Editing Sprint (running) (section)

==Rules==

=== Rule differences between governing bodies ===
Each governing body sets its own rules for how competition is deemed fair.&nbsp; World Athletics sets the competition rules internationally.&nbsp;The World Athletics rulebook<ref>{{Cite web|title=Book of Rules {{!}} Official Documents|url=https://www.worldathletics.org/about-iaaf/documents/book-of-rules|access-date=2021-07-30|website=www.worldathletics.org|language=en}}</ref> is broken into 4 separate books.

===The start===
[[File:Start Jeremy Wariner 2007.jpg|thumb|[[Jeremy Wariner]] beginning a race from the starting blocks]]
[[Starting blocks]] are used for all competition sprints (up to and including 400&nbsp;m) and relay events (first leg only, up to 4x400&nbsp;m).<ref name=IAAF>[http://www.iaaf.org/download/download?filename=7c4c7e46-8979-453d-a355-a736fdac2281.pdf&urlslug=Competition%20Rules%202012-13 Competition Rules 2012-13], IAAF</ref> The starting blocks consist of two adjustable footplates attached to a rigid frame. Races commence with the firing of the [[Starting pistol|starter's gun]].<ref name=IAAF /> The starting commands are "On your marks" and "Set".<ref name=IAAF /> Once all athletes are in the set position, the starter's gun is fired, officially starting the race. For the 100&nbsp;m, all competitors are lined up side by side. For the 200&nbsp;m, 300&nbsp;m, and 400&nbsp;m, which involve curves, runners are staggered for the start.

In the rare event that there are technical issues with a start, a green card is shown to all the athletes. The green card carries no penalty. If an athlete is unhappy with track conditions after the "on your marks" command is given, the athlete must raise a hand before the "set" command and provide the Start referee with a reason. It is then up to the Start referee to decide if the reason is valid. If the Start referee deems the reason invalid, a yellow card (warning) is issued to that particular athlete. If the athlete is already on a warning, the athlete is disqualified.

===False starts===
{{main|False start#Athletics (track and field)}}
[[File:Skyttis athletics tracks.jpg|thumb|Sprint lanes in [[Örnsköldsvik]], [[Sweden]], as seen from the 100 m starting point]]
According to the World Athletics (WA) rules, "An athlete, after assuming a full and final set position, shall not commence his starting motion until after receiving the report of the gun or approved starting apparatus. If, in the judgement of the Starter or Recallers, he does so any earlier, it shall be deemed a false start."<ref name="IAAF"/>

The [[100 m]] Olympic gold and silver medallist [[Linford Christie]] of Great Britain famously had frequent false starts that were marginally below the legal reaction time of 0.1&nbsp;seconds. Christie and his coach, [[Ron Roddan]], both claimed that the false starts were due to Christie's exceptional reaction times being under legal time. His frequent false starting eventually led to his disqualification from the [[1996 Summer Olympics]] 100&nbsp;m final in [[Atlanta]], the US, due to a second false start by Christie.  Since January 2010, under WA rules, a single false start by an athlete resulted in disqualification.

In 2012, a new development to the false start rule was added. Because certain athletes could be disqualified for twitching in the starting blocks, but some athletes could make a twitch without the starter noticing and disqualifying the athlete, it was decided that twitching in the starting block while being in the 'set' position would only carry a maximum penalty of a yellow card or a warning. To instantly be disqualified for a false start, an athlete's hands must leave the track or their feet must leave the starting blocks, while the athlete is in their final 'set' position.<ref>{{cite news |last1=Cherry |first1=Gene |title=Twitch or flinch no longer a false start |url=https://www.reuters.com/article/uk-oly-athl-falsestart-adv3/twitch-or-flinch-no-longer-a-false-start-idUKBRE86N18M20120724 |access-date=22 June 2022 |work=[[Reuters]] |date=4 July 2012}}</ref>

===Lanes===
[[File:Bundesarchiv Bild 183-1987-0822-034, Sabine Busch, Cornelia Ulrich.jpg|thumb|upright|The finish of the 1987 East German athletics championships]]
For all Olympic sprint events, runners must remain within their pre-assigned lanes, which measure 1.22&nbsp;metres (4&nbsp;feet) wide, from start to finish.<ref>''2009 USATF Competition Rules'', Rule 160(1)</ref> The lanes can be numbered 1 through 8, 9, or rarely 10, starting with the inside lane. Any athlete who runs outside the assigned lane to gain an advantage is subject to disqualification. If the athlete is forced to run outside of his or her lane by another person, and no material advantage is gained, there will be no disqualification. Also, a runner who strays from his or her lane in the straightaway, or crosses the outer line of his or her lane on the bend, and gains no advantage by it, will not be disqualified as long as no other runner is obstructed.

===The finish===
The first athlete whose torso reaches the vertical plane of the closest edge of the finish line is the winner. To ensure that the sprinter's torso triggers the timing impulse at the finish line rather than an arm, foot, or other body parts, a double Photocell is commonly used. Times are only recorded by an electronic timing system when both of these Photocells are simultaneously blocked.
[[Photo finish]] systems are also used at some track and field events.