Ball Exercises for the Abs and Butt
Lie down with the shoulder blades resting on the ball and your feet firmly planted on the ground. Keep the abdominals contracted to maintain the trunk straight. Hold a small to medium size weight in each hand, elbows flexed and pointed out, hands turned up.
Proceed to slowly lift the weights toward the ceiling, without locking your elbows. Resume the starting position. Repeat 10-20 times.