SETUP: Take a D-handle in each hand then step forward away from the stack, letting the cables pull your shoulders back to create an angle where your elbows naturally want to sit behind the line of your body. This places the biceps in their lengthened state, allowing you to train them through a full range of motion without interference from other muscle groups.
REP: Keeping that elbow position, start curling the weight by squeezing your biceps hard until you can’t get them any higher.
TIP: If you have one arm noticably stronger than the other, you can smooth it out by doing a behind-the-back cable curl (the single-arm version of this exercise).