I don't know if this has been mentioned before now. I really think that bike riding should improve the athletic skill. I don't understand why it doesn't. I almost never buy cars for my Sims, I would rather spend the cash on a gorgeous house. So they ride their bikes every where. If I were to ride my bike across town (which will probably NEVER happen) every single day, I would be super fit! I just think its a little impractical is all.