Select the appropriate resistance on the weight stack. Get on your knees. There should be a cable with a rope that is attached to a high pulley. Grab it and pull it to place your hands in front of your head.
Using your abdominal muscles, curl your spine and move your elbows toward your hips. Exhale during the movement. Return to the starting position in a smooth movement while you inhale. The moving weights should not touch the rest of the stack.TIPS: The exercise key is quality over quantity. The trick is to perform the exercise using proper form.