Lets see...
My Dad had hair to his a** in HS, protested to get a more friendly locker room or something like that, and I'm pretty sure he toked it up SOME. Never went to college, never played sports. He is AWESOME though; outright hilarous, all my teammates love him. He is now 6'2"-ish and a bit over weight, but ears 6 figures from working his a** off and being tough for not going to college. (but he is working on his weight, and when I graduate HS this year my present to him is going to be a membership in the Walk Run Acomplishment Program at the running store I work at).
My Mom, like my dad, never did sports, but apparently really like to run...she jsut never got involved though because they moved so much (military kid like my Dad). Didn't go to college, but got an Assoc. Degree somewhere...
Quit working in like '99 or '00, gained some weight, now trying to lose it with my Dad. Really proud of her; present to her will be the same thing.
So really, I don't think I shold be a [good?] runner. My Dad's family is all obese adn lazy. But the one explainatory thing could be the fact that my Mom's family consists of a bunch of bean poles who have worked Kentucky farms until the most recent generation....maybe that is it.
My generation seems to be rather full of the endurace athletes, for my cousin is a National class swimmer and has won a bunch of Junior Olympics and an assortment of other random National Titles.