Exercise Advice: Using a large exercise ball, lay your back on the ball with your feet placed firmly on the floor. Your lower back should be centered on top of the ball. Place your hands on either side of your head. Crunch your upper body forward and roll your shoulders towards your hips. Be sure to contract your abs at the top of the movement for a one-count. Slowly return to the starting position and repeat. Also, for added muscle building, hold a weight plate across your chest for added resistance.