Start by lying on your back on a bed with your legs straight and arms resting by your sides. Bend one leg and bring the knee towards your chest.
Bend the straight leg and bring that knee towards your chest and at the same time straighten the other leg, keeping it close to but not touching the bed. Bend and straighten the legs alternately, without resting the legs on the bed in-between.
This exercise strengthens your abdominal muscles and works on the range of motion of your knees and hips.
