Bicep curls are a fundamental exercise for building strength and size in the biceps. To perform this exercise, stand with your feet shoulder-width apart, holding a dumbbell in each hand with your arms fully extended at your sides. Keep your elbows close to your torso and curl the weights upward by flexing your elbows, ensuring that only your forearms move. Squeeze your biceps at the top of the movement, then slowly lower the weights back to the starting position. Maintain a controlled motion throughout the exercise to maximize muscle engagement and minimize the risk of injury.