Olympic and world sprint champion Usain Bolt says he has been saddened by the focus on doping in the run-up to the World Athletics Championships, but said it was up to all clean athletes, not just him, to save the sport.
Bolt also insisted he is in good shape to beat his main rival, American Justin Gatlin, who has been banned twice in his career for doping.
Bolt said: "For me, I am running for myself. That's what I do. People say I need to win for my sport. I'm here.
"There are a lot of other athletes running clean and have run clean throughout their career. It's a responsibility of all the athletes to show that they save the sport. It's not only on me but all the athletes."
Bolt's main rival twice banned
Bolt admitted the issue of doping had dominated the run-up to track and field's showpiece event.
He said: "It's sad it's at the forefront of a world championships and not about the competition that's coming up ahead. For me it's sad."
Although he refused to be drawn on the dark doping past of his main rival in the 100m and 200m, he did say: "The rules are there and the rules are there for a reason, if the rules say he can get banned and he can get back in the sport, I can't really do anything about it.
"That's not my call. He's still going to line up and I still have to compete against him. For me I abide by the rules and that's pretty much all."