Lay on your back. Raise both feet off the ground so you have a 90 degree angle at the hip and the knees. Raise both arms up to the ceiling hands above your shoulders. Push your lower back into the floor and draw in your belly button. Extend one arm behind your head and the opposite leg towards the floor. Just before the arm and leg touch the ground raise back to the starting position and repeat on the other side. Exercise description and photo by Michael Diebler.