
Tones: Abs, back, shoulders, buttocks, and hamstrings
One Set: 15 to 20 repetitions
Starting Position: Lie facedown on the ball so that it's between your chest and your belly. Your arms should hang down perpendicular to the floor. Your legs should be shoulder-width apart, stretched out diagonally, with your toes touching the floor to keep your body stable.
One Rep: Lift and extend your left arm out in front of you so it's parallel to the floor—and at the same time lift and extend your right leg so it's also parallel to the floor. Hold this position for 2 seconds. Then lower them back to the starting position and repeat the move with the right arm and the left leg. That's 1 rep.