The Court of Arbitration for Sport (CAS) has rejected an appeal by South African middle-distance runner Caster Semenya against new athletics regulations that set an upper limit for testosterone in certain women’s events.
From now on women who want to compete in international competitions at distances of between 400 meters and one mile will have to reduce their blood testosterone level to below five nanomoles per litre for at least six months before the event, and then keep it there. For Semenya, the double Olympic and triple World 800m champion, it is a crushing blow.
If she wants to defend her title at this autumn’s World Championships, or next year’s Olympic Games, Semenya will have to undergo hormone treatment to artificially lower her testosterone levels to what the IAAF has deemed acceptable. It's been predicted this could result in her running seven seconds slower over 800m.
The decision made by CAS was a majority one. In a statement released by the group admitted the rules "are discriminatory". It said: "such discrimination is a necessary, reasonable and proportionate means of achieving the IAAF’s aim of preserving the integrity of female athletics in the Restricted Events."
Semenya has hyperandrogenism, which means her body produces more testosterone than other women. Testosterone undoubtedly plays an important role in sporting performance. It makes muscles bigger and bones stronger, and increases levels of oxygen-carrying haemoglobin in the blood. “More protein will be laid down within each muscle fibre and the fibres will increase in size and diameter,” explains John Brewer, a professor of sports science at Buckinghamshire New University. “If you look at a number of sports, having a larger amount of muscle bulk will improve performance – the size of the muscle tends to be linked to the power it can produce.”
Men’s bodies make up to ten times as much testosterone as women’s, starting from puberty, which is when performance differences between the sexes start to emerge. The IAAF argues that it is trying to preserve the integrity of women’s athletics, and empower women and girls who want to compete for the chance to win medals on a ‘level playing field’.
The head of the IAAF's health and science department said after the ruling that it believed this would make comeptition fair. “Historically the reason why we have separate male and female categories is that otherwise females would never win any medals,” Stéphane Bermon said. “Testosterone is the most important factor in explaining the difference."
The legal wrangling goes back to 2014, when Indian sprinter Dutee Chand was suspended due to hyperandrogenism, missing out on the Commonwealth Games and Asian Games as a result. In 2015, the CAS suspended that ruling, and ordered the IAAF to present clearer scientific evidence. Since then, scientists have found that testosterone plays a particularly important role in middle distance running events, and explosive throwing events such as the hammer and shot-put.
The IAAF says that women with elevated testosterone levels have an advantage of up to nine per cent over other women. Sports scientist Ross Tucker has predicted that lowering her testosterone to 5nmol/L could knock between five and seven seconds off Semenya’s 800m time. She would still be an elite athlete, but it would take her out of medal contention.
With both sides claiming to be on the side of fairness, it’s a complex issue. Supporters of Semenya and other women with so-called disorders of sex development argue that it’s unfair to force people to change who they are with medical treatments so they can compete. “There is no solution that will please everyone,” says Sarah Shephard, a sports journalist and author of Kicking Off: How Women In Sport Are Changing The Game. “But I can’t accept that banning someone from competing because of something that they were born with is the fairest one.”
Athletics has a long history of policing who counts as a woman. The first sex verification tests started in the 1950s with physical examinations, which at one point were mandatory for all female athletes due to fears that males would unfairly pose as females in order to compete. Women were given a “certificate of femininity” to take with them to future competitions.
By the 1968 Olympics in Mexico City, officials had adopted a chromosome test – generally, women have two X chromosomes, while men have one X and one Y. But sexual characteristics are determined by a wide range of different factors, not just genetics. The interactions between DNA and hormones can create a panoply of different conditions, some which influence athletic performance and physiology, and others which don’t.
Some women have mosaicism, where they have three sex chromosomes instead of two. Others, like Spanish hurdler Maria José Martínez-Patiño, have XY chromosomes combined with androgen insensitivity syndrome, which means they get no athletic benefit from elevated testosterone. Martínez-Patiño only found out when she forgot to take her certificate of femininity to the 1985 World University Games, and when she failed the chromosome test she had to take as a result, she was banned from competing.
Martínez-Patiño was eventually reinstated, and by the Sydney Olympics in 2000, chromosome testing had been abandoned as a means of sex verification. Hormone-based tests seem to offer a clearer link to athletic performance – but people don’t suddenly stop being women once their testosterone reaches a certain point.
There’s no scientific reason why hyperandrogenism should be treated any differently to other genetic differences that confer increased athletic performance. Sprinters such as Usain Bolt have benefitted from fast-twitch muscle fibres, while the swimmer Michael Phelps has abnormally large feet and hypermobile ankles that effectively act as flippers, and an unusually long arm span with relatively short legs that reduce drag. “People who are seven feet tall are favoured in basketball and we don’t require them to play on their knees,” says Professor Ruth Wood, an expert on hormones at the University of Southern California.
Wood says that in decades of sex verification, there’s never been a case of a man trying to pass himself off as a woman to gain an athletic advantage. Like Semenya, most of the people caught out by rule changes have been intersex individuals born and raised as women.
Critics of the proposed changes have pointed out that although the IAAF found evidence that testosterone influences performance in throwing events too, they’ve only changed the eligibility criteria for middle distance running events, in a move that seems targeted at one athlete. There are athletes in other sports who are far more dominant than Semenya - the swimmer Katie Ledecky, for example, has beaten her competitors by the length of a pool at times.
It has also been argued that although these conditions are not necessarily more prevalent in certain countries, the regulations unfairly target women in the developed world who are perhaps less likely to have been identified as intersex at an earlier age and given hormone treatments.
For Semenya and other athletes with hyperandrogenism, being forced to artificially lower their testosterone levels now will come at a cost. The new ruling takes effect immediately “You would expect to see muscle size gradually start to decrease in size, and the muscles would produce less power,” says Brewer.
There could also be a psychological effect, according to Wood. “It will presumably have noticeable effects in terms of her own sense of vitality and energy,” she says. “She will still be a formidable competitor and a world class athlete, but we’re talking about very small performance differences that separate winning from coming in second.”
She will still have some advantages from “legacy physiology”, says Brewer – testosterone can influence height and the size of the heart and lungs, and taking hormones won’t change that. There has been some controversy around the guidelines set by the International Olympic Committee on athletes who have transitioned from male to female, who will also have to lower their testosterone levels in order to compete as women.
Brewer thinks we could see a separate athletics category being set up for intersex athletes, with classifications based on testosterone levels in a similar fashion to Paralympic classifications. But that opens up the possibility of athletes gaming their testosterone levels in order to compete in the category which suits them the most.
Despite the ruling, this is a debate that is unlikely to go away. It’s not entirely clear that this is something that science can really answer on its own. The regulations are a fairly arbitrary line in the sand based on a combination of gender – which is socially determined, and sex - which is biological. Neither are binary characteristics. The tricky science behind the Semenya case demonstrates that sport, with its hard and fast rules and general lack of nuance, may not be the best arena for this particular fight.
This article was originally published by WIRED UK
