Dumbbell curls are a popular strength training exercise that primarily targets the biceps, the muscles located at the front of the upper arm. To perform this exercise, you hold a dumbbell in each hand with your arms fully extended at your sides. As you curl the weights upward towards your shoulders, you engage your biceps, then lower them back to the starting position. This exercise can be done standing or seated and is often included in weightlifting routines for building arm strength and muscle definition. Proper form is essential to avoid injury and maximize effectiveness, so it's important to keep your elbows close to your body throughout the movement.