Try this if you are in need of another exercise to tighten those abs and increase core strength. While seated with your legs extended lean back against the wheel so that it's lined up to the middle of your back. Roll back and over the wheel so that your shoulders are on the floor. Tighten your core by pulling the belly button into the ribs and lift and lower your legs just using your abdominal muscles. After you finish with your abs, use the wheel to roll out your back. It's a great way to balance everything out!