This Olympic champion could be forced to make herself more 'female'. Or race against men.

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.

It’s that definition the two-time Olympic champion is currently challenging.

Caster Semenya vs the IAAF.

The Swiss-based Court of Arbitration for Sport is in the process of deciding on an appeal lodged by the 28-year-old against hormone standards proposed by the International Association of Athletics Federations in April 2018.

The new IAAF regulation states that 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 have to keep their testosterone levels below the set amount “for at least six months prior to competing”.

“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 IAAF’s controversial regulation, which was due to come into effect in November, remains suspended until the court delivers its verdict, reportedly towards the end of April.

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 spoken about any specific diagnosis. Instead, she speaks openly, proudly about simply being born "different".

A statement issued via her lawyers last month read: "Ms Semenya does not wish to undergo medical intervention to change who she is and how she was born. She wants to compete naturally.

"Ms Semenya hopes and dreams that one day she can run free of judgement, free of discrimination and in a world where she is accepted for who she is.”

And in her own words?

“Too fast? Too bad,” she wrote on Twitter back in September. “I was born to do this.”