World Athletics 2011 Campbell on the psychology of the sprint start
Darren Campbell, 200m silver medallist at the Sydney Olympics, talks BBC Sport's Tom Fordyce through the psychology of the sprint start, and demonstrates with a game of 'slaps'.
Usain Bolt, disqualified from the 100m final at the World Championships last weekend after a false start, goes for gold in the 200m on Saturday in Daegu.
Listen to Darren and the BBC Radio 5 Live team commentate on Bolt's race on Saturday at 1320 BST.
Available to UK users only.