Lie flat on your back on an exercise mat with your knees bent and feet flat on the floor. Lift your left leg and cross it over your right leg, so that your ankle is resting on your lower thigh. At the same time lift your right foot off the floor, bringing your right knee towards your chest. Clasp your hands together underneath your right thigh. Use your hands to pull your right leg towards your chest, at the same time trying to keep your lower back pressed into the floor and using your left elbow to push your left knee away from you. You should feel a deep stretch in your glute and hamstring. Hold for the recommended amount of time, then repeat on the other side.