deep snorkeler", in that I rarely penetrate 10m (it sounds like more if you say 30ft). I've never trained for more, although this past year have given it some thought, at least until I had open heart surgery to have my pericardium removed. Thankfully, I'm much better now and almost to where I was when I left off. I have a pair of picasso fins (black) which work well for me and have been excersizing regularly for a couple of months now.

Again, Thanks to all the replys,
Sean

[Jon]

Sean,
Do you have a training partner?

I live in Madison, but go back to Milwaukee once or twice a week to freedive the wrecks there. That's just a little bit south of where your at. You are the closest person that I have seen post so far. If you want to get together for a dive email me.

Jon

[Gattaca]

Originally posted by melarvie
Judging from your intelligent post it is apparent that prolonged apnea is indeed not harmful, and probably, beneficial

Win Wenger, an accelerated learning guru and author of many books on maximizing human intellectual performance (including "The Einstein Factor", "Beyond Teaching and Learning", and "How to Increase your Intelligence") maintains that dynamic AND static apnea are the most effective methods of improving the physical condition of the brain.

Forgive my non-scientific explanation, but Dr. Wenger states that the Carotid arteries (which feed blood to the brain) expand in response to increased levels of CO2. The long-term effect of CO2 enrichment of the blood (brought on by apnea) is a permanent increase in the diameter of the Carotid arteries. This, he claims, has the effect of permanently improving the brain's circulation.

Dr. Wenger also relates a major shift in his intellectual ability to the time when he began dynamic apnea training (for fun) during the summer of 1959, when he had to take summer classes to make up for failing grades in highschool.

Without sounding like a boastful idiot (I hope), I'd also like to relate my "long-term" experience with apnea training. I started apnea training (after reading Dr. Wenger's book) when I nearly failed out of highschool. I'm definitely not an apnea superstar. After training off and on for a few years, I can handle about 1:30 dynamic and 3:30 static (pool training), but I did it to improve my mental faculties, not to compete with the super freediver studs who frequent this forum.

What was remarkable (forgive my loose cause-and-effect) was the change in my academic and intellectual performance thereafter. I went from a below average student in highschool to a top 5 graduate at my University, and actually qualified for a MENSA membership last year. It sounds crazy, but I am certain that apnea training contributed to this. In short, I think you are 100% correct in your statement.

[Peter Sheard]

Hi Guys;

Eric is quite right that no firm evidence exists to support the notion that extended breath-hold does your brain any significant damage.

Some speculative thoughts on possible 'damaging' processes following blackout and/or samba are available in:

Sheard, Peter (2001) Myoclonus and hypoxia (or "sambas" and "blackouts"). Freediver 11: 30-32. ISSN 1466-089X

DeeperBlue will posting the piece at a later(?) date on this website.

As Eric suggests, the risk, if it exists at all, seems to follow 'hypoxic events' or, in the freediving world, 'sambas and blackouts.'

Even in the realm of freedivng blackouts there is no firm evidence for longterm damage occuring. Then again they said the same thing about repeated heading of a soccer ball and near concussions in ice hockey and American football players.

However, recent neuropshycological studies are beginning to show disturbing changes in cognitive ability ('brain power') after repeated concussion or near concussion incidents.

I am currently setting up a project to test freedivers after extended freediving sessions to -30m and following occasions of blackout or samba. Maybe then we will be able to approach the beginnings of understanding the lingering effects of breath hold diving and the accidents inherent in our chosen sport.

Until then, avoid blackouts!!!

Cheers,
Pete