cable standing crunch (with rope attachment)

Attach a rope to a cable machine at chest height. Stand facing away from the machine with your feet shoulder-width apart. Hold the rope with both hands and bring it behind your head, keeping your elbows bent. Engage your abs and slowly crunch your torso forward, bringing your elbows towards your knees. Pause for a moment at the top of the crunch, then slowly return to the starting position. Repeat for the desired number of repetitions.