What is a hook breath?

[fuzz]

Seen it mentioned, but tried searching for it and couldn't find anything.

Thank you!

[M-2]

Hey Fuzz! A hook breath is something that they used to teach fighter pilots to do after coming out of pushing a lot of g's. Some have adapted it to freediving after deep dives or long breath holds. Basically the idea is to take a breath and bare down as if trying to push it into your blood stream (or like you might bare down if you were wishing you had a laxative ). The idea is that taking the breath and applying pressure like that helps get more oxygen back into the bloodstream quicker. It's supposed to help speed up recovery so that you don't pass out. They teach it in some of the clinics. What I've been told is 3 good hook breaths on breaking the surface after a deep dive and then back to normal breathing with nice slow deep breaths.

Hope this helps. Maybe one of the DB physiology guru's can shed more light on the subject than I have.

Cheers,

-Mike

[M-2]

Maybe I should have been more specific. The way I was taught is that you inhale, then push (bare down) for only about a 2 count, then exhale and repeat.

-Mike (again )

[fuzz]

Thank you much.

That's a perfect explanation, very appreciated.

[shaneshac]

I wouldn't try one of those after a hot curry.

[Erik]

There are variations on the lengths of exhalation and the tempo of breaths, but M2's explained it.
Hook breaths are used by fighter pilots primarily while under heavy G's,when the vehicle is arcing in a position that pools blood away from the head; the main benefit of hook-breathing is to force blood up into the head, maintaining BP and keeping the supply of O2 moving.
Cheers,
Erik Y.

[Gerald]

Just as Erik explained before:

The 'hook breath' or 'pilots anti-G breath' is inhaling, holding and at the same time pushing your breath for around 2 seconds, and let go. It gives better uptake of oxygen and pushes blood towards the brain.

At our training camp in Dahab (Jan 05-19, 2004) Wolfgang Dafert and I have been applying this technique systematically and it really works! It reduces the urge to breathe, diminishes the risk of Samba/BO and keeps the diver from ventilating frantically after a maximum dive.

B. T. W. - a detailled account of this training camp is posted in this forum under:
freediving stories: Freedivecamp in Dahab 2004.

Pictures about this camp are available on my hp either by single access (indexed),
or by starting at my picture overview from where You can skip wherever You want to.

cheers
Gerald

[flyboy748]

Fantastic explanation Mike! Thanks! I understood hook breathing to be just simply a breath-hold-breath-hold, didn't know about the "pushing" it into the blood. I understand perfectly now as I used that during aerobatics years ago to avoid loosing conciousness during G load. I believe this is the thing the Air Force calls it the M-1 maneuver or something like that? Anyway it makes perfect sense to me how this could both elevate O2 levels in the blood and at the same time increase blood pressure.

Thanks again! That clarifies things.
Aaron

[Aetius]

What exactly do you mean by "pushing" o2 into the bloodstream? I think I sorta get it...

[Erik]

Originally posted by Gerald
At our training camp in Dahab (Jan 05-19, 2004)
Gerald

Awesome pics and reports from Dahab. I recognise most of it, and I miss it very much. Say Hi to Roland next time you're there.
Cheers,
Erik Y.

[Veronika]

Hi,
sounds as if hook breathing would have great potency producing right-to-left shunts in people suffering a PFO. It would consequently increase the risk of suffering a DCS after deep dives dramatically...
Any ideas / thoughts / whatever on that matter ?

Best regards,

Veronika

[pat fish]

PFO Frequency: In the US: Patent foramen ovale is detected in 10-15% of the population by contrast transthoracic echocardiography. Autopsy studies show 27% (!) prevalence of probe-patent foramen ovale. This difference is probably due to the ability to directly visualize patent foramen ovale on autopsy study, while contrast echocardiography relies on detection of secondary physiologic phenomena [...]

Medical Care: Most patients with a patent foramen ovale as an isolated finding receive no special treatment. [...]

Diagonsis: external/invasive Echocardiography

http://www.emedicine.com/med/topic1766.htm


me personally rememebering Benjamin Franz suffering from a stroke in 2002 during the preparation for a world record attempt (no speculations at all on that particular case but there exists a significant correlation between pfo and strokes) , I would rather leave the technique of hook breathing apart and recommend a good safety diver and o2 inhalation after repetitive deep dives, good hydration, vitamin E, omega-3-fatty-acids and eventually some platelet aggregation inhibitor like aspirin.

yours pat

[Veronika]

Hi pat fish,

I'm not an expert on that subject, but my thoughts are the following:

I would rather leave the technique of hook breathing apart and recommend a good safety diver and o2 inhalation after repetitive deep dives, good hydration, vitamin E, omega-3-fatty-acids and eventually some platelet aggregation inhibitor like aspirin.

Prevention of Microbubbles certainly is a good thing and the main way to go. On the other hand, I doubt that they can be avoided altogether (no scientific freediving data though. Another point why I don't unterstand that nobody seems to have done any Doppler-Research so far ! ). So given that you have some bubbles in your venous bloodstream, post-dive breathing of O2 does not help it if you are producing a right-left-shunt in the first place !

Could you give me a short description of the roles of vitamin E and omega-3-fatty-acids ? I must admit that my knowledge about that stuff is rather everyday knowledge and not very *ummmh...* in-depth.

Regards,

Veronika

[pat fish]

patent foramen ovale and decompression sickness sure is an endlessly discussable theme - if you are freediving on a certain level a prophylactic examination in that term could be a way to find out if you have to worry about it. but do you know of anybody among the top freedivers in the world (reaching depths in multiple dives below 30m) who have done an echocardiography to detect a potential pfo? i don't. but considering the consequences and the frequency of pfo it's worth a discussion...

i will leave the discussion about the building up of microbubbles to someone else with a better knowledge on that (there is lots of research ahead in the field of freediving). I can shortly explain my opinion on the inhalation of o2: the size and frequency of n2 microbubbles is overall significantly reduced by the inhalation of o2 because of the wellknown effect of the increased nitrogen gradient. so the input saturation of n2 to tissues and venous system is reduced. overall probability for bigger microbubbles in the venous stream should be reduced.

for the benefits of vitamin e and omega-3-fatty-acids and especially aspirin: refer to other threads discussing this matter. generally spoken: they reduce platelet aggregation and thus the probability for strokes.

that's about it...
i agree with you - research outputs in the field of freediving are unfortunately rare ...

pat

[samdive]

old thread I know but...

I had an echocardiogram to look for PFO when I got DCS a couple of times in a row... didn't have one though which was actually a bit disappointing as it would have at least explained why it happened! friend of mine found he had one and had it fixed - all quite easy so if you ever need it, don't worry about it! the only tough bit is sitting around topless for ages while two doctors poke around your chest with the echo machine... : ) maybe not so much a problem for the boys....