Sit down on the floor or you can also use a decline bench and hook your ankles underneath the pad. While holding the medicine ball overhead perform normal situps. This version of the exercise greatly increases the difficulty of the exercise and should be built up to over time. A very good and fun variation to this exercise is passing the medicine ball back and forth between you and a partner. As you come up perpendicular to the floor throw the ball out and catch it on the way down.