Are you ready to sweat? We mean, really sweat. Check out the amazing, indoor cycling classes at Flywheel Sports, with two locations in Chicago. The classes are set up stadium-style facing the instructor, with the lights turned way down low so that your focus is solely on your efforts. Feeling competitive? Create a nickname for yourself to add to the "TorqBoard," so you can watch how your outputs are compared to other riders. Individual classes $28.