Here's one way supermodels Heidi Klum and Naomi Campbell whittle their middles in the gym, according to their trainer, David Kirsch. Lie face-up on a flat bench with your legs extended in the air directly above your hips, feet spread wide in a "V," feet flexed.

Contract your abs to bring your spine into a neutral position and in contact with the bench.Maintain this position and curl your pelvis upward in a small reverse crunch. Relax hips to the bench and repeat. Do 2 to 3 sets of 15 to 25 reps.