If you hate doing ab exercises on the floor, here is a great alternative. The stability ball crunch is a classic "ball" exercise. It is relatively easy to perform. First, position the ball on the middle/lower back area. The starting position is with the torso flat on the ball. The hands can be used to support the head, or they can be placed across the chest. Next, crunch the abs and exhale. Hold the position for 2 or 3 seconds and repeat the exercise.

IMPORTANT: The abdominal crunch is different from a sit-up. The range is much shorter in an abdominal crunch. Accordingly, the upper torso should only come up a few inches. In the sit-up exercise, the torso comes all the way up.