If you find long yogi breath-holds interesting, you should read the book 'Path of Fire & Light, vol 1' by Swami Rama. In it, he describes in detail what happens when the yogi holds his breath for various lengths of time.
For example, he says that a retention of 10'48" results in withdrawal of the physical senses. A full retention is 13.5 minutes and results in samadhi. He says that by resisting the contractions, the vagus nerve is stimulated, which in turn slows the heart to almost complete cessation, after which the yogi can remain in apnea for ages.
He says that after 68 minutes of apnea, he says that the air in the lungs becomes so stale that the body tries to expel the air through the digestive system. He says that around the 68 minute mark, the air will suddenly try to enter the alimentary canal (i.e. oesophagus), and the air will force its way through the belly & intestines and try to exit the digestive system from below. He says the yogi must clench his pelvic floor muscles to prevent the escape of the air, and this can be painful in the beginning. Then, once the air has moved into the digestive system, he explains what happens as the yogi holds his breath for 1h20, 2h42, and even longer. The longest breath hold he mentions is 60,000 seconds (1000 minutes = 16.7 hours), although he himself never claims to have reached such a time.
Don't be fooled into thinking that these breath-holds are simply a matter of mind power or concentration. Swami Rama clearly explains that extended kumbhaka (apnea) is not possible until the nadis (nerve channels) have been purified (which is done by practicing certain exercises for months or years). Only after the nerve channels have been purified is it possible to control the involuntary system. He also explains that the secret to breath holding is to learn how to control the exhale. All of the yoga exercises involve very slow exhales (through the nose), even after very long apneas. Freedivers never exhale slowly (and hardly ever exhale through their nose), and thus it seems that freedivers might lose the mystical benefits of their apnea. Swami Rama states that the way to increase kumbhaka is to learn to control the exhalation, and by controlling the exhalation, the yogi eventually learns to control the entire involuntary system.
Eric Fattah
BC, Canada
I like that!
