The Court of Arbitration for Sport imposed a four-year suspension on American sprinter Erriyon Knighton after upholding appeals from World Athletics and the World Anti-Doping Agency. The 21-year-old athlete recorded a positive test for trenbolone, a muscle-building substance, during March 2024. An independent arbitrator previously cleared Knighton to participate in the 2024 Olympics, where he placed fourth in the 200-meter event. His legal team presented evidence suggesting meat contamination caused the positive result. Officials rejected this defense, determining the proof failed to meet the required standards and was statistically implausible.
The appeals panel found no evidence supporting claims that imported oxtail contained sufficient trenbolone residues to produce the adverse test result. Knighton received immediate enforcement of his ban and was absent from the American team roster for the World Championships taking place September 13-21 in Tokyo. Ethiopian middle-distance runner Diribe Welteji faces similar circumstances with a provisional suspension upheld by the court. The 23-year-old 1500-meter silver medalist from the 2023 World Championships was charged with refusing to provide a doping sample. Her case remains under review while she misses the upcoming competition.
The appeals panel found no evidence supporting claims that imported oxtail contained sufficient trenbolone residues to produce the adverse test result. Knighton received immediate enforcement of his ban and was absent from the American team roster for the World Championships taking place September 13-21 in Tokyo. Ethiopian middle-distance runner Diribe Welteji faces similar circumstances with a provisional suspension upheld by the court. The 23-year-old 1500-meter silver medalist from the 2023 World Championships was charged with refusing to provide a doping sample. Her case remains under review while she misses the upcoming competition.
