Exercise No. 5: Straight Abdominal Crunches

Lie back in a bent knee sit-up position with hands behind your head or touching your temples. In a controlled way, slowly lift your head and shoulders 30º off the ground. Hold the position for a second (tensing the abs. hard). Release and go back to the starting position. Don't "pull" your head up with your hands. Each repetition done properly, will take at least two seconds.