Technique of Bhastrikā: rapid and vigorous inhalations and exhalations through the nose, with the abdomen expanding and contracting like bellows.

The rhythm must be stable and controlled, not chaotic. Typically 1-2 per second, maintaining a constant rhythm for rounds of 20-30 breaths.

Between rounds, kumbhaka (retention) is done with bandhas. This combination of bellows and retention is what produces the profound effects.