Clarence DeMar DeMar did not return to serious competition until 1922, when he again won the Boston marathon in a course record 2:18:10. He repeated the victory in 1923 and 1924. In the latter year the full Olympic distance – 26 miles, 385 yards – was run. He was selected as one of the six runners on the U.S Olympic marathon team for the 1924 Summer Olympics, where he finished third. DeMar continued his success with a second-place finish at the 1925 Boston marathon, and a third-place finish the next year. He followed that with five consecutive marathon victories: at the Baltimore
2012 Olympic Marathon Course as 42.195 km and specifically state that the course must not be less than this distance. The rules further state that in Olympic competition the standard distance may not be exceeded by more than 0.1%. In order for a marathon performance to be ratified as a world record by the IAAF, the course must also meet other criteria that rule-out "artificially fast times" produced on courses aided by downhill slope or tailwind: the distance between start and end points when measured in a straight line should not exceed 50% of the length of the course (21.092 km in the case