In which sport did Emil Zatopek excel?

Emil Zátopek (19 September 1922 – 22 November 2000) was a Czechoslovak long-distance runner best known for winning three gold medals at the 1952 Summer Olympics in Helsinki. He won gold in the 5,000 metres and 10,000 metres runs, but his final medal came when he decided at the last minute to compete in the first marathon of his life. He was nicknamed the "Czech Locomotive".

In 1954, Zátopek was the first runner to break the 29-minute barrier in the 10,000 metres. Three years earlier in 1951, he had broken the hour for running 20 km. He was one of the greatest runners of the 20th century and was also known for his brutally tough training methods. He was the originator of interval training and hypoventilation training. In February 2013, the editors at Runner's World Magazine selected him as the Greatest Runner of All Time. He is the only person to win the 5,000 metres, 10,000 metres, and marathon in the same Olympics.