Chicago marathoners: where do they come from?

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.

A global map of major marathons

Using a newly-uncovered online tool called CartoDB (thanks Alex!), I assembled a map of all the marathons available at arrs.net based on location and number of participants (in 2014). Some have a participation number of '0' because the actual number wasn't available to me.

My criteria was a minimum 50 500 runners, and/or a winning time (male) of 2:40-ish. I've included marathons that don't fit this criteria if they happen to be in an interesting place (such as Easter Island). Certainly there's also a few I've missed. Among those listed, it's surprising how many marathons can be found deep inside Siberia. Conversely, only a handful of registered marathons exist in the Rift Valley a.k.a. the heart of running. Might one even claim an inverse relation to marathon density and local talent?

Since it did not take much additional effort, I also included PM_2.5 concentrations (μg/m³) at each marathon location. The WHO determined breathing values higher than 25 μg/m³ are 'less than ideal'. Perhaps factor that into your next 'destination' marathon (and if you'd like to see more discussion and a ranked list of clean-air marathons, check out the piece I wrote for Canadian Running).

Without further ado, here's the map. Click on individual races to get more info.

In case the above map does not survive, here's a static image: