“The yogi’s life is not measured by the number of days but by the number of his breaths.” –BKS Iyengar.
Prana translates as breath or life-force. Yama means “discipline,” and ayama means “expansion” or “non-restraint.” Pranayama is the practice of mindful breath control. Breathing is often involuntary, and when breath stops, life stops. Methods of measuring, holding, and controlling the breath are taught to purify the body and the mind, removing toxins and distractions.
Practicing pranayama produces tapas, which is the inner cleansing fire. This tapas will purify the nadis, or subtle nerve channels. As the physical and subtle nerves calm, the mind can meditate and concentrate.
If you’ve been to a yoga class, you probably already know that the ability to breathe deeply and calmly enhances asana – but it also enhances the yamas and niyamas. For instance, consider the yama bramacharya, restraint and responsible behavior. It is easier to keep your temper or avoid panicked decisions when you take a deep breath. Consider the niyama saucha, purity. Healthy food and nutrition supplements can’t give you their full benefit if you aren’t fully oxygenated. Keeping your mind calm will dispel tension, which allows your blood to move freely and oxygenate your body. This allows beneficial nutrients to do their work because they aren’t impeded by stress chemicals or constricted blood vessels.