Lie facing up on the floor with knees bent, feet flat on the floor, toes pointing forward about shoulder width apart.
Lift hips off the floor until knees, hips and shoulders are all even. Fully contract the glute muscles. (Do not raise the hips to far off the floor hyper-extending the back. This places excessive strain on the lumbar spine.)
Hold for 2 seconds.
Slowly return to starting position.
Repeat for prescribed number of repetitions.