[lordCarbonFiber]

Ignoring why the WSA chose 5nmol/L over something closer to the average cis woman's upper quartile (which is closer to 2 [45ng/dL as seen in [0]], not .6 as you're implying with the 7.5x figure), Im not sure what their reasoning is on that without more research.

Trans women don't tend to have testosterone levels that high anyway, and if they did their doctors would be worried about it. Obviously not a comprehensive study but, have the testosterone levels of a trans woman [0] (she's relatively normal, other than the fact she insists on debating strangers on the internet). That's ~.4 nmol/L (why sports and medicine use two different measures is also very confusing, unit conversion here [1]. Given the advantages testosterone gives in sports [3] I'd wager most women competing aren't hovering around the minimum levels (which is where most trans women are going to be by virtue of how anti-androgens work). Instead of unscientific blog spam, how about a study published by the National Collegiate Athletic Association [4].

Basically as the knowledge of the underlying science grows the idea of simple binary for fair sporting competition makes increasingly less sense, I wouldn't be surprised if elite institutions started to drift more toward "hormonal weight classes" (and so thinks these scientists [4])

[0] https://imgur.com/a/z9DR2cD

[1] http://unitslab.com/node/136

[2] https://sci-hub.tw/10.1210/er.2018-00020

[3] “[t]he available, albeit incomplete, evidence makes it highly likely that the sex difference in circulating testosterone of adults explains most, if not all, the sex differences in sporting performance.” https://sci-hub.tw/10.1210/er.2018-00020

[4]“[a]ny athletic advantages a transgender girl or woman arguably may have as a result of her prior testosterone levels dissipate after about one year of estrogen therapy.” https://www.ncaa.org/sites/default/files/NCLR_TransStudentAt...

[themgt]

Caster Semenya is not transgender and has not had testosterone blocking hormone therapy, which is what these regulations/debates are about.

I'd wager most women competing aren't hovering around the minimum levels (which is where most trans women are going to be by virtue of how anti-androgens work). Instead of unscientific blog spam

Again, Semenya is not transgender[1] and her T hormones are not hovering around the minimum levels, which is the entire reason for the ongoing debate. The "unscientific blog spam" was referencing the IAAF study of competing athletes[2]

not .6 as you're implying with the 7.5x figure ...

which indeed showed the average T level for 1332 female athletes was 0.67. 5 / 0.67 = 7.46

[1] https://www.washingtonpost.com/arts-entertainment/2019/05/03...

[2] https://sci-hub.se/https://pubmed.ncbi.nlm.nih.gov/28673896/

[lordCarbonFiber]

So, first off, that number is not the average, it's the median. Quoting from Table2 "Data are presented as median (25th percentile–75th percentile]." The paper isn't on nonfree testosterone in general, but in the opening statement the implication is the tail is rather long "Among the 1332 female observations, 44 showed an fT concentration >29.4pmol/L.17 Twenty-four female athletes showed a T concentration >3.08nmol/L which has been calculated to represent the 99th percentile in a previous normative study in elite female athletes."

The performance advantages they measured, in the events inwhich there were any, are explicitly linked to fT not non free testosterone and even then aren't being presented as causative.

"Our study design cannot provide evidence for causality between androgen levels and athletic performance, but can indicate associations between androgen concentrations and athletic performance. Thus, we deliberately decided not to exclude performances achieved by females with biological hyperandrogenism and males with biological hypoandrogenism whatever the cause of their condition (oral contraceptives, polycystic ovaries syndrome, disorder of sex development, doping, overtraining). As a consequence, the calculated mean fT value in the present study is higher than the 8.06pmol/L median value previously reported in a similar female population."

They certainly don't appear to be arguing that hyperandrogenism in women should be a disqualifying condition. Especially in running events like the ones Semenya competed in since the performance gains appear most significantly in the throwing events.

"Our hypothesis is that ...androgens exert their ergogenic effects on some sportswomen through better visuospatial neural activation."