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sportsmarathonrunningolympic historySeptember 14, 20264 min read

Why Is a Marathon 26.2 Miles? A Legend, a Royal Box and a Committee

By the BrainSnail editorial team. How these articles are written and checked, and how to tell us when one is wrong.

Every marathon in the world is 42.195 kilometres, or 26 miles and 385 yards, a distance too specific to be a round number in any system. It is not an ancient measurement and it was not chosen for any athletic reason. It is the length of one particular course laid out in London in 1908, which became the rule thirteen years later because it happened to be the course of the race everyone remembered.

The legend of Pheidippides

The name goes back to the Battle of Marathon in 490 BCE, when an Athenian army defeated a Persian invasion force on the plain of Marathon about 40 kilometres from Athens. The story that a runner carried news of the victory to Athens, announced it and dropped dead is first told by the writer Lucian some six centuries later. The historian Herodotus, writing much closer to the events, has a runner named Pheidippides covering the far greater distance from Athens to Sparta and back to ask for help before the battle, about 240 kilometres each way, and surviving.

The dying messenger is almost certainly a legend, but it was the legend that Michel Breal, a French scholar, had in mind when he suggested a long race from Marathon to Athens for the first modern Olympic Games in 1896. That race was about 40 kilometres and was won by a Greek water-carrier, Spyridon Louis, which sealed the event's popularity in its home country.

Forty kilometres, more or less

For the next decade the marathon had no fixed length. The 1896 race was around 40 kilometres, the 1900 Paris race about 40.26, the 1904 St Louis race just under 40, and the early Boston Marathon, first run in 1897, was about 39.4 kilometres. Organisers picked a start and finish that suited the city and measured what they got. Nobody thought the exact figure mattered, because no two courses were comparable anyway.

London, 1908

The London Olympics of 1908 planned a marathon of about 26 miles from Windsor Castle to the new stadium at Shepherd's Bush. The story most often told is that the start was moved onto the castle's east lawn so that the royal children could watch from the nursery windows, and the finish was placed in front of the royal box in the stadium, which together produced 26 miles and 385 yards. The details are disputed and the route was adjusted several times for practical reasons, but the final measured distance is not in doubt.

The race itself became famous for its ending. The Italian runner Dorando Pietri entered the stadium first, collapsed several times on the track, was helped across the line by officials and was disqualified, with the gold medal going to the American Johnny Hayes. Queen Alexandra gave Pietri a special cup the next day, the newspapers made him a hero, and the marathon was suddenly the most talked-about event in athletics.

How the odd number became the rule

The 1912 and 1920 Olympic marathons were run over 40.2 and 42.75 kilometres, so London's figure was not yet a standard. What fixed it was the professional racing craze that followed Pietri's collapse. He and Hayes turned professional and raced each other repeatedly in the United States, and promoters advertised the events as being over the London distance, which was the one the public knew. By the time the International Amateur Athletic Federation met in 1921 to set a standard, 42.195 kilometres had become the marathon in the public mind, and the committee adopted it. It has been the distance ever since, including at every Olympics from 1924. The steps that produced it:

  • 1896: a 40-kilometre race from Marathon to Athens, inspired by legend
  • 1897 to 1907: courses of roughly 40 kilometres, none the same
  • 1908: the London course from Windsor to the stadium measures 26 miles 385 yards
  • 1908 to 1920: the Pietri drama makes the London distance the famous one
  • 1921: the IAAF adopts 42.195 kilometres as the standard

What the distance does to a runner

The number is arbitrary, but it happens to sit just beyond the point where the body's stored carbohydrate runs out. A trained runner carries roughly 2,000 calories of glycogen in muscle and liver, enough for about 30 kilometres at racing pace, after which the body must burn fat, which it cannot do as quickly. The result is the wall, the sudden heaviness runners describe at around 20 miles, and much of marathon training and fuelling is about pushing it beyond the finish line.

Had the London organisers laid out 24 miles, the event would be a different sport, hard but without its signature collapse. The royal nursery, if the story is true, gave the marathon its cruelty as well as its distance.

The takeaway

A marathon is 42.195 kilometres because that was the length of the 1908 London Olympic course, which became famous through Dorando Pietri's collapse and was adopted as the standard in 1921. The distance owes nothing to ancient Greece beyond its name and its legend, and by chance it runs a few miles past the point where the body's fuel gives out.

Practise this

Questions from The Olympics

Reading about something is not the same as being able to recall it. These are real questions from the The Olympics unit in our Sports track, answers and explanations included. The unit has 120 in total across 21 steps.

  • Fact or fibLevel 1

    1. The 100 meter sprint is one of the fastest races at the Summer Olympics.

    Answer: True

    The 100 meter sprint crowns the fastest runner at the Games.

  • Match the pairsLevel 2

    2. Match each Olympic fact to the right answer.

    Answer: Ancient Olympics = Olympia, Greece; First modern Olympics = Athens, 1896; Olympic founder = Pierre de Coubertin

    The ancient Games were at Olympia, the first modern Games were in Athens in 1896, and Pierre de Coubertin was the founder.

  • Fill the blankLevel 1

    3. A silver medal is given for finishing in ____ place.

    • secondcorrect
    • first
    • third
    • last

    Silver goes to the athlete who comes in second.