A trans-identified athlete's continuous record-setting performances are causing concern among those who fear that allowing biological males to compete in women's sports will damage the integrity of women's athletics.

Lia Thomas, a trans-identified male who has been competing on the University of Pennsylvania's women's swimming and diving team this season, has shattered records even though the athlete competed on the men's swim team in previous seasons.

As the University of Pennsylvania noted in a statement published over the weekend, Thomas completed the women's 200-yard freestyle at the Zippy Invitational in Akron, Ohio, in 1 minute and 41 seconds, beating the second-place finisher by nearly seven seconds.

A detailed list of results reveals that Thomas' performance marked the fastest completion of the 200-yard freestyle in the history of the Zippy Invitational and the fastest finish in any competition at Ocasek Natatorium at the University of Akron, where the event took place.

Thomas broke other records at the event, finishing the preliminary 500-yard freestyle in 4 minutes and 46 seconds.

Thomas finished the 500-yard freestyle finals in 4 minutes and 34 seconds. The University of Pennsylvania described the time as "the best in the country in the event."

On Sunday, the third and final day of the competition, Thomas completed the 1,650-yard freestyle in 16 minutes, beating the second-place finisher by 38 seconds.

Thomas previously swam for Penn's men's team from 2017 to 2020 under the name Will Thomas. In the 2018-2019 season, Thomas placed second in the Ivy League Championships in three freestyle events — the 500-yard freestyle, the 1,000-yard freestyle and 1,650-yard freestyle. In the 2019-2020 season, Thomas won a 500-yard freestyle event against Villanova.

Thomas' performance at a previous competition invoked a strong reaction from Clay Travis, radio host and founder of the sports website OutKick. Travis noted that the athlete "swam as a man" for three years before joining the women's team.

In his remarks just days before the Zippy Invitational began, Travis lamented that "this man, who is now competing as a woman, is destroying female athletes after having competed for three years as a male swimmer."

"If you think it is in the interest of athletic competition for a male athlete to decide to become a woman and then dominate female athletes with the advantages of the height, the strength, the weight of a male athlete, this represents the potential destruction of female athletics," he argued. "It's absurd, it's ridiculous. It shouldn't be allowed to happen."

Travis further argued that "women should not be losing to biological men, especially not biological men who were good enough to be competing on college swim teams before they decided to identify as women."

While data from the advocacy group Women's Liberation Front reveals that nine states have passed laws that require athletes competing at the K-12 level to play on sports teams that correspond with their biological gender as opposed to their gender identity, efforts to restrict participation in women's sports to biological females have been less successful at the collegiate level.

The National Collegiate Athletic Association, one of several associations regulating collegiate sports in the U.S., has threatened to move tournaments out of Idaho in response to the state's passage of a law banning biological males from competing in women's sports. The NCAA doubled down on its support for letting athletes compete on teams that match their gender identity in an appearance before the U.S. Senate last year.

Opposition to biological males competing in women's sports is not limited to conservatives. Thomas' record-breaking performances at the Zippy Invitational came less than a week after Richard Dawkins, a prominent scientist and outspoken atheist, signed an online document called the "Declaration on Women's Sex-Based Rights."

The declaration aims to "lobby nations to maintain language protecting women and girls on the basis of sex rather than ‘gender' or ‘gender identity.'" The preamble asserts that "Men who claim a female ‘gender identity' are being enabled to access opportunities and protections set aside for women."

The declaration argues that such accommodations for trans-identified athletes in women's sports is "a form of discrimination against women, and endangers women's fundamental rights to safety, dignity, and equality."

Article 7 of the declaration seeks to reaffirm "women's rights to the same opportunities as men to participate actively in sports and physical education." The document argues that because of "physiological differences between women and men," biological males competing in women's sports means that "women are placed at an unfair competitive disadvantage."

The document notes that the Convention on the Elimination of All Forms of Discrimination Against Women adopted by the United Nations General Assembly in 1979 contains a provision requiring state parties to ensure girls and women have the "same Opportunities to participate actively in sports and physical education." The declaration calls for clarification to Article 7 that would allow "girls and women to participate in sports and physical education on a single-sex basis."

Critics of trans-affirming sports policies contend that the anatomy of male bodies is different from female bodies as they tend to have increased bones density and muscle mass.

Progressive organizations, such as the American Civil Liberties Union, deny that any "unfair" advantage exists for trans-identified biological males who compete against women or girls. The legal group argues that "athletes vary in athletic ability just like cisgender athletes" and success often depends on mastering techniques and dedication to training.