Macey's career has been dogged by injury
British decathlete Dean Macey has retired from athletics after failing to qualify for the 2008 Olympic Games.
The 30-year-old from Canvey Island scored 7,491 points, 209 points short of the required B standard, at a meeting last weekend.
"I can carry on but not to the level I want to be at - I didn't think quitting would be as painful as it has been," Macey told BBC Radio 5 Live.
"It's going to take a few weeks days and months before I get used to it."
The 2006 Commonwealth Games champion said he battled through pain to complete his final decathlon in Hexham.
"I gave it my best shot but I tore both my left and right groin and had to carry on with the help of injections," he added.
"If it was going to be my last decathlon then I was determined to finish it."
He told BBC Radio London 94.9: "With two events to go I had two legs that didn't work.
"If I was ever to put on a Great Britain vest again it would be to do my county proud but I can't do the training to reach those performances."
Macey's breakthrough season came in 1999 when he won silver at the world championships in Seville.
But injury hampered his progress in the sport and it was not until 2001 that he managed to get on the medal podium again when he took bronze at the world championships in Edmonton.
More years of injury followed before Macey's moment of glory came, winning gold at the 2006 Commonwealth Games in Melbourne.
His two appearances at the Olympics, in 2000 and 2004, ended with two fourth-placed finishes.
However, a third appearance proved a step too far and Macey's failure has given a chance for 20-year-old Daniel Awde to prove his worth for Great Britain in the decathlon in Beijing.
"My only regret is that I didn't have a shot at the title more often," Macey said.
"Athletics is everything I've ever known."