Usain Bolt shunned the media after training on Thursday, two days before he takes to the track at the world championships, but coach Glen Mills said the sprinter was motivated, healthy and "in good shape to run very well".

The distinctively tall figure of Bolt, dressed in a black, yellow and green Jamaican T-shirt, strode around the sunbaked training track in Moscow in front of a crowd of fans and journalists.

As some of his team- mates came over to talk to the media, the triple Olympic champion in 2008 and 2012 put on headphones and walked across the infield in the opposite direction, pausing only to greet other athletes on his way.

The world 100m and 200m record holder will start his bid to regain his world 100 title - which he lost to compatriot Yohan Blake in Daegu after false-starting in the 2011 final - in Saturday's heats. If there are no hiccups, he will line up in Sunday's final as the hot favorite for gold.

Bolt trained with a large bandage behind his right calf, but Mills said it was to protect a small cut.

"He's in good health," Mills said, as pop music drifted on the breeze from the sports complex's building. "It's a scrape from a spike, it's nothing."

Reuters