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IAAF announces new testosterone rule for female runners

New guidelines to address perceived unfair performance advantages by athletes with DSD

Caster Semenya

On Sunday the U.K.’s Guardian newspaper reported the IOC’s intention to introduce new rules on allowable blood levels of testosterone in female athletes, due to the perception of an unfair advantage by intersex and transgender athletes. Today the IAAF announced a similar rule change, to take effect on November 1 of this year, and applying to the 2020 Tokyo Olympics, though its focus is on female runners born with differences of sexual development (DSDs). The new maximum for testosterone is five nanomoles per litre, half what it was before the rule was dropped in 2015. It affects females racing in the 400m, 800m, hurdles, mile, 1,500m, and combined events over the same distances.

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The rule is designed to address the issue posed by Caster Semenya, the South African double gold-medallist at the recent Commonwealth Games who was born with hyperandrogenism (naturally high levels of male sex hormones, including testosterone) and Dutee Chand, the Indian sprinter who shares the condition and whose case sparked an easing of the rules in 2015. After winning the world championship in 2009, Semenya was required to take testosterone-lowering drugs for the purpose of competition until that rule was dropped in 2015. Under the new rule she will now be required to lower her hormone level to half of what was permissible prior to 2015.

The complex issue of female athletes’ hormone levels has been debated for years, and the issues of DSD and transgender athletes poorly understood. In 2004, transgender athletes were allowed to compete in the Olympics provided they had had gender reassignment surgery and two years of hormone-replacement therapy (HRT). In 2015, the surgery requirement was dropped and the period of HRT reduced to one year. 

Research is ongoing into whether a transgender athlete who has taken hormones retains an unfair advantage over other women in athletic competition. However, the latest rule change is focused more around the issue of DSD athletes, such as Semenya and Chand. The IAAF claims that such athletes’ natural testosterone levels may be as high or in some cases even higher than that of normal males, such that their athletic performance is significantly and unfairly enhanced (possibly in excess of nine per cent), because of the resulting increased muscle mass and circulating haemoglobin.

Some sports scientists have speculated that the new rules could diminish Semenya’s performance in the 800m by a whopping five seconds.

The IAAF notes that the purpose of the new guidelines is to ensure a level playing field for all athletes (which are already separated by age and sex), and that athletes who do not wish to lower their hormone levels may still compete at the national level, and in distances shorter than 400m or greater than the 1,500m at the international level. However those who opt to compete within the new guidelines will be required to maintain their hormone levels even outside of competition in order to remain eligible to compete.