Begin kneeling on the floor, hands directly under your shoulders, knees at a 90-degree angle.  Lift one leg so that the foot is flexed to the ceiling and knee is bent at 90-degrees.  Maintaining this position, contract the glutes and press the flexed foot toward the ceiling.  Maintain as many reps as you can until you reach fatigue.  Repeat on opposite side.

Model: Sheila Hutchinson