Ten seconds still defines men's hundred-metre greatness
The 100 metres is track's shortest common outdoor sprint, run down the home straight of a 400-metre oval. Men have raced it at every modern Olympics since 1896, women since 1928. Breaking ten seconds has long marked an elite man; the best women finish in about eleven or less.
Races start on three cues: "on your marks" sends runners to their blocks, "set" raises them into position, and then the gun fires. Sensors in the gun and blocks time each athlete's first push, and anything under a tenth of a second counts as a false start, since no one can hear and react that fast. The rules have tightened over time. Sprinters once got two false starts each, which let big finals restart again and again. From 2003 the field shared one warning, and some slower starters exploited it by deliberately jumping to make rivals hesitate. Since 2010 a single false start means instant disqualification.
Sprinters hit top speed just past halfway and then slow down, so training focuses on holding that peak, not on tactics. A race is won when the torso, not the head or an outstretched arm, reaches the near edge of the line, with photo finishes settling close calls. Wind matters: records count only with a tailwind of 2 metres per second or less. Thin air at altitude helps too, because the oxygen for such a short dash is already in the body.
Jim Hines, Ronnie Ray Smith and Charles Greene first dipped under ten seconds on one evening in June 1968, the Night of Speed, and Hines ran the first electronically timed sub-ten at that year's Olympics. More than 200 men have since done it. Marlies Göhr became the first woman under eleven in 1977. Usain Bolt set the men's record of 9.58 seconds in Berlin on 16 August 2009, cutting 0.11 from his own mark, and Florence Griffith Joyner's 10.49 has stood since the 1988 US trials.
Doping has stained the event, most famously when Canada's Ben Johnson lost his 1988 Olympic gold and record. The Olympic winner is informally crowned the world's fastest human; Noah Lyles and Julien Alfred hold those Olympic titles now.
Source: 100 metres
