FAQ: How Caster Semenya's defeat in IAAF gender case may affect participation in sports

Caster Semenya, a two-time Olympic champion runner, lost her appeal against proposed IAAF rules to limit her testosterone levels. Foto Olimpik/NurPhoto via Getty Images

On Wednesday, the Court of Arbitration for Sport (CAS) handed down a highly anticipated ruling in the case regarding South African runner Caster Semenya. She had appealed regulations proposed by the International Association of Athletics Federation (IAAF) that would require female athletes with naturally occurring, higher levels of testosterone to lower those levels to compete in the 400-meter, 800-meter and 1,500-meter/1-mile races.

For much of her decade-long career, Semenya has been embroiled in controversy because of the questions about her gender. These issues are often messy and complicated, so here's an explanation for what's going on, how we got here and what it all means.

Q: Who is Caster Semenya?

A: Semenya, 28, is an Olympic middle-distance runner from South Africa. Following her victory in the 800 meters at the 2009 world championships -- her first on such a significant stage -- the IAAF, citing her rapid drop in times and overall improvement, subjected Semenya to sex-verification testing. She has never publicly discussed or disclosed those results. She reached an agreement with the IAAF to keep her medal in November of that year and was cleared to compete in the women's category in July 2010. She went on to win Olympic gold medals in the 800 in 2012 and 2016.

Q: What were the arguments put forth before the CAS?

A: Put simply, the IAAF argued that athletes who are found to have "differences of sex development" (DSD) -- specifically higher levels of naturally occurring testosterone -- have a significant advantage over others and therefore need to be regulated to ensure fair competition. DSD is a catch-all description applying to a variety of sex differences, but in this case the IAAF is arguing only to address "46 XY DSD," or those individuals who have XY chromosomes but compete in the female category.

On the surface, having XY chromosomes may seem disqualifying for women, but there are situations where that's not the case, such as an athlete being diagnosed with partial or complete androgen insensitivity syndrome. People with CAIS can develop vaginas and might be raised as women. Because Semenya has not commented publicly on her medical records, we don't know if she fits into this category.

Semenya argued that the proposed regulations unfairly discriminate because they target only female athletes and only those with specific physiological traits. She also argued that the rules are unnecessary and could cause serious harm through medical treatments and resulting side effects from attempting to lower naturally occurring levels of testosterone.

Q: What did Wednesday's ruling from the CAS actually say?

A: By a 2-1 margin, the CAS dismissed Semenya's claim, arguing that "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 30 days to appeal the ruling.

It's worth pointing out that the restricted events named in the ruling are the ones that Semenya runs. Though her Olympic medals are in the 800, Semenya has competed in the 400 and the 1,500 professionally. The regulations do not include sprinting events, like the 100 meters and 200 meters, which is notable because, prior to this latest challenge, Indian sprinter Dutee Chand won her 2015 case against the IAAF after the organization tried to force her to limit her testosterone levels. The 2015 ruling gave the IAAF two years to provide evidence that testosterone gave women a significant advantage. The IAAF later informed the court it would rescind the regulations challenged by Chand and institute new policies. The new policies are the ones Semenya challenged. (Chand did not make it beyond her first 100-meter heat at the 2016 Olympics in Rio de Janeiro.)

Even though the CAS ruled in favor of the IAAF this week, the panel cautioned the IAAF in implementing the lower testosterone regulations in the 1,500 meters and the mile because the evidence presented by the IAAF showed "difficulty to rely on concrete evidence of actual (in contrast to theoretical) significant athletic advantage." The panel suggested regulations should not immediately be applied to those events, but the IAAF said Thursday morning that it would indeed apply them to those events.

The CAS also left the door open to future challenges should athletes experience significant side effects and/or struggle to remain in compliance with the new regulations. That means that the harm done to athletes, should such harm occur, could outweigh the need for this discriminatory policy.

The CAS has only publicly released an executive summary of the judgment and not the entire 165-page document. The executive summary doesn't provide specific details of the science that was presented as evidence, only that the argument was accepted.

Q: So what are these new regulations, exactly?

A: To address what the IAAF sees as a fairness problem, the organization instituted a policy in April 2018 that would require female athletes wishing to run in the 400, 800 and 1,500 meters and the mile to lower their naturally occurring testosterone levels to 5 nanomoles per liter (nmol/L), or half of the previous accepted level of 10 nmol/L. The rules were set to go into effect in November 2018, but following Semenya's challenge, the IAAF decided to wait to implement them until after the CAS ruling.

Q: Testosterone is a male hormone anyway, so won't this ruling protect women competing in sports?

A: Not exactly; it's far more complicated than that. Women also produce testosterone, which aids in a variety of physiologic functions. Dr. Katrina Karkazis, a senior visiting fellow at Yale University and the author of the forthcoming book "Testosterone: An Unauthorized Biography," calls it "ideology," not "science," that testosterone is considered to be a male-only sex hormone.

"The combined belief that testosterone is problematic in women and an athletic performance accelerator make this regulation seem scientific," Karkazis said in a phone interview. "Everyone's testosterone is important for their own performance. What you can't do is say that women with slightly higher levels or women with the highest levels will perform better. There is not a clear and consistent relationship between someone's testosterone and athletic performance."

Q: So women who have higher levels of testosterone don't have an advantage at all?

A: Again, it's complicated. Despite the desire to make sport an even playing field, the reality is that much of sport is unfair. Athletes have all kinds of advantages, and the combination of those advantages (and disadvantages) is unique to each participant.

"Yes, there is an advantage in certain events, but there is an advantage to being taller in certain sports. There is no question that the athletes who are at those levels are there because they had biological or environmental advantages," Yale professor emeritus and endocrinologist Myron Genel said in a phone interview. "If you were born female, and raised female, you should be able to participate in athletics according to your birth gender."

Q: How will this ruling impact Semenya and other athletes moving forward?

A: Any athlete looking to compete in the 400, 800, 1,500 and the mile at the elite level must comply with the new testosterone limit. That already includes more athletes than just Semenya. Rio 800-meter silver medalist Francine Niyonsaba, for example, has said publicly that she has high levels of natural testosterone. And transgender women, who under previous policies only had to lower their testosterone levels to 10 nmol/L, will also be impacted by the ruling; they'll have a higher barrier to participation at the elite level.

More broadly, this ruling sets a dangerous precedent about the validity of using testosterone as an indicator for an advantage. The CAS confirmed the idea that the presence of higher levels of natural testosterone creates a significant unfair advantage in elite competition, which reinforces the notion that testosterone is an accelerant for athletic performance. This idea could filter down through athletic culture to inform arguments about who gets to participate in sport and under what conditions, ultimately affecting intersex youth, transgender youth and anyone who doesn't conform to gender norms.

Sport has been divided into a rigid binary of men's and women's sports, and no one (including Semenya) is arguing that the system should be abolished. But the unintended consequences of such a system are that it's not designed to cope with such nuanced issues and identities involving sex and gender. The cultural assumption is that while gender may be a social construct and a spectrum, sex is not. But that's not the case. Sex is composed of many factors: external genitalia, internal reproductive organs, hormones, chromosomes and secondary sex characteristics. For many people, all of those factors do not align in the way we assume they always do. Sex, too, is a spectrum.