Exhalation is the key to yoga breathing. Breathing exercises begin with the exhalation. The more stale air exhaled out of the lungs, the more room the lungs have to inhale clean air. During exhalation, the air should be fully expelled from the abdomen and then the chest.
Abdomen! Do we really have air in our abdomens? When we breathe fully, yes. Have you ever watched an infants breathe? Notice that their little bellies rise and fall as they breathe. Infants use their abdomens, chest cavities, and nostrils to inhale and exhale. Babies are perfectly relaxed, completely unconscious of their breathing. There is nothing shallow about a baby’s breath.
The lower abdominal tract is where the body’s impurities settle. Through our exhalation these impurities are eliminated. Most of us exhale unconsciously, so when we do begin to consciously exhale, it may seem like an effort to really expel all the stagnant air. Exhalation should be effortless, not forced. During exhalation you will feel the abdomen contract. Do not push the abdominal region to contract; rather, exhale gently and with awareness, letting the air push out of the abdomen. This will expel the remaining air from the lungs. The process should be naturally passive, not intentionally active.