Start: Put an ankle strap around the middle of a barbell and attach it to the low pulley. Select a light cable weight. Kneel on an exercise mat with your back to the weight stack and the cable between your legs. Grab the bar with an overhand, shoulder-width grip.
Finish: Roll the bar away from you and follow it with straight arms as far forward as you can go, then roll it back. The cable helps you pull the weight back but adds resistance to the negative portion of the exercise, providing a new challenge for your muscles.