Strengthen your entire back with this one simple move. The first variation, in which your legs are on the floor, targets the upper and mid-back muscles. The second variation kicks up the intensity by also training your buttocks and legs.
Lie face down on a level, padded surface. Straighten your legs behind you with your toes down and your inner ankles facing each other. Place the palms of your hands flat on the floor near your rib cage, elbows bent and tucked in close to your body. Inhale, contract your upper back muscles to raise your chest, shoulders and head off the floor. Pause for three breaths.
Exhale while you keep your upper back raised. Inhale again, but this time extend your arms back, reaching your fingertips toward your feet. Now raise your legs off the floor. Keep your knees straight and your feet close together. Hold this position for three breaths, release and rest face-down on the floor for 15 seconds. Repeat two or three times.
Source: Los Angeles Times