Caster Semenya celebrates her silver medal at the London 2012 Olympic games. Original photo by Jon Connell, via flickr.

By Kelsey E. Rector

South African runner Caster Semenya is a two-time Olympic gold medalist and has dominated track events like the 800 meter and other mid-distance races over the last decade.[1] All her life, Semenya has been questioned about her sex, especially with respect to competing as an elite female track athlete.[2] Her performance came under fire because Semenya, who was raised as a woman, presents as a woman, and identifies as a woman, has differences in sex development (“DSD”) which cause her body to naturally produce more testosterone than the average female.[3] DSD has many potential causes,[4] but in the most general terms, means that a person has an “atypical development of their chromosomal, gonadal, and/or anatomic sex.”[5]

In competitive sports which rely on gender binaries to group athletes for fair competition, one of the major issues has been to determine how to handle challenges that DSD women are not “female” for the sake of competition.[6] As a result, the recent solution by World Athletics (formerly the International Association of Athletics Federations, or “IAAF”) has been to adopt new rules to protect fair competition which would require DSD women, who are considered “relevant athletes,” to regulate their elevated testosterone levels or bar them from competing in certain women’s track events.[7]

Last month, Semenya lost her appeal challenging the World Athletics regulation which prohibits certain athletes with elevated testosterone levels from competing as females in specified track events.[8]

The regulations set forth by World Athletics state that “relevant athletes,” like Semenya, are barred from competing in restricted events, such as the women’s 800 meter, unless they reduce their blood testosterone to a level of less than five nmol/L for at least six months and sustain it thereafter to maintain eligibility.[9] Similar regulations were proposed by the IAAF in 2014, but when challenged the IAAF failed to produce enough scientific evidence to justify the necessity of the regulation.[10] Despite conflicting studies regarding whether increased testosterone even provides a significant competitive advantage for DSD athletes, the IAAF proposed the current regulations and claimed that they were essential to preserving fair competition for women.[11]

Semenya filed a claim against IAAF in the Court of Arbitration for Sports (“CAS”), claiming that the DSD regulations were “unfairly discriminatory, arbitrary and disproportionate and therefore violate the IAAF Constitution . . . .”[12]

There are several issues with regulations such as these. First, the regulation explicitly targets those individuals who do not fit within a convenient, traditionally defined, binary division of sex. The regulation applies to DSD individuals, but not non-DSD women who may also naturally produce testosterone at high levels.[13] Second, the regulation only applies to certain track events and not to other sports or events.[14] It is interesting to note that the events in the restricted category are restricted to those events in which identified DSD athletes compete in the most significant numbers, but not to those where the performance gap between DSD women and non-DSD women was the widest.[15] Third, and perhaps most troubling, the regulation requires artificial lowering of natural testosterone levels—which can have side effects—in order for an athlete to compete as a woman.[16] We do not ask Michael Phelps to shorten his ridiculously long arms for fair competition, nor do we question Usain Bolt’s long legs in men’s racing—so is it even appropriate to regulate naturally produced hormones which may only give athletes a slight advantage?[17]

Following arbitration, CAS found that the DSD regulations were discriminatory, but upheld them because the regulations were “a necessary, reasonable and proportionate means of achieving the aim of what is described as the integrity of female athletics and upholding of the ‘protected class’ of female athletes in certain events.”[18] The court noted several concerns with the regulations, such the potential for compromising athletes’ confidentiality, the ability of the IAAF to practically apply the regulations, risks to athletes’ health from hormonal treatment, and the inclusion of certain events (the 1,500 meter and 1 mile) as restricted events.[19] The court implied that it was not its place to determine whether a different regulation could be implemented that was more fair and less discriminatory.[20] Instead the court stated that its role was limited to evaluating the regulation as presented in order to determine if it was necessary, reasonable, and proportionate.[21]

Following the CAS decision, the World Medical Association (“WMA”) released a statement encouraging doctors not to take part in implementing the regulations.[22] Specifically, the WMA president stated, “We have strong reservations about the ethical validity of these regulations. They are based on weak evidence from a single study, which is currently being widely debated by the scientific community.”[23] Nevertheless, the regulation was upheld on appeal by the Swiss Federal Supreme Court.[24]

