1. Chicago Marathon
Photo: Courtesy of Chicago Marathon
2. Arlington Million
Photo: Horsephotos/Getty Images
3. Shamrock Shuffle
Photo: Courtesy of Shamrock Shuffle
4. Bike the Drive
Photo: Courtesy of Bike the Drive
5. Chicago Polar Plunge
Photo: Jason Brown
6. Susan G. Komen's Mother's Day Race for the Cure
Photo: Dan Brinnehl
7. Chicago Triathlon
Photo: Ali Engin
8. AIDS Run & Walk Chicago
Photo: John Gress
9. PAWS 5K Walk/Run
Photo: Rene Flores
10. Race to Mackinac
Photo: Matt Knighton