An official for USA Swimming resigned from her job of over 30 years this month over what she believes is the unfair development of permitting transgender female swimmers to compete against biologically female swimmers.

University of Pennsylvania transgender swimmer Lia Thomas — a biological male now competing as a female — has generated controversy for demolishing her competition, which are biologically female swimmers.

Swimmers on the University of Pennsylvania’s female swimming team, along with parents, have voiced frustrations over what they believe are unfair circumstances.

Under NCAA rules, transgender athletes must complete one year of testosterone-suppression treatment before being able to compete as a transgender male athlete, which Thomas has completed. But Thomas still has a clear physiological advantage over the competition. Additionally, Thomas is a talented swimmer who earned the honor of being named a second-team All-Ivy League athlete while competing as a male during the 2018-2019 season.