100 metres

Athletics
100 metres
London 2012 Olympic 100m final start.jpg
Start of the men's 100 metres final at the 2012 Olympic Games.
Men's records
WorldJamaica Usain Bolt 9.58 (2009)
OlympicJamaica Usain Bolt 9.63 (2012)
Women's records
WorldUnited States Florence Griffith-Joyner 10.49[a] (1988)
OlympicUnited States Florence Griffith-Joyner 10.62 (1988)

The 100 metres, or 100-metre dash, is a sprint race in track and field competitions. The shortest common outdoor running distance, it is one of the most popular and prestigious events in the sport of athletics. It has been contested at the Summer Olympics since 1896 for men and since 1928 for women.

Women's 100M Final – 28th Summer Universiade 2015

The reigning 100 m Olympic champion is often named "the fastest man in the world". The World Championships 100 metres has been contested since 1983. Christian Coleman and Shelly-Ann Fraser-Pryce are the reigning world champions; Usain Bolt and Elaine Thompson are the men's and women's Olympic champions.

On an outdoor 400 metres running track, the 100 m is run on the home straight, with the start usually being set on an extension to make it a straight-line race. There are three instructions given to the runners immediately before and at the beginning of the race: ready, set, and the firing of the starter's pistol. The runners move to the starting blocks when they hear the 'ready' instruction. The following instruction, to adopt the 'set' position, allows them to adopt a more efficient starting posture and isometrically preload their muscles: this will help them to start faster. A race-official then fires the starter's pistol to signal the race beginning and the sprinters stride forwards from the blocks. Sprinters typically reach top speed after somewhere between 50 and 60 m. Their speed then slows towards the finish line.

The 10-second barrier has historically been a barometer of fast men's performances, while the best female sprinters take eleven seconds or less to complete the race. The current men's world record is 9.58 seconds, set by Jamaica's Usain Bolt in 2009, while the women's world record of 10.49 seconds set by American Florence Griffith-Joyner in 1988 remains unbroken.[a]

The 100 m (109.361 yards) emerged from the metrication of the 100 yards (91.44 m), a now defunct distance originally contested in English-speaking countries. The event is largely held outdoors as few indoor facilities have a 100 m straight.

US athletes have won the men's Olympic 100 metres title more times than any other country, 16 out of the 28 times that it has been run. US women have also dominated the event winning 9 out of 21 times.

Race dynamics

Start

Male sprinters await the starter's instructions

At the start, some athletes play psychological games such as trying to be last to the starting blocks.[3][4][5]

At high level meets, the time between the gun and first kick against the starting block is measured electronically, via sensors built in the gun and the blocks. A reaction time less than 0.1 s is considered a false start. The 0.2-second interval accounts for the sum of the time it takes for the sound of the starter's pistol to reach the runners' ears, and the time they take to react to it.

For many years a sprinter was disqualified if responsible for two false starts individually. However, this rule allowed some major races to be restarted so many times that the sprinters started to lose focus. The next iteration of the rule, introduced in February 2003, meant that one false start was allowed among the field, but anyone responsible for a subsequent false start was disqualified.

This rule led to some sprinters deliberately false-starting to gain a psychological advantage: an individual with a slower reaction time might false-start, forcing the faster starters to wait and be sure of hearing the gun for the subsequent start, thereby losing some of their advantage. To avoid such abuse and to improve spectator enjoyment, the IAAF implemented a further change in the 2010 season – a false starting athlete now receives immediate disqualification.[6] This proposal was met with objections when first raised in 2005, on the grounds that it would not leave any room for innocent mistakes. Justin Gatlin commented, "Just a flinch or a leg cramp could cost you a year's worth of work."[7] The rule had a dramatic impact at the 2011 World Championships, when current world record holder Usain Bolt was disqualified.[8][9]

Mid-race

Runners normally reach their top speed just past the halfway point of the race and they progressively decelerate in the later stages of the race. Maintaining that top speed for as long as possible is a primary focus of training for the 100 m.[10] Pacing and running tactics do not play a significant role in the 100 m, as success in the event depends more on pure athletic qualities and technique.

Finish

The winner, by IAAF Competition Rules, is determined by the first athlete with his or her torso (not including limbs, head, or neck) over the nearer edge of the finish line.[11] There is therefore no requirement for the entire body to cross the finish line. When the placing of the athletes is not obvious, a photo finish is used to distinguish which runner was first to cross the line.

Climatic conditions

Climatic conditions, in particular air resistance, can affect performances in the 100 m. A strong head wind is very detrimental to performance, while a tail wind can improve performances significantly. For this reason, a maximum tail wind of 2.0 m/s is allowed for a 100 m performance to be considered eligible for records, or "wind legal".

Furthermore, sprint athletes perform a better run at high altitudes because of the thinner air, which provides less air resistance. In theory, the thinner air would also make breathing slightly more difficult (due to the partial pressure of oxygen being lower), but this difference is negligible for sprint distances where all the oxygen needed for the short dash is already in the muscles and bloodstream when the race starts. While there are no limitations on altitude, performances made at altitudes greater than 1000 m above sea level are marked with an "A".[12]

Other Languages
العربية: 100 متر
aragonés: 100 metros lisos
বাংলা: ১০০ মিটার
español: 100 metros
Esperanto: 100-metra kurado
فارسی: دو ۱۰۰ متر
Bahasa Indonesia: Lari 100 meter
italiano: 100 metri piani
latviešu: 100 metri
Lëtzebuergesch: 100-Meter-Laf
lietuvių: 100 m bėgimas
Bahasa Melayu: Lari 100 meter
norsk: 100 meter
ਪੰਜਾਬੀ: 100 ਮੀਟਰ ਦੌੜ
português: 100 metros rasos
slovenčina: Beh na 100 metrov
српски / srpski: Трка на 100 метара
srpskohrvatski / српскохрватски: Trka na 100 metara
Türkçe: 100 metre
українська: Біг на 100 метрів
Tiếng Việt: 100 mét
吴语: 100米赛跑
中文: 100米賽跑