Assume the classic pushup position with a medicine ball by your right hand. Place your right hand on the ball, then lift your left hand off the follor - balancing briefly on the ball with just your right hand - and place it on the ball. Next, place your right hand on the floor to the right of the ball, then place your left hand on the floor, next to your right hand. (The ball should now be by the outside of your left hand.) Repeat in the opposite direction. That's one repetition. Start with eight repetitions in week 1. Do 10 reps in week 2, and 12 in week 3 and 4.