Sit on a preacher bench with a dumbbell in each hand, palms facing up and elbows resting on the pad. Curl the dumbbells up towards your shoulders, keeping your upper arms stationary and your palms facing up. At the top of the curl, rotate your wrists so that your palms are facing down. Slowly lower the dumbbells back down to the starting position, rotating your wrists back to the starting position as you do so. Repeat for the desired number of repetitions.
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