[thrower123]

When you get to the very pinnacle of athletic performance, freak genetics plays an outsized role. Michael Phelps is one obvious example to point at, or Usain Bolt, but another is Eero Mantryranta[1], who had a natural gene variant that was equivalent in effect on red blood cell effectiveness to massive EPO doping.

[1] https://en.wikipedia.org/wiki/Eero_M%C3%A4ntyranta#Genetics_...

[dspillett]

This is one of the areas where the system is heavily weighted against some female athletes. Phelps has a genetic thing that means his blood is more efficient at carrying oxygen and he is called lucky and lauded for his (still impressive) efforts anyway. A woman who naturally produces more testosterone than the normal range is either not permitted to compete or has to be "drugged down" to do so.

[ponsin]

source? I don't recall any sports that limit the amount of testosterone women can have. By women I mean people with XX chromosomes.

[beefalo]

https://www.nytimes.com/2019/05/01/sports/caster-semenya-los...

[jaytaylor]

Paywall bypass: http://archive.is/oEC0q

[dragonwriter]

Track & field (governed the IAAF):

https://www.npr.org/sections/thetwo-way/2018/04/26/606039409...

And this has, in fact, affected actual (not merely theoretical) XX females:

https://www.nytimes.com/2019/05/01/sports/caster-semenya-los...

[username90]

Caster Semenya is an XY female, she wasn't lucky she just got male genes.

[ponsin]

wow, that's crazy