Sochi 2014: Speed skating
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Action from an Olympic speed skating race
The Netherlands' enthusiasm for speed skating - often given the prefix 'long-track' to differentiate from its short-track counterpart - is evident in the sport's origins, when locals would skate the nation's frozen canals in winter.
The first competitions are recorded as having taken place as far back as the 17th century, and the first World Championships took place in 1889.
Speed skating has been on every Winter Games programme since its inauguration in 1924, with a women's race added in 1960.
At Sochi 2014 there are 12 Olympic speed-skating disciplines, with both men and women competing over 500m, 1,000m, 1500m, 5,000m and 10,000m distances, and men's and women's team pursuit events also taking place.
Races have a head-to-head format over a purpose-built, 400m oval rink. Racers switch lanes on the home straight on each lap to ensure an equal distance is contested. The athlete in the inner lane must give way.
In the team pursuit, two teams of three start at opposite sides of the track and race over six or eight laps, with the winners determined by the fastest time. The Winter Olympic team pursuit involves a straight elimination format.
To differentiate between the two competing athletes, the skater starting on the outer lane must wear a red armband, and the competitor starting on the inner lane wears a blue armband.
Blades on the skates are long - typically between 42cm and 46cm. Long-track skates have a semi-detachable heel, so that each time an athlete lifts his heel the blade remains on the ice, enabling him to maintain his speed and maximise his pushing power. Racers also wear skin-tight race suits.
The Netherlands leads the way in speed skating's all-time medal table with a total of 82, including four in Vancouver in 2010.
Sven Kramer remains a force on the World Cup circuit but is yet to match the Olympic exploits of his idol Ard Schenk, who won three individual golds at the 1972 Sapporo Games.
Veteran Canadian Jeremy Wotherspoon, a four-time world champion, announced his comeback in 2013.
Ireen Wüst is the world's best woman but has some way to go to match Russia's Lidiya Skoblikova, who won six Winter Olympic gold medals in the 1960s.
The speed skating at Sochi 2014 takes place at the Adler Arena.