https://www.apnews.com/543c78d943144874a661f31e88c1f8e6
This is an interesting situation.
Women typically have testosterone levels <2.0 nmol/l, far below typical male levels of >7.0.
Higher testosterone helps muscle development, which is an advantage in power sports (weightlifting, sprint running events, etc).
Some women naturally have high testosterone levels, closer to that of some men. It's a rare genetic trait called hyperandrogenism. It may not make much difference in ordinary life but in the context of power sports, its a genetic blessing.
It turns out that some - maybe a significant number - of the top female athletes in those power sports have this genetic trait.
The international sport body (CAS) and international track and field body (IAAF) have established a limit of 5.0 mmol/l for female athletes in certain sprint running events, of 800 meters and less. They will require women to be tested and, if needed, take drugs to lower their testosterone to the limit.
This is playing out in the case of one particular runner, a South African woman named Caster Semenya. But the rule is likely to affect a number of female athletes from various countries and of various races, who have this genetic trait.
One issue raised is, should athletes who are genetically blessed for a particular sport be penalized to level the playing field?
A woman's sprinter's testosterone being above 5 nmol/l is a genetic advantage for that particular sport, but so is a male basketball player being 7 feet tall (various NBA players) or a male swimmer being double-jointed or having a genetic trait that reduces lactic acid generation (Michael Phelps) or a female gymnast being under 5 feet tall or a male road cyclist having a VO2Max above 90 (Greg LeMond) etc.
Put that way, this doesn't seem like a particularly hard issue to me. To reach the highest levels of many sports requires being genetically blessed; >99% of people cannot do it no matter how skilled they are or how hard they work. There's nothing "genetically fair" about top level sports. To be a world class sprinter you must have the ability to build muscle mass, lots of fast twitch muscle fiber, the right build and height, lots of genetics you were born with. Weren't born with those characteristics? Too bad, the event is probably not for you - at least, not if you have to be the best in the world.
And therefore no sports body is trying to regulate VO2Max or height or jointedness.
So the reason this situation has arisen is the other issue, what is a "woman" and a "man"?
Increasingly society is trying to deemphasize that distinction by requiring equal treatment of all genders. But sport (at least human powered sport) has a rigid distinction: you're a woman and compete in women's events, or you're a man and compete in men's events. I think that distinction is necessary, or you basically eliminate top level female athletics. So, how do we define woman and man?
The traditional way is by their genitalia. This athlete, Semenya, is a woman by that standard (the IAAF required her to submit to a physical inspection). She was born with female genitalia, by the way. This is not a trans-sexual case which raises other issues.
The sports bodies are now adding another definition. You have to have female genitalia and testosterone level below that of typical men.
And that's where I'm having trouble figuring this out. Do we really need to add to the definition of woman vs man? If we do, isn't there some biological marker that is more fundamentally determinative of one's sex? It feels like testosterone was picked because it has a direct relation to athletic performance. But it seems that's the wrong reason to pick the marker (see first issue). Seems you should pick a biological marker - maybe a chromosonal characteristic - that isn't simply a proxy for performance.