PSA: Trying to hold your breath for a long time is dangerous, especially if you hyperventilate first. People die this way.
The hyperventilation thing is because your brain needs oxygen to live, but your impulse to breathe is driven by carbon dioxide saturation. When you hyperventilate, you get rid of a ton of carbon dioxide, and you can get into a situation where you don't have enough CO2 buildup to trigger the signal to breathe, but you have so little oxygen that your brain is dying.
The hyperventilation thing is because your brain needs oxygen to live, but your impulse to breathe is driven by carbon dioxide saturation. When you hyperventilate, you get rid of a ton of carbon dioxide, and you can get into a situation where you don't have enough CO2 buildup to trigger the signal to breathe, but you have so little oxygen that your brain is dying.
Personally, not something I'd like to mess with.