400 metres hurdles to 400 metres, or one lap of the stadium, and the number of hurdles was reduced to ten. The official height of the hurdles was set to 91.4 cm (3 feet) for men and 76.20 cm (2 ft, 6 inches) for women. The hurdles were now placed on the course with a run-up to the first hurdle of 45 metres, a distance between the hurdles of 35 metres each, and a home stretch from the last hurdle to the finish line of 40 metres. The first documented 400 m hurdles race for women took place in 1971. The International Association
Athletics at the 1968 Summer Olympics – Men's 400 metres hurdles then John Sherwood edged past him at the line. The men's 400m hurdles competition started with four heats, where the four fastest runners from each race qualified to one of the two semifinals groups. The top four competitors from each semifinals group advanced to the final. Prior to the competition, the existing World and Olympic records were as follows. Heat 1 Heat 2 Heat 3 Heat 4 Heat 1 Heat 2 Athletics at the 1968 Summer Olympics – Men's 400 metres hurdles The Men's 400 metres hurdles competition at the 1968 Summer Olympics in Mexico City, Mexico took place on