How it works
Four athletes each complete one 400m lap. The first lap is run in designated lanes, as is the second - until the beginning of the back straight. Thereafter runners usually battle to hold the inside line. Each runner must carry a baton during his or her leg and hand it to the subsequent runner within the changeover zone, which is sited 10m either side of what will be finish line.
History
Though the concept can be traced to Ancient Greece, where a 'message stick' was delivered via a series of couriers, modern relays emulate the charity races organised by the New York fire service in the 1880s, in which red pennants were handed over every 300 yards. The first Olympic relay took place in 1908 – but was split into two legs of 200m, followed by one of 400m and another of 800m. The first Olympic 4x400m relay for men took place in 1912; the first for women was in 1972.
Did you know
Michael Johnson ran a staggering unofficial split of 42.94 to anchor the USA to gold at the 1993 World Championships.
Gold standard
The USA have dominated the men’s scene, winning 16 of the 21 Olympic titles. American women, meanwhile, have won four of the nine Olympic golds. Nigeria, Jamaica, the Bahamas and Great Britain (among the men) and Russia and Jamaica (among the women) are the other major forces.