They say you only weigh one tenth of your body weight when you're in water--that would make swimming an ideal exercise for someone with RA. It's true. I have moderate-severe RA and I breast stroke 132 lengths of my forty foot pool every day (that's a mile). There's no weight on my joints and I hardly notice any pain. I do this even when I'm having a small flare. I do stretching exercises before entering the pool and when the temp falls below 75 degrees I don a Stohlquist shirt (kinda like a wet suit). Then I finish off my routine by jumping into a 100 degree warm hot tub for twenty to thirty minutes. I used to run when I was a teen--young adult but now that would be too much pounding on the joints. Swimming is a wonderful cardiovascular substitute for joint-pounding aerobic exercise. When I was first diagnosed with RA I didn't feel like exercising at all--I was very fortunate to have discovered swimming.