Sets: As many as needed Reps: 65
Lie back on a bench and grab the sides for support by reaching behind your head. Your body should form a straight line. Contract your abs and raise your hips up off the bench so that your legs point into the air. Lower your legs until you're about to lose the tension in your abs, and then raise them back up. Perform 65 total reps, doing as many sets as you need to (and resting as needed in between) until you hit that number.