To take a full yogic breath you inhale by first relaxing the abdomen. Next expand the chest and finally the collarbones. As you exhale let the collarbones and chest deflate first, then pull the belly in completely. The diaphragm drops down to expand the lungs and contracts up to expel the air. As you inhale feel the back area of the lower ribs relax and expand. On the exhale be sure to keep the spine erect and steady; do not bend or collapse the chest area. For some beginners, breathing is paradoxical; that is, instead of relaxing the navel on the inhalation, some breathe only into the upper chest as the navel pulls in towards the spine. Pay attention to the proper breath and paradoxical habits will give way to a natural energizing and cleansing breath.
For beginners: A good way to approach learning the natural breath is to lie down on your back with a phone book spread open across the navel. In this relaxed position, inhale and watch as the phone book rises; exhale and watch the book relax back down. It may take some time but patience pays and as this natural deep breath grows more familiar, you can begin practicing in Easy Sitting Pose with your hand on your navel. Again, observe the navel expand on the inhalation and draw back toward the spine on the exhalation.
By taking a deep yogic breath you can expand the lungs by about eight times. If you establish a habit of breathing long, deep, and slowly you will develop endurance and patience. If you can establish a breath rate of eight times per minute or less the pituitary starts secreting fully. If the breath is less than four times per minute the pineal gland starts functioning and deep meditation is automatic.