• Welcome to the DeeperBlue.com Forums, the largest online community dedicated to Freediving, Scuba Diving and Spearfishing. To gain full access to the DeeperBlue.com Forums you must register for a free account. As a registered member you will be able to:

    • Join over 44,280+ fellow diving enthusiasts from around the world on this forum
    • Participate in and browse from over 516,210+ posts.
    • Communicate privately with other divers from around the world.
    • Post your own photos or view from 7,441+ user submitted images.
    • All this and much more...

    You can gain access to all this absolutely free when you register for an account, so sign up today!

IQ increases through freediving

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.


New Member
Jul 3, 2003

Recently I found a site on the internet, written by a Dr Win Wenger, claiming that held breath underwater swimming increases your IQ via vasodilation of the carotid artery (the artery going to your brain) and that:

"For accumulating 20 hours of held-breath underwater swimming within 3 weeks from start to finish-- you will experience:

* the previously-promised 10 or more points I.Q. gain;
* better span of attention; better span of awareness;
* better awareness of the interrelatedness of things and of ideas and/or perceptions;
* finding yourself way better at winning arguments or disputes!"

You can read it at :


He quotes a scientific article. I only read the abstract. It agrees with the dilation effect, but makes no further conclusion as regards to any effects on IQ. Here is the URL:


I don't freedive (yet). I am practicing the underwater swimming slowly in my school pool. (I'm a teacher in Japan). Recently I became interested in this and other ways to increase IQ. I'm a skeptical person but I'll try anything once. I notice that my breathing is getting easier and I can read things faster, although whether this is due to the swimming or something else I don't know.

I don't push my times. I only stay under for 45 seconds max now. Yet I experience slight headaches every evening after the underwater swimming. I follow techniques for freediving, slow movement, relaxed body, etc.

So, does anyone know anything about this? Have you noticed any changes in your IQ or perceptual abilities? Any scientific studies?

Any help greatly appreciated.
  • Like
Reactions: DeepThought

I think my brain is getting or IQ whatever that is getting worse from all the headaches I get from freediving . Usually I get bad headaches after spearfishing up and down all day :(

Welcome Fugusuki.
Interesting post for your first one. :)

20 hours in 3 weeks is almost one hour a day.
First of all I want to ask if the ratio of apnea to breathing is mentioned, asuming that an hour of apnea a day is not the intention.

About those headaches, I never got any headaches during apnea activity except once, after I've done an intensive Co2 training (table) which I assume led into a Co2 headache. I did the same table a few days later with modifying my breathing according to that table and it became relativley easy.
Maybe you should work more on your breathing or change the ratio of apnea to breathing. I don't think that headaches are supposed to come with positive results.

About IQ, I rather have my subjective feeling telling me if I'm doing good to my brain then IQ tests, I don't think they are good enough tool, although they may show results. anyway, my feeling tells me I do gain energy, clarity, improved health and a good buzzy feeling for the rest of the day.

There was also an old thread here talking about freediving and intelligence, also mentioning Win Wnger's studies:

Last edited:
I don't know anything about any of these theories, studies, papers, etc. I know very little about biology. I don't have my IQ measured, nor anything else for that matter. I don't even think that IQ is a useful measure -- how can one number be representitive of something as complex as human intelligence?

What I can provide is an anecdote. I've been freediving for roughly a year and a half now, having taken 2 of Kirk Krack's 12 week clinics. Through last summer and this spring I was freediving at least once per weekend (~3 hours) with numerous pool sessions sprinkled between. During times when I'm actively diving I feel much more awake, alert, and able to focus on work. Tasks at work (software engineering) seem to get done faster and better. I can find problems more quickly. I sleep better, and deal with stress better. In short, it sucks that I've been out for a month due to having a cold!!

I can't attribute any of this to apnea, or even provide concrete evidence that it is true. Simply the exercise involved does me good, not to mention getting outside more, and the zen nature of relaxing, stretching, and preparing to breathhold. For me its all a package, however, and I know it has done me a world of good.
Thanks guys

The headaches have stopped happening after the pool sessions. I am surpirsed at how quickly the body seems to adapt. In only 1 week af doing this most days, for only about 2 hours total pool time, perhaps 20-30 mins 2m underwater, I have seen the amount of time I can comfortably stay in the water double to about 1:30. I train when the kids are in the pool, so the Japanese swim instructors are there in case something goes wrong. You should see the look on the kids faces when I come up after two 25m lengths underwater without gasping! I made sure to warn the kids not to try the same thing though.

I'm pretty sure the time increase is mainly a factor of improved technique, more than physiological changes, although I'm sure these play their part. So I expect that my time underwater will level off soon. The headaches are reminiscent of headaches I used to get as a kid whenever it was a very hot day. I wonder if it was increased blood flow or pressure that caused them.

I am still looking for any scientific evidence of IQ increases, but thanks for the anecdotes.
I am still looking for any scientific evidence of IQ increases, but thanks for the anecdotes.

