Sitting on the Exercise Ball with knees bent to 90? and holding a Medicine Ball with both hands, raise the Medicine Ball up and overhead to the right. Keeping your core engaged and neutral shoulders, make a chopping (twisting) motion as you take the Medicine Ball down and to the left. Repeat on the opposite side: raise the Medicine Ball overhead to the left and then make a chopping motion diagonally toward the bottom right. **Watching the ball will challenge your stability more.