Hammer curls target the brachialis muscle ... strengthening the muscle for improved shape. Hold a dumbbell with both hands and lift it overhead, keeping your elbows close to your ears.

Stop wasting your time on ineffective arm exercises. We reveal six essential moves for sculpting bigger, stronger biceps and triceps.

Curl the dumbbell up ... Return to the start. Why: The dumbbell extension is a classic triceps move—but the way most guys do it, with the weight overhead, is often ineffective and performed ...