With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Athletics at the Summer Olympics includes contests for athletics.
text_B: Racewalking , or race walking , is a long-distance discipline within the sport of athletics .. sport of athletics. 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 .. running. running. This is assessed by race judges .. race judges. Referee. Typically held on either roads or on running tracks , common distances vary from 3000 metres -LRB- 1.8 mi -RRB- up to 100 kilometres -LRB- 62.1 mi -RRB- .. running. running. 100 kilometres. 100 kilometres race walk. There are two racewalking distances contested at the Summer Olympics  : the 20 kilometres race walk -LRB- men and women -RRB- and 50 kilometres race walk -LRB- men only -RRB- .. Summer Olympics. Summer Olympics. 20 kilometres race walk. 20 kilometres race walk. 50 kilometres race walk. 50 kilometres race walk. Both are held as road events .. road. road. The biennial IAAF World Championships in Athletics also features the same three events .. IAAF World Championships in Athletics. IAAF World Championships in Athletics. 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 .. IAAF World Race Walking Cup. IAAF World Race Walking Cup. The IAAF World Indoor Championships featured 5000 m and 3000 m race walk variations , but these were discontinued after 1993 .. IAAF World Indoor Championships. IAAF World Indoor Championships. Top level athletics championships and games typically feature 20 km racewalking events .. athletics championships and games. List of international athletics championships and games. 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 .. pedestrianism. pedestrianism. 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 .. 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 .. cadence. Cadence ( gait )
related.