According to B.K.S. Iyengar, “Pranayama is a conscious prolongation of inhalation, retention and exhalation.” This very pared down definition doesn’t explain why someone might want to consciously change their rate of breathing. To understand pranayama, it’s helpful to understand prana. Yogi Bhajan said “Praana is the most powerful and most creative thing God ever created, because out of praana came life.” So what is prana? Classical yogic texts describe prana as the energy of the universe. This energy is the creator, sustainer, and destroyer, and because it permeates everything in the universe it is considered the breath of life.
Yogis can access this prana, and increase its flow in the body, through various breathing practices (pranayama) honed by generations of yogis through the ages. Pranayama practices manipulate the breath in various ways: extending or shortening the lengths of inhalation and exhalation, suspending the breath, or breathing in a syncopated fashion. The effects of these practices on the body and mind can be profound, shifting the mood and energy in the body noticeably. In Kundalini yoga, breathing practices are often combined with mudras (hand positions) and mantras to achieve very specific results. In other styles of yoga, such as Ashtanga and Bikram, specific pranayama practices are regularly used as part of daily practice.