m runner (back injury) Laura Ikauniece, Latvia heptathlete Testosterone rule The three 2016 Olympic medallists in the women's 800 metres were all excluded from the 2019 World Athletics Championships under the IAAF's testosterone rules. Caster Semenya, Francine Niyonsaba and Margaret Wambui all acknowledged they had a difference in sex development (DSD) which resulted in their bodies producing levels of testosterone above the limits set by the IAAF for women's competition. The IAAF rules stipulate such athletes must take testosterone-reducing medication in order to compete in women's races. Caster Semenya's appeal to the Court of Arbitration for Sport (CAS) against this rule was ongoing at the time of the World Championships. All three athletes declined to adhere to the IAAF's ruling and thus could not compete. CAS had previously made a decision in May 2019 to uphold the IAAF's rules on the grounds that they were discriminatory to athletes with a DSD, but that discriminatory action was "a necessary, reasonable and proportionate means of achieving the legitimate objective of ensuring fair competition in female athletics". Kenyan athletes, 800 m national champion Jackline Wambui and Linda Kageha, who was in the mixed relay team, were excluded from selection for Kenya as they refused to submit to a testosterone test. Because of the testosterone rule, 400 metres world No. 3 Aminatou Seyni competed in the women's 200 metres instead of women's 400 metres. Anti-doping Working alongside the Local Organising Committee and the Qatar Anti-Doping Commission, the IAAF's Athletics Integrity Unit oversaw an anti-doping programme at the World Championships for the second time, having been created two years earlier. The 2019 World Championships was the first in which national federations were obligated to ensure all athletes they selected had been subject to three out-of-competition tests and one in-competition test prior to the competition. This rule resulted in the exclusion of two Kenyan runners, Michael Kibet and Daniel Simiyu, who had not failed a test but had not been tested sufficiently before Doha. At the host venue, around 700 athletes' blood samples were collected as part of the biological passport scheme designed to identify the use of steroids, EPO or human growth hormone. A further 500 in-competition tests are due to take place, mostly urine-based. Samples taken at the World Championships will be transferred to a World Anti-Doping Agency-accredited laboratory outside of the host country, in order to remove conflicts of interest that had affected