I believe it's becomming generally accepted in the medical community that the increased blood flow from excercise floods the brain with blood and oxygen just as it does the other internal organs. Any internal organ regualrly flushed with blood and oxygen through excercise becomes healthier and its primary functions recieve a perfomance boost, the brain included. Several studies have been conducted involving seniors and excercise, to come to these conclusions. The seniors particpating in excercise programs showed marked improvemnts in cognitive reasoning and memory after periods as short as one weelk. Freediving is exercise and excercising is good for the brain.

The fact that freediving opens up blood to the brain still further makes this info even more interesting.
Wrong conclusion?

Hi im new on this forum , and i think that many of the subjects is really intresting.
Recently i read an article in a swedish newspaper that said the opposite, it was an article about Tanya Streeter and her world record dive, A doctor in the Swedish Scuba-organisation ( Hans Örnhagen) ,were interviewed about the dangers of free-diving , and the risks you put yourself at when you try to pushing your limits.
He says that holding your breath for to long may causing brain-damage, wich would be the opposite to gaining iq, but he refers to the competitive form of free-diving, when you pushing your limits.
I dont know what happens with my brain when i dive ( i never compete). But it feels really good both physical and intellectual when i dive, i dont have any medical expertise , and i wonder if its dangerous to compete in static as an example ?
Dont know if Hans Örnhagen has right about everything he says. when he also talk about free-diving as the most dangerous sport in the world and when he says that a competitive form of free-diving is a game of death.
I hope hes wrong because i love freediving and i admire thoose men and wimen that competes with exellent results.
I think he could be right about those things you quote him for, and that Freediving could still be both a healthy and fun sport.

I feel good after dynamic apnea too.

Everything in reasonable measures, I think.
Great find! I think all the evidence we need can be found in Eric Fattah.

Another bit of fuel to further my passion for Freediving.
A friend of mine who is a really serious spearfisher,have heard about an research on Italian spearfishers or freedivers,that there is a risk at the elderly ages a neurologic disorder that goes with syncopes(Maybe Alzheimer??). Did anyone in the forum heard anything about this study??
Fre DiVinG gUd!

Not HurT BrAIn!

mE sTilL KnOw hoW usE CuMpOoteR!

  • Like
Reactions: naiad

My last input on this thread was awfully immature.

And, of course, my Animal Farm-like jeer at scuba-heads is all in good fun.

I tend to believe that freediving is one of the only activities that makes me feel more alive, sharpened, shape and somewhat elite. I'm all about the idea that it dialates more blood to the head. I feel like a glowing Hindu deity after a really good session...totally relaxed, not wiped out...more aware of my surroundings, not just aware to sounds after being in aquatic silence...and a whole lot happier, not an asphyxiated buzz.

I'll just say this. Do what you enjoy doing for as long as you can.

Trust me. I may not be a doctor, but I've always pictured myself playing one on T.V.

Just about EVERYTHING anyone does comes with a certain amount of compromises. Whether it be their diet, training, habits, or daily activities, people run the risk of hurting themselves from immediate or gradual causes.

Personally, I don't think I can find anything wrong with apnea-related activities. As for the competitive freedivers out there (of which I'm seemingly years away from becoming), I think everyone knows the immediate risks. I shouldn't need to mention them.

Perhaps it's braving those very reasons, to see how far our species can go, that makes "competitive" freediving so appealing to a certain breed of person, and admired by others atuned to that mindset.

Mind you, I hyphened the word COMPETITIVE because it seems like a group effort, whenever I read articles and stories of how divers seem to support eachother, even though they all want to be the deepest diver.

I guess my point is that...even IF there is some underlying risk tied to an apnea-related activity, if you like to do it, and it makes you feel better, whether it be your I.Q., general health, mental well-being, or just like the feeling of being closer to nature, do it.

Life isn't a dress rehearsal. You got one shot at it. Live it up.

A close friend of our family, who ultimately died of cancer in her 40s, used to say, "If I'd known I was going to end up like this, I'd of eaten desserts BEFORE and after dinner."

So for the sake of "blissfull ignorance", I'll just sport the philosophy...

If it feels right, stick with it. You're body is good at telling your brain when to slow down. If there's little room for error in what you're doing, then just pay attention to your health all the more closely.

...for now.

Which brings me to my usual disclaimer:

This post reply may be subject to change. Offer void in Maine.

Interesting topic
  • Like
Reactions: DeepThought
Your IQ may increase. First time I have ever heard about it before. But hey, it could be possible. ;)
Freediving may help to dissolve psychological blockages because of the relaxed state. This releases "CPU capacity" which once was only used to think in loops endlessly on the same "problem".
DeeperBlue.com - The Worlds Largest Community Dedicated To Freediving, Scuba Diving and Spearfishing


ISSN 1469-865X | Copyright © 1996 - 2024 deeperblue.net limited.

DeeperBlue.com is the World's Largest Community dedicated to Freediving, Scuba Diving, Ocean Advocacy and Diving Travel.

We've been dedicated to bringing you the freshest news, features and discussions from around the underwater world since 1996.