Looking for a quick, simple workout that you can whip through in about 20 minutes? We'll do you one better: How about a five-minute workout?

Yes, it's possible—and it'll pay major dividends, helping you burn calories and chisel away body fat in about the shortest amount of time we can imagine for a single workout.

Start by warming up with high knees, a deceptively difficult cardio blast made even more challenging by the fact that the rest periods regress with each set. Run in place, driving with your legs and pumping your arms. Each knee should rise above hip level. Rest 20 seconds after the first set, then 15, then 10.

Then it’s on to two circuits that alternate training for the upper and lower body, allowing one area to recover while the other works. Finally, you’ll finish with burpees—possibly the most exhausting body-weight exercise—then jumping jacks, which is your cooldown. Perform the exercises for time rather than reps—this ensures that you can adjust the pace to your own fitness level. (For example, if you can’t do many pushups, we won’t ask you to do, say, 10. Just do as many as you can in 20 seconds.) Try to keep track of how many reps you get on each move so you can track your progress.

Each exercise is demonstrated on the following slides.