Interesting. Haven't read the article, but it leaves me wondering where females with naturally high testosterone levels compete? Men's category? or not at all?
In the article, they explain how they came up with the number. A woman with naturally high testosterone - but not intersex or transgender - would almost certainly be OK.
Here's the quote with the details:
"...until last year, the policy in place said that women could compete only if their testosterone levels were below an upper limit. That upper limit, 10 nmol/L, was set up based on a study done on all the women competing in the World Championships in 2011 and 2013. The researchers took the average testosterone levels of women with a condition called Polycystic Ovary Syndrome, which was already elevated at 4.5 nmol/L, and then added 5 SD to it.
The addition of 3 SD (which created a level of 7.5 nmol/L) would have meant that 16 in 1000 athletes would exceed the cutoff. That’s why the extra 2 SD were added, to make sure that the upper limit would apply only to those with hyperandrogenism (or those who are doping).
99% of female athletes, by the way, had testosterone levels below 3.08 nmol/L. So the upper limit of 10 nmol/L was three fold higher than a level that applies to 99 in 100 women participants."
I still feel bad that if you are intersex, there may not be a category for you... I don't know if the answer is to try to run a third category, but it just feels wrong that someone may want to compete and they are told they can't, they don't belong anywhere.
While the rule was in place, intersex women were able to compete as women if they chose to do something to lower their testosterone, e.g. hormone suppressing drugs. During that time, Caster Semenya was not a medal contender. Now that she can race with her natural level of testosterone, she's considered to have a lock on Olympic gold in several events.
Some intersex women can lower testosterone levels by having their testes surgically removed. Four female athletes failed the test at the 2012 Olympics and subsequently had this surgery. It was highly controversial since athletes were having surgery simply to comply with a rule, not for any medical reason.
You're right - it's impossible to come up with a solution that seems fair and kind to everyone. I also feel bad for the women who no longer have a chance in their sport because this rule was rescinded. If they took testosterone to improve their performance, that would be doping.
From the IAAF (International Association of Athletics Federations):
"Although athletics events are divided into discrete male and female categories, sex in humans is not simply binary,” the court added. “As it was put during the hearing: ‘Nature is not neat.’ There is no single determinant of sex.”
It continued: “Nevertheless, since there are separate categories of male and female competition, it is necessary for the I.A.A.F. to formulate a basis for the division of athletes into male and female categories for the benefit of the broad class of female athletes. The basis chosen should be necessary, reasonable and proportionate to the legitimate objective being pursued.”
Also the challenge of transitioning while you are in a competitive sport, eg, all female schools and an athlete transitions.