This is an excellent exercise for the waistline or a weak back, but even more for stooped shoulders. It should be taught to all children at home and at school to counteract their tendency to slouch, for slouching, in addition to being ugly, develops a bad and unhealthy posture as it prevents the lungs from expanding as they should. It is a great exercise for beginners along with alternate nostril breathing described below.
Stand straight with feet together. Put your hands behind your back and interlock the fingers, palms upward. Now turn the palms down. This will automatically give a twisting movement to your elbows.
Inhale deeply, then bend forward, while exhaling, at the same time raising the arms until they are stretched out. Do not bend the elbows, which should remain straight throughout. Keep your head down, trying all the while to swing your arms a bit higher and higher.
Remain a moment in this position, holding your breath; then slowly return to the standing position without unlocking your fingers. Repeat the whole exercise two or three times.
Another version is done in a kneeling position. The procedure is the same, except that here you bend over until your forehead touches the floor."