PHILADELPHIA — Wearing a blue swim cap, Lia Thomas dived into the pool and sprinted ahead to the first turn. The University of Pennsylvania swimmer had already pushed through weeks of attention, online criticism and scientific debate, so nothing was slowing her down Saturday at Sheerr Pool in the final home meet of a collegiate career that had been completely unremarkable until exploding into the latest flash point in an ongoing culture war.

The 22-year-old zipped past her competitors from Yale and Dartmouth and was again first to the wall. It looked effortless, providing more proof that she’s among the best female college swimmers in the country — and more evidence that her detractors will use to say she doesn’t belong in the pool.

For three years, Thomas had competed for the men’s swimming team at Penn. After undergoing more than two years of hormone replacement therapy, the transgender woman now competes for the school’s women’s team, and her fast times have sparked a debate from the starting blocks to online message boards to cable news networks.

Thomas has shattered school records and has posted the fastest times of any female college swimmer in two events this season. She’ll probably be a favorite at the NCAA championships in March, even as people inside and outside the sport debate her place on the pool deck.

Her success has sent waves of controversy across the swimming world, too. Parents of other Penn swimmers sent a letter to the NCAA and the school last month expressing concern about the rules that allow Thomas to compete against women and the precedent she is setting, which the parents called a “direct threat to female athletes in every sport.”

“All you expect is a fair chance,” one parent said in a recent interview, speaking on the condition of anonymity to protect her daughter’s privacy. (Her daughter and other Penn swimmers, including Thomas, were not made available for interviews.) “There is no chance this year. They train hard but know that they cannot beat Lia.”

The Equality Act is a positive step forward for the LGBTQ community. But it came with swift backlash from conservative lawmakers. (Monica Rodman, Sarah Hashemi/The Washington Post)

Classifying transgender athletes has amounted to a delicate balancing act for officials in several sports, a tug-of-war of sorts between inclusivity and fairness. The NCAA’s transgender athlete policy allows transgender women to compete in women’s events after completing a full year of testosterone suppression treatment. Thomas has been undergoing treatment for the past 2½ years and says it has depleted her of the strength and speed she had when competing for the men’s team.

But some researchers say Thomas’s times show one year of treatment isn’t necessarily enough to level the playing field, and detractors say her continued participation is unfair to the other swimmers.

Since she obliterated two school records and posted nation-leading times at a meet last month, Thomas has garnered attention from across the swimming community and right-wing media. Credentialed media at Saturday’s meet included Fox News, Newsweek, the Daily Mail and ESPN. Tennis icons Martina Navratilova and Chris Evert have publicly said Thomas has no business competing in women’s swimming, as has Olympian Erika Brown, who said last month it’s “time to start standing up for women’s sports.”

“A few years of testosterone blockers and estrogen doesn’t change the fact that she will have more powerful muscles, a larger heart and greater lung capacity [than] a biological woman,” Brown, who won two relay medals at the Tokyo Games last summer, wrote in an Instagram story post.

Last week, both Penn and the Ivy League issued statements supporting Thomas. The school said it is “committed to being a welcoming and inclusive environment for all our student-athletes, coaches and staff,” while the conference expressed an “unwavering commitment to providing an inclusive environment for all student-athletes while condemning transphobia and discrimination in any form.”

Nancy Hogshead-Makar, chief executive of Champion Women, a women’s sports advocacy organization, said concerns around Thomas’s spot on the women’s team aren’t rooted in transphobia or discrimination. Hogshead-Makar’s issues are with the rule book that allows Thomas to compete in women’s sports and with sports officials whom the advocate argues are putting Thomas’s competitors at a disadvantage.

“This topic is very uncomfortable for people. They don’t understand it, and so they took the lazy way out,” said Hogshead-Makar, who won four swimming medals at the 1984 Los Angeles Olympics. “The lazy way out is saying, ‘Put them in the women’s category.’

“To blow up the women’s category is just not the answer. This makes the women’s category meaningless.”

‘Nowhere close’

Thomas began swimming at 5 and eventually spent three years competing for the men’s team at Penn. She realized in the summer of 2018 that she was transgender, she has said, which cast uncertainty on her swimming career. Thomas continued competing on the men’s team even after beginning hormone replacement therapy in May 2019.

That fall, she came out to her teammates but remained on the men’s team as she transitioned, she said during an appearance on a SwimSwam podcast last month.

“It was a very awkward experience of basically being a woman competing in a men’s meet,” she said.

In summer 2020, Thomas began submitting medical paperwork and doctors’ notes to the NCAA, which cleared her to compete as a woman. After the coronavirus pandemic wiped out the 2020-21 swim season, Thomas returned to Penn last fall as a member of the women’s team.

She said the spironolactone treatment resulted in muscle loss and she has been unable to replicate her previous training and race times.

“I have to readjust my goals and what I think of as a good time or a good pace to hold in practice,” she said on the podcast. “Times and paces I held in meets before, I’m often nowhere close to now.”

While her times haven’t matched what she posted as a member of the men’s team, they’ve been significantly better than what most female swimmers manage.

Her fastest 200-yard freestyle time before this year was 1 minute 39.31 seconds. This season, she posted a 1:41.93, a 2.6 percent drop. That’s the fastest time by any female college swimmer this year, 0.64 seconds faster than Olympian Torri Huske. Thomas also has posted the nation’s best 500-yard freestyle time this season at 4:34.06, nearly three seconds faster than Olympian Brooke Forde.

