In an apparent mini-series of marathon maps, today I plotted the travel origin for runners of the 2014 Chicago marathon. I colour-coded separately for states, Canadian provinces, and international countries. Hover over each region to find out how many travelled from that location in order to race.
Why did I choose the Chicago marathon in particular? Two reasons:
1) It's a large, international-friendly race, which makes such a global map worth plotting
2) There's a comprehensive Google spreadsheet for all the data, which is not always easy to find.
I'm not sure if you can learn anything too deep from this data. I was maybe a little surprised just how many racers are local; 42% of all Chicago marathon runners come from the state of Illinois. On an international scale, an unexpectedly large contingent of Brazilians came to race (361), more than from any single European country. No jet lag, which is a plus, but I thought those from Brazil had tougher visa conditions than Europeans to travel stateside, but perhaps that doesn't matter for a race like this. Also there are many marathon races to choose from in Europe, with comparatively fewer in South American cities. Anyhow, it reminds me I'd like to go visit Argentina again sometime soon.