Her case is the latest in a number of doping-related embarrassments for U.S. track team. Among those banned for the Olympics are the reigning world champion at 100 meters, Christian Coleman, who is serving a suspension for missing tests, and the American record holder at 1,500 and 5,000 meters, Shelby Houlihan, who tested positive for a performance enhancer she blamed on tainted meat in a burrito.
