Metrication in the United States traditional mile-based lengths. In the Olympics, athletes run 1500 meters, not 1600 meters. Running races in the U.S. are usually run in metric distances (e.g., the 100 metres dash or the 5K run), although the mile distance remains popular. But even 5 and 10 kilometer races most often have mile markers on the course, and no kilometer markers. Long-distance races are often measured in kilometers, although exceptions exist (generally 10 mile races). The marathon is referred to as a 26.219-mile race (the official marathon standard distance originally being in English units — 26 miles, 385 yards) rather than 42.195 km.
Athletics at the 1908 Summer Olympics – Men's marathon yards on the track") eventually became the origin of the modern Marathon distance of "no less than 42.195 km". According to the book "The Marathon Makers" by John Bryant, the first mile of the 1908 Olympic Marathon course was remeasured by John Disley in the late 1990s and was found to be 174 yards (159 m) short. The official report lists the leaders at each mile from the fourth to the twenty-fourth: Thomas Jack (miles 4–5); Frederick Lord (miles 6–14); Charles Hefferon (miles 15–24). Dorando Pietri of Italy caught Hefferon and sped up between Old Oak Common Lane and Wormwood