Cable Lying Alternating Bent-Leg Jackknife

Lying with the head toward a low pulley, the hands pull the cable over the chest as the shoulders curl up to meet one bent knee, alternating legs.

How to do it

Setup

Lying on the back, head toward a low pulley, the handle in both hands behind the head, legs long.

Steps

Curl up, pulling the handle over the chest, as one knee comes to meet it.
Lower the shoulders and the leg together.
Bring the other knee in on the next rep.

Common mistakes

Pulling the cable with the arms alone: the curl brings the hands forward. Letting the stack drag you back: lower slowly. Straight leg lifting off the floor: keep it long and down.

Breathing

Exhale on the crunch, inhale on the stretch.