Imagine an exercise that offers big cardio benefits, works every major muscle group, and torches mucho calories. That’s a burpee (aka, a squat thrust) in a nutshell. Developed in the 1930s and used by the military to test the fitness of World War II army recruits, burpees use your own natural body resistance to tone and tighten. Like plyometrics, they’re all about explosive power and developing agility, too. Fitness buffs have been doing them (and love/hating them) for ages, and trendy fitness gurus are getting on the burpee bandwagon now, too—Demi Lovato’s trainer Joey Rubio gave a shout out to burpees recently.

The best thing about burpees: you can do them pretty much anywhere, no gimmicks or gear required. They’re insanely easy and strangely kind of fun, even for exercisers who say they loathe the repetitive moves that remind them of high-school gym class. Sports medicine physician Jordan Metzl, MD, author of The Exercise Cure, has broken down the burpee into four simple steps—each should be done in one quick motion with no breaks.

Step 1: While standing with your feet hip-width apart, squat down and place your hands on the floor in front of you, palms down.

Step 2: Jump your feet back, arms extended, so your body is long and symmetrical in a plank position.

Step 3: Pull your legs back under you so you’re back in a squat position, your palms face down against the floor.

Step 4: Stand and jump straight up into the air, your arms stretched out toward the ceiling, landing back on your feet.

Aim for at least two sets of 10 burpees in your next circuit workout—four sets of 10 if you’re in top shape. And if you feel like an extra challenge? After Step 2, when you’re in a plank position, do a push-up before moving on to Step 3, suggests Dr. Metzl.

For more great total-body toning moves, check out these intense workouts that'll get you sweating in no time:
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