To achieve a zen-like mastery of the cold, all you must do is submit yourself to controlled hyperventilation. Not panicky, gasping breaths, but strong, deep inhalations at a rapid pace (one second in) without a deliberate exhalation (allow some air to leave naturally rather than pushing it out). Fill your lungs and repeat this 30 times. Now comes the tricky part: without force, allow all of the air out of your body and then don’t breathe in again until you sense your body really needs oxygen. Complete another round, aiming to extend the period before you inhale. Then go again.
On the final round, after expelling all the air from your lungs, Hof encourages participants to complete a round of press-ups. Not as a display of masochism, but rather to demonstrate the improved muscular endurance that comes from your body being engorged by oxygen – the essential fuel for exertion.I'm guessing that by "press-up" they means "push-ups".