n.
In track and field , a form of racing in which the competitor's advancing foot must touch the ground before the rear foot leaves it.
Walking as a sport dates from the later 19th century. Walking races of 10 mi and 3,500 m were added to the men's Olympic program in 1908, but since 1956 the Olympic distances have been 20 km and 50 km. A women's 10-km walk was introduced in 1992.