Anyone wishing to spot changes from our pre-print:
1. We included a section on pre-pubertal differences (that is, even young boys outperform young girls, thus the performance gap is not solely down to pubertal T).
2. We extended our analysis of CV capacity changes and potential impact on endurance performance (although we had acknowledged a likely effect, we have drilled deeper into mechanism).
3. We have *significantly* extended our discussion of impact on athlete transwomen and the mitigating effects of exercise (that is, moderate training can mitigate or even reverse muscle/strength loss during T suppression).
The remaining differences are minor, and represent no significant change from the pre-print.
Why male advantage in sport is not a social construct: height.
Height is a key difference between males and females. What is nature v nurture? What does that mean for sport?
Bigger skeletons are most obviously driven by longer bone growth. Key bones like those in your thigh (“long bones”) grow from their end to get longer, making you taller.
The site of bone lengthening is called the “epiphyseal plate” or “growth plate”. Here, cells divide/enlarge, making new tissue that pushes the bone ends apart. This tissue calcifies and is replaced by bone, leading to lengthwise growth.
Let’s set a concrete example: the 10 second barrier (100m sprint).
Wiki - allowing for small errors - tells me that around 200 male sprinters have broken it. We know, of course, that no female sprinter has been close (Flo Jo record 10.49s).
For the following, I’m going to ignore the premise that humans might be close to biomechanical limits over a 100m sprint. It’s just an illustration.
If we follow world record progressions, we see trends (not just in sprinting, the graph below is from a swimming event).
As the latest on Olympic boxer Imane Khelif is reported, a diagnosis of 5ARD is almost certain. I and others first raised the likelihood of this DSD a few months ago.
Understanding how the developmental biology of DSDs interacts with sports categorisation is crucial.
I spoke about this with Andrew Gold during the competition:
And I recently gave a talk at a meeting, on DSDs, male advantage and sports categorisation. I will add some slides below.
In August, we were invited by the Scandinavian Journal of Medicine & Science in Sports @WileyGlobal to make an argument for screening for eligibility into the female category.
We proposed a cheek swab screen of DNA, performed before an athlete is thrust into the spotlight, with follow up care in the case of unexpected results.
@WileyGlobal This month, two responses to this editorial have been published side-by-side.