The inside story of the banned trans swimmer who has split sport: Lia Thomas competed as a man named Will before transitioning, team-mates were uncomfortable - and even Caitlyn Jenner spoke out before Olympics axe

Depending on who you ask, former University of Pennsylvania swimmer Lia Thomas is a threat to women's sports, an inspiration to marginalized trans athletes, or a mere talking point for those using the 25-year-old as some sort of political football.

One thing she's not: an Olympian.

Thomas was banned from competing in elite women's races earlier this month by The Court of Arbitration for Sport panel, which ruled that she was ineligible to challenge World Aquatics policy on trans athletes. 

Recognized by the International Olympic Committee as the sport's governing body, World Aquatics set a high bar in 2022 by requiring trans competitors to complete their transition before age 12 in order to be able to swim in the women's division. And since Thomas was already a college student at Penn by the time she transitioned in 2019, this ruling precludes her from participating in the 2024 Paris Games this summer. 

But while many are celebrating this outcome, few believe it's the final word on the subject of trans women in sports. Now, with Thomas' swimming future in question, DailyMail.com looks back on her life and career, which has divided athletes and parents across amateur and professional sports, the swimming world, and even her own team. 

Growing up in Austin, Texas, Thomas began swimming at age 5 and only got better with the passing years.

At Westlake High School, which produced Super Bowl-winning quarterbacks Drew Brees and Nick Foles, Thomas earned a sixth-place finish among teenage boys at the Texas state championships.

Colleges quickly took notice.

Thomas ultimately followed her brother to Penn's swim team, where she began focusing on distance races – and her growing unease with her own body.

She'd already begun questioning her gender in high school, but those feelings only intensified at the Ivy League college in Philadelphia.

Of course, nobody would have guessed there was a problem judging by Thomas' results. Although critic and former rival Riley Gaines has characterized Thomas a 'mediocre male athlete,' the Austin native's career bio tells a different story. 

While competing under her birth name, Will, Thomas recorded the sixth-fastest national time in the men's 1,000-yard freestyle in 2017 (57.55 seconds), and had several other impressive performances in the 500-yard freestyle and 1,650-yard freestyle.

Thomas was even better the following year, finishing second at the Ivy League Championships in the men's 500 freestyle, 1,000 freestyle and 1,650 freestyle.

But although Thomas was still racing as a man in the spring 2019, she was already beginning to identify as a woman. In fact, Thomas came out to her family as transgender a year earlier, in the summer of 2018. 

As she told Sports Illustrated in 2022, Thomas initially put off hormone replacement therapy (HRT) fearing that it would interfere with swimming. Even when she began the treatments in May of 2019, Thomas knew her career in the pool was in jeopardy. 

'I did HRT knowing and accepting I might not swim again,' Thomas told SI. 'I was just trying to live my life.'

But while the treatments were a slow process, the results were undeniable for Thomas, whose unease over her gender dysphoria began to subside.

'It surprised me,' Thomas said of her transition. 'I felt, mentally, a lot better and healthier pretty quickly. The relief it gave me was quite substantial.'

To Thomas, transitioning was the right answer. Not only was she comfortable with her new body, but her family, friends, teammates and coaches remained largely supportive of her decision. 

She was still competing as a man in 2019-20, occasionally wearing a women's swimsuit, but her times suffered dramatically due to the HRT treatment. Ultimately Thomas raced in only four of eight regular-season events that year, and outside of a win in the 500 freestyle against Villanova, was a non factor for the Quakers.

With her testosterone levels dropping, Thomas decided to move to the women's division, not just for herself, but for other trans athletes facing the same obstacles. 

'I just want to show trans kids and younger trans athletes that they're not alone,' Thomas told SI. 'They don't have to choose between who they are and the sport they love.' 

There was, of course, some pushback. 

Even LGBTQ+ icon Martina Navratilova took issue with the trans swimmer, reposting a DailyMail.com article on Twitter and writing: 'It is not fair for women to race against transgender Lia Thomas.'

At the time, the NCAA was requiring transgender women to go through one year of HRT treatment before being able to compete in women's sports, and Thomas coordinated with both Penn and NCAA officials to ensure that she remained compliant. 

Those policies quickly became more complicated.  

In January of 2022, the NCAA announced it would defer to the rules of each sport's governing body when it came to trans athletes in women's sports. USA Swimming followed by updating its own criteria, requiring trans women to have minuscule testosterone levels for 36 months in order to compete in the women's division.

Regardless, Thomas remained eligible while posting the best 200-meter freestyle time in the country as the NCAA was beginning its own transition from the imperial to the metric system. 

In one race, she beat the nearest competitor by 40 seconds.

The national media soon became fixated. As a result, her final home meet in Philadelphia required additional media seating as national and international news outlets hashed out the growing controversy. 

Meanwhile, outside Penn's Sheer Pool, protestors had begun chanting against Thomas' inclusion in women's swimming. 

