When 800m runner Caster Semenya rocketed across the line to claim gold at the 2009 World Championships, the distance she’d put between herself and the competition provoked as many questions as it did applause. While some commentators and competitors saw an athlete in peak form, others pointed to the South African’s appearance, as if her apparently ‘broad shoulders’ or ‘square jaw’ explained her success.

“Just look at her,” Russian runner Mariya Savinova told media.

Italy’s Elisa Cusma Piccione went further. “For me she is not a woman,” she said. “I am also sorry for the other competitors … It is useless to compete with this, and it is not fair.”

Caster Semenya has since (unintentionally, it seems) become the face of hyperandrogenism: a medical condition that causes a female to produce excessive levels of male sex hormones, including testosterone.

In the world of competitive athletics, it’s precisely those levels that determine whether or not an athlete can compete as a woman. In other words, sporting officials have defined what it means to be – or not to be – female.

Last year, the two-time Olympic champion stood up and formally challenged that definition. And this week, she lost.

Caster Semenya vs the International Association of Athletics Federations.

The Swiss-based Court of Arbitration for Sport on Wednesday dismissed an appeal lodged by the 28-year-old against hormone standards proposed by the International Association of Athletics Federations (IAAF) in April 2018.

Under the IAAF regulation, females with a “difference of sexual development” (in other words, have testosterone levels above the prescribed threshold) must either take hormone-lowering medication or race against men.

This applies to women in track events from 400m up to one mile (1.6km), and requires that athletes keep their testosterone levels below the set amount “for at least six months prior to competing”.

In delivering its verdict this week, the court stated: “The Panel found that the [regulations] are discriminatory but that, on the basis of the evidence submitted by the parties, such discrimination is a necessary, reasonable and proportionate means of achieving the legitimate objective of ensuring fair competition in female athletics in certain events and protecting the ‘protected class’ of female athletes in those events.”

????‍♂️ pic.twitter.com/FHmm10npfx

— Caster Semenya (@caster800m) May 1, 2019

Announcing the regulations last year, the IAAF peddled that same idea: ‘fair’ competition.

“The latest research we have undertaken, and data we have compiled, show that there is a performance advantage in female athletes with DSD over the track distances covered by this rule,” Dr. Stephane Bermon, of the IAAF’s medical and science department, said in a statement at the time.

“The revised rules are not about cheating, no athlete with a DSD has cheated,” IAAF President Lord Sebastian Coe added. “They are about levelling the playing field to ensure fair and meaningful competition.”

The controversial regulations, which were suspended while the court considered Semenya’s case, will now come into effect on May 8.

In a statement issued via her lawyers, the athlete said she would not be deterred by the ruling: “I know that the IAAF’s regulations have always targeted me specifically,” she said. “For a decade the IAAF has tried to slow me down, but this has actually made me stronger. The decision of the CAS (Court of Arbitration for Sport) will not hold me back. I will once again rise above and continue to inspire young women and athletes in South Africa and around the world.”

Regulating hormones: A sporting issue or a human rights issue?

The IAAF rule has not only been criticised by the likes of sporting legends Billie Jean King and Ed Moses, but also by the United Nations.

The UN Human Rights Council discussed the issue at its 40th session in March, at which it expressed concern that requiring female athletes with DSD to medically reduce their testosterone levels could "contravene international human rights".

Yet in the sporting world, the debate around hyperandrogenism remains a pressing and, many would argue, valid one. As sports scientist, Professor John Brewer, previously told The Telegraph:

“There is a reason that testosterone is a banned substance, it has an anabolic affect and increases muscle strength and power, so someone with more of it is likely to have more speed. And that’s clearly an advantage. It’s not a level playing field. But what can you do about it? Do you ban them? Do you have a cut-off point? Do you have a separate category?

"The row will keep rumbling on."

I’m not ugly... I’m just ready to bite ???????? @Koketsomogapilj pic.twitter.com/NhUmJReBXL

— Caster Semenya (@caster800m) April 2, 2019

It should be noted, the results of the hormone tests to which Caster Semenya has been subjected have never officially been made public, though elements were leaked to the press in 2009, leading some outlets to claim she has intersex traits. However, Semenya has never commented on any specific diagnosis.

Instead, she speaks openly, proudly, about simply being born "different".

Her millions of followers and even her country embrace that difference.

In a statement issued after the CAS verdict this week, South Africa's Minister for Sport and Recreation, Tokozile Xasa, had a message for the Semenya.

"You remain our golden girl. What you have done for our people and girls is enormous. You have flown our flag high, you have united a nation and inspired a rural girl. For that we thank you."