The Swiss Court stated that it could only evaluate “whether the CAS decision violates fundamental and widely recognized principles of public order.”[25] The court determined that fairness in sport was a legitimate concern and that DSD athletes were not being forced to undergo examinations or treatment.[26] While technically the court is correct that athletes aren’t being forced into evaluation or treatment, if an athlete withholds her consent, she will be barred from competing.[27] That doesn’t exactly seem like a fair choice.[28]

So what comes next? First, given the concerns expressed in the CAS opinion, there may be challenges to the application of the DSD regulation once it starts to be enforced.[29] For example, an athlete who agrees to adjust her testosterone levels through hormone treatment may not be able to consistently keep them at the required level throughout her eligibility period.[30] If World Athletics chooses to enforce the policy anyway, that athlete would have a strong argument that she attempted to follow the regulation and that it would be unfair to bar her from competition for fluctuating testosterone levels.[31] In the meantime, Semenya will likely take her case to the European Court of Human Rights to determine “whether demanding women with intersex variations to change their natural bodies as eligibility condition for a certain sport events conforms to the European Convention on Human Rights.”[32]


[1] Athlete Profile: Caster Semenya, World Athletics, https://worldathletics.org/athletes/south-africa/caster-semenya-14330057 (last visited Oct. 20, 2020) (showing races won, current season times, world ranking, and other statistics).

[2] Robyn Dixon, Gender Issue Has Always Chased Her, L.A. Times (Aug. 21, 2009), https://www.latimes.com/archives/la-xpm-2009-aug-21-fg-south-africa-runner21-story.html. See also Erin Buzuvis, Caster Semenya and the Myth of a Level Playing Field, 6 Modern Am. 36 (2010) (discussing how Semenya’s voice, musculature, and speed provoked questions about her gender after she won the 800m at the World Championships in 2009).

[3] See Sofia Christensen, Semenya Lawyer Prepares Testosterone Rule Challenge in European Court, Yahoo News (October 1, 2020), https://sports.yahoo.com/semenya-lawyer-prepares-testosterone-rule-142841526.html.

[4] DSD is a term encompassing a variety of conditions including but not limited to: 46 XX congenital adrenal hyperplasia, 5-alpha reductase deficiency, Klinefelter syndrome (47 XXY), Swyer syndrome (46 XY gonadal dysgenesis), and Androgen insensitivity syndrome. Kyla Boyse, Disorders of Sex Development (DSD) Resources, Mich. Med. (updated Nov. 2012),  https://www.med.umich.edu/yourchild/topics/dsd.htm.

[5] Semenya v. Int’l Ass’n of Athletics Fed’n, CAS Case No. 2018/O/5794, at 110–11 (Ct. Arb. Sport Apr. 30, 2019), https://www.tas-cas.org/fileadmin/user_upload/CAS_Award_-_redacted_-_Semenya_ASA_IAAF.pdf.

[6] See generally Maayan Sudai, The Testosterone Rule—Constructing Fairness in Professional Sport, 4 J. L. & Biosciences 181, 182 (2017) (stating that the issue of sex classification has plagued professional sport authorities since at least 1968).

[7] See World Athletics, Eligibility Regulations for the Female Classification, 2 (effective Nov. 2019) https://www.worldathletics.org/download/download?filename=656101dc-7716-488a-ab96-59d37941e9ac.pdf&urlslug=C3.6%20-%20Eligibility%20Regulations%20for%20the%20Female%20Classification; Testosterone Rules for Female Athletes ‘Unscientific’, BBC (Mar. 21, 2019), https://www.bbc.com/news/health-47640359.

