Her Secret -- Jessical Biel's workout

From AC: (please note that some of her exercises are very hard on your joints, especially plyometrics. It's worth the money to hire a personal trainer so you don't hurt yourself.)

Warm-up: Walking lunge. With your feet together, lunge with your right leg. Bring your left foot alongside your right. Then, lunge with your left leg. Do about 8-10 lunges per leg.

Cardio: half-mile jog, then run 200-meter, 150-meter, and 100-meter sprints on a track.

Abs: hanging leg raises which, as Jason Walsh (Biel's trainer) says, flatten the stomach. Hang from a high bar or rings so that your feet don't touch the ground, pull your knees slightly above the waist. Do this fifteen times in three sets.

Plyometrics, as Walsh says, "hurt." But they are important to building a toned body. To do these, jump from the bottom step of a flight of 20 or more stairs up to the third step. Do this until you reach the top, skipping one stair each jump.

Weight training, Jessica uses lighter weights but does more reps. Walsh keeps her moving so that this becomes a cardio workout as well.

Tone the waist, Jessica does what's called the Russian Twist. To do this, sit down on the floor and lean back slightly. Holding a 5-lb. medicine ball, twist from side to side. Do this fifteen times again in three sets.

Shoulders and biceps: stand with your knees slightly bent, Jessica holds one 10-lb. weight in each hand. Curl them up to your chest. Rotate your hands with your palms facing outward and press the weights overhead together. Do three sets of 10-12 reps.