Many studies show with in ~10% female ranges of ability , but, having more fast twitch muscle fiber and bone mass from male puberty if they went through it. Bone mass does eventually drop to female levels but over decades not years so athletes would likely be out of athletic prime before that happens. Studies showing more dramatic results that stand out in my memory that lean toward transwomen outperforming transwomen are studies done on military veterans comparing to general population metrics of muscle mass for athletic activity levels also done with a very low population count I believe they only looked at under 300 trans women. Regardless we need more research, but there are a comically small amount of trans athletes seeking professional level sports, like I think <20 for all college level for instance.

Anecdotally, I found as a deskjob, pilates and casual weight lifting trans woman, I lost dramatic amount of strength and muscle mass. 20 pounds now feels like 50 pounds did for myself pre-transition. I usually participate with women and the instructor/personal helps with modifications usually aimed at women just getting into fitness. Running joke amongst friends is how easily I am outperformed by my female friends at the gym/pilates/etc. However, that's since my body is low testosterone even for females, its checked twice a year because of it, normally It's once a year for most trans people. Other friends retained a lot of their strength, but are mechanics, so its really situational in my opinion, and its a super hard and interesting topic of research because of it

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

Regularly. It's the competing women who are complaining, though. They feel it is unfair to compete with men.

"born as" (not sure the best way to phrase it)

The usual term is "cisgender", or "cis" for short.

"Cis" and "Trans" both come from Latin; the former means "the same side of" and the latter means "the other side of". If you are happy to be on the same side of the gender binary as what you were assigned when you were born then you are "cisgender"; if you are unhappy with that state of affairs (regardless of how much work you have put into changing it) then you are "transgender".

Certainly some of the high profile cases have been fairly absurd. A mid-tier male athletic transitions, and then blows the female record out of the water and gets gold. What I don't know is whether there are wider stats rather than some really big notable cases. It wouldn't surprise me, I just don't have the facts at the moment.

> 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.

There is no standard 'trans athlete'. Every case is different.

Transition is a process. Potentially a long one without a clear point of completion. Which makes things more complicated.

No idea on the hard data. but... We classify competitions for a reason. The competition is more interesting when the competitors are categorized into similar ability.

You can't bring your formula1 to a touring car race just because you feel like it is a touring car.

Personally I think at the top level there should be an unlimited class. within the rules of the sport anyone can enter, then at various lower prestige levels participation is limited according to some parameter.

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

No, both because there are very few trans athletes in competition, and because trans athletes (except trans women who have not started or are less than a year into hormone therapy) have net athletic disadvantages, when considering all factors relevant to performance in almost any real sport, compared to cisgender people of the same gender identity.

I mean, if you had a sport that isolated grip strength alone, trans women would have an advantage over cis women, but aside from rather contrived cases like that, they don't.

There's a reason the poster woman for the political movement around this in the US is a cisgender woman whose story of "unfair competition" is tying with a trans woman for fifth place behind four other cisgender women (and having to hold a sixth place trophy in photos, since there were not duplicates on hand for the same rank) in an intercollegiate swimming competition.