STARTING POSITION:
Select the appropriate resistance in the weight stack. Stand straight with your feet at shoulder width apart. There should be a cable bar that is attached to a low pulley. Grab it at shoulder width apart. Your palm should point towards the roof. Keep the elbows close to the body. Contract your pelvic floor and core while keeping your chest up. Contracting your biceps, bend your elbows around 90º.
MOVEMENT:
Fully bend your wrists making sure you don't move any other part of your body. Return to the starting position in a smooth movement while you inhale.
TIPS: The exercise key is quality over quantity. The trick is to perform the exercise using proper form.