I don’t have a lot of time to write this morning, what with preparing for the afternoon’s practice and worrying about what makes sense for the sixty kids at my school who have shown up for cross country this fall.

Sixty kids — that’s 12% of the school population. When we try to spread out to stretch, we take up half the quad.

It’s not just at my school: cross country is a popular sport in high school (I mean “popular” in the sense that lots of kids participate, not “popular” in the sense that those who participate are the cool kids… ). According to the latest survey by the Massachusetts Interscholastic Athletic Association (MIAA), over 12,500 high school boys and girls run cross country each year. Although that doesn’t compare with the big three of soccer, basketball, and baseball/softball, it does make interscholastic cross country more popular than swimming, tennis, volleyball, skiing, and golf.

But unlike for those sports, interest in running cross country beyond high school and college evaporates almost completely, and this is a strange paradox, because running is immensely popular among adults. In the U.S., millions of people participate in road races each year, and in 2013, there were more than half a million who finished a marathon. If cross country is so popular among high school kids, and distance running is so popular among adults, why don’t more adults run cross country races?

Perhaps it’s more difficult to stage a cross country race? I would guess that there are few venues for hosting an off-road event, compared to the endless expanse of paved roads available for local road races. On the other hand, the last few years has seen a steep increase in the number of people participating in Tough Mudders, and other military-style obstacle course events.

Perhaps it’s concern about safety? Maybe race directors are concerned with sprained ankles and other hazards of racing over hill and dale… but, again, cross country is fairly tame compared to the gratuitously dangerous things people will do nowadays.

Maybe runners are too obsessed with their times, and being able to compare races with more precision than cross country allows. It’s true that runners are obsessed with numbers, but it’s also true that there’s a lot of variation in road race courses, and if runners really cared about precision, they’d be more interested in running track races.

No, I think the real reason is that for all but a few of those thousands of high school cross country runners, it’s not really an individual sport at all — it’s a team endeavor. There’s nothing quite like facing a cold, wet, muddy course as a team — and when you’ve graduated, and have to do it on your own, well, interest wanes. If you’re in love with off-road running, you’ll run longer and gnarlier courses (think trail marathons). If you’re a fan of tough terrain, you’ll rise to the challenge of mountain or fell running.

And so the humble 5k cross country race on the local golf course will be abandoned by all. the kids who weren’t much into running anyway, will drift away from the sport, or maybe find some pleasure in running local 5ks. The hard-core runners will find something harder core, and will scoff at the tame ups and downs of the courses that seemed so challenging, when they were just kids, racing with their friends — and when they were wet and cold and happy.