Proper, purposeful relaxation offers the greatest amount of renewed strength in the shortest length of time. After extended exertion or stress, perfect rest in the form of relaxation is the principle which revitalizes the nerve centers, collects the scattered forces of energy and invigorates the body. The three relaxation poses of Yoga for complete relaxation are Matsya kridasana, Shavasana and Advasana.
This is considered best for sleeping, as it is the most comfortable. To take the pose, lie relaxed with your right arm under your head, using it as a pillow. By lying passively on the right side, you favor emptying of the stomach and make breathing movements easier. In practice, it has been found that sleeping in this manner generally inhibits dreams and nocturnal emissions and improves digestion. A short period of sleep becomes the equivalent of a longer sleep for recuperative purposes. It is also recommended for short periods of waking relaxation.
This is recommended for use when the student of Yoga experiences fatigue during any of his exercises. This pose is described in the tracts as "destroying fatigue of the body; quieting the agitation of the mind." Lie face up with your feet extended. Remain motionless with a sense or feeling of sinking down like a corpse. Gradually relax every muscle of the body by concentrating on each individually, from the tip of the toe to the end of the skull. Exercise absolute resignation of will by trying to forget the existence of your body and detaching yourself from it. Hold this posture until you feel restored.
Medical authorities have confirmed that the Shavasana pose brings about a fall in the blood pressure and pulse rate and establishes an even rate of respiration. If this pose is kept for more than ten minutes, the deepened respiration and lowered circulation in the brain will probably bring about a tendency to sleep.
Lie down with your head on your folded arms, as if on a pillow, and concentrate as in Shavasana. Relax all your muscles. Then stretch your hands and legs out fully, and permit the power of gravity to take over the weight of your body as you relax every voluntary muscle.