The participation of transgender women—or biological males who transition—in elite women’s sports has generated intense debate in recent years. Critics argue that physical advantages rooted in male puberty, including bone density, muscle mass, and long‑term physiological development, can persist even after hormone therapy, potentially undermining fair competition in women’s divisions. Supporters counter that inclusive policies recognize gender identity and follow medical guidelines for testosterone suppression and other criteria.
The participation of transgender women—or biological males who transition—in elite women’s sports has generated intense debate in recent years. Critics argue that physical advantages rooted in male puberty, including bone density, muscle mass, and long‑term physiological development, can persist even after hormone therapy, potentially undermining fair competition in women’s divisions. Supporters counter that inclusive policies recognize gender identity and follow medical guidelines for testosterone suppression and other criteria.
A central and widely publicized example is Lia Thomas, a swimmer born male in May 1999 who transitioned and competed in women’s events at the University of Pennsylvania during the 2021–2022 NCAA season. Thomas won the NCAA Division I women’s 500‑yard freestyle championship in March 2022, becoming the first openly transgender athlete to win a Division I title in any sport. That victory sparked immediate controversy and policy reevaluation across collegiate athletics.
Iszac Henig (rights holder), Lia Thomas in Boston, Massachusetts, CC BY-SA 4.0
In response to Lia Thomas’s win and broader concerns, the International Swimming Federation (FINA) introduced a policy in June 2022 barring transgender women who began male puberty beyond Tanner Stage 2 or after age 12 from competing in professional women’s swimming, effectively preventing Thomas from competing at the elite international level.
By mid‑2025, the University of Pennsylvania reached a settlement with the U.S. Department of Education, agreeing to strip Thomas’s women’s swimming records, rescind her NCAA and Ivy League titles, and issue apologies to female athletes who had lost to her during the 2021–22 season. The university also pledged to ban biological males from women's athletic programs under newly enforced, biology-based definitions of sex .
This agreement followed Executive Orders by the Trump administration (such as EO 14168 and 14201) that reinterpreted Title IX protections based on assigned sex at birth and spurred athletic governing bodies—including the U.S. Olympic and Paralympic Committee—to prohibit transgender women from competing in women’s categories.
There is often confusion surrounding Brittney Griner in this context. Some online misinformation has claimed she is a biological male, but these claims have been thoroughly debunked by fact‑checkers including PolitiFact, Snopes, and USA Today Fact Check, all of which confirm Griner is a cisgender woman with no evidence to the contrary. As a WNBA champion, Olympic gold medalist, and Hall-of-Fame‑level player, Griner’s achievements are entirely separate from the controversy surrounding transgender eligibility in women’s sports.
The Lia Thomas case has driven many organizations and states to enact or reinforce bans on transgender women in female sports categories. As of July 2025, at least 27 U.S. states and several major national and international sports bodies restrict participation of transgender women who began male puberty beyond early adolescence.
Ultimately, the Lia Thomas situation highlights a core tension: balancing inclusivity and recognition of gender identity against concerns over fairness and physiological advantage in elite competition. Whether and how sport governs categories—by hormone levels, timing of transition, or birth-assigned sex—remains a contentious and evolving policy area. As institutions refine eligibility criteria and enforcement, the broader debate about fairness, identity, and competition continues to evolve.
Important Clarification: Brittney Griner is a cisgender woman, not a transgender female, and her name is often incorrectly conflated in social media misinformation with biological-male controversy. There is no factual basis connecting her to transgender eligibility debates.