World track championships open Saturday

BERLIN, Aug. 14 (UPI) -- The 12th World Track and Field Championships begin Saturday and the stars of the show will make an immediate appearance in Berlin.

Usain Bolt of Jamaica, who dominated the sprints while setting world records at the Beijing Olympics, will begin his run through the 100-meter heats en route to a potential gold medal performance on Sunday.

Bolt's chief challenger is expected to be defending world champion Tyson Gay of the United States, who has regained his form after struggling through an injury-plagued Olympic year.

Three finals will be held on the first day of the nine-day competition, those coming in the men's 20-kilometer walk, the women's 10,000-meter run and the men's shot put.

The center of attention, however, will be the 100, in which the first two rounds will be held. The semifinals and finals will be held Sunday.

Bolt set world marks in both the 100- and 200-meter dashes in Beijing and then ran on Jamaica's gold medal winning 400-meter relay team.

This year's world championship field will include former world record holder Asafa Powell of Jamaica, Olympic silver medalist Richard Thompson of Trinidad & Tobago, former world champion Kim Collins of St. Kitts & Nevis and newly crowned American champion Michael Rogers.

Defending Olympic champion Tomasz Majewski of Poland will be favored to capture the shot put, but the women's distance race should be wide open with the recent withdrawal of double Olympic champion Tirunesh Dibaba of Ethiopia.

There will be 47 gold medals awarded during the championships.