The Supreme Personality of Godhead said: Sitting on a level seat that is not too high or too low, keeping the body straight and erect yet comfortable, placing the two hands on one’s lap and focusing the eyes on the tip of one’s nose, one should purify the pathways of breathing by practicing the mechanical exercises of pūraka, kumbhaka and recaka, and then one should reverse the procedure (recaka, kumbhaka, pūraka). Having fully controlled the senses, one may thus practice prāṇāyāma step by step.