Triple Olympic and world sprint champion Usain Bolt of Jamaica said on Monday he expects years of fast feats to ease doping doubts in athletics and has no plans to play American football.

Appearing on ESPN programs and in light-hearted races outside the television sport network's studios, Bolt said he feels he must prove himself to a skeptical sports world in the wake of past doping scandals.

"I have to prove myself to the world that you can run fast without it," Bolt said.

Bolt cited the speeds he and countryman Asafa Powell and American Tyson Gay have achieved without positive doping tests.

"We just (have to) continue to run fast," Bolt said. "In a couple of years everyone will continue to watch again and have less doubts."

Bolt won gold in the 100m, 200 and 4x100 relay in world record times at last year's Beijing Olympics and last month in Berlin set world records of 9.58 secs in the 100 and 19.19 in the 200 and helped a relay title in a World Championships treble.

"I want to be a legend in the sport. For me it's all a focus on winning championships after championships," Bolt said.

"I don't consider myself a legend. When I defend my titles I will consider myself a legend."

Bolt's defending of World and Olympic gold should be the feature attraction of the 2011 IAAF World Championships in Daegu, South Korea, and the 2012 London Olympics.

Introduced for a live appearance on a news recap show filled with National Football League highlights, Bolt made it clear the gridiron is not in his future, in part because his size would preclude him from his favored position.

"I wouldn't want to play in the NFL," Bolt said. "If I did, I'd want to play running back but they say I'm too tall. They would want me to play wide receiver. They get hit too much. I'm not in the mood to be hit that much."

Bolt, 23, would not rule out giving "real" football a try.

"It could be good. I would definitely give soccer more consideration," Bolt said.

Bolt is looking at adding the long jump and 400m to his event list at some stage, saying he "probably" will someday attempt the 400 but "I don't want to train for it" while looking at the long jump as a late-career move.

"I want to do that before I retire," Bolt said. "It's not anything I want to do now. When young guys start coming up and beating me I will probably do the long jump."

The Jamaican superstar credited becoming the "world's fastest man" to dedication and work but stopped short of calling himself a "larger than life" figure.

"Definitely you have to have the talent but you've got to work hard," Bolt said. "I feel very good because I train so hard. I'm not larger than life. But I'm working on it."

Bolt says he does not worry about verbal intimidation from rivals.

"You can say whatever you want to say but what goes on is when you show up in the race," Bolt said.

Bolt wore the world medals he captured last month at Berlin for his ESPN appearance, the metal clinking on his yellow shirt as he made his signature "Lightning Bolt" pose and said he saw no ultimate 100 time goal. I really don't think about that," Bolt said. "For me I aim for winning. The time will come."