In recent weeks the International Association of Athletics Federations (IAAF) has defended itself over charges laid in articles by The Sunday Times, in collaboration with German TV company ARD, that it has neglected to follow up numerous athletes with “suspicious” blood levels and sought to block publication of a potentially embarrassing survey of athletes’ attitudes to doping conducted at the 2011 World Championships in Daegu.

“All I’ve been hearing over the past couple of weeks is just ‘doping, doping, doping’,” Bolt told a press conference organised by his kit sponsor Puma two days before the World Championships begin here.

“It’s taken centre stage.

“Definitely it’s sad that it’s at the forefront of the Championship and not the competition.

“For me I can’t do anything about it because you are the ones writing about it.

“InitialIy I’m running for myself, that’s what I do.

"People say I need to win for my sport, but I can’t do that by myself, I think it’s also the responsibility of all the other athletes - because I think there a lot of athletes out there who are running clean.”

Bolt said he is “definitely feeling good” about defending his world 100 and 200 metres titles here, although he wishes he could have had more racing practice after making a late start to the season because of a lingering injury problem.

The Jamaican has only broken 10 seconds for the 100m twice - running 9.87sec in both the heats and final of last month’s IAAF Diamond League meeting in London - and has not raced over 200m.

In the meantime Gatlin has produced four sub-9.80 100m times, including the 2015 best so far of 9.74, and Bolt’s team-mate Asafa Powell has clocked 9.81.

Bolt, who turns 29 tomorrow, was buoyant, however, as he assessed his chances of repeating the success he had in the Bird’s Nest in his breakthrough year of 2008, when he claimed three Olympic gold medals and set world records of 9.69 in the 100m and 19.30 in the 200m.

“I’m definitely feeling good,” he said.

“I only wish I could have brought more races to the Championships, but it’s just one of those things.

“My start is always an issue, but my coach and I worked on a few things coming into the Championships, everything is all right, the way it’s supposed to be, I did a final session yesterday and my coach was smiling.

 “I’m at my best. I’m having great fun, I’m happy with where I’m at, I’m running good, my start has come together at the right time, I‘m happy. I’m ready to go.”

Asked about his injury, he responded: “I don’t know if you should call it an injury, I had slight joint problems that meant I wasn’t able to get enough power out of my legs because I wasn’t getting any flex.

"So I had to go and see the doctor to work out what I needed to do.

“I had the two races in London last month, I was hoping I would get a chance to run a bit more before the Championships but it’s just one of those things.

 “I haven’t run a 200 since I got back into shape although I have done time trials over different distances, racing over 100m has given me confidence, I’m not worried, as long as my coach is happy, which he is.”

Bolt admitted that it had been “frustrating” watching others performing well earlier in the season.

“Watching athletes at home - it’s always frustrating.

"Seeing another time has been set is really frustrating - you can’t go out there and improve yourself, you want to be on top of things.

"But when I am at Championships everything comes together for me.”

Asked to reflect upon his 6-1 record over Gatlin, Bolt responded: “Competition is competition, it’s always who is in the best form and executes well.

"I’m ready now, all I need to do right now is execute - that’s the key thing."

Asked if he was “battling for the soul” of the sport following the recent bad publicity over doping allegations, he replied: “For me, initialIy I’m running for myself, that’s what I do.

"People say I need to win for my sport, but I can’t do that by myself.

"I think it’s the responsibility of all the other athletes - because I think there a lot of athletes out there who are running clean.

"It’s not only just on me because I can’t do it by myself, it’s also up to the other athletes to show the sport can go forward, and that you don’t cheat.

“I try to just do what’s right, by the rules of the IAAF and WADA (World Anti-Doping Agency).

"We all know the rules and we’ve just got to abide by theme.

"As I said, it’s not only up to me, I can’t do it myself, because I’m not the only one in the sport, so all the athletes need to understand the rules and abide by them."

Bolt will be a bearded presence in Beijing - which he explained was a conscious decision.

“Over the years people sometimes ask me if I have any superstitions, I’ve noticed that every other big year, I’ve always shaved, but for World Championships, I have a beard," he said. 

"At the World Championships I don’t cut my hair, so next year for the Olympics I will have a low cut.”

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