Inhale and exhale rapidly through your
nose, keeping your mouth closed but relaxed. Your breaths in and
out should be equal in duration, but as short as possible. This is a noisy breathing exercise.
Try for three in-and-out breath cycles per second. This produces a quick movement of the diaphragm, suggesting a bellows. Breathe normally after each cycle.
Do not do for more than 15 seconds on your first try.