In the athletes' village at the Olympic Park in east London, everyone has to improvise. For Usain Bolt today, arriving in the vast 5,000 seat dining room for a spot of lunch, that meant assembling a makeshift security cordon from his Jamaican team-mates. A pair of broad shot putters anddiscus throwers sporting chunky headphones in the yellow, green and black of Jamaica formed the advanced guard while a 400m runner and a 100m relay sprinter made up the rear cordon.