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
400 metres hurdles of Athletics Federations (IAAF) introduced the event officially as a discipline in 1974, although it was not run at the Olympics until 1984, the first Men's World Champion having been crowned the year before at the inaugural IAAF World Championships in Athletics. A special edition of the Women's 400m Hurdles happened in the 1980 IAAF World Championships in Athletics in response to the Women's 400m Hurdles not being included in the boycotted 1980 Moscow Olympics and the Liberty Bell Classic. Many athletic commentators and officials have often brought up the idea of lifting the height of the women's 400 m