How to Burn Fat Faster

Exercise to lose weight fast. Here’s how to push your body into the ultimate workout zone.

For almost two decades, we’ve been hearing the seductive call of the "fat-burning zone," in which you burn a greater percentage of fat calories. And, we’ve been told, you get there by doing moderate—not hard—exercise.

Turns out, it’s not that simple. The catch? When you exercise at 60 to 70 percent of your maximum heart rate, in that so-called "zone," you burn fewer calories per minute during and after your workout. To crank your metabolism, you need to push your body harder—a lot harder.

The Exertion Scale Picture your activity level on a spectrum. On one end is the effortless kind, like sitting at your desk or walking to a meeting. "When you’re not exerting yourself, your body actually burns a higher percentage of calories from fat than it does when you’re active," says Alex Koch, Ph.D., an associate professor of health and exercise sciences at Truman State University in Missouri. That’s partly why the "fat-burning zone" was so appealing—it sounds awesome. But of course that doesn’t mean sitting at your desk or wandering the halls at work will shrink your hips faster than doing jumping jacks or running a sprint will. "You’re maybe burning one to two calories a minute," Koch explains, "which doesn’t add up to a lot of fat."

Toward the other end of the activity spectrum is a superintense workout that sends your heart rate way beyond the classic fat-burning zone. At this point, your body needs quick energy, so it starts burning less flab and turns instead to carbohydrates, which enter the bloodstream faster than fat does. The upside: The harder you work, the more calories you burn. "At your max effort, you could be burning 20 to 30 calories a minute," Koch says. And more calories burned, of course, equals more pounds lost.

In fact, research shows that the harder you go, the better. "Besides burning more calories per minute, high-intensity exercise—such as intervals, in which you alternate between short, hard efforts and easy periods or complete rest—unleashes a flood of hormones, including epinephrine, which helps your body burn calories even when you’re not working out," Koch says. For example, people who cycled at a high intensity for 20 minutes torched more calories for hours after their workouts than they did after cycling at a low intensity for 30 to 60 minutes, according to a study reported in Medicine & Science in Sports & Exercise. "Exercising in the classic fat-burning zone doesn’t offer these benefits," he says.

The New Fat-Burning Zone That doesn’t mean light-to moderate-intensity exercise is out of the picture. Mellow efforts can still be part of your workout: As a warmup or cooldown, they ease your body into and out of an intense session. They also reduce stress, amp up your cardiovascular health, increase bone density, and, of course, burn off some calories.

However, to fry flab faster, follow the principles of interval training. You’ll know you’re in the zone when you combine short bursts of activity that require you to breathe so hard you can’t utter a word, followed by easier efforts that let you catch your breath. This new fat-burning zone isn’t really a single zone at all. It’s more like a cocktail of efforts that, when mixed together the right way, delivers a mega calorie crush to reveal a slimmer physique.

Try this workout two or three times a week for maximum results:

1. Pick your cardio of choice (bike, elliptical, treadmill, pool, rowing machine, or running outdoors at a park or track), and then estimate your maximum heart rate using this easy formula: 220 - your age = max heart rate. (So if you’re 28, your max heart rate would be roughly 192 beats per minute.)

2. Warm up for 10 minutes at a low intensity. Like we said, the old-school "fat-burning zone" can still fit into your workout.

3. Speed up until you’re sprinting at 90 percent of your max heart rate; continue at that pace for 20 to 30 seconds.

4. Return to a low intensity until your heart rate drops to about 120 beats per minute, usually about two to four minutes, depending on your fitness level.

5. Do another 20-to 30-second sprint, followed by another round of active recovery. Continue until you have done a total of six to eight intervals.

6. Cool down at a very low intensity (such as walking on the treadmill) for at least five to 10 minutes before stopping exercise completely.

How to Burn Fat Faster