Men's 100 metres world record holder Usain Bolt shows the shoes he will use during the Olympic Games after a press conference in Beijing yesterday. - AP

RENOWNED TRACK and field coach Stephen Francis believes it's going to take a superhuman effort to beat his sprint star, Asafa Powell, in Beijing.

Powell, according to Francis, who has been his coach since 2001, said since Usain Bolt's 9.72 seconds world record run at the Reebok Grand Prix in New York on May 31, Powell was a totally different athlete.

Bolt's run erased Powell's previous world mark of 9.74 but, according to Francis, this was a blessing in disguise.

"Since May (when Bolt broke the record), Asafa had been almost reformed," Francis was quoted by Australia's Melbourne Age as saying.

"It has done wonders for his performance," Francis said of Powell, who ran 9.88 seconds to beat Bolt in London.

Powell had a season best 9.82 to win in Monaco last month and appears to be rounding into top form.

"He's in great, great shape and it's going to take a superhuman effort to beat him," said Francis.

Meanwhile, news coming out of China is that Bolt was unaware that his coach Glen Mills had disclosed he would run the sprint double at the Games.

At a news conference yesterday, Bolt said he was "80 per cent sure I'll be doubling".

But, according to several media outlets, when Bolt was told that Mills had already said he would run both, he said: "Well, it seems like I'm doubling then.

"I thought I was 80 per cent sure I would be doubling, now I'm 100 per cent."