Well, yes, OK, we all know the differences, many of them delightful, between teenage boys and girsl: they’ve grown out of the stage of being either snails and puppy dog tails or sugar and all things nice and are growing into reasonable simulacrums of adults. But as always when sex (or if you prefer, gender) rears its ugly head we do need to realise that while there is equality, that’s not quite meaing the same. As PJ O’Rouke has pointed out there are times when it’s vital to note the differences between men and women, as, for example, when attempting to make babies. There are also times when the differences are not important, like when trading bonds.

It would appear that one of those times when the differences are important is when teenagers play sport. Now we already do this at least in part: we know that boys tend to be faster and stronger, so there are few sports with mixed teams. But there are other more subtle differences that we should take note of too:

Girls and boys diverge in their physical abilities as they enter puberty and move through adolescence. Higher levels of testosterone allow boys to add muscle and, even without much effort on their part, get stronger. In turn, they become less flexible. Girls, as their estrogen levels increase, tend to add fat rather than muscle. They must train rigorously to get significantly stronger. The influence of estrogen makes girls’ ligaments lax, and they outperform boys in tests of overall body flexibility — a performance advantage in many sports, but also an injury risk when not accompanied by sufficient muscle to keep joints in stable, safe positions. Girls tend to run differently than boys — in a less-flexed, more-upright posture — which may put them at greater risk when changing directions and landing from jumps. Because of their wider hips, they are more likely to be knock-kneed — yet another suspected risk factor.

This divergence between the sexes occurs just at the moment when we increasingly ask more of young athletes, especially if they show talent: play longer, play harder, play faster, play for higher stakes. And we ask this of boys and girls equally — unmindful of physical differences. The pressure to concentrate on a “best” sport before even entering middle school — and to play it year-round — is bad for all kids. They wear down the same muscle groups day after day. They have no time to rejuvenate, let alone get stronger. By playing constantly, they multiply their risks and simply give themselves too many opportunities to get hurt.

The implication of all this is that male and female (or boys and girls if you prefer) sporting programs should be differently designed in those teenage years. While boys might be encouraged to find their best sport and stick to it, girls probably should not: they should be encouraged to be athletic, of course, but in a much more varied manner.

The things we continue to find out, eh?