I think I have run more half marathon races than any other distance, and it might be my favorite type of race. It always surprises me when non-runners don't seem to know how far that is. There are probably a lot of runners who don't know exactly what the distance is, why it is that distance, or why it is such a strange and random goal.
Technically, the half marathon is 13 miles and 192.5 yards long. Most people I know would say a half marathon is 13.1 miles long, probably because I know a lot of Americans and we are allergic to thinking of things in yards. The distance of the marathon is, naturally, based on the distance of the full marathon. Lets do some math.
The full marathon is 26 miles and 385 yards long. There are 1,760 yards in a mile. The marathon is often said to be 26.2 miles long, but you might notice there's a bit of rounding in there. When a race course is certified they make sure it is 26 miles and 385 yards, not 26.2 miles, not 26 miles and change. I think we can all agree that after running 26 miles most of us wouldn't want to just carry on for a few blocks. Are you starting to get the sense that running a marathon is a weird distance? Let's take a moment and appreciate how weird it is to decide to run exactly half that weird distance.
I am still impressed by the tangled path that led us to the distance of the full marathon. It wasn't always that distance, and I think the case could be made that no one knows the original distance. The marathon race was originally cooked up as a tribute to a historical event, or at least an event that might have happened, or a legend.
In 500 ish BC Phillipides(or a similar spelling) was said to have run 25 miles (or 40 kilometers) from the city of Marathon, Greece to Athens to deliver news of the victory of the Battle of Marathon. In 1896, the Olympic Games were revived in Athens and the organizers included a long distance running race in honor of Phillipides famous run, on approximately the same course of the fabled/mythical/details lost to history run. The distance of the Olympics marathon was about 25 miles.
In 1908 the Olympics were held in London. The route for the marathon started at Windsor Castle and ended at White City Stadium, making it 26 miles. Someone decided it would be nice for the finish line to be directly under the royal box, which added that all important 385 yards. After that race the distance of marathons continued to be 25 miles plus or minus a few miles and yards. In 1921, for no reason that anyone is quite sure about but clearly taking inspiration from the London Olympics, the official distance for the marathon was set at 26 miles and 385 yards.
To sum up, someone ran a long way about 2,500 years ago. We're not exactly sure how far he ran or even exactly what his name was. Races in honor of that run were over various distances. One particular race had a very precise and strange distance, and now we only run that distance. The half marathon is half of that very strange distance. Half marathons are incredibly popular, and if you want to run a race that will require training, be rewarding, and be a well organized there is a good chance it will be 13 miles and 192.5 yards long.