Russian Twist (On Stability Ball, Arms Straight)

Instructions

1. Sit on a stability ball and walk your feet forward until your upper back rests on the ball, hips lifted.
2. Extend your arms straight overhead, hands clasped or palms together.
3. Keeping arms straight, rotate your torso to one side as far as comfortable.
4. Return to center and rotate to the opposite side.
5. Repeat for the target number of reps, keeping hips level throughout.