In 2019, the Court of Arbitration for Sport (CAS) ruled that athletes with differences in sex development (DSD), resulting in elevated levels of the male sex hormone testosterone, would have to medically or surgically reduce their testosterone levels to less than 5nmol/L, in order to compete in several women’s athletic events.
This controversial ruling applied to events including the 400m, 400m hurdles, 800m, 1500m and one mile.
Following the 2019 CAS ruling, three-time world 800m champion and DSD athlete Caster Semenya began legal proceedings against athletics governing body, the IAAF, to challenge the decision.
On Tuesday, Semenya lost her appeal when a Swiss federal tribunal announced its support of the 2019 CAS decision. The tribunal agreed that, although discriminatory to DSD athletes, the ruling was “necessary, reasonable and proportionate” to protect the integrity of women’s sport.
Semenya disputes this decision, saying that “Excluding female athletes or endangering our health solely because of our natural ability puts world athletics on the wrong side of history”.
It is an undisputed biological fact that the physiology of male athletes gives them a significant advantage over women. It is for this reason that sporting events have historically been divided into a binary classification of gender in which women and men compete separately. However, what happens when someone doesn’t fit in these binary classes?
Difference of Sex Development (DSD) is a term used to describe a group of conditions that are characterized by an atypical development of biological sex. For example, a DSD individual may possess the male determining Y chromosome however may, for a variety of biological reasons, develop the physical attributes of a woman.
Female DSD individuals tend to have elevated levels of the male sex hormone testosterone, and therefore are more likely than women without a DSD to develop masculine attributes that are believed to improve sporting performance. These attributes may include an increased muscle mass, a stronger bone structure and a larger heart.
The IAAF deems naturally occurring elevated levels of testosterone to provide an unfair advantage, and therefore requires DSD athletes to medically reduce their testosterone levels below 5nmol/L in order to compete in women’s middle-distance athletic events.
Unlike athletes who have experienced an unfair athletic advantage due to deliberate acts of doping, DSD athletes benefit from naturally occurring elevated testosterone levels. Therefore, many argue that the advantages experienced by DSD athletes are no different to other genetic abnormalities that are celebrated in professional sport – such as Michael Phelps’ ability to produce less lactic acid than other athletes.
“Her [Caster Semenya’s] genetic gift should be celebrated, not discriminated against”.Caster Semenya's Legal Team
The IAAF’s decision has also been criticised on the grounds that it lacks evidence to prove that DSD athletes experience a significant genetic advantage.
Leading sports scientist Professor Ross Tucker describes the evidence provided by the IAAF as “totally lacking to the point of being fatally flawed”. He also suggests that the medical and surgical methods of reducing testosterone could pose a significant potential health risk to DSD athletes.
Unable to defend her 800m title at the Tokyo Olympics next summer without undergoing potentially harmful hormone therapy, Semenya is now forced to consider other options. She has suggested that she may turn her attention to the 200 meters – an event that is currently not regulated by IAAF policy – however, she may also choose to compete over a longer distance such as the 3000 meters or to retire from sport entirely.