Do this routine once a week, in addition to the Metabolism Booster and Extend Your Burn Bikini Body cardio workouts in the Summer issue (page 103). Supplement these routines with 30 to 60 minutes of moderate-intensity aerobic exercise on two other days (so you're doing cardio five days a week).

SHAPE UP YOUR REAR VIEW
Find a staircase with at least one flight. (We like to do this workout in a stairwell or at a track with bleachers.) Warm up Jog (or walk) up and down the first flight one step at a time. Take the next flight two steps at a time (jog down in between if you only have one flight).

1. Stand with right side facing stairs and step up one or two at a time crossing left foot over right. Run down and switch sides. Next, face the stairs and walk up one step at a time, criss-crossing one leg in front of the other. Jog or walk down. Repeat this pattern from the beginning for 10 minutes, then rest until you feel you've recovered enough to go again.

2. Sprint up one flight, then walk down and repeat two more times. Repeat the stair pattern in step #1 for 10 more minutes, then recover.

3. Repeat the three sprints from step #2 one more time, then follow that with 15 minutes on your favorite cardio machine at a moderate intensity. Cool down for 5 minutes.