The 400 metres, or 400-meter dash, is a sprint event in track and field competitions. It has been featured in the athletics programme at the Summer Olympics since 1896 for men and since 1964 for women. On a standard outdoor running track, it is one lap around the track. Runners start in staggered positions and race in separate lanes for the entire course. In many countries, athletes previously competed in the 440-yard dash (402.336 m)—which is a quarter of a mile and was referred to as the 'quarter-mile'—instead of the 400 m (437.445 yards), though this distance is now obsolete.
Sex verification in sports occurs because eligibility of athletes to compete is restricted whenever sporting events are limited to a single sex, which is generally the case, as well as when events are limited to mixed-sex teams of defined composition. Practice has varied tremendously over time, across borders and by competitive level. Issues have arisen multiple times in the Olympic games and other high-profile sporting competitions, for example allegations that certain male athletes attempted to compete as women or that certain female athletes had intersex conditions perceived to give unfair advantage. The topic of sex verification is related to the more recent question of how to treat transgender people in sports. Sex verification is not typically conducted on athletes competing in the male category because there is generally no perceived competitive advantage for a female or intersex athlete to compete in male categories.
Foekje Dillema was a Dutch track and field athlete. She competed in sprinting where she was a rival of Fanny Blankers-Koen. When she refused a sex verification test, she was banned from competition by the International Association of Athletics Federations in 1950. After her death, it was determined that she was an intersex person.
Irena Szewińska was a Polish sprinter who was one of the world's foremost track athletes for nearly two decades, in multiple events. She is the only athlete in history, male or female, to have held the world record in the 100 m, the 200 m and the 400 m.
Gabrielle Lisa Thomas is an American track and field athlete in 100 and 200 meter sprint. She won the bronze medal in the 200 m and a silver as part of the women's 4 × 100 m relay at the 2020 Tokyo Olympics. On August 25, 2023, she claimed the 200m silver medal in the 2023 World Athletics Championships in Budapest with a time of 21.81 seconds. She would also go on to win gold as part of Team USA in the women's 4x100m relay final with a championship record of 41.03 seconds.
The principal sports in Namibia are football, rugby union, cricket, golf and fishing. Boxing and athletics are also popular. The home stadium for all national teams is Independence Stadium in Windhoek, while Sam Nujoma Stadium in Katutura is also occasionally used.
Mokgadi Caster Semenya OIB is a South African middle-distance runner and winner of two Olympic gold medals and three World Championships in the women's 800 metres. She first won gold at the World Championships in 2009 and went on to win at the 2016 Olympics and the 2017 World Championships, where she also won a bronze medal in the 1500 metres. After the doping disqualification of Mariya Savinova, she was also awarded gold medals for the 2011 World Championships and the 2012 Olympics.
Francine Niyonsaba is a Burundian runner who specialized in the 800 metres and shifted to longer distances in 2019. She was the 2016 Rio Olympics silver medalist in the women's 800 metres. Her silver medal was the first Olympic medal for Burundi since 1996. Niyonsaba won a silver in the event at the 2017 World Championships.
Geraldina "Dina" Rachel Asher-Smith, OLY is a British sprinter.
Dutee Chand is an Indian professional sprinter and current national champion in the women's 100 metres event. She is the first Indian to win a gold medal in 100m race in a global competition. She is the third Indian woman to ever qualify for the Women's 100 metres event at the Summer Olympic Games. However, in the 2016 Summer Olympics, her 11.69 s in the preliminary round did not qualify her for the next round. In 2018, Chand clinched silver in women's 100m at the Jakarta Asian Games. It was India's first medal in this event since 1998. In 2019, she became the first Indian sprinter to win gold at the Universiade, clocking 11.32 seconds in the 100 m race.
The women's 800 metres event at the 2016 Summer Olympics took place between 17–20 August at the Olympic Stadium.
Shericka Jackson, OD is a Jamaican sprinter competing in the 100 m, 200 m, and 400 metres. In 2022, she became the fastest woman alive and second fastest woman of all time in the 200 metres.
Maximila Imali is a Kenyan sprinter. She competed in the women's 400 metres at the 2017 World Championships in Athletics. In 2019, she won the bronze medal in the women's 4 × 100 metres relay at the 2019 African Games held in Rabat, Morocco. Imali is among the athletes to shift from competing in the 400m and 800m to the 100m and 200m due to World Athletics' regulations on testosterone levels for athletes with XY disorders of sex development in women's competition.
The women's 200 metres event at the 2020 Summer Olympics took place on 2 and 3 August 2021 at the Japan National Stadium. 41 athletes from 31 nations competed. In successfully defending her title, Elaine Thompson-Herah became the first woman in history to win both the 100 and 200 metres titles at successive games. Her winning time of 21.53 secs, moved her to second on the world all-time list behind Florence Griffith Joyner, and broke Merlene Ottey's 30-year-old Jamaican record.
The women's 400 metres event at the 2020 Summer Olympics took place from 3 to 6 August 2021 at the Japan National Stadium. 45 athletes from 34 nations competed. Shaunae Miller-Uibo won the gold medal in a personal best of 48.36 secs, a time which ranks her sixth on the world all-time list. In successfully defending her title, Miller-Uibo joined Marie-Jose Perec as the only women to win two Olympic 400 metres titles.
Aminatou Seyni is a Nigerien track and field sprinter.
The testosterone regulations in women's athletics are a series of policies first published in 2011 by the IAAF and last updated following a court victory against Caster Semenya in May 2019. The first version of the rules applied to all women with high testosterone, but the current version of the rules only apply to athletes with certain XY disorders of sexual development, and set a 5 nmol/L testosterone limit, which applies only to distances between 400 m and 1 mile (inclusive), other events being unrestricted.
Christine Mboma is a Namibian sprinter who competes in the 100 metres and 200 m. At the age of 18, she won a silver medal in the 200 metres at the 2020 Tokyo Olympics, becoming the first ever Namibian woman to win a women's Olympic medal and breaking the world under-20 and African senior record. Mboma also won the event at the 2021 World Under-20 Championships and Diamond League final, improving her record mark to 21.78 seconds.
