Janet, one thing you might want to try if you have a pool nearby is an aquafitness class. I've always wanted to do it but I'm too chicken to go alone! My boyfriend is big into fitness and he's told me that working out in water is one of the best things you can do. Here is a website that explains it better than I can!
http://www.calainc.org/Aquafitness/aquafitness.htm