1. Lie comfortably on your back, concentrating on keeping both your head and buttocks in contact with the floor.
2. Slowly extend one leg upward, grasping it with both hands, either around the calf, the hamstrings, or a combination of both.
3. Exhale and pull your leg toward your chest, keeping it straight allowing the tension to build up in your hamstrings.
4. If necessary, use a towel wrapped around your foot, in order to keep your head on the floor.