I recently suffered a minor knee sprain, but was getting antsy as I recovered. I still had some pain when I ran, but cycling was the perfect remedy. It worked out great because I could break a sweat without the pain of running. I had been mountain biking a lot recently, but a nice road tour is just what my knee needed. I still will continue to mountain bike when it's in season, but when I get older, I see myself investing in a nice road bike to keep myself in shape. I will probably go without the matching spandex shirt/shorts outfit though.