All those gym signs reminding sweaty bench-pressers to "wipe down equipment after using?" Yeah, they may not be quite effective enough.
FitRated looked into the cleanliness of gyms by gathering bacteria samples from 27 different pieces of equipment at three different gyms, and the findings weren't pretty. Turns out, the average treadmill, exercise bike, and free weight are all crawling with germs-more than 1 million per square inch apiece. (BRB, showering immediately.)