1500 metres
The 1500 metres or 1,500-metre run (typically pronounced 'fifteen-hundred metres') is the foremost middle distance track event in athletics. The distance has been contested at the Summer Olympics since 1896 and the World Championships in Athletics since 1983. It is equivalent to 1.5 kilometers or approximately  miles. The demands of the race are similar to that of the 800 metres, but with a slightly higher emphasis on aerobic endurance and a slightly lower sprint speed requirement. The 1500 metre race is predominantly aerobic, but anaerobic conditioning is also required. Each lap run during the world-record  race run by Hicham El Guerrouj of Morocco in 1998 in Rome, Italy averaged just under 55 seconds (or under 13.8 seconds per 100 metres). 1,500 metres is three and three-quarter laps around a 400-metre track. During the 1970s and 1980s this race was dominated by British runners, along with an occasional Finn, American, or New Zealander, but through the 1990s many African runners began to win Olympic medals in this race, especially runners from Kenya, Ethiopia, Morocco and Algeria. In the Modern Olympic Games, the men's 1,500-metre race has been contested from the beginning, and  at every Olympic Games since. The first winner, in 1896, was Edwin Flack of Australia, who also won the first gold medal in the 800-metre race. The women's 1,500-metre race was first added to the Summer Olympics in 1972, and the winner of the first gold medal was Lyudmila Bragina of the Soviet Union. During the Olympic Games of 1972 through 2008, the women's 1,500-metre race has been won by three Soviets plus one Russian, one Italian, one Romanian, one Briton, one Kenyan, and two Algerians. The 2012 Olympic results are still undecided as a  result of multiple doping cases. The best women's times for the race were controversially set by Chinese runners, all set in the same race on just two dates four years apart at the Chinese National Games. At least one of those top Chinese athletes has admitted to being part of a doping program. This women's record was finally broken by Genzebe Dibaba of Ethiopia in 2015. In American high schools, the mile run (which is 1609.344 metres in length) and the 1,600-metre run, also colloquially referred to as "metric mile", are more frequently run than the 1,500 -metre run, since US customary units are better-known in America. Which distance is used depends on which state the high school is in, and, for convenience, national rankings are standardized by converting all 1,500-metre run times to their mile run equivalents. Strategy. Many 1500 metres events, particularly at the championship level, turn into slow, strategic races, with the pace quickening and competitors jockeying for position in the final lap to settle the race in a final sprint. Such is the difficulty of maintaining the pace throughout the duration of the event, most records are set in planned races  led by pacemakers or "rabbits" who sacrifice their opportunity to win by leading the early laps at a fast pace before dropping out. All-time top 25. Women. Annulled marks. The following athlete had her performance (superior to 3:56.31) annulled due to a doping violation: Other sports. 1,500 metres is also an event in swimming and speed skating. The world records for the distance in swimming for men are 14:31.02 (swum in a 50-metre pool) by Sun Yang, 14:08.06 (swum in a 25-metre pool) by Gregorio Paltrinieri; and by women 15:25.48 (swum in a 50-metre pool) by  Katie Ledecky, and 15:19.71 (swum in a 25-metre pool) by Mireia Belmonte García. The world records for the distance in speed skating are 1:40.17 by Kjeld Nuis and 1:49.83 by Miho Takagi.