Grasp a Barbell or Dumbbell and sit on a Ball with your feet firmly placed on the floor.
Lower your body so your upper abs are the only part of your body supported on the Ball.
Bring the Barbell or Dumbbell to your chest with your arms extend.
In an arcing motion raise the Barbell or Dumbbell over and behind your head towards the floor.
Return to starting position.
Repeat.