Muscles Targeted: Torso
If you want to be strong and powerful then you need to have a strong Torso. This means you have to do more than crunches and leg raises. You need to do heavy torso training as well as hitting the trunk from all angles.
The Side Raise on the GHR is a great movement for the Side Obliques. I guarantee this will work better for you than that sissy movement where you lay on the ground and drop your knees to the side and crunch. Save that one for the ab class you will never need to take.
Hope up on the GHR and hook you feet under the heal pads with you hips resting on the GHR pad. While keeping tension on the outside leg bend to the side until you feel a stretch in the side obliques. As you crunch up keep very tight contraction on the abdominal and try to flex the side obliques as hard as you can.