The ‘21s’ method is a muscle-building technique that has stood the test of time—but you rarely see it applied to anything other than biceps curls.

The concept is simple: During a set of 21 reps, you’ll progress through three different ranges of motion to focus on building strength at different phases of the movement.

You do the bottom half of the movement for the first seven reps, the top half for the next seven, and then the full range for the final seven reps.

By ironing out the sticking points at the top and the bottom of the rep, 21s can stimulate new muscle growth.

Related: THE 21-DAY METASHRED—an At-Home Body-Shredding Program From Men’s Health That Strips Away Fat and Reveals Hard Muscle

“You can apply this to any movement,” says Men’s Health Fitness Director BJ Gaddour. 

Ready to try it out? Watch Men’s Health Australia Training Advisor Cam Byrnes demonstrate how to apply the 21s technique to the dumbbell chest press.

“I recommend you do three sets with a two-minute break in between,” says Byrnes. That’ll allow your chest enough recovery time to attack the next set with max effort.