CHICAGO -- Lance Armstrong's lifetime ban by the U.S. Anti-Doping Agency will keep him from running next month's Chicago Marathon.

Marathon officials said Friday that Armstrong never formally registered for the Oct. 7 race. But he was considering running with Livestrong's charity team, runners who do the marathon as a fundraiser for the Lance Armstrong Foundation. Preventing Armstrong from running with them is "frustrating and unfortunate," foundation president and CEO Doug Ulman said, and could harm the group's fundraising efforts.

The marathon is sanctioned by USA Track and Field, and Armstrong's ban prevents him from entering any events organized, authorized or sanctioned by federations that follow the World Anti-Doping Agency's rules. Ironman France barred Armstrong for similar reasons after USADA filed doping charges against him in June.

"The code is very clear regarding the ineligibility of sanctioned athletes to compete in other sports," USATF spokeswoman Jill Geer said in an email. "USATF is a signatory to the WADA code, and we confirmed with the U.S. Anti-Doping Agency that Mr. Armstrong's ban extends to track and field, road running and all of our sport's disciplines."

USATF sanctioning is important for the race beyond increasing its prestige. It guarantees that race results are formally recognized around the world, including records.

Armstrong has long denied doping, but chose last month not to fight the USADA charges. USADA wiped out 14 years of his results -- including his record seven Tour de France titles -- and barred him for life after concluding he used banned substances.

One accolade Armstrong may be able to keep is his bronze medal from the 2000 Sydney Games.

A senior IOC member told The Associated Press that it was unclear if the Olympic body can take the time trial medal from Armstrong.

"It's an interesting case on a legal point of view," said Denis Oswald, a Swiss lawyer and longtime member of the IOC's legal commission.

Information from The Associated Press was used in this report.