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What is a hook breath?

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New Member
Jun 25, 2010
You guys are right in part but not entirely.

Part of our mammalian dive reflex constricts blood vessels in the arms and legs, redirecting the blood to our core for use in keeping the organs warm and supplying oxygen to the organs that need it most.. primarily the heart and brain. At the same time blood vessels in the brain dilate to suck in as much oxygen as possible.

At the end of a dive your heart rate will start to increase. Your heart needs to work harder to circulate the low oxygen blood so that it's self, and the brain can get as much as possible. This raises your blood pressure.

When you reach the surface and exhale everything in your lungs the blood vessels around the alveoli suddenly have room to expand and your blood pressure drops. All of a sudden your brain has less oxygen and you black out.

Hook breaths and cleansing breaths don't allow the blood vessles in your lungs to rapidly dilate which solves the problem.

You are not trying to 'bear down' or pressurize your lungs. do 3 hook breaths, consisting of exhaling the top half of your lungs (breath with your chest, not your diaphragm), inhaling and holding for a count of 3. after the 3 hook breaths do three cleansing breaths, which are the same as hook breaths except without holding. TOP HALF OF YOUR LUNGS ONLY!
Maybe hook breathing before a dive could help to avoid packing blackouts? It might help to reduce the sudden change in blood pressure and the effects of over-ventilating.

Just an idea...

If you used hook breaths for your breathup you would probably still hyperventilate. Hyperventilation is simply breathing more air than your metabolism needs. Just do relaxed breathing and try to lower your heart rate before your dives.

For dives of less than 80' your surface time should be at least twice your dive time.
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Well-Known Member
Jun 8, 2007


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Well-Known Member
Oct 24, 2003
Thank you Johnson for the file, it's nice to read and refresh and refine something one already knows and have used successfully.

Hook breathing really has helped a lot of divers stay concious through those difficult resurfacing moments.

But I must say that often people forget to not climb the rope high(!) out of the water, this allows the blood to flow from the head easily.
I believe William Truebridge could benefit of learning to just have 1 hand up locking in high on the rope, and his head just 10cm above the water and perform his well practices hooks. In his Blue hole there are no waves to disqualify his dives. In places where there are waves one would have a bit more margin, though the judges are instructed to be forgiving in regard to waves smashing over the mouth of the dives for at least 1 wave, I believe.
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