Those numbers are up dramatically from 2012, when the cancellation of the New York City Marathon had a significant impact on the totals. Without as many as 47,000 runners from New York, there were 487,000 finishers in 2012.
By comparison, 518,000 completed a marathon in 2011, which was up nearly 11,000 from 2010.
The number of finishers in 2013 was impacted by a pair of weather-related race cancellations -- the MetroPCS Dallas Marathon and the St. Jude Memphis Marathon -- and the bombings at the Boston Marathon, which prevented 5,633 runners from completing that race.
Boston and the two canceled marathons knocked an estimated 13,000 runners from the 2013 total. The New York City Marathon, which became the first marathon ever with over 50,000 finishers (50,266), helped push the 2013 number to an all-time high.
The number of women finishing marathons has steadily increased since 1980, when only 10 percent of finishers were women. That number rose to 26 percent in 1995, 38 percent in 2000 and 41 percent in 2005, before hitting 42 percent last year.
There were also a record number of marathons held in the United States in 2013, with more than 1,100 races taking place. Of those, 92 had at least 1,000 finishers, the third-most ever in a year (the record is 94 in 2011 and 2012). The BMO Harris Bank Phoenix Marathon (1,434) and the Edward Hospital Naperville Marathon (1,079) were two inaugural U.S. marathons with more than 1,000 finishers.
After a steady decline in the median finish times for U.S. marathons in the late 1990s, marathon runners are getting faster, too.
The median finish time for male marathoners in 1980 was 3:32:17, and for women it was 4:03:39. Those numbers jumped as high as 4:20:29 for men in 2005 and 4:56:46 for women in 2002.
The men's number number dropped to a low of 4:16:14 in 2010, and was 4:16:24 in 2013. The women's median time of 4:41:38 in 2013 is an all-time low.