> Do trans-athletes regularly out perform "born as" (not sure the best way to phrase it) athletes?

The closest controlled study we have on this topic is not in athletes but in U.S. military servicemembers and their standard fitness test: https://pubmed.ncbi.nlm.nih.gov/36271916/

This isn't a good study for professional athletes training for competition because the fitness test is not analogous to professional competition. They only need to pass with a reasonable score but most are not competing for the top position like in the Olympics

The study found that

> transgender females' performance showed statistically significantly better performance than cisgender females until 2 years of GAHT in run times and 4 years in sit-up scores and remained superior in push-ups at the study's 4-year endpoint.

So of the 3 simple activities they tested their performance remained higher in one test (run times) until 2 years, another test (sit-ups) until 4 years, and remained higher at the end of the limited 4-year study period in the last test (push-ups).

This study was widely circulated as "proof" that hormone therapy erases sex-based gains after only 2 years, but that's not even an accurate read of the study. It's also not measuring athletes who are training or trying to compete.

Depending on the sport, hormone therapy cannot be expected to compensate for sex some important sex differences like physical structure. Male anatomy is simply different in ways that provide different types of leverage or angles (like Q Angle, which runners will talk about, or reach, which is important to boxers)

This is a very taboo topic to discuss and honestly I'm a little nervous to even comment about it here pseudonymously. The popular culture discussion of the topic is very different than the sports science discussion of the topic, where sex differences have long been accepted to be innate and irreversible, regardless of hormone therapy.