And now you have me scared. I've recently had a couple of accidents (skiing, not biking) and have been sitting for unusually long periods, though never for more than 1-2 hours. Now I've developed weird cramping in my right quad - like 10% of the muscle and always in the same place, and usually after I just get up from sitting and go down stairs. Never had anything like it. Seems to be getting worse. I'm trying to get back to it and have started doing easy roller rides and it even cramps on the rollers, though I can ride through it. This morning I went for a walk and it cramped then, too.