congratulations Running mom's son!
It is just fantastic when kids enjoy keeping fit - I work in a junior school - and during pe lessons some of the kids actually panic and think they are ill, because they feel warm and can feel their hearts beating in their chests :(
I just thought I'd share with you this pic of my daughter taken a few years ago when she became under 6 champ of the midlands mountain bike series. I've never won a sporting event in my life but like you said, I must have set a good example somewhere along the way!
http://www.doubleard.co.uk/gallery/M...iz_ben_web.jpg
..and yes, she did ride in those wellies! :D