[8] George Ramsay & Jill Martin, Caster Semenya Loses Appeal in Swiss Court over Restriction of Testosterone Levels, CNN (Sept. 9, 2020), https://www.cnn.com/2020/09/09/sport/caster-semenya-ruling-athletics-spt-intl/index.html; Lena Holzer, The Decision of the Swiss Federal Supreme Court in the Caster Semenya Case: A Human Rights and Gender Analysis, Opinio Juris (Sept. 30, 2020), http://opiniojuris.org/2020/09/30/the-decision-of-the-swiss-federal-supreme-court-in-the-caster-semenya-case-a-human-rights-and-gender-analysis/; Sean Ingle, Caster Semenya’s Olympic Hopes Fade as Runner Loses Testosterone Rules Appeal, The Guardian (Sept. 8, 2020), https://www.theguardian.com/sport/2020/sep/08/caster-semenya-loses-appeal-against-world-athletics-testosterone-rules.  

[9] World Athletics, supra note 7, at 4–5. The regulations define relevant athletes as those with listed DSDs, testosterone levels higher than five nmol/L, and who have androgen sensitivity allowing the testosterone to have an androgenizing effect. Id. at 4. Restricted events currently include the women’s 400 m, 400 m hurdles, 800 m, 1,500 m, and 1 mile. Id.

[10] See Alexandria Adkins, Comment, Trapped in the Binary Divide: How Forced Contraceptives Violate the World Anti-Doping Code, 35 Am. U. Int’l L. Rev. 531, 542–43 (2020). These regulations required hyperandrogenic females to reduce natural testosterone levels through the use of oral contraceptives. Id. at 542.Dutee Chand, a hyperandrogenic sprinter from India successfully challenged the necessity, reasonableness, and proportionality of the regulations. Id. at 543.

[11] Sudai, supra note 6, at 186–89.

[12] Semenya v. Int’l Ass’n of Athletics Fed’n, CAS Case No. 2018/O/5794, at 2 (Ct. Arb. Sport Apr. 30, 2019), https://www.tas-cas.org/fileadmin/user_upload/CAS_Award_-_redacted_-_Semenya_ASA_IAAF.pdf.

[13] Adkins, supra note 10, at 561.

[14] Id. at 562.

[15] Semenya, CAS Case No. 2018/0/5794, at 156.

[16] Adkins, supra note 10, at 556.

[17] Matt Butler, Nobody Asked Bolt to Shorten His Legs or Phelps to Shrink His Feet, so Why is Caster Semenya Being Told to Reduce Her Testosterone?, i News (Sept. 16, 2020), https://inews.co.uk/sport/athletics/caster-semenya-iaaf-testosterone-cas-sebastian-coe-260629. But see Malcom Gladwell & Nicholas Thompson, Caster Semenya and the Logic of Olympic Competition, New Yorker (Aug. 12, 2016), https://www.newyorker.com/sports/sporting-scene/caster-semenya-and-the-logic-of-olympic-competition (rationalizing the regulations by stating that these are different types of advantages, and that testosterone places Semenya outside the protected class of women).

[18] Semenya, CAS Case No. 2018/0/5794, at 160.

[19] Id. at 152–160.

[20] Id. at 160.

[21] Id.

[22] WMA Reiterates Advice to Physicians not to Implement IAAF Rules on Classifying Women Athletes, World Med. Ass’n (May 2, 2019), https://www.wma.net/news-post/wma-urges-physicians-not-to-implement-iaaf-rules-on-classifying-women-athletes/.

[23] Id.

[24] Press Release, Swiss Fed. Sup. Ct., DSD Regul.: Caster Semenya’s Appeal against the Decision of the Ct. of Arb. for Sport Dismissed (Sept. 8, 2020). The court opinion is in French (which I do not speak), as such I cite to the Press Release which was released in English. The case citation is: Tribunal Fédéral [TF] [Federal Supreme Court] Aug. 25, 2020, 4A_248/2019 (Switz.).

[25] Press Release, Swiss Fed. Sup. Ct., supra note 24.

[26] Id.

[27] World Athletics, supra note 7, at 5.

[28] Holzer, supra note 8.

[29] Semenya v. Int’l Ass’n of Athletics Fed’n, CAS Case No. 2018/0/5794, 158–59 (Ct. Arb. Sport 2019).

[30] Id.

[31] Id.

[32] Holzer, supra note 8.