Athletics trainer Alberto Salazar has to serve his four-year suspension for doping violations.
Salazar's appeal before the International Court of Justice (CAS) failed, as did the also banned endocrinologist Jeffrey Brown, who had treated Salazar's athletes.
Salazar, who trained with Britain's running star Mo Farah and ran the now-discontinued Nike Oregon Project, was suspended in 2019.
The misconducts that the American anti-doping authority had compiled in the Salazar case cover the years 2010 to 2014.
The native Cuban is said to have manipulated doping samples and acted with prohibited means. In July, Salazar was banned from the American Safe Sport Center for life after athletes from the Oregon Project accused him of sexual and emotional misconduct. The former marathon runner admitted "callous or insensitive" comments but denied that women athletes suffered abuse or discrimination under his supervision.