Even when he is not running, Usain Bolt is the star of the World Championships.

With an impromptu autograph session before Friday's medal ceremony for his world record in the 200 metres, Bolt got the crowd at the Olympic Stadium cheering.

After the ceremony, with the gold medal draped around his neck, the crowd sang "Happy Birthday To You" to the man who turned 23 yesterday.

The day off

Bolt had the day off from the track, even though the Jamaican sprint team qualified for the 4x100 relay final.

Earlier, fans and volunteers were taking off their shirts to get the Jamaican sprinter's autograph on their clothing, and Bolt was obliging everyone.

He signed autographs for about 30 minutes on items such as tickets, straw hats and flags. And when he was signing, he was leading the tens of thousands of fans in a clapping session.

At this year's worlds, Bolt has shattered two of his world records, lowering the 100 mark to 9.58 and the 200 to 19.19.