The fitness ball? what are some good exercise that i can do to strengthen my core? by gerben | 10-Apr-03 | Body | 1 comment Related Blogs 1 Comment mholtz on 2010/04/03 at 19:03 I bought a great dvd by Denise Austin called Shrink your female fat zones and it uses the ball to exercise the whole body. The dvd is a great workout and I saw a difference in my body within three weeks. It is challenging but after a couple times it starts to be a really fun workout. You can find her dvd, which are all good, on ebay or amazon. Those sites often have them for a better price than the stores.