1. Chicago Marathon
Photo: Joseph Oliver
2. Arlington Million
Photo: Cal Sport Media via AP Images
3. Shamrock Shuffle
Photo: Courtesy of Bank of America Shamrock Shuffle
4. Bike the Drive
Photo: Anne Evans
5. Chicago Polar Plunge
Photo: Courtesy of Chicago Polar Plunge
6. Susan G. Komen's Mother's Day Race for the Cure
Photo: Michael Rataj
7. Chicago Triathlon
Photo: Ali Engin
8. AIDS Run & Walk Chicago
Photo: Ashley Brown and Brian Solem/AFC
9. PAWS 5K Walk/Run
Photo: Brian Hlavacek
10. Race to Mackinac
Photo: Courtesy of Chicago Yacht Club