The best way to burn fat: you'll lose the jiggle and extra padding faster than ever with this speedy routine

Shape, Dec, 2008 by Jeanine Detz

Your mission

Don't waste a single second doing cardio "overtime" in the name of fat loss. This calorie-torching plan takes just 20 minutes but outperforms workouts that last twice as long. Its secret: alternating high-intensity intervals with easier recovery periods. In a recent Australian study, women who did this type of routine lost a whopping three times more body fat during a 15-week period than those who worked out for 40 minutes at a steady effort level. Researchers believe bursts of high-intensity activity increase levels of fat-burning compounds in the body. So consider this plan your scientifically proven trick to firming up fast.

What to do

Pick a cardio machine, set it to manual, and start moving. To increase the intensity, pick up your pace and/or increase the resistance or incline. Alternate between challenging 60-second intervals and 90-second recovery periods. (During the intervals, it should be tough for you to eke out more than a few words between breaths.) Cool down, then try the must-do move.

your workout plan

time (min.)        what to do        RPE* (1-10)

0:00-3:00    warm up gradually         3-4

3:00-4:30    increase the intensity    6-7

4:30-5:30    increase the intensity    8-9

5:30-7:00    decrease the intensity     5

7:00-8:00    increase the intensity    8-9

8:00-9:30    decrease the intensity     5

9:30-10:30   increase the intensity    8-9

10:30-12:00  decrease the intensity     5

12:00-13:00  increase the intensity    8-9

13:00-14:30  decrease the intensity     5

14:30-15:30  increase the intensity    8-9

15:30-17:00  decrease the intensity     5

17:00-20:00  cool down gradually       3-4

workout intensity moderately hard
equipment needed any cardio machine (or do the workout outside)
total time 20 minutes
calories burned 180 **
* See page 174 for RPE chart.
** Calorie burn is based on a 145-pound woman.

Shape's 20-minute playlist

LOAD THIS MUSIC ONTO YOUR MP3 PLAYER

"Crowded Room"

The Academy Is ... (3:07)

"Damn Regret"

The Red Jumpsuit Apparatus (2:46)

"Run (I'm a Natural Disaster)"

Gnarls Barkley (2:40)

"Lucid Dreams"

Franz Ferdinand (3:41)

"Nu Rock" Morningwood (2:30)

"The Champion in Me"

3 Doors Down (3:32)

"So What" Pink (3:34)

Total time: 21:50

Online bonus!

You'll dig for stronger muscles from your shoulders to your legs with this must-do move.

body bar shovel

* Hold a 5- to 8-pound body bar in front of your thighs, right hand on the end of the bar, palm facing behind you, and left hand in the center, palm facing forward. Stand with feet hip-width apart. Lunge to the left as you reach the bar toward the floor as if you were digging [A].

* Press off left foot to stand up as you pull right hand to right hip and bring left hand up and to the right (as if you were throwing what you dug up behind you) [B]. Lunge to the left again and repeat. Switch sides to complete set.

Go to shape.com/playlist to buy and download this mix and others.