On March 17, 2022, Lia Thomas of the University of Pennsylvania won the Division I women’s 500-meter freestyle event with a time of 4:33.24: a season record and 1.75 seconds faster than second-place Emma Weyant, who competed in the Tokyo Olympics.

Thomas’ victory is distinctive in many ways, beyond just the fact that it was the fastest time of the season. For one, Thomas is the first transgender athlete to capture a DI NCAA title in any sport.

But even more importantly, Thomas brought forth the topic of the inclusion of transgender women in sports to the forefront of public discourse.

To understand the current debate, it’s important to take a step backwards and look at the decisions leading up to the NCAA permitting transgender athletes to compete in collegiate sports. Thomas’ win follows a long and complicated history paved by transgender athletes and activists who came before her.

In 2003, the International Olympic Committee, or IOC, released a decision stating that transgender athletes were allowed to compete in the games if they had undergone complete gender reassignment surgery. This year is notably the first time transgender athletes were permitted to compete at the highest level.

It wasn’t until almost one decade later in 2011 that the NCAA ruled transgender athletes were allowed to compete in collegiate sports. Transgender women, however, had to meet the requirement of having been on hormone-suppression therapy for no less than a calendar year.

In 2015, the IOC reevaluated its policy on transgender participation in sports and enacted a new one — transgender men could compete without restriction while transgender women had to meet a testosterone requirement of less than 10 nanomoles per liter.

Though this new policy opened the door for some transgender women to compete, it also managed to exclude other athletes like Caster Semenya. The track star was ruled ineligible to compete in the Olympics on the basis that her natural testosterone levels were too high.

The IOC’s current policy on transgender athletes’ participation is that each individual sport should set its own guidelines. It does not want to prohibit involvement on the basis of testosterone levels, and recognizes the many differences between sports that could influence physiological advantages and disadvantages transgender athletes might have.

As the ever-changing rules and regulations over the years have shown, using science to determine who fits into the construct of gender in order to participate in sports is almost impossible. This is because there is no one biological factor that determines sex.

The debate over what the guidelines should be for transgender inclusion in sports is a complicated one, made even more complicated by many Republican-led state legislatures’ attempts to pass bills banning transgender women and girls from competing in female sports.

For instance, the Utah senate just recently managed to pass a bill barring transgender participation in girls’ sports after it was vetoed by Republican Gov. Spencer Cox. This has already proven to be greatly detrimental to the mental and physical health of transgender women and girls across the state.

Utah is not alone in this, as 11 states before it set the precedent with similar bills already in place. Pennsylvania, the state in which Thomas competes, is even attempting to pass its own ban that Democrat Gov. Tom Wolf has adamantly stated he will veto.

When Thomas bravely dove into the pool at the 2022 NCAA DI Championships, she wasn’t just making history — She also forced the NCAA and other governing bodies to restructure the existing rules in place.

Since Thomas’ victory, USA Swimming has changed its rules for transgender athletes’ participation. The benchmark to having low testosterone has now been moved from 12 months to 36 months, which is the longest out of any other governing body.

In the future, governing bodies will face the challenging task of balancing inclusion for transgender athletes with the question of how to determine to what extent the advantages or disadvantages transgender athletes have over their cisgender competitors. Furthermore, they will have to define how that affects the integrity of competition in sports.

Nevertheless, one thing is for certain: Every effort should be made to include transgender athletes in a fair and equitable way. The progress the IOC and NCAA have made towards inclusion should not be undermined by state legislatures’ attempts to politicize an ethical issue.