Muscles Targeted: Glutes, Hamstrings

To begin this exercise, loop a band around a power rack. Lie on your back with your feet on top of the stability ball. Hook your feet and ankles around the band. Begin by raising your hips off the ground by squeezing your glutes. Once up in this position, your hips should not touch the ground until you've completed all your reps. Keeping your hips up high, pull your heels toward your butt by contracting your hamstrings. Slowly return to starting position (hips off the ground.)

The band is added for more tension at the top.