Sit on the preacher bench with a dumbbell in each hand.
With your elbows flexed, place the backs of your upper arms flat on the arm rest.
Pronate your wrists (rotate them so that your palms face away from you).
Keeping your wrists pronated, inhale as you lower the dumbbells until your elbows are almost fully extended.
Exhale as you curl the dumbbells back up toward your shoulders.
At the top of the movement, hold for a count of two and squeeze your biceps.
Repeat for the prescribed number of repetitions.
Comments and tips
You can perform the dumbbell reverse preacher curl with both arms simultaneously, as described, or with one arm at a time.
Positioning your elbows in front of your body and pronating your forearms, as you do with the dumbbell reverse preacher curl, puts your biceps brachii into a state of mechanical disadvantage. In this position, the brachioradialis is a stronger elbow flexor than the biceps brachii and brachialis, which is why it is the target muscle.
The long head of the biceps brachii is activated more than is the short head because the long head is more stretched in this position and can therefore make more of a contribution.