Answer:
Practice deep breathing. Before holding your breath, inhale and exhale slowly from deep within your diaphragm. By doing this, you're ridding your lungs of low-quality air.[1] Spend five seconds breathing in, then hold the breath for one second, before breathing out for ten seconds. Continue deep breathing for two minutes, and be sure that when you exhale, you push out every last "drop" of air.
Step-by-step explanation:
The hyperventilation reduces the body's carbon dioxide content but does not affect oxygen content much, but the Fio2 of 100 kPa considerably increases the total oxygen content. Hyperventilation before diving enables breath hold divers to stay down longer but is very dangerous.