Bolt vows "never again" after emotional London farewell

After embarking on a special lap of honour so slow that you could not believe that we were saying farewell to the world's fastest man, Bolt was asked by reporters already missing him whether he might ever change his mind.

"No, I've seen too many people come back and make things worse and shame themselves. I won't be one of those people who come back," Bolt said firmly.

Twenty four hours earlier, the 30-year-old Jamaican's matchless sprint career had ended painfully on the last leg of the 4 x 100 metres relay final as he crumpled to the ground in the London Stadium with a hamstring injury.

Bolt, who admitted that it had been a terrible end of a "stressful" championship for him after also losing his 100 metres crown, said he had felt consoled on Sunday when someone told him "Muhammad Ali lost his last fight too -- so don't be too stressed about it".

Already he was looking forward to an exciting future, he said, with his management camp talking to IAAF President Sebastian Coe, about what he might be able to do for the sport in an ambassadorial capacity.

He also revealed that his coach Glen Mills, the sage of Jamaican athletics, wanted him to become his coaching assistant.

"So we'll see how that goes," Bolt smiled about the man who has put him through a lifetime of pain.

And the great man even had reporters laughing when he gave them a vision of what a 50-year-old Usain Bolt might end up doing.

"I've no idea. Hopefully, with three kids, married, still in track and field, trying to help the sport, watching it grow," he said.

"I don't know if I'd take my kids to the track, though. I won't be one of those parents who force their kids into things they don't want to do."

It was a wonderful night of celebration for athletics' greatest entertainer with Bolt honoured one last time at the stadium where he achieved the second of his three Olympic sprint doubles.

Coe and the Mayor of London, Sadiq Khan, presented him with a piece of the 2012 track as a memento before he embarked on his celebration lap, slowly soaking up all the non-stop cheers from the 56,000 full house - all to a Bob Marley soundtrack.

He went over to the 200 metres and 100 metres start lines, knelt down and crossed himself.

"I was saying goodbye to my fans but to my events also," he said, admitting he had been close to tears.

And after taking rather longer than the 9.63 seconds it took him to win the 100 metres crown here in 2012, he eventually stopped at the finish line and gave everyone his trademark lightning bolt impression.

Before he had set off on the lap, he had told the crowd he just wanted to entertain and put on a show.

He did just that before also getting a rare round of applause in the press room from "some of you guys who wrote bad things about me".

Asked what he hoped his legacy would be, he paused for a moment before saying: "I've proved with hard work anything is possible. I personally think this is a good message to the kids. 'Push on, be strong, be as good as you can be' - that's a good legacy to leave'."

He was also adamant that he would "preach" to youngsters about avoiding the evil of performance-enhancing drugs.

"The sport hit rock bottom last year and the year before and now we're on the way back up," he said.