Funny you say that. I traveled for business all week and it's been seven days since my last ride. I usually try to ride every other day. I did 55 miles today and about an hour in my left knee started aching. It did that for the first couple weeks of this season but stopped as I rode more frequently. I could only surmise that the week off let my muscles get soft again and now I have to go through this annoying pain thing for awhile again.