The British runner Mo Farah has a chance to make some history on Saturday in Russia, at the IAAF World Championships in track and field.
He's already won the 10,000 meters race, and if he wins the 5,000 this weekend he'll become just the second man to complete the distance double at both the Olympics and the Worlds.
Jamaican sprinter Usain Bolt could also complete a similar double if he wins the 200 meters on Saturday.
Bolt already won the 100 in Moscow, and he won both races in the 2012 Olympics in London, just as Farah did last summer.
We speak to BBC sports commentator and retired world track champion Steve Cram, who has been covering the championships.
This segment aired on August 15, 2013.