A marathon is an endurance foot race which covers 26 miles, 385 yards (42.2 kilometers). It is named after the Greek Battle of Marathon, which occurred in 490 BCE. In addition to being an Olympic event for both men and women, marathons are run all over the world on a variety of terrain types by athletes at various skill levels. To perform well in a marathon, an athlete undergoes a vigorous period of training to develop stamina and learn his or her physical limitations.
According to legend, after the Greeks were victorious over the Persians at the Battle of Marathon, they sent a runner to Athens with the news. The runner, Pheidippides, ran the entire distance to Athens without stopping, announced the victory, and then dropped dead, due to the physical stress on his body caused by the long run. Numerous authors included the story in poems and songs, including Robert Browning in 1876. Browning's poem inspired Michel Breal, who organized the revival of the Olympic games in 1896 and included a marathon.
History, however, seems to suggest that Pheidippides was actually sent from Athens to Sparta to request assistance at Marathon. This is how Herodotus, who wrote extensively about the Greco-Persian wars, told the story. A runner was certainly sent from Marathon to Athens to relay the news, but it may not have been Pheidippides, and the journey was probably not completed without a single stop.
In a modern marathon, organizers set out a race course which meets the distance requirement, which was set in the 1908 Olympic games at London. Depending on the race, runners either all begin together in a mass start, or are dispatched in waves, separated by gender and ability. The course is left open for a set period of time, usually around four hours, and runners who fail to complete the course are picked up and brought to the finish line. In marathons with a larger group of less experienced runners, the course may be left open longer, to allow them to finish.
Long distance running is very demanding on the body. Runners have an extensive training program which mixes endurance running with resting, so that the body is not damaged. They also monitor their physical health during the race, in an effort to maintain the proper electrolyte balance so that they do not suffer from hyponatremia, a potentially dangerous condition caused by an imbalance of salts in the body. It is common to feel sore and experience a depressed immune system after running a marathon.