The Drop a Jeans Size Workout

Cardio Workout 1: 20-Minute Circuit

Calorie Crunchers
Yeah, yeah -- you've heard it before: You have to hustle to cut the flab. Here's incentive to love, not loathe, those speed bursts: "Studies show you can net nine times the fat loss by doing intervals rather than keeping a steady pace," Schoenfeld says. Do three of these workouts a week -- stick with one or mix it up -- to get lean.

20-Minute Circuit
This series of one-minute PE classics packs almost the calorie burn of Spinning -- ideal for living-room exercisers.

• March in place for 3 minutes (360 steps)
• 60 Jumping Jacks
• March 1 minute (120 steps)
• 60 Jumping Jacks
• March 1 minute
• 30 Squat-Thrusts*
• March 1 minute
• 30 Squat-Thrusts
• March 1 minute
• 30 Squat-Thrusts
• March 1 minute
• 30 Squat-Thrusts
• March 1 minute
• 60 Jumping Jacks
• March 1 minute
• 60 Jumping Jacks
• March in place 2 minutes to cool down

CALORIES BURNED: 145 (Calorie burns are based on a 140-pound woman)

*From standing, crouch down, place palms on floor, jump legs back into full push-up position, then jump legs back to crouch pose and stand up. Repeat.

Get a FREE podcast complete with audio instructions & move-it music for this cardio session