Marathon from the start at Windsor Castle to the royal entrance to the White City Stadium, followed by a lap (586 yards 2 feet; 536 m) of the track, finishing in front of the Royal Box. The course was later altered to use a different entrance to the stadium, followed by a partial lap of 385 yards to the same finish. The modern standard distance for the marathon was set by the International Amateur Athletic Federation (IAAF) in May 1921 directly from the length used at the 1908 Summer Olympics in London. An official IAAF marathon course is 42.195 km (42
Long-distance swimming Some of the better-known long-distance swims are crossings of the English Channel, Catalina Channel, Fehmarn Belt and Cook Strait. Ultra-long distance swimming is sometimes referred to as marathon swimming. The minimum distance that constitutes a marathon swim has dramatically shortened over time. Different organizations adopt various minimum distances. The swimming marathon events at the Olympic games have a distance of 10 km. Long-distance swims tend to fall into one of two categories: (1) swims in which the start date and start time are chosen by the individual swimmer (often called solo-swims), and (2) swims that involve a group-start. Long-distance swimming