I will never forget the day I tried zumba for the first time last year. I felt just fine after the class, but the next morning I couldn't get out of bed. I ended up with the worst flare that I have ever had! My hips and SI joint flared for the next 2 months, and then continued to give me moderate pain for another 6 months. What made it weird to me was that I have been exercising and quite active for the last 6 years, so it wasn't due to over-doing it. I had to stop tap dancing about 4 years ago because of the joint pain, so it looks like for me, dancing is not something I can continue with.
Everyone is different, so be careful with the activities you choose. You may find that zumba and jazzercise work for you. I am sad I can't dance anymore, but at least I am still able to remain active in other ways (recumbent bike, gardening, pilates).
Psoriatic arthritis dx 7/2013, minus the psoriasis. SI joint, hip, knee, elbow, and foot pain since 2006. HLA B27 positive, mom has AS. Currently on Predinsone and will start drug trials in September.