Begin on your back with arms fully extended out to the sides. Your body should be in the shape of a T with your palms touching the floor. With knees slightly bent and your back flat against the mat, raise your legs until they form a 90 angle with your torso.

Keeping your feet together, slowly (three-count) lower your legs as far as you can to the left, then hold for one to three seconds. Do this by rotating at the waist and concentrating on the downward motion. Keep your abdominals tight during the entire repetition. Attempt to keep both shoulders on the mat throughout the movement, applying pressure against the mat with the opposite shoulder. (The opposite shoulder may come off the mat slightly until you become more skilled at performing the exercise). Keep your legs together and try to bring them as close as possible to the mat. Then return to the starting position by contracting your oblique muscles. Without stopping, continue through to the right side and hold for one to three seconds. This constitutes one full repetition.

Added difficulty: As you become stronger, place a small medicine ball between your ankles or knees (wherever you can get the best grip). Using abdominal strength, apply more power on the upward motion.