Lay on your back on a mat or the floor with your knees bent and feet flat or just have your heels touching the mat/floor. Lift your head and tuck your chin slightly toward your chest. Keep the lower back on the mat at all times and keep your abdominal muscles engaged while maintaining constant breathing. Reach toward your left heel. Come back to the center, then reach toward the right heel. Repeat 10 - 15 times on each side, rest, then repeat the exercise sequence if desired. Alternately, you can do all desired repetitions on one side, rest, then do the other side.