wow this is an old poll, not sure how it ended up on top, but anyway...
My parents put me on skates when I took my first steps (dad played hockey, mom skated but just for fun, they met at the rink), and I've been skating ever since.  Competed on a national scale (synchro team and ice dance) from the time I was 10-20, competed internationally in high school in synchro.  Took two years off jr/sr year of college due to lack of time but started competing again last year.  
Also did color guard in high school, drum corps, and college marching band (spun rifle), which I have to thank for my killer shoulders and arms.  Not dorky band...we were hard core.
Ran cross country/track in jr high/9-10 grade, trained with team but didn't do meets jr/sr year becaue it conflicted with skating.
Also swam my whole life and was on my college's synchronized swimming team.  
Also played softball in summers since I was 8.
Honestly, 99% of the muscles on my body are from sports.  I build muscle easily and can get away with not lifting for a while and still maintain it.  Problem is I have a hard time losing fat.