This exercise is called the Punch Crunch, as you advance it will be called a Power Crunch when you are able to hold your body up in a “V” shape. For the Beginner level, you can simply fold your knees and punch as far as you can across your torso. If you are comfortable enough to cycle your legs, go for it.

In the Advanced level, you will sit on your butt with your body in a “V” shape while proceeding with the same motion and cycling your legs. For the Freak of Nature level, you will do the same thing, but add weights such as ankle weights, weighted vest, and dumbbells while proceeding with the same motion.