The marathon is one of the most difficult tests of endurance that many people in the fitness world will ever attempt.
The 25-mile footrace is a test of training, strength, fitness, resilience, resolve and preparedness, with rehydration tablets being a vital part of making it through the distance without having to pull out or risking aggravating your body.
It was named for the city in Greece that the famous runner Philippides ran from, at the time in the midst of a brutal military battle, to the city of Athens, where according to legend he shouted that the Athenian army had won before dying.
However, there is another part to the story, one that claimed he had run a distance so great that some of the fittest athletes in modern times were not sure it was even possible. Naturally, that means they would attempt the run themselves.
The Spartathlon is 155 miles long covering the distance that Pheidippides ran from Athens to Sparta, a city in the southernmost part of Greece in a day and a half, which would be an average speed of 4.3 miles per hour assuming a runner did not sleep.
For comparison, this is the distance equivalent of running six marathons consecutively in potentially very hot Greek weather during the day and the abject cold of cloudless nights.
John Foden, a long-distance runner and member of the RAF, was curious about whether such a distance was actually possible and travelled with four officers to attempt the run in 1982.
Only one of them managed to complete the course in the specified time limit, with John Scholtens completing the distance in 34 hours 30 minutes, although Mr Foden himself and fellow officer John McCarthy came close with times of 37 hours 37 minutes and 39 hours respectively.
A year later, the event became officially sanctioned under SEGAS, with 45 competitors (44 men, one woman) and 75 checkpoints along the course, each with strict cut-off times to ensure that runners are kept safe if they fall behind.