Really fidgety what could it be?

Almost all my life I've been very wiggly and fidgety, since the time I was born. It never really bothered me until I hit high school this year. I am constantly fidgeting! I twirl my legs, bite my nails, bounce my erasers on the desk, click my pens, doodle, squirm in my seat, and twirl my pens/pencils. I find it pretty hard to concentrate sometimes, not always. I seem to have tons of energy! I surf, bike, and run track (long distance) and it never wears me out. I go to bed at maybe midnight and wake up at five, no trouble. When I have to sit still, though, I just can't! It's starting to be an issue. What is this, if anything? I'm 14.