Athletics at the 1908 Summer Olympics – Men's marathon view of the final yards, the direction of running was changed to "right-hand inside" (i.e. clockwise). This meant the distance in the stadium was shortened to , and the total distance became officially "about 26 miles plus 385 yards on the track". A modified version of the Polytechnic Harriers' April 1908 map was issued in June 1908 incorporating the changed ending and omitting the "Long Walk" start used for the Trial Marathon. This was published in the newspapers and in the official programme for the games. This distance (ignoring the word "about" in the phrase "about 26 miles plus 385
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