Instructions:

1. Stand up straight with a dumbbell in each hand, palms facing forward.
2. Place your upper arms against the preacher bench and keep your elbows slightly bent.
3. Curl the dumbbells up towards your shoulders while keeping your upper arms stationary.
4. At the top of the movement, rotate your wrists so that your palms are facing downward.
5. Slowly lower the dumbbells back to the starting position, rotating your wrists back to the starting position as well.
6. Repeat for the desired number of repetitions.