dumbbell lying pronation

Lie flat on a bench with your chest facing down and your arms extended straight down, holding a dumbbell in each hand.

Rotate your palms so they are facing up.

Keeping your upper arms stationary, exhale and curl the dumbbells as you rotate your palms to face down.

Inhale and slowly lower the dumbbells back to the starting position.

Repeat for the desired number of repetitions.