STARTING POSITION:
Select the appropriate resistance in the weight stack. Sit on a bench in front of the pulley. There should be a handle that is attached to a high pulley. Grab it with your right hand and place the right elbow on your tigh. The elbow should be completely bent. Contract your pelvic floor and core while keeping your chest up.
MOVEMENT:
Contracting your triceps, fully extend your right elbow while you exhale. Make sure you only move the forearms. Return to the starting position in a smooth movement while you inhale. The moving weights should not touch the rest of the stack. Repeat the movement for the specified amount of repetitions and then switch sides and repeat with the other arm.
TIPS: The exercise key is quality over quantity. The trick is to perform the exercise using proper form.