There are many ways you can burn calories in the gym. Most involve some combination of dumbbells, BOSU balls, landmines, TRX straps, and a serious understanding of how to use all that crap.

But what if there were one exercise that could take the place of an entire workout? A single move so insanely tough that it essentially functioned as a full workout? Do you think you could handle it? Could you do it for 20 minutes straight?

According to research from the University of Wisconsin, La Crosse, the exercise you’re looking for requires only one piece of equipment—a kettlebell—and one maneuver: a snatch. With the kettlebell snatch, you'll quickly learn how to burn calories efficiently and effectively.

In the study, researchers found that men and women who performed 15-second intervals of the kettlebell snatch burned 20.2 calories per minute. That’s the equivalent to what you’d burn running a six-minute mile.

“That’s about as good as you get in terms of energy expenditure,” says researcher John Porcari, Ph.D., director of the exercise and health program at La Crosse. That’s because the kettlebell snatch hammers virtually every muscle in your body. Plus, when you push the intensity, you create a powerful after-effect. Your also body burns calories in the process of repairing your muscles, clearing workout byproducts from your system, and restoring your body temperature to baseline, Porcari says. That’s on top of those 400 calories you expend during your sweat session.

So consider this your challenge: One exercise, 20 minutes, 400 calories—or more. Get ready to burn calories faster than ever before.

The Workout

Following a brief warm-up (walking, cycling, and dynamic stretching are good), grab a 12-, 16-, or 20-kg kettlebell—whatever you can comfortably lift over your head. Then set a timer to go off at 15-second intervals. (We like the Interval Timer app, available from iTunes or Google Play.) In that amount of time, perform as many kettlebell snatches as you can with your dominant hand. Then rest for 15 seconds, and repeat the move with your non-dominant hand. Repeat that circuit—15 seconds on, 15 off, for both hands—for a total total of 20 rounds, or 20 minutes.

Remind me—what’s a kettlebell snatch?

Stand tall with your feet hip-width apart, holding a kettlebell between your legs with one hand, palm facing your body. From here, push your hips back and bend your knees slightly to swing the bell back between your legs. Then, quickly and explosively, straighten your hips and knees, and then your ankles, to swing the bell in front of you and up over your head. (If you generate enough power, your feet may briefly leave the floor.) The swift movement should propel the kettlebell over your fist, and you’ll settle back into a quarter squat as you catch it against the outside of your arm.

Once you have your balance, stand to finish the move. Now slowly lower the bell to your shoulder and then return to the starting position. That’s one rep.

If you’re new to this lift, work on perfecting it before pushing your limits with high-intensity intervals, Porcari says. Your form needs to be tight before you accept this 20-minute challenge or try out any other workout with kettlebell snatches.

Want a workout you can do anywhere? Download the Spartan Bodyweight Training Plan.