Pranayama is loosely translated life force through breath control. The ancient yogis developed many breathing techniques to maximize the benefits of prana. Pranayama is used in yoga as a separate practice to help clear and cleanse the body and mind. It is also used in preparation for meditation, and in asana, the practice of postures, to help maximize the benefits of the practice, and focus the mind.
Breathing is so simple and obvious we often take it for granted, ignoring the power it has to affect body, mind and spirit. With each inhale we bring oxygen into the body and spark the transformation of nutrients into fuel. Each exhale purges the body of carbon dioxide, a toxic waste. Breathing also affects our state of mind. It can make us excited or calm, tense or relaxed. It can make our thinking confused or clear. What's more, in the yogic tradition, air is the primary source of prana or life force, a psycho-physio-spiritual force that permeates the universe.