US authorities, under pressure from world anti-doping authorities, have done a U-turn on allowing runner Shelby Houlihan to compete in Olympic trials starting Friday. USA Track and Field had initially said it would allow the 28-year-old, who blames a burrito for a positive anabolic steroids test, to compete for a spot on the team until all avenues of appeal had been exhausted, reports USA Today. US Olympic & Paralympic Committee CEO Sarah Hirshland, however, said Thursday that the committee will abide by World Anti-Doping Agency rules that ban Houlihan from participating. Houlihan, who holds the US records for the 1,500- and 5,000-meter runs, has been banned from competing for four years.
The ban was upheld by the Court of Arbitration for Sport this week. USATF CEO Max Siegel said Houlihan was taken off start lists after the Athletics Integrity Unit anti-doping body officially notified USATF of the suspension, the AP reports. "Process is important, particularly when individuals' careers and lives are at stake," Siegel said. Houlihan denies ever taking performance-enhancing substances and says the positive result must have come from pig offal in a burrito she ate 10 hours before the doping test, CNN reports. Her only chance of a reprieve in time for Olympic trials will be if Switzerland's top federal court fast-tracks the case and grants her relief, an outcome analysts consider highly unlikely. (Read more track and field stories.)