How long does each "hook" takes when you hook breathe after a NEAR LIMIT dive?

I don't know anything about the divers in the videos but I imagine it is something that is very individual. Hook breaths usually feel good to me, and after a long/hard dive feel best. I also usually take long ones, similar to what you describe. In the ocean when spearfishing since I don't have to answer to a judge, I usually submerge my face during the hold part of the hook as well--just feels good. From tests that I've done (ON MYSELF), a ton of recovery breaths aren't really necessary to re-oxygenate, but if I am running what is for me a very high CO2 level, usually from serial drops with very short surface interval, or in a pool if doing sprints/aggressive interval work, I breathe just to vent CO2. The divers in the videos would also have very high CO2 tolerance, and very healthy O2 exchange--their body would respond and clear the BO/samba danger threshhold after even just a few small breaths, even though they would still be hypoxic in a medical sense... People who have watched me in a comp say that I don't seem to breath much on recovery which is probably true--when I'm trained I have a pretty high CO2 tolerance, and (so far) in comps am usually ending a swim/hold with CO2 levels that I doubt are much higher than I achieve in training, so after a few breaths my O2 levels are on their way back up, and CO2 levels and HR never really got high enough to make me feel like I need huge breaths. One other thing to realize about the divers in the videos is that they are likely pushing hard, possibly very near samba. From my own limited experience, as you near samba, it can become hard to breathe--small breaths are all you can manage, and to an observer, it seems like the diver is barely breathing....

ComputerBoy said:

I've done "recovery breaths with breaks" naturally from the first times training breath holding before knowing its name "hook breathing". And later on, as I dove deeper and holded my breath harder, my hook breathing has developed to a "strange pattern" that scared my instructor in my SSI freediving course: It takes so looooong each hook, usually 3 long hooks "5 sec - 3 sec - 2 sec".

However, watching some pro freedivers on the Internet, I'm so supprised to see them did nearly no hook at all, and they even seemed not need recovery breathing!? Can any one explain "no hook" recovery breathing like in following videos?

• - [ame="[MEDIA=youtube]rD5Mg0eiJdE[/MEDIA]"]Sara Campbell - 104m CWT[/ame]
• - [ame="[MEDIA=youtube]AlB7Bui7YSU[/MEDIA]"]Natalja Molchanova 214 DYN[/ame]

Ref: Some threads on DeeperBlue about "hook breathing"

• - What is a hook breath? - There are good explanations.
• - Proper hook breathing with video - A nice video of hook breathing in high G-force pilot training.
• - G Force Pilot Training And Swbo
• - Breath up's and recovery breathing

Click to expand...

Just make sure you do not do it too long. Too long of a hook breath can inhibit venous return to the heart and cause the blackout you are trying to prevent.

To quote the Air Force's guidance on the "Hook" maneuver -

"The only drawback was the problem with some individuals holding the pressure (closed glottis) for an excessively long time. Holding a very-high intrathoracic pressure for 7 to 10 seconds, even with concurrent skeletai muscle tensing, can markedly reduce return of venous blood to the heart. This can result in loss of consciousness, similar to that which results when performing a sustained Valsalva maneluver (no concurrent skeletal muscle tensing). Complete closure of the glottis not to exceed 5 seconds was considered the upper limit of maintaining increased chest pressure." (Yes, "skeletai" appears to be misspelled in the original - before the days spell check, I think.)

The whole text for this is available at -
http://www.freedivingsolutions.com/index.php/resources/education/breathing/the-hook-maneuver