Ironman World Championship miles to link it to the start of the marathon course. In 1981 the race was moved to the less urbanized Big Island, keeping the distances the same: a open water swim in Kailua-Kona Bay, a bike ride across the Hawaiian lava desert to Hāwī and back, and a marathon (26 miles 385 yards, 42.195 km) run along the coast of the Big Island from Keauhou to Keahole Point and back to Kailua-Kona, finishing on Alii Drive. Since 1982, the race has been held in the fall each year, before which it was held in the spring, giving two races
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