Reducing carbon dioxide levels through methods like cyclic hyperventilation lowers the impulse to breathe, enabling longer breath holds.

“What you're doing is you're getting rid of a lot of carbon dioxide, and therefore, you're removing the impulse or lowering the impulse to breathe so that when you enter that breath hold phase after the hyperventilation, it's a much longer period of time before you feel the anxiety and the hunger and the impulse to breathe.”