Select desired weight. Stand near right side of cable cross machine, and adjust that pulley to the lowest position. Place ankle strap attachment onto the pulleys carabiner. Place strap securely around left ankle. Face away from the weight stack, and step away from it so that the weight is lifted off the stack when your left leg is extended behind you. Stand tall with abs engaged and weight balanced on your right foot. Lift your left foot off the ground, foot flexed.
EXHALE: Drive your left knee up, bringing thigh parallel to the floor as arms move in a "running" motion.
INHALE: Slowly return to the start position (with leg extended behind you), switching the swing of the arms to complete one rep.
Finish set on this leg and then switch sides.
Keep your lower back flat--make sure it does not arch. Keep your head and neck relaxed into the support. Focus on using the abs, not just the upper body, to lift.
Muscles Worked: Hip flexor