When I was 13 I ran my first marathon. I ran my first half-marathon when I was 12, a few months before. I trained with a youth marathon/half-marathon group. Now I am 15 (almost 16) and I run cross country and track for my high school. I've never been significantly injured from training beyond minor aches and pains.

Most of the people who are strongly set against long distance running for kids (there will probably be some in this thread) do not understand that you don't have to do many miles per week to complete a marathon or even a half marathon. When I ran my first marathon (seventh grade), my training looked like this:

Mon, Tues, Thurs: runs from 2-4 miles each day Sat: A long run every other week from 4 miles to 22 miles (increasing by 2 miles each run). The other off weeks I ran 6 miles.

I did this for two years (7th and 8th grade) with the summer months completely off. For the marathon I ran 4:34 the first year and 3:53 the second. By the end of the second year I ran a 1:34 half marathon. Obviously these times aren't that great, but most of the kids I trained with, including myself, were rarely injured. I have seen much more injuries in my year and a half on cross country/track.

Runners will usually say, "what's the point of running so long so young?" "why are you doing this?" Well, I guess there's no easy answer to that question, but it's probably something to do with a love to run.

That said, if I had the choice to re-evaluate my decision, I probably would have decided to join a private track team. But that is something that is very individual for your kid... He needs to decide whether he is more interested in having fun running --like this half-marathon-- or if he wants to be more competitive.