(NewsNation) — University of Pennsylvania swimmer Lia Thomas, 22, became the first known transgender athlete to win an NCAA Division I championship Friday but the debate around her and other trans athletes’ eligibility in competition remains a hot-button issue for debate.

Some, including tennis star Martina Navratilova and one of Thomas’ own teammates, have said the rules allowing Thomas to compete need to change. Meanwhile, nonbinary Princeton diver Griffin Maxwell Brooks, who uses they/them pronouns, told NewsNation’s Mike Viqueria that they felt the questions around Thomas’ eligibility were “nonsense.”

“I think the cause for debate is necessary. I just think that people have made a lot of conclusions based off of a one-person case study which is just not something we do in the field of science,” they said.

The considerations that go into setting the rules in competition are intricate.

In high-level competitions, separating men and women makes sense, said Joanna Harper, a member of the Loughborough University team researching transgender athletic performance.

That’s because the changes that occur with the influx of testosterone in boys as they go through puberty, and after, make their bodies more “athletic” than women’s, generally speaking, Harper said.

“Trans women who don’t go on to medical treatment before puberty will go through male-typical testosterone levels, a male puberty and all of that that entails greater height, greater musculature, higher hemoglobin levels … more muscle, all of the quote-unquote advantages that men have when it comes to sports,” Harper said.

Last month, USA Swimming announced new rules for transgender women. To compete, they must demonstrate testosterone levels below five nanomoles per liter for three years before competition. They must also provide evidence that they do not have “a competitive advantage from being born male.”

The NCAA chose not to adopt those new rules this year. They require demonstrated testosterone levels below 10 nanomoles per liter.

Hormone therapy can generally level the playing field enough for meaningful competition to take place, Harper said.

“I would say, in general, in endurance events, if we put trans women onto hormone therapy, any remaining advantages will be very minor,” Harper said.

It’s not as clear what potential advantages or disadvantages trans athletes might encounter in other sports. The data just isn’t there yet, Harper said.

“People have different benefits based on how they were raised and their bone structure and things like that, which is not only dependent on biological sex,” Maxwell Brooks said. “When we isolate Lia’s advantages as being caused by her status as a transgender person, it kind of just ignores the fact that there is a lot of genetic diversity within sexes, arguably more, that we don’t really think about in this situation because we’re isolating her identity as the prime cause for this.”

As Harper and her colleagues conduct additional research, it’s important for the general public to keep things in perspective, she said. Carefully considered rules about allowing trans athletes to compete might be appropriate at higher levels, but most people play recreationally, Harper said.

“Most trans people shy away from sports, which is really unfortunate. And then, you know, there are these people who look at successful trans athletes, and say, ‘we can’t be letting trans women into sports, period.’ And I think that’s, that’s a horrific thing that has happened,” Harper said. “And we very much need to differentiate between the science that is important for elite performance and letting trans people lead normal lives, including participating in sports.”