The arm curl or biceps curl is a highly recognizable weight training exercise that utilizes dumbbells or barbells, or even kettlebells, to work the muscles of the upper arm, the biceps, and to a lesser extent, the lower brachialis and brachioradialis. Amazon.com : Valor Fitness CB-6 Adjustable Arm Curl Bench : Preacher Curl : Sports & Outdoors This article will shed some light on the science of how many sets….