Learn & Understand

26.2 Miles: The History Behind the Marathon

The marathon's peculiar distance — 26.2 miles, or 42.195 kilometers — seems arbitrary, and its origins reach back to an ancient legend and a royal request at an early Olympics. Behind every marathon pacing plan lies a story of a messenger, a distance that was almost round, and the infamous “wall” that punishes those who pace it wrong.

The Legend of Pheidippides

The marathon takes its name from an ancient Greek tale: a messenger, Pheidippides, is said to have run from the battlefield of Marathon to Athens to announce a victory, then collapsed and died. Whether or not the story is literally true, it gave the long-distance race its name and its heroic, do-or-die character when the modern Olympics revived the event.

The Odd Distance

The marathon was not always exactly 26.2 miles. Early marathons varied in length, roughly the distance of the legend. The precise figure was fixed at an early twentieth-century Olympics, reportedly so the race could start at a royal residence and finish before the royal box — stretching the course to its now-standard, oddly specific distance, which was then adopted permanently.

The Wall

The marathon is defined not just by its length but by a physiological cliff runners call “the wall.” Around the later miles, the body's stored carbohydrate can run low, and energy crashes dramatically. Runners who start too fast burn their reserves early and hit the wall hard, which is why marathon pacing is a discipline of restraint as much as speed.

Why Pacing Rules the Race

Over such a distance, small pacing errors compound enormously. Going out even slightly too fast in the early miles can cost far more time later. This is why marathoners build detailed pacing plans — exact split targets at each checkpoint — and hold to them with discipline. The marathon rewards the patient and punishes the impetuous, a lesson written into its long, storied distance.

Planning Your Marathon

To build a marathon pacing plan, use the Marathon Pace Calculator. Try the half distance with the Half Marathon Pace Calculator, and predict your time with the Riegel Race Time Predictor.