BERLIN, August 12, 2009 (AFP) - It's hard to imagine bettering three Olympic gold medals and three world records but Jamaican Usain Bolt will be endeavouring to repeat the trick at the World Athletics Championships here.

The 22-year-old goes into the event nigh on invincible, though, with the caveat that he has not faced major rival Tyson Gay this year.

While Bolt enjoyed the Beijing Games Gay - who goes into the championships as the defending champion in the 100 metres, 200m and also the 4x100m relay - endured a miserable time failing even to make the 100m final.

Despite the American setting the fastest times this year in the 100m and 200m the Jamaican is confident he can see off his challenge.

"Personally, no disrespect to Tyson, but that (breaking the 100m record) is going to be a hard task for him," Bolt has said of the American.

Bolt though, who attracted criticism from IOC president Jacques Rogge last year for what he saw as showing a lack of respect for his fellow athletes with his showboating style, does accept that at some point he will be beaten.

"I am ready for anything that comes my way. I am not invincible, I am not unbeatable. Other people will have a good day when I don't, but until then I'll keep winning," he said.

Bolt and his fellow Jamaican sprinters, who dominated the Olympics climaxing with a world record in the men's 4x100m relay, have come under a cloud with the recent revelations that five of their team-mates had tested positive for drugs, though, they were later cleared to run at the championships.

However, Bolt is adamant that it won't distract him from his target at the championships.

"Definitely it's sad to know there are still drugs (in the sport) but for me it doesn't really matter, as long as I'm clean I'm just going forward," he said.

"It's sad for the sport because the sport was getting on so well, I was trying to bring it back. This is probably a step backwards because people start questioning everybody, especially from Jamaica.

"For me it doesn't matter because I will be going out there, day after day, doing my best. I get tested all the time. It shows that people get tested and they get caught if they are on drugs."

Jamaica will be looking to Bolt to lift the shadows of doubt hanging over their athletes and confirm that he really is the master of the sprinting world - not just a bolt out of the blue.