Sitting on an exercise ball, walk your feet in front of you, rolling the ball up your back until your torso is resting on it, knees bent and feet flat on the floor. Reaching your arms toward your knees, pull your navel in toward your spine and lift your head, neck and shoulders [A]. Inhale and extend your right arm overhead [B]. Exhale and lift your left arm overhead as you lower your right arm to your side. Switch arms 10 times, then rest. (This is one set.) Work up to 3 sets.