First lay belly face down on top of the ball and walk yourself out until the ball meets your calves and hold here. For a more advanced move, lift one leg at a time and hold (this takes balance).
In the same original position, now bring only your knees into your chest and then back out. The ball adds a lot of resistance. For a more advanced version, contract your abs bring your hips into a pike position and lower. The ball should follow you into this position. Do a total of eight reps and you will be hurting.
Thank you for all of your routines. They have been so helpful for me as a new instructor.
Enjoy
Tiffany