Many arm exercises look simple, but looks can be deceiving. Sure, it seems like you just pick up a dumbbell and curl the damned thing, or do the same with a barbell or cables. HUNTER'S HACK ROTATE YOUR WRIST
Even your grandma has probably heard of dumbbell curls, but the secret sauce to making this timeless biceps exercise particularly appetizing is a little hand rotation. It seems like such a small thing, but if you concentrate on internally and externally rotating your hand during the curl, you'll ensure that you're really stretching and working the muscle.
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