A couple of month's ago, Men's Health asked Alwyn Cosgrove, C.S.C.S.—one of the world's top trainers—to create a cutting-edge fat loss program forMen's Health. And, of course, he obliged. But a curious thing: One of the workouts in the plan featured just two exercises.

That's right: When asked to create a super-effective, calorie-torching routine, Cosgrove gave us a workout that had readers do only a dumbbell swing and a squat thrust. This confused some folks, who wondered, "How can you lose fat with just two exercises?"

Kettlebell (or Dumbbell) Swing
Bend at your hips, and hold a kettlebell (or dumbbbell) with both hands at arm’s length in front of you. Now, rock back slightly and “hike” the kettlebell between your legs. Then squeeze your glutes, thrust your hips forward forcefully, and swing the weight to shoulder height. Allow momentum to swing the weight—you're not trying to actively lift it with your arms. Reverse the movement, so that you swing the kettlebell between your legs again. Make sure you don't round your lower back at any time; it should stay naturally arched when you bend at your hips. Continue to swing back and forth. Watch the video below to see fitness expert David Jack show you how to do the kettlebell swing with perfect form: