Marathons at the Olympics Olympics marked the introduction of the now standard distance of 26 miles, 385 yards (42.195 km). However, it was not until the 1924 Paris Olympics that this distance became the standard at the Olympics. The Olympic marathon proved immediately popular in the Western world and quickly spawned numerous long-running annual races, including the Boston Marathon in 1897, the Tour de Paris Marathon in 1902, the Yonkers Marathon in 1907, and the London Polytechnic Marathon in 1909. Such marathons played a key role in the expansion of the road running movement internationally over the course of the 20th century. It has
Bangkok Marathon course passes many historical landmarks of cultural and ethnic importance. The marathon starts and finishes in front of The Royal Grand Palace at Sanam Chai Road. The race course is sanctioned by The Association of International Marathons and Distance Races (AIMS) and the Amateur Athletic Association of Thailand (IAAF Rules). In 2013, the course of the half marathon was changed at the last minute because of concurrent Bangkok street protests which reduced the distance of the half marathon from 21.1 km (13.1 miles) to 19.7 km (12.2 miles). In 2015, the half marathon was accidentally extended from 21.1 km (13.1