Russian Twist On Ball

Set Up: Holding a medicine ball in both hands, sit on a ball with your feet flat on the floor, shoulder-width apart. Extend your arms in front of you so that your hands are at about shoulder height. Walk your feet forward and lean back until your upper back and shoulders rest on the ball.

Action: With your arms extended, rotate your torso to your right until your shoulder touches the stability ball. Return to the center, then rotate your torso to the left, directing your outstretched arms at the same time. Return to the center and continue, alternating sides.