As Olympic champion Usain Bolt prepares for the world championships, he finds himself immersed in the conversation that has dominated track and field this past year: the issue of doping. 

And Bolt insists he can't be the only symbol for clean racing. 

"I can't do it by myself," he said Thursday, per ESPN.com. "People say I need to win for the sport. But there are a lot of other athletes who are running clean, and they've been running clean their whole career. It's not just on me but on all the athletes."

He was also disappointed that the conversation of doping has become the dominant topic surrounding his sport: "All I've been hearing about the past couple weeks is doping, doping, doping. It definitely is sad that it's in the forefront of the world championships, and it's not about the competition that's coming up."

Doping was brought to the forefront once again in early August, when the Sunday Times and German broadcaster ARD reported that 146 Olympic and world-championship medals in non-sprinting events were won by athletes with suspicious drug test results after gaining access to a database with 12,000 blood tests from 5,000 athletes.

The sprinters haven't been immune to doping issues, however, as Bolt will be facing Justin Gatlin, Tyson Gay and Asafa Powell on Sunday, all of whom have been suspended in the past for failing drug tests but have been reinstated after serving those suspensions. 

"Rules are rules and are there for a reason," Bolt said. "If the rules say you can get back in the sport, I can't do anything about it. I abide by the rules and that's pretty much all."

Bolt has been the dominant force in the world of sprinting for the past seven years, winning gold in the 100m, 200m and 4x100m relay in the past two Olympic Games and eight golds and two silvers in the world championships. He also holds the world record in the 100m, 200m and 4x100m events.

While his reign over the sport will one day come to a close, he'll still be the favorite at the world championships and next year's Olympic Games. The fact that Bolt has never been found guilty of doping in an era where it has been such an issue in the sport makes his accomplishments all the more impressive.