The reverse-grip barbell biceps curls develop size and strength of the biceps. The reverse grip for this motion is an overhand grip which helps engage the forearms as well as the biceps.
Grab a barbell with an overhand grip with hands shoulder-width apart. Keep a tight posture, and stand upright with your feet about shoulder-width apart.
Keeping the upper arms steady, curl the bar up to your chest. Squeeze your biceps at the top of the motion, pause for a moment, and then slowly lower the bar to the starting position. Repeat until desired reps are completed.
Keep your elbows stationary and tucked at your sides.
Perform the movement with a controlled pace, not allowing momentum to contribute.