'Stand up for women!' they shouted, as quoted by The Associated Press. 'Even when they're swimming! Men cannot be women!'

There was even discord within the Quakers' locker room, where some teammates, like Paula Scanlan, were growing uncomfortable.

'Is anyone going to apologize for forcing us to undress with him 18 times a week?' asked Scanlan, who testified on the subject before a congressional subcommittee in 2023. 

While Thomas has insisted coach Penn Mike Schnur and teammates were 'unbelievably supportive,' a letter purportedly signed by 16 anonymous Penn athletes was sent to the NCAA demanding that she not be allowed to compete in the national championships. 

Penn and the Ivy League followed by issuing their own statements in support of all transgender athletes, and Thomas ultimately moved on to the biggest meet of her career: The 2022 NCAA Championships. 

Swimming in the 500-yard freestyle, Thomas would post an impressive 4:33.24, beating Olympic silver medalist and University of Florida star Emma Weyant by 1.75 seconds to finish first overall. 

However, the victory was marred by a flurry of boos in the crowd, and one spectator's decision to yell 'cheater'  while Thomas was on the block, according to Swimswam.com. And as Thomas was finishing the 500 with 11th fast time in NCAA history, another spectator yelled 'he's a man' and 'protect girls sports!'

But for all of Thomas' supposed advantages, her time in the 500 freestyle was still nearly 15 seconds slower than her personal best in the men's division (4:18.72). And while 27 all-time NCAA records were broken at the 2022 championships, Thomas' performance in the 500 was still far from Katie Ledecky's collegiate best of 4:24.06.

Curiously, Thomas' best times in the men's and women's 500 freestyle are both about 10 seconds off the NCAA records in each respective division. 

But while much of the data remains inconclusive, many public figures are certain that Thomas had an unfair advantage. 

Republican Florida Governor Ron DeSantis released a proclamation after the NCAA championships, declaring Weyant to be the winner of the 500 freestyle. 

'By allowing men to compete in women's sports, the NCAA is destroying opportunities for women, making a mockery of its championships, and perpetuating a fraud,' DeSantis wrote on X.

Colorado congresswoman Lauren Boebert introduced a bill honoring Weyant.

Even gold-medal winning Olympic decathlete Caitlyn Jenner — who is, herself, a trans woman — came down strongly against Thomas: 'It's not transphobic or anti-trans, it's common sense!'

For many politicians, the debate over Thomas became a springboard for wide-ranging legislation at the high school level.  By June of 2022, 19 conservative-leaning states all enacted some legislation prohibiting public schools from allowing trans girls to participate in girls sports.

House Republicans then passed a bill banning transgender athletes from competing on girls or women's sports teams at federally supported schools and colleges, but that — and other similar legislation — is not expected to pass the Democrat-led senate. 

With her college career over, Thomas continued to prepare for the 2024 Paris Games amid the ongoing debate about trans women in sports. 

Some, like the IOC, argue there is no 'presumption of advantage' for trans women.

Many academics disagree, including Manchester Metropolitan University Institute of Sport professor Alun Williams, who authored a paper disputing the IOC's stance. 

'The IOC's framework says there is no ''presumption of advantage,'' but the data shows there is physical development that takes place during adolescence in males that gives clear athletic advantages.

'Male development during puberty results in large performance advantages in athletic sports, such as larger muscle mass, heart size, lung capacity, bones, strength, and circulating haemoglobin, which are integral to sports performance.

'It is this exposure to testosterone during adolescent development, not the level of testosterone present in adults, that underpins the difference between the male and female categories, and there is currently no evidence that testosterone suppression in transgender women can reverse male development and negate these advantages.'

Ultimately it wasn't legislators or professors who ended Thomas' Olympic dream, but World Aquatics and the Court of Arbitration for Sport.

Thomas had challenged World Aquatics' 2022 decision to ban anyone who had gone through puberty as a male from the women's division. In the end, the court's three-judge panel ruled that Thomas was ineligible to challenge that ban because she had not previously competed in female events 'for the purpose of qualification or selection' with World Aquatics.

'The panel concludes that she lacks standing to challenge the policy and the operational requirements in the framework of the present proceeding,' read the court's final ruling.

Thomas reacted to the decision in a statement provided by her attorney: 'Blanket bans preventing trans women from competing are discriminatory and deprive us of valuable athletic opportunities that are central to our identities.'

But while she won't be competing in the Paris Games, Thomas may leave a bigger mark on sports than anyone who will — not that you'll ever hear that from her. 

Thomas has largely avoided the media over the last few years, even while being ripped in the press by critics such as Jenner and Gaines, both of whom have emerged as leading voices on the other side of the debate. 

And to Thomas, that may have been the point: She can't do anything about her critics, but she can still live whatever life she chooses for herself. 

'I knew there would be scrutiny against me if I competed as a woman,' Thomas said in June of 2022. 'I was prepared for that. But I also don't need anybody's permission to be myself and to do the sport that I love.'