Lia Thomas: Transgender swimmer fails in challenge to rules that bar her from elite women's races

The Court of Arbitration for Sport's panel of three judges dismissed Thomas' request for arbitration with the World Aquatics governing body, in a ruling released on Wednesday.

World Aquatics banned transgender women who have been through male puberty from competing in women's races. It also created an 'open' category for which transgender athletes would be eligible.

Thomas had asked the sports court in Switzerland to overturn the rules approved in 2022 that she felt were 'invalid, unlawful and discriminatory'.

Thomas swam for the University of Pennsylvania and won an NCAA title in meets that are outside the World Aquatics competitive system.

The world swim body argued to CAS that Thomas was not a member of its member federation USA Swimming when the legal case was started. She also had not competed in female events "for the purpose of qualification or selection" for World Aquatics competitions, such as the Olympics or world championships.

"The panel concludes that she lacks standing to challenge the policy and the operational requirements in the framework of the present proceeding," the court said in its ruling.

In January the ruling said, USA Swimming granted her request for "self-identity verification" as part of its policy on athlete inclusion.

The judges said USA Swimming had no authority "to modify such scope of application" of the world governing body's rules.

World Aquatics said it welcomed the CAS decision in a case "we believe is a major step forward in our efforts to protect women's sport".

"World Aquatics is dedicated to fostering an environment that promotes fairness, respect, and equal opportunities for athletes of all genders and we reaffirm this pledge," the governing body based in Lausanne said in a statement.

Swimming's policy on transgender athletes was followed by other top-tier Olympic sports, track and field, then cycling, in excluding from women's events those who have potentially gained lasting physical advantages from male puberty.

The International Cycling Union noted last year "it is also impossible to rule out the possibility that biomechanical factors such as the shape and arrangement of the bones in their limbs may constitute a lasting advantage for female transgender athletes".

Thomas was represented at CAS by Toronto-based Tyr, the legal firm that has represented two-time Olympic champion runner Caster Semenya.

Semenya is excluded from running in her specialist 800m event due to World Athletics rules on athletes with differences in sex development who have elevated levels of testosterone.