Kelly Holmes, who raced to double victory at the 2004 Olympic Games, announced today that her athletics career is officially over.

"This has been a very tough decision to make," Holmes, the reigning Olympic 800 and 1500 meter champion, said in a statement distributed to media this morning. "Hanging up my spikes forever is a big step."

Her announcement, made at a press conference in London today, ended speculation that the 35-year-old former army sergeant would conclude her career with an attempt to defend her 1500 meter title at the Commonwealth Games in Melbourne in March.

"I would have loved to compete in Melbourne, but know that the time is right for me to move on and take up some of the amazing opportunities that have been presented to me."

Culminating an up-and-down international career that began with the 1994 Commonwealth Games title in the 1500, Holmes became one of the biggest celebrities in Great Britain after her double victory in Athens last year, and was later named the nation's sport personality of the year. She was also named a Dame by Queen Elizabeth.

In 1995, Holmes was a double medallist at the 1995 World Championships, finishing second at 1500 meters, and taking the bronze in the 800. Running with a stress fracture at the 1996 Olympic Games in Atlanta, she was fourth in the 800 and 11th in the 1500, finishing well behind double winner Svetlana Masterkova, whose feat she would emulate eight years later. She claimed her first Olympic medal in 2000, where she finished third in the 800.

Since her Athens triumph, Holmes hinted on numerous occasions that finding the inspiration to continue competitive sport was a difficult chore. Still hampered by injury, Holmes was forced to bypass the World Championships in Helsinki this year, and raced just four times in 2005, twice indoors and twice outdoors. In her final appearance on the track, still injured, she hobbled home in eighth place against a modest field in the 800 meters at the Norwich Union Super Grand Prix in Sheffield, England. Holmes plan to stay active in the sport. She is an Ambassador for the London 2012 Olympic Organizing Committee, will continue to work with young athletes, and perhaps as an IAAF Ambassador, an invitation she received today from the world governing body's President, Lamine Diack.

"I have a number of irons in the fire," she said. "It is an exciting time for me but also daunting."

David Moorcroft, chief executive of UK Athletics, said: "Kelly has had a very long and successful career in athletics and we will always remember those marvellous moments in Athens when she went from the status of great athlete to true legend by winning the 800m and 1500m titles."