Symptoms

Dozer, I am far from being an expert, but my guess would be that the best thing would be to keep exercising but do it a little less intensely or for a little shorter time than you had - in other words, keep moving but try to stop short of the pain.

I had never heard the word "arthritis" before (that is, I'd never heard the word aimed at me!) until this summer when a doc told me tersely that I had severe osteoarthritis in my right hip - see my post somewhere below. I was shocked. But then when I started to think back, about 5 years ago, when I'd try to get into a semi-Lotus position to meditate, my right hip wouldn't allow my right leg to relax all the way down..... and, an avid horseback rider, I'd started to hurt sitting in the saddle.

I had perceived my pain to be sometimes in my knee, sometimes groin, sometimes outer thigh. Apparently hip pain is often "reflected" elsewhere.

My mom just had a hip replacement, and they told her that pre-and post-surgery, good exercises would include things to strengthen those muscles around the hip joint - squeezing the buttocks together, squeezing the thigh muscles.

I've done a lot of googling to try to learn the differences between rheumatoid and osteo arthritis.... you might start there, to familiarize yourself with the lingo, and then find a doctor who might be able to help you more about exercise or possible anti-inflammatory meds.
Good luck!