Flatten Your Belly in 3 Weeks

If you want toned abs in less time (who doesn't!), add a ball, disc, or roller to your workout. Their wobbly surfaces will challenge your core twice as much as traditional crunches, says a recent Auburn University study. That means you can get away with doing only 2 moves and still see fabulous results. The ball routine is the easiest because the large surface area provides more stability. As the props become smaller, there's less contact with your body and the floor, increasing the challenge.

THE PLAN

Do your chosen ab workout 3 times a week on nonconsecutive days, completing 2 or 3 sets of each exercise.

FOR FASTER RESULTS

Include 30 to 45 minutes of moderate-intensity cardio 3 to 5 times a week to burn off the fat that's hiding your abs.

THE EXPERT

Kristin McGee, a yoga, Pilates, and fitness instructor in New York City and creator of the DVD Pilates for Beginners, designed this workout.

 

EASY

Ball Routine

To make the ball easier to control, release a bit of air from it; to increase the difficulty, pump it up. Bonus: You can sit on the ball during strength-training to add a balance challenge.

Leg Extension

Targets rectus (front abs), transverse (deep abs), quads, inner thighs

Sit up straight on top of ball with knees bent, insides of legs touching, and arms extended to sides, palms down. Press knees and inner thighs together while lifting right foot and straightening leg. Lower foot and repeat with left leg for 1 rep. Do 8 to 10 reps.

 

MAKE IT EASIER

Place hands on ball by hips.