If you live in an area where there is a pool, I'd say, jump in girl, best darn work out and no impact like on land! most areas now have water arobics, deep water would be perfect for you, as you wear a belt and never touch bottom!! Ladies and men of all sizes go, it's awesome, not to mention really good for toneing muscles, and you get a cardio as well.

Good Luck
( geez, how can you tell I've been addicted to water exercise for more years than i want to say!)

Kathy