Place your feet flat on a wall behind you, toes pointing to the floor, and lie your belly overtop a physioball, holding a medicine ball at your chest. Straighten your back to lift your torso off the ball, keeping the med ball close to your chest as you move. When your back is fully straight, extend your arms to lift the med ball away from your chest. Hold for a second, then lower the weight and reverse the movement until you reach the starting position.
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