Racewalking, or race walking, is a long-distance discipline within the sport of athletics. Although a foot race, it is different from running in that one foot must appear to be in contact with the ground at all times. Race judges carefully assess that this is maintained throughout the race. Typically held on either roads or running tracks, common distances range from up to 100 kilometres (62.1 mi). There are two racewalking distances contested at the Summer Olympics: the 20 kilometres race walk (men and women) and 50 kilometres race walk (men only). Both are held as road events. The biennial World Athletics Championships also featured these two events, in addition to a 50 km walk for women, until 2019. The 50km race walk was replaced by the 35 kilometres race walk as standard championship discipline in 2022. The IAAF World Race Walking Cup, first held in 1961, is a stand-alone global competition for the discipline and it has 10 kilometres race walks for junior athletes, in addition to the Olympic-standard events. The IAAF World Indoor Championships featured 5000 m and 3000 m race walk variations, but these were discontinued after 1993. Top level athletics championships and games typically feature 20 km racewalking events. The sport emerged from a British culture of long-distance competitive walking known as pedestrianism, which began to develop the ruleset that is the basis of the modern discipline around the mid-19th century. Since the mid-20th century onwards, Russian and Chinese athletes have been among the most successful on the global stage, with Europe and parts of Latin America producing most of the remaining top level walkers. However, it has been particularly affected by doping, with many Russian world and Olympic champions testing positive for banned performance-enhancing drugs. Compared to other forms of foot racing, stride length is reduced; to achieve competitive speeds racewalkers must attain cadence rates comparable to those achieved by world-class 800-1,500 metre runners. Rules There are only two rules that govern racewalking. The first dictates that the athlete's back toe cannot leave the ground until the heel of the front foot has touched. Violation of this rule is known as loss of contact. The second rule requires that the supporting leg must straighten from the point of contact with the ground and remain straightened until the body passes directly over it. These rules are judged by the unaided human eye. Athletes regularly lose contact