Your arthritis sounds exactly like mine! Pain free for weeks & months and then aches! Depending on the intensity and joint affected, I can usually wrap that area with a tensor and still workout but there are some days where you just can't. My type is somewhat rare: it's "palaendromic" ( or something like that? ) moves around from joint to joint and will last usually 24-48 hours. I try to push through it and remind myself that I am stronger than it is!