1. Begin on the floor laying on your back with your feet on top of the ball. Make sure that your head and neck are fully supported using a rolled towel or an ab pad.
2. Position the ball so that when your legs are extended your ankles are on top of the ball. Legs are hip width apart and toes pointed towards the ceiling. This will be your starting position.
3. Raise your hips off of the ground, keeping your weight on the shoulder blades and your feet. Keep your upper body relaxed and your lower back should not be arched.
4. Flex the knees, pulling the ball as close to you as you can, contracting the hamstrings. This movement is slow and controlled. Try to relax your ankles. Hips remain in the same position during the entire number of reps.
5. After a brief pause, return to the starting position.