My symptoms are fairly mild now and I never had symptoms severe enough to require rx'd meds, except for a few nights during the worst time.
I did eat way too much Advil/Motrin when trying to continue at work..

I've used treadmill, elliptical, exercise bike with no problems, I don't hold on to the support bars continuously, but the elliptical does have the arm movement support/handles- it is a smooth movement and it works out OK for me, more so than static hold positions.

I tried Curves a few times but having to change to the next machine so quickly was a pain as well as the equipment could be padded better and smoother operating.
I wouldn't recommend it as most is resistance or magnet driven, and the one size fits all approach.

I can do most any normal activity, but I do avoid having my arms up overhead & a lot of looking up (some c spine bone spurs)
I also avoid hand writing LOL the fine finger coordination is shot..

I just got some yoga DVDs from the library so I plan to see if there are any that work for me.