Jamaican sprinter Asafa Powell has insisted that his "best is yet to come", despite the fact that he turns 33 later this year.
The sprinter, who held the 100m world record between 2005 and 2008, is a former Olympic, World Athletics Championships and Commonwealth Games gold medalist.
However, ahead of the Worlds in Beijing this August, Powell has warned his competitors that he still has improvements to make.
"I think I'm capable of doing a lot more than most of the sprinters out there. My best is yet to come, so it's just to be patient," he told Reuters.
"I feel a lot stronger. I'm a lot more focused and I think I'm smarter now, so I know what it takes to do it. It's just to put myself out there and do what I'm supposed to do."
Powell returned to action in July 2014 after his 18-month doping suspension was overturned by the Court of Arbitration for Sport.
