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
300 metres hurdles hurdles for those divisions. By that time, 27-inch hurdles were embedded in the rulebook. Women also do the 300 hurdles, W50 to W65 divisions. Like the men, the W50 and W55 divisions do 30-inch hurdles, W60 and W65 do (27 inch) hurdles, and W70+ do the 200-metre version over 27-inch hurdles. The idea of using 27-inch (68.6 cm) hurdles was introduced in Europe in 2000. The increment does not exist on standard hurdles, which caused resistance from some NGBs, but the rules were adopted worldwide. Many modern hurdles will not go to that height or would at least require modification