It’s time to stop thinking of the triceps as the sidekick to the biceps. The three-headed triceps brachii muscle makes up roughly two-thirds of the mass of your upper arm. Surely these muscles deserve equal time in the gym (or even more time), even if you only valued your triceps for aesthetic reasons.

But the triceps also play a key role in the extension of the elbow joint and the straightening of the arm, working with the lats to bring the arm toward the body. Try swinging a bat, racket, or golf club without the triceps. It can’t be done. Nor can a swimmer execute a stroke without the triceps, which explains why Michael Phelps, Katie Ledecky, and company have perhaps the best triceps in sports.

RELATED: The Best Triceps Workout for Beginners

Everyday movements—from signing your name to raising your hand—are impossible without the triceps. So let’s raise a glass (triceps move, too) in appreciation of the triceps, perhaps our most underrated muscles.

Actually, let’s raise a dumbbell. Or two.

How It Works: The 30-Minute Dumbbell Workout

This 30-minute dumbbell workout to build your triceps is designed as a circuit workout. We’ll hammer through four rounds of seven moves, alternating between pushing and pulling movements, so we can produce maximum results with minimal time and equipment. Do not rest between exercises, and rest only briefly between rounds of the circuit.

Pete Williams is a NASM certified personal trainer and the author or co-author of a number of books on performance and training.