Squeeze a foam roll between your thighs and lay flat on your belly, tucking your tailbone toward the mat. Place your hands under your shoulders, with elbows up, and push the tops of your feet into the floor. Next, inhale and push up into cobra, opening your chest and pulling your rib cage forward. Be sure to keep your shoulders down. Exhale and release, lowering yourself slowly and carefully, one set of ribs at a time. Repeat three times.