The Court of Arbitration for Sport rejected Claudia Pechstein's urgent request to let her compete at the speedskating World Cup races in Berlin starting Friday.
The five-time Olympic champion from Germany is appealing a two-year ban imposed by the International Skating Union for suspected blood doping.
Pechstein had been told she cannot race before the court delivers a verdict, which is expected within two weeks.
A CAS panel of three arbitrators on Friday refused to change an interim ruling that lets her train but not race competitively.
"In particular, (Pechstein) had not established in her request that her non-participation ... would cause her 'irreparable harm,'" the court said in a statement.
Pechstein wanted permission to race in Berlin this weekend and at the World Cup meet held Nov. 11-13 in Heerenveen, Netherlands.
Germany's most successful Winter Olympian hopes to be cleared by the court and then compete in her sixth games in Vancouver next February.
Pechstein has won a gold medal at four straight Olympics, and also has two silver medals and two bronzes in her career.
The ISU banned the 37-year-old Pechstein in July, saying she returned blood samples with abnormal levels at the World Allround Championships held last February at Hamar, Norway.
The governing body compared samples Pechstein had given since 2000 before banning her until Feb. 9, 2011.
Pechstein denied doping and was supported by the German skating federation at her two-day appeal hearing last month.
