2. Yes, cycling develops 3 of the 4
quad muscles (you've got a number of other muscles in your leg too). The muscle in question is the Vastus Medialis ... the quad muscle on the inside of the leg.
That muscle doesn't become tight, what happens is that the knee doesn't track correctly, which can lead to knee problems, particularly patello-femoral syndrome.
http://www.ultracycling.com/training/centuries3.html
