I have been using what I call the almost upside down machine. Where you have your feet above you, under the roller, and lay down. Then you rose, hold, before slowly going back. I have got up to 80 on this one.
I am still doing the laying on the ball on your back, and bringing your torso up onto a crunch.
With the treadmill, squats and dancing at home, I am starting to increase my workouts,