STARTING POSITION:
Select the appropriate resistance in the weight stack. Stand up straight with your left shoulder pointing to the pulley. There should be a handle that is attached to the lowest level of a pulley. Grab it with your left hand. Contract your pelvic floor and core while keeping your chest up.
MOVEMENT:
Using your oblique muscles, bend your spine towards the right side while you exhale. Return to the starting position in a smooth movement while you inhale. Repeat the movement for the specified amount of repetitions and then repeat with the other side.
TIPS: The exercise key is quality over quantity. The trick is to perform the exercise using proper form.