Reverse Spider Curl

The reverse spider curl combines two constraints that each remove something. Lying face down on an incline bench with the chest supported places the arms in front of the body and makes momentum impossible: there is no way to help with the hips or the shoulders, so the load on the bar is the load the muscle moves. The pronated grip then puts the biceps at a mechanical disadvantage and hands the work to the brachialis and the brachioradialis, the muscles that add thickness to the upper arm and the forearm. Combined, they produce one of the most honest arm exercises there is, and one of the least forgiving. The weights will be very light compared with a supinated curl, which is the price of removing every form of assistance. Set the bench at a shallow angle so the arms hang clear of the floor, and choose an EZ bar over a straight one if the pronated grip bothers your wrists.