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World International sports court upholds testosterone testing for women against Caster Semenya challenge

South Africa's Caster Semenya competes in the athletics women's 1500m final during the 2018 Gold Coast Commonwealth Games at the Carrara Stadium on the Gold Coast on April 10, 2018.


A landmark ruling by the international high court for sports has opened the door to testosterone testing for women and could restrict the number of female athletes competing at major events, including the Olympic Games.

The decision released Wednesday by the Court of Arbitration for Sport (CAS) upheld a regulation introduced last year by the governing body for track and field which set a testosterone threshold for female runners in certain events. In a 2-1 ruling, the CAS panel said that while the regulation by the International Association of Athletics Federation (IAAF) was discriminatory, “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.”

The case centred around South Africa’s Caster Semenya, a double Olympic champion in the 800-metre race who has differences of sex development, or DSD, which causes her body to produce high levels of testosterone. The IAAF has spent years grappling with what to do with Ms. Semenya and other DSD athletes, who the federation argues have an unfair advantage because of their extra testosterone. The IAAF’s new rule, upheld by the CAS, requires all women competing at major championships in events ranging from 400 metres to one mile to meet a testosterone limit. If they exceed that limit, they must either take drugs to lower their testosterone or compete against men.

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Ms. Semenya has vowed to keep competing and her lawyers are considering an appeal. “I know that the IAAF’s regulations have always targeted me specifically,” Ms. Semenya said in a statement. “For a decade the IAAF has tried to slow me down, but this has actually made me stronger. The decision of the CAS will not hold me back.”

The case has raised difficult questions about ethics, gender and whether any sports organization has the right to determine who is female.

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“The decision is a huge defeat for inclusive and respectful sport, athletes’ rights and women’s rights, and I fear that the implementation of the IAAF rule around the world will unleash a medical war of terror on female runners,” said Bruce Kidd, a former Canadian Olympian and former principal of the University of Toronto Scarborough.

Although Ms. Semenya is not transgender, the CAS ruling will be watched closely by trans athletes preparing to compete at the 2020 Olympics in Tokyo. Transgender athletes don’t have to undergo reassignment surgery to compete at the Games. However, athletes transitioning from male to female have to meet a similar testosterone threshold imposed by the International Olympic Committee (IOC). The IOC had been considering lowering it’s level to the IAAF limit and was waiting for the CAS ruling. Transgender athletes have been gaining more visibility lately, particularly in the United States at the high school level, and more are expected to participate at the 2020 Games than in previous Olympics.​

Katrina Karkazis, an expert on global health justice at Yale University, called the ruling a setback for women in sports. "For me it’s disappointing that it endorses discrimination against women in sport, and that it allows sports governing bodies to require medically unnecessary interventions for continued eligibility. That violates women’s bodily autonomy and integrity and it doesn’t protect nor benefit women’s sport,” said Dr. Karkazis who testified for Ms. Semenya at the CAS hearing.

One of her concerns is that the CAS has accepted using testosterone as the determining factor in deciding if someone is male or female. In its ruling the CAS panel found that testosterone was “the primary driver of the sex difference in sports performance between males and females.” It set the range of testosterone for women at 0.06 nanomoles a litre to 1.68 nanomoles a litre, and men from 7.7 to 29.4 nanomoles a litre. The IAAF has set its limit at five nanomoles a litre. The panel said that while many factors go into athletic performances by men and women – such as training facilities, coaching and other genetic factors – “the only factor that is available only to men is exposure to adult male testosterone levels.” As a result, it said that because DSD athletes have testosterone levels approaching the male range, they “enjoy a significant performance advantage over other female athletes.”

Dr. Karkazis said there was no strong scientific evidence proving that testosterone gave DSD athletes a real edge. And she said controlling testosterone levels was difficult without major surgery. “Testosterone is incredibly dynamic,” she said. “It’s not like lowering the volume on a radio where you can set something to five and it stays there.”

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The IAAF has said that athletes will take conventional oral contraceptives and no one will undergo an invasive medical procedure. But the CAS panel raised “serious concerns” about whether that will work. The panel said there could be side effects to the drugs and it noted the challenge of maintaining testosterone at a certain level for a prolonged period. It also said there was a “paucity of evidence” to justify including the 1,500 meters and one mile events in the policy. The IAAF has yet to address the concerns and said the new rule comes into effect May 8 in time for the World Championships in Doha this fall.

Many athletes and experts welcomed the CAS ruling and said testosterone-based regulations were the best way to ensure fairness for women in sports. "One of the most important advances in the last 100 years in the lives of women has been the emergence of women’s sports. And if we want women to win things, like Olympic medals, if we want women to earn professional sports contracts, then we have to find an appropriate way of separating female athletes from male athletes,” said Joanna Harper, a transgender athlete in Oregon who is also a medical adviser to the IOC. She added that the dividing line should be based on science "and with the level of science we have in 2019, testosterone is the best available biological marker.”

In South Africa, the case has generated an outpouring of support for Ms. Semenya and a pledge by the government to back an appeal of the ruling. The IAAF regulations will “trample on the human rights and dignity of Caster Semenya and other women athletes,” Sports Minister Tokozile Xasa said in a statement.

One of Ms. Semenya’s lawyers, Canadian Jim Bunting, called on the IAAF to hold off on the regulation and appoint an independent panel of experts to examine the issues. He also noted the panel’s concern about the application of the regulation and added: “I think putting it simply that leaves the door open to where this goes in the future. I don’t think this is the final word on the issue.”

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