Please note that while I have done a good amount of research about testosterone and its effects physiologically, I am not a doctor or a biologist by degree. And, while I do understand the NCAA's policy on trans athletes having swam as a transgender man on a D1 team, I do not speak for the NCAA. These comments are my interpretations.
I competed for Harvard Men’s Swimming from 2015-2019. Harvard Swimming a Division 1 NCAA program governed by the NCAA (National Collegiate Athletic Association).
The NCAA's policy for the inclusion of transgender athletes, titled the “NCAA Inclusion of Transgender Student-Athletes” was published in 2011 shortly after Kye Allums, the first openly transgender collegiate athlete in the NCAA, came out in 2010. (Kye Allums competed for GW's women's basketball team as an openly trans man.)
The NCAA policy is segmented into two parts: pertaining to folks assigned female at birth (trans masculine folks like me) and folks assigned male at birth (trans feminine folks). (See my page regarding trans terminology if these terms confuse you.)
As of 2015, the NCAA policy is mirrored by the IOC - the International Olympic Committee. This means that the Olympics follow these rules as well.
The NCAA and IOC rules are as follows--
If you are assigned female at birth:
If you are assigned male at birth:
There are no surgery requirements of any kind for anyone. All regulations are based on hormone levels as stated above. Having or not having a penis does not significantly impact one's athletic ability.
For more about testosterone, visit my page on testosterone.
For more on trans folks competing in sport, check out this post:
A few more relevant posts: