You Tube 4x400m Relay World Championships. Reaction and analysis after britain's 4x400m relay teams win bronze. Here are all the relay splits and final results from.

World athletics indoor championships, indoor | final | 4×400 metres relay | results Rai benjamin, the 400m hurdles bronze medallist, extended usa’s lead on the last leg and went on to cross the line first in 2:57.31, earning usa’s ninth gold medal.