Reverse Grip Preacher Curl

The reverse grip preacher curl is performed with the palm facing down rather than up, which changes which muscle does most of the lifting. Pronating the forearm puts the biceps at a mechanical disadvantage and hands the work to the brachialis underneath it and the brachioradialis along the top of the forearm, two muscles that add visible thickness to an arm and that a conventional curl trains only indirectly. The preacher bench supplies the second half of the exercise: with the upper arm fixed on the pad, there is no way to swing the torso or help with the shoulder, so the muscle receives exactly the load on the dumbbell. Expect that load to be considerably lighter than on a supinated curl. Straighten the arm fully at the bottom, without bouncing out of the stretched position.