The biceps brachii consists of two muscular heads: the short and the long head. Functionally, the biceps can do two things: flex the elbow and supinate the forearm. Supination is simply the act of turning the palms face up. The dumbbell curl is a classic biceps exercise. The following are instructions for how to perform the dumbbell curl:

From a standing position, hold two dumbbells by your sides. Your wrists can either be in a neutral position or facing forward. Next, raise both dumbbells up to shoulder height. As you do so, ensure your palms are face up. Then slowly lower the dumbbells back to the starting position. Repeat the exercise as needed.