dumbbell lying supination

Lie flat on a bench with your feet flat on the ground.

Hold a dumbbell in each hand with your palms facing up and your arms fully extended.

Keeping your upper arms stationary, curl the dumbbells towards your shoulders by contracting your forearms.

Pause for a moment at the top, then slowly lower the dumbbells back to the starting position.

Repeat for the desired number of repetitions.