4 × 100 metres relay

The 4 × 100 metres relay or sprint relay is an athletics track event run in lanes over one lap of the track with four runners completing 100 metres each. The first runners must begin in the same stagger as for the individual 400 m race. Each runner carries a relay baton. Before 2018, the baton had to be passed within a 20 m changeover box, preceded by a 10-metre acceleration zone. With a rule change effective November 1, 2017, that zone was modified to include the acceleration zone as part of the passing zone, making the entire zone 30 metres in length. The outgoing runner cannot touch the baton until it has entered the zone, and the incoming runner cannot touch it after it has left the zone. The zone is usually marked in yellow, frequently using lines, triangles or chevrons. While the rule book specifies the exact positioning of the marks, the colours and style are only "recommended". While most legacy tracks will still have the older markings, the rule change still uses existing marks. Not all governing body jurisdictions have adopted the rule change.

The transfer of the baton in this race is typically blind. The outgoing runner reaches a straight arm backwards when entering the changeover box or when the incoming runner makes a verbal signal. The outgoing runner does not look back, and it is the responsibility of the incoming runner to thrust the baton into the outstretched hand and not let go until the outgoing runner takes hold of it without crossing the changeover box and stops after the baton is exchanged. Runners on the first and third legs typically run on the inside of the lane with the baton in their right hand, while runners on the second and fourth legs take the baton in their left. Polished handovers can compensate for lack of basic speed to some extent, and disqualification for dropping the baton or failing to transfer it within the box is common, even at the highest level. Relay times are typically 2–3 seconds faster than the sum of best times of individual runners.

The United States men and women historically dominated this event through the 20th century, winning Olympic gold medals and the most IAAF/World Athletics championships. Carl Lewis ran the anchor leg on U.S. relay teams that set six world records from 1983 to 1992, including the first team to break 38 seconds.

The current men's world record stands at 36.84, set by the Jamaican team at the final of the 2012 London Olympic Games on 11 August 2012. As the only team to break 37 seconds to date, Jamaica has been the dominant team in the sport, winning two consecutive Olympic Gold Medals and four consecutive World Championships. The Jamaican team also set the previous record of 37.04 seconds at the 2011 World Championships.

The fastest electronically timed anchor leg run is 8.65 seconds by Usain Bolt at the 2015 IAAF World Relays, while Bob Hayes was hand-timed as running 8.7 seconds on a cinder track in the 1964 Tokyo Games Final. The Tokyo Games also had electronic timing. High-speed modern video analysis shows his time to be a more realistic 8.95-9.0 seconds in the final, a much more consistent time relative to his Fully Automatic Timing 10.06s 100m world record and more in line with the usual +0.25s-0.3s hand time to FAT conversion.

The women's world record stands at 40.82 seconds, set by the United States in 2012 at the London Olympics. The fastest anchor leg run by a woman was run by Christine Arron of France, timed unofficially at 9.67s.

According to the IAAF rules, world records in relays can only be set if all team members have the same nationality.

From the beginnings to the first official world record
If on the European continent the metric system is the one almost exclusively used (4 × 100 metres, or a lap of 400 m), where the imperial system is still used (UK, USA and Australia, mainly) this relay was rather ran over the distance of 4 × 110 yards, a total of 402.34 m, and that, until the late 1960s. The runway at Hayward Field was shortened to 400 m only in 1987.

Paradoxically, the first race recognized as certain, without however being an official world record, dates back to 1897, shortly after the creation, on 8 May, of the Česká amatérská atletická unie (ČAAU). On June 26 of that year, during Sparta's 5th match in Prague, the organizing team, AC Sparta Praha, defeated MAC Budapest, in 48 1/5 seconds.

Unlike the "long" 4×400 m relay, whose origins are clearly American, because it derives from the 4×440 yards, the 4×100 m relay is therefore of European origin. The Scandinavians, in particular, have introduced this new specialty into their programmes, in the hope of being able to play a decisive role in it.

Before World War I, this foundation period of the relay was gradually enhanced by various German or Swedish teams (such as AIK Stockholm), until the semi-finals of the Stockholm Olympic Games (1912) where this event made its Olympic appearance:


 * in the 1st semi-final, the Great Britain team (consisting of David Jacobs, Henry Macintosh, Victor d'Arcy, and William Applegarth) reached 43 seconds 0 tenths (43 s) for the first time, behind the Americans who had finished in 42 seconds 5, but who were disqualified for passing the baton out of the area;
 * in the second semifinal, the Swedish team (Ivan Möller, Charles Luther, Ture Person and Knut Lindberg) took this record to 42 s 5, ahead of Hungary in 42 s 9.

These two runs have not been recognized by the IAAF as the first world records, despite their official nature. The first officially recognized world record for the fast relay is that of the German team, which on 8 July 1912, during the 3rd semifinal, runs in 42 seconds 3 tenths. The team consisted of Otto Röhr, Max Herrmann, Erwin Kern, and Richard Rau. In the final Great Britain, despite having finished second again, behind the favorites and the new world record holders, still won the gold medal, due to the loss of the German baton. Sweden is second in 42 s 6. The bronze medal is not awarded, because the Americans, still clumsy in passing the baton, were also downgraded. The German record in the semifinal (42"3) will remain the best result of the year. In 1913 it will be recognized by the newly formed IAAF as the first official world record of the specialty.

After this first Olympic event, in addition to the 4×400 m relay, the 4×100 m relay established itself as a classic Olympic event and will always remain on the programme, first for men, then extended to women. The two relays undergo little transformation over time. However, since 1926, the baton bearer has to remain in the baton transmission area, which is 20 m long. It wasn't until 1963 that the rules were relaxed: a 10m run-up zone, before this zone, allowed him to better tackle the run-up.

Continental records
Updated 25 August 2023

All-time top 10 by country
Key to tables:

X = annulled due to doping violation

Men

 * Updated July 2022

Women

 * Correct as of August 2023

Men

 * Updated May 2024

Note:
 * A USA team ran 37.04 in London in 2012 but the performance was annulled due to use of performance-enhancing drugs by Tyson Gay
 * A Jamaican team ran 37.10 in Beijing in 2008 but the performance was annulled due to use of performance-enhancing drugs by Nesta Carter
 * A USA team ran 37.38 in the heats in London in 2012 but the performance was retrospectively disqualified following drug test failure by Tyson Gay, even though Gay only ran in the final and not the heat.
 * A UK team ran 37.51 in Tokyo in 2021 but the performance was annulled due to use of performance-enhancing drugs by Chijindu Ujah

Women

 * Correct as of July 2024