Usain Bolt pledged to keep pushing the barriers after the Jamaican team's astonishing relay triumph on Saturday but admitted he may have reached his peak at the London Olympics.

The sprint superstar anchored the 4x100m relay team to a world record of 36.84sec and matched his triple gold showing in Beijing in 2008, in a typically showmanlike finale to his Olympic campaign.

"For me it's just great that we closed the show on a bang, that is what it meant to me," said Bolt, who took the baton from Yohan Blake, the man he beat to retain both his 100m and 200m titles.

"I knew we could do it because the guys came out here, they were very hyped, they were ready, they were focused," said Bolt.

"It's always a beautiful thing to end on this note," said the 25-year-old. "Last year we did it at the world championships, this year we did it again so for me it's a wonderful feeling," he added.

But as thoughts turn to the next Olympics in Rio de Janeiro in 2016, he admitted he may not be able to repeat his feats of Beijing and London.

"I think at the age of 30 it's going to be hard to do great things then but for me I am going to enjoy the moment.

"I did what I came here to do so I am happy with myself."

He said it was possible he would remain in the sport until Rio, but achieving a third consecutive 100-200-sprint relay gold medal treble could be beyond him.

"I think that the possibility is there but it's going to be very hard to do that because these young guys are coming up.

"Yohan Blake, he is going to be 26 then and he's going to be in great shape so it's going to be hard to really do that."

Bolt has now won seven titles in the eight individual events in which he has competed since the 2008 Beijing Games, his one blip coming when he was disqualified for a false start in the 100m final in the 2011 Daegu worlds.

The world record holder in both the short sprints has also been the key cog in the Jamaican relay team that won all four golds on offer in that time.

But he said the record-breaking Jamaicans were not finished yet as they continue to strive for new standards.

"For me as a person I like to push the barriers, to do things that no one has ever done before because it sets you off from different people, it sets you off from everybody else," said Bolt.

"That's why I change the game, I like to mess around, do fun stuff... We have to continue pushing barriers and there will be some great talent coming out of Jamaica so it's going to be wonderful."

Bolt had knelt and kissed the finishing line in a fond farewell to the Olympic Stadium where he became the Games' brightest star.

He praised the fans in London for pushing him and his relay team to new heights, saying they were the highlight of the Games for him, packing every session of the athletics to capacity and roaring their support.

"To me the fans, without a doubt, they were great, they were loud. I remember I came out in the 100 metres and I was slightly nervous but after they cheered it was gone, I was relaxed."

Bolt said he would be running the rest of the season for his fans because "this is going to be my first time running as a living legend."

But first he intended to celebrate his momentous achievements.

"I don't know if (a party) is in the making, but I'm going out," he said with a laugh.

London Games chief organiser Sebastian Coe, speaking before the 4x100m final, hailed Bolt as "fantastic" for the sport of athletics.

"He's a powerful influence. Is he over the top? It's fine, it's him. It's like telling Daley Thompson to behave in the decathlon," he said.

"Athletics is not a sport of automatons. He's fantastic... part of the beauty of our sport."