This upper-body workout from Men’s Health Fitness Director B.J. Gaddour is incredibly simple and ridiculously effective.

All you need is one dumbbell and 20 minutes.

You’ll perform 10 reps of the single-arm chest press every minute on the minute for 10 minutes straight. Then you’ll follow the same protocol for single-arm supported rows.

The routine packs a ton of chest and back work into a short amount of time, says Gaddour.

And since you’re working each side of your body independently, you’ll kick your stabilizing system into action, too, he explains. This improves coordination, chisels your core, and corrects muscle imbalances between sides.

Watch Gaddour perform the workout in the video above. Then grab a dumbbell—one that’s challenging to press and row for 10 reps—and give it a shot.