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
Sprint hurdles at the Olympics world record has been broken only once, by Annelie Ehrhardt at the inaugural 1972 Olympic final. In contrast the 80 m hurdles world record was set at the Olympics in 1932 (four times), 1936, and 1952 (twice). Only three athletes have won two Olympic sprint hurdles gold medals: on the men's side, Lee Calhoun and Roger Kingdom, and on the women's side Shirley Strickland. Strickland is also the only athlete to win three such Olympic medals, having won a bronze medal before her victories. Alvin Kraenzlein is the only athlete to have won two hurdles medals at the same Olympics,