Pat

1) Well, that seems to depend on the individual. When some people get fit, they get toned and wirey. Other people tend to build bigger muscles. From cycling, my legs are pretty muscular and developed but not the rest of me. But as I said, I have seen other cyclists who ride hard and fast and do not have really big legs.

2) Your knees should not hurt when you cycle. In facts, cycling is sometimes used for knee rehabilitation. Your knee pain could be from a poor bike fit. Most of the time, it is from having the saddle too low. Another problem could be that you are not running a high enough RPM. A third thing is that many new cyclists just push down on the pedals. Try pedalling faster in easier gears. They do not lift their legs for the return. That means they are pedalling harder and putting more strain on their knees. Try lifting your legs on the return stroke. Lifting your legs called "pedalling in circles" reduces the wear and tear on your legs but feels a bit odd at first. I suspect that your problem is probably a combination of the three above - saddle too low, riding in gears that are too hard and not lifting your legs on the return stroke.