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
Athletics at the 1904 Summer Olympics – Men's marathon research on "purposeful dehydration," even though dehydration is potentially fatal. The marathon ended with the worst ratio of entrants to finishers (14 of 32) and by far the slowest winning time, 3:28:45, almost 30 minutes slower than the second slowest winning time. These were the standing world and Olympic records (in hours) prior to the 1904 Summer Olympics. "(*)" Distance was also 40 kilometres The first to arrive at the finish line was American runner Fred Lorz, who had actually dropped out of the race after nine miles and hitched a ride back to the stadium in a car, waving