"However hard today is, finally closing the door on that dream, at least I can know that I truly have tried absolutely everything," Radcliffe said in a statement.
"Not one day was wasted in getting treatment, scans or interventions that might help. I cross-trained as hard as I could whenever I was unable to run to give myself every chance should the pain settle. Now is the time to accept that it is just not going to settle in time.
“As desperate as I was to be part of the amazing experience of the London Olympics, I don’t want to be there below my best.”
Radcliffe has not won a medal in the past four Olympics. She finished 23rd in Beijing after failing to finish in Athens.
She came fourth in the 10,000 meters in Sydney in 2000 and was fifth in the 5,000 in Atlanta, the AP said.
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