Erriyon Knighton: Court of Arbitration For Sport Details Why America's Next Big Sprint Icon Was Banned For Four Years

The Athletics Integrity Unit (AIU) has released the decision of the Court of Arbitration for Sport (CAS) Panel, which upheld the AIU’s appeal against Erriyon Knighton, the 21-year-old US sprinter and double World Championships medallist.

The panel imposed a four-year ban following a positive test for a metabolite of Trenbolone in an out-of-competition sample collected in March 2024.

Trenbolone, an anabolic steroid used to enhance muscle mass and strength, is banned both in and out of competition by the World Anti-Doping Agency (WADA). It is also commonly used in the US meat industry to promote growth in cattle.

Initially, a sole US arbitrator accepted Erriyon Knighton’s claim that he had consumed contaminated oxtail from a Florida restaurant, which could have caused the positive result, and ruled that he bore no fault or negligence, imposing no period of ineligibility.

However, both the AIU and WADA appealed, arguing that the Trenbolone concentrations in meat obtained from the same restaurant could not have caused the levels found in Knighton’s sample, and that his evidence “fell short of the required proof of source on a balance of probabilities.”

The three-member CAS Panel, chaired by Jacques Radoux, concluded that Erriyon Knighton had failed to establish the source of the substance.

The panel found several assumptions made by Erriyon Knighton’s experts to be ‘highly unlikely’ and determined that the evidence did not support the idea that imported or local meat could contain Trenbolone at levels sufficient to produce his positive test.

While the contamination scenario was not ‘scientifically impossible,’ the panel ruled it was not ‘plausible’ and certainly not more likely than intentional use.

The CAS Panel also highlighted that Erriyon Knighton failed to prove a lack of intent, noting that factors such as low concentration, negative tests near the time of the positive, or polygraph results could not exclude deliberate use.

As a result, the panel upheld the AIU’s appeal, banning Erriyon Knighton for four years. The athlete’s results from March 26 to April 12, 2024, were disqualified, though he received credit for the provisional suspension he served from April 12 to June 19, 2024.