Place weight between ankles or use no weight. Grasp and hang from high bar.
Raise legs by flexing hips and knees until hips are fully flexed. Continue to raise knees toward shoulders by flexing waist. Return until waist, hips, and knees are extended. Repeat.
Exercise can be performed without added weight until more resistance is needed. Also see Hanging Leg Hip Raise with Ab Straps. Rectus Abdominis and Obliques dynamically contract only if actual waist flexion occurs. With no waist flexion, Rectus Abdominis and External Oblique will only isometrically contract to stabilize pelvis and waist during hip flexion. It may be necessary to completely flex hips before waist flexion is possible. See Spot Reduction Myth and Lower Ab Myth. Also Weighted Hanging Leg Raise.