Transgender swimmer Lia Thomas, who rose to international prominence by competing in female categories in the United States, faced a difficult time competing in the 2024 Paris Olympic Games this week. After months of legal wrangling, the Arbitral Sports Court (CAS) rejected her appeal against World Aquatics rules restricting the participation of transgender competitive athletes.

The decision represents a milestone in the discussion on inclusion, sporting equity and the limits of gender competition. The CAS concluded that while the inclusion of trans athletes is a legitimate and important issue, sports federations have the right to establish criteria that guarantee equity in women’s competitions.

Lia Thomas, the first transgender swimmer to win a women’s university championship in the U.S., struggled to secure her right to compete internationally. The New World Aquatics Rules, implemented in 2022, stipulate that transgender athletes can only compete in the female category if they have completed transition before puberty—a criterion that disqualifies Thomas.

Organizations advocating for women’s rights in sports hailed the decision as a “crucial step in protecting the integrity of women’s sports.” Athletes and former athletes have also spoken out, highlighting the importance of maintaining a level playing field, especially in sports where physical advantage can be crucial.

On the other hand, supporters of trans exclusion complained and stated that the fight for rights and recognition continues. “The decision can be seen as a setback for sport,” said a spokesperson for the Athlete, an organization that supports LGBTQIA+ athletes.

Lia Thomas, in turn, has not yet made any public comments following the decision, but her representatives stated that she will continue to defend changes to the international rules.

With the Paris Games approaching, the debate over the participation of trans athletes remains lit, dividing opinions and questioning the balance between inclusion and competitive equity.