Racewalking, or race walking, is a long-distance discipline within the sport of athletics. Although it is a foot race, it is different from running in that one foot must appear to be in contact with the ground at all times. This is assessed by race judges. Typically held on either roads or on running tracks, common distances vary from 3000 metres (1.8 mi) up to 100 kilometres (62.1 mi). 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 metres runners.