If it wasn’t already obvious how much Chicagoans love their parks, a new map from Strava makes that abundantly clear. The heat map shows fitness patterns of people from around the globe, and may have gotten into a little trouble revealing sensitive information about U.S. military bases.

Nonetheless, the exercise tracking map illuminates Chicago in a fascinating way. City parks are lit up and the Lakefront Trail is white hot as a result of all the runners. Look closely and you can make out the bottom half of the Chicago Marathon route too.

The 606 Trail, Jackson Park and Millennium Park are popular for runners. Zoom in on Maggie Daley Park or Buckingham Fountain and you can see the circular patterns runners have made around those areas.

As for cyclists in the city, Milwaukee Avenue is a the brightest bike-friendly street. It’s pretty easy to figure out which avenues bikers avoid too. Compare Milwaukee, or even Elston, with Ashland’s faint glow.