Swimming is an individual or team sport that requires the use of one's entire body to move through the water. Competitive swimming is one of the most popular Olympic sports, with varied distance events in the butterfly, backstroke, breaststroke, freestyle, and individual medley.
World Championship pools must be 50 metres long and 25 metres wide, with ten lanes labelled zero to nine. Zero and nine (or one and ten) are usually left empty in semi-finals and finals. The lanes must be at least 2.5 metres wide.
Evidence of recreational swimming in prehistoric times has been found, with the earliest evidence dating to Stone Age paintings from around 10,000 years ago. Written references date from 2000 BC, with some of the earliest references to swimming including the Iliad, the Odyssey, the Bible, Beowulf, the Quran and others.
Men's swimming became part of the first modern Olympic Games in 1896 in Athens.