Usain Bolt, the world's fastest man, should dominate the sprints at the worlds in Moscow, but he can't beat the drug shadow engulfing his sport, writes Tym Glaser.

There is one race Usain Bolt can't win at the IAAF Track and Field Championships in Moscow, which starts on Saturday.

As fast as his lanky frame can power through the 100 and 200 meter events, the world record holder in both sprints will not be able to outpace a tide of skepticism which has engulfed the sport due to a spate of star athletes testing positive for illegal substances.

His greatest rival heading into the Russian capital, due to the injury-enforced absence of compatriot and reigning worlds 100m champion Yohan Blake, would have been Tyson Gay, who had clocked the fastest time this year of 9.75, a 10th of a second quicker than the man dubbed 'Lightning'.

However, the US star threw his hands up last month and basically said mea culpa after testing positive for a banned substance at a meet in May.

In a month now of track infamy, Bolt's great Jamaican rival, Asafa Powell, also conceded a positive in July, but still wouldn't have competed in Moscow as he flopped miserably at the Caribbean island's national trials.

No Gay, no Blake, no Powell pretty much just leaves former banned drug cheat Justin Gatlin as the only man who could match strides with Bolt in the blue riband 100m.

Gatlin outpaced Bolt in their sole clash this year over the distance at the Roma meet in June by .01 of a second - 9.94 to 9.95 - but Bolt, coming off an injury, was severely underdone then and should comfortably atone for his false-start debacle in the 100m at the last worlds in Daegu, South Korea.

The fastest man in the world, who will turn 27 just after the championships, is well aware of his sport's growing malaise and his role in trying to cure it.

"I can't let those scandals cloud my job," Bolt wrote in an e-mail to Associated Press. "I see running as a gift given to me to inspire people.

"Of course there is an impact (from the positive tests), but I have to remain focused on making my country proud. Right now, my only focus is winning three gold medals at worlds."

Jamaica is an extremely "proud" sprinting nation but has been rocked by further positives tests by track darlings and Olympic gold medalists Veronica Campbell-Brown, the reigning 200m world champion, and Sherone Simpson, a stablemate of Powell at the MVP Track Club.

Campbell-Brown and Simpson could have pushed for medals in both sprints and formed half of the Jamaican women's 4x100 team.

The 100 now looks a straight-out duel between Olympic champion and Jamaican pocket dynamo Shelly-Ann Fraser-Pryce and US veteran Carmelita Jeter. Although, Nigeria's Blessing Okagbare should not be completely ruled out as she ran a sizzling 10.79 last month at a London meet to beat a final lineup which included Fraser-Pryce (who it must be noted ran 10.77, the world's leading time this year, in the semis).

With no Campbell-Brown, the women's 200 is pretty much reigning Olympic champion Allyson Felix's for the taking. However, the American could have to chase down Fraser-Pryce, who also boasts the fastest 2013 time in that event (22.13).

As close and keenly-fought as those women's dashes will be, the sprints are all really about showman Bolt.

Young clubmate Warren Weir could push him for about 150m in the 200, but Bolt will probably be more concerned about beating his world record of 19.19 than his pal.

On a newly-laid, blue Mondo track at Moscow's Luzhniki Stadium, he could also chase down his otherworldly record of 9.58 in the 100. But, will track and field skeptics care?

The dude from the parish of Trelawny has dominated at every level he has competed in since he was in high school, but more brilliant runs will just raise eyebrows even higher.

Sorry, mon, you just can't win.

(China Daily 08/06/2013 page22)