Researchers from the Mayo Clinic, Duke University and Marquette University recently studied Thomas’s times from before and after she transitioned. They found her recent times were about 5 percent slower across all distances, according to an article they published. The gender gap between elite college and international swimmers is 10 to 15 percent for shorter distances and 7 to 10 percent for longer ones, they wrote.

“Everybody wants to maximize each individual’s opportunity to participate and be as inclusive as possible,” one of the researchers, Michael Joyner, a physiologist at the Mayo Clinic, said in an interview. “But how do you balance that inclusion at the individual level with the fairness to the entire field? That’s really the split-the-baby question.”

Joyner, who has spent his career studying human performance, notes that elite male and female swimmers start to diverge around ages 11 and 12 as boys hit puberty and testosterone levels begin to spike. He said Thomas’s times might be illustrating that taking suppressants doesn’t negate the hormonal impact of puberty.

“The thing you have to ask yourself is, ‘To what extent are there potential legacy effects of testosterone?’ ” he said.

A decade-old policy

The NCAA issued a 38-page handbook in 2011 to outline its stance on transgender athletes, saying that “any strength and endurance advantages a transgender woman arguably may have as a result of her prior testosterone levels dissipate after about one year of estrogen or testosterone-suppression therapy.”

The NCAA did not respond to a request for comment last week, but in a video posted in April, LaGwyn Durden, the organization’s director of sports medicine, said this is a complex issue and noted the science is far from definitive.

“The science/medical community really hasn’t reached a consensus on testosterone threshold,” she said. “We don’t have a definitive answer about that. If there is a threshold, what should that threshold be? That’s one piece that really makes this problematic when we’re trying to make policy.”

Others dismiss the idea that Thomas unfairly benefits from biological advantages. Before transitioning, she consulted with Schuyler Bailar, a former Harvard athlete and the first openly trans swimmer to compete in Division I. Bailar says biodiversity is an innate part of sports and many great athletes benefit from certain biological or genetic gifts.

“Lia is a great athlete because she is a great athlete and has worked hard for 17 years to be great at something she loves,” Bailar recently posted on social media. “The belief that all [people assigned male at birth] are better at sports is rooted in the sexist belief that boys are, by default, better at sports than girls, which is false.”

There have been a handful of transgender college athletes before Thomas, and many made headlines simply by transitioning and continuing to compete. Sports, for many, are core to their identity — both before and after transitioning. As Thomas said on the podcast, she’s able to “continue to do the sport I love as my authentic self.”

“That experience in swimming,” she said, “and being in a swimsuit 20 hours a week has helped me accept my body as it is and being proud and comfortable in my body and who I am.”

The transgender college athletes who came before Thomas haven’t challenged records or put themselves in position to hoist championship trophies. While her recent success quickly exploded into a cultural debate for some, many in the swim world are focused on the competitors chasing her to the final wall.

“For me, fairness is the most important thing. I think the NCAA policy issued in 2011 was not really based much on scientific knowledge,” said the parent. “So this is all about the rules. It’s not really about Lia. She followed the rules.”

Parents say several Penn swimmers have shared their concerns with the coaches but the school has continuously voiced its support for Thomas.

No coaches or swimmers were made available to reporters at Saturday’s meet. Thomas said on the podcast last month that her team has been nothing but supportive this season and she tries to avoid any chatter from outside the Penn program.

“I don’t engage with it,” she said. “It’s not healthy for me to read it or engage with it at all.”

A cold reception

Despite freezing temperatures, two women shouted into bullhorns and waved signs near the entrance to Sheerr Pool on Saturday afternoon. “Stand up 4 women,” one sign read.

“Come on, Penn, we know you’re cheating,” one of the protesters shouted. “This is not fair; this is not sport. It is that simple. Males and females are different.”

Inside the building, the bleachers were only half-full as coronavirus restrictions closed the meet to all but select family members and supporters. The swimmers themselves provided the energy, circling the pool and cheering on teammates.

By now, Thomas has grown accustomed to finishing first, and Saturday’s meet was no different. In the 200 free she posted a winning time of 1:48.73, nearly two seconds ahead of the next-fastest swimmer. Later, in the 500, she finished in 4:57.20, nearly 1½ seconds ahead of the field but more than 23 seconds off her season-best time from last month.

Thomas also lost a pair of races: the 100 free and the 4x100 freestyle relay. She finished sixth in the short sprint, nearly three seconds behind Yale’s Izzi Henig, and then found herself struggling to chase down Henig’s Bulldogs in the anchor leg of the relay.

Henig is a transgender male on the Yale squad but has put off hormone therapy for now and continues to compete on the school’s women’s team.

Though Thomas’s times Saturday were well off her season-best marks, they probably won’t quiet any dissent.

Along with Navratilova, Hogshead-Makar is part of the Women’s Sports Policy Working Group, an advocacy organization that says it’s trying to affirm girls’ and women’s sports “while including transgender athletes.”

While she says transgender women who’ve never experienced male puberty should be permitted to compete against women, Hogshead-Maker says it’s possible there are enough transgender athletes in some sports to merit a wholly new competitive category.

Roger Pielke Jr., director of the Sports Governance Center at the University of Colorado, noted that sports organizations have always grappled with complicated classifications, from disabled athletes to competitors switching nationalities. He noted that international soccer players are “cap-tied” and at the elite level cannot compete for one country and then change nationalities and compete for another.

“This would make sense for gender as well,” he said. “If an athlete competes in men/women categories, [he or she] would no longer be eligible to change categories.

“Just like in Paralympic classification, science does not make these decisions for us, but science can certainly help to inform our decisions,” Pielke added. “Ultimately, classification decisions reflect our values, who we are and what we want sport and the society of which it is a part to be.”