Attach cable ankle straps to both ankles, then attach ankle straps to cable. Lie supine on floor, mat, or bench back far enough so cable is taut. Grasp support behind head.
With knees straight, raise legs by flexing hips until thighs are just past perpendicular to torso or before hips raise off of mat. Return until hips are extended. Repeat.
Rectus Abdominis and Obliques only contract dynamically if actual waist flexion occurs. With no waist flexion, Rectus Abdominis and External Oblique will only act to stabilize pelvis and waist during hip flexion. It may be necessary to completely flex hips before waist flexion is possible; see Cable Lying Leg-Hip Raise. Knees can flex along with hips to decrease intensity; see Cable Lying Leg Raise. Also see Spot Reduction Myth and Lower Ab Myth.