LONDON • Jamaican sprint legend Usain Bolt has labelled himself "the underdog" as he seeks to round off his glittering track career by retaining his world 100m title this week.
"That's what I keep reading and what my team keeps telling me, so I've got to prove myself again," the 30-year-old said, ahead of the blue riband event of the IAAF (International Association of Athletics Federations) World Championships.
He started this season in sluggish form, running two 10-second-plus times before hitting some form at the Monaco Diamond League.
"The last race I ran was 9.95sec, which shows I'm going in the right direction," he said.
"Usain Bolt has retired unbeaten in an individual event, unbeatable, unstoppable - for me that would be the best headline. If I show up at a championships, you know I'm fully confident and I'm ready to go."
His target in London is clear - to sign off with a fourth 100m title and a fifth 4x100m relay gold - taking his world haul to 13, to add to his eight Olympic golds.
But he refused to single out who would be his closest rival for the 100m, with heats tomorrow before the semi-final and final on Saturday at the same stadium where he won three gold medals at the 2012 Olympics.
"The seven people who are going to be in that race with me, they're the biggest challengers," he said.
Bolt holds world records of 9.58sec and 19.19sec in the 100m and 200m, both set when winning at the 2009 Berlin worlds. But he picked his then-world record breaking victory (19.30sec) in the 200m at the 2008 Beijing Olympics as his standout performance.
"It's definitely Beijing, the 200m, because I never knew I could break the world record," he said. "That was my main dream growing up - I always wanted to be Olympic 200m champion."
He insisted that motivation was not lacking despite devoting his life athletics since the age of 10.
"Every year you find something else to motivate you," he said. "I thrive on competition."
Athletics has been mired by doping over the years, and track and field's governing body, the IAAF, has been on the back foot over widespread state-sponsored doping in Russia. Russian athletes were barred from the Rio Olympics and will also miss London, although some have been cleared to compete as neutrals.
Bolt has issued a stark warning to his fellow athletes that they must stop doping otherwise track and field will die.
"I don't think it gets any worse than that," he said, referring to the problems in Russia that left the sport at rock bottom.
"But it's on its way back up now. Over the years we're doing a better job, it's getting clean and we're catching up to a lot of athletes. There's an understanding that if you cheat you will get caught.
"Hopefully, athletes will see what's going on and understand that if they don't stop what they're doing, the sport will die."
AGENCE FRANCE-PRESSE, THE GUARDIAN, REUTERS