Swimming takes the pressure off but is great exercise. I hate wearing a swimsuit but there is a company called Junonia which makes some great plus size swimwear. I bought one and it is almost like a diving suit only it covers to the elbows and knees--loved it, squished everything tight like a seal.

Also, plain old walking works wonders. I am not large chested but I feel like my weight is strangely distributed and causes weird aches and pains.