Bigger Biceps Workout (Dumbbells Only!) To hit more of the inner biceps (short head), grab two dumbbells, rotate your palms outward, and do lateral curls with a strong supination at the top. For the outer biceps (long head), lean slightly to one side and perform single-arm drag curls. And to grow the brachialis and brachioradialis, do cross-body hammer curls, bringing the dumbbell across your torso like this. Size & Shred Training program 👉🏻 deltabolic.com | Andrew Kwong