Despite his amazing record-breaking feats, Jamaican sprint phenomenon Usain Bolt says his sole aspiration is to write his name in history as a legend.

Bolt, who celebrated his 23rd birthday yesterday, ran a mind-boggling 19.19 seconds to shatter his own 200 metres record and win the event at the World Championships here Thursday.

The feat was Bolt's second record of the meet after he clocked an amazing 9.58 seconds in blazing his way to another world record in the 100 metres and capturing the event last Sunday.

But with speculation now swirling over how much faster he can run, Bolt was quick to reiterate his real goal in athletics.

Headwind

"I keep telling you - my main (goal) is to become a legend. That's the aim for me and that's what I'm working on," he told reporters.

"I don't know (if) I would have gone under 19 seconds without a headwind. I guess, maybe, (but) you never know. For me, I don't worry about anything because it's a part of life, I just go out there and run and try to do my best at all times."

Bolt's astonishing exploits come on the heels of his results at last year's Beijing Olympics where he also snatched the sprint double in amazing world-record fashion.

He added the 4x100 metres relay to his haul then to finish with three gold medals and said he was also looking forward to leaving the historic German city with a similar number.

"First, we've got to get through the rounds (in the 4x100). Last year, the girls from Jamaica were the favourites to win and they messed up the baton change, so the first thing is to get the baton around," said Bolt.

" ... For me, I'm just hoping we get the baton around and we win so I get a third gold medal and go home smiling."

With records in the 100 and 200 metres, speculation has also raged over Bolt's pursuit of the 400 metres title.

Extra hard

The sprint sensation again distanced himself from the event, stressing he was not even remotely interested in taking on the lap.

"I've got to work extra hard to run the 400 metres," Bolt said.

"Everybody knows I'm not going to run the 400 metres unless my coach gives me a really good reason. I'm just trying to stay as far away from that as possible."