Metric Miler wrote:
From appearances you could say the testosterone is allowing Caster to have much higher muscle mass than other females. This can only be confirmed with tests. But consider that many female elites have testosterone levels that overlap with elite males.
First, thanks for posting the link earlier on T levels. Although it did not link to the actual study itself, I was able to track it down. I think the following is a great example of how researchers interpret data to create a pre-determined outcome.
In their article Debating a testosterone “sex-gap†published in the online magazine Science, anthropologist Katrina Karkaziz and sociomedical scientist Rebecca Jordan-Young question the validity of testosterone as the primary differentiator between male and female athletes. To craft their argument, Karkazis and Jordan-Young examine the contradictory results of two studies: the GH-2000 study, conducted by the IOC and World Anti-Doping Agency on 446 men and 234 women across 15 highly varied Olympic events in 2000, and the Daegu study, conducted by IAAF researchers on 849 elite women athletes in track and field from the 2011 Daegu World Championships (1). The results from the GH-2000 study showed that 13.7% of female athletes had testosterone levels above the typical female range, and 4.7% were within the typical male range. The study also showed that 16.5% of male athletes had testosterone levels below the typical male range, with 1.8% falling in the female range (1). By contrast, the results of the 2011 Daegu study showed that only 1.5% of female athletes had testosterone levels above the typical female range, directly contradicting the GH-2000 study (1).
For the males who were below normal, we know that intense training can reduce T levels in men, so let's only consider the women.
In 2000, 13.7% of females were above the normal female T level range. In 2011, it had dropped to 1.8%. Why? Read this from the article...
According to Karkazis and Jordan-Young, the Daegu study omitted them because Daegu researchers deemed “intersex†women as having hormonal disorders that made them unfit to be included in reference ranges for female athletes.
So when we omit intersex women from the data, only 1.8% of elite women were outside the normal female range. How far out were they? Were they outside by 30%? 40%? Or were they outside by 300%, as Semenya was rumored to be?
I'll try to find out the next time I have medical library access because the full study is behind a pay wall. If you have access, here is the link.
Karkazis, K. & Jordan-Young, R. (2015, May 22). Debating a testosterone “sex gap.†Retrieved May 21, 2015, from
http://www.sciencemag.org/content/348/6237/858.full