1. Minneapolis-St. Paul Minnesota
Credit: Jeff Hathaway / Getty Images

Long, cold winters and hot, humid summers are no barrier for the fit residents of the Twin Cities. The metro area boasts more parks, bike paths, running trails, tennis courts, ball fields, and golf courses than most warm-weather cities, plus several in-town lakes for kayaking, canoeing, and kiteboarding. When winter hits hardest, these people pedal to work on fatbikes and bust a sweat at the city's many top-end fitness centers, where thousands train for the region's many marathons, triathlons, and running and biking races. Also, thanks to extensive indoor skywalk systems in both cities' downtowns, workers can go for miles-long midday walks without having to brave the cold. All this exercise is paying off: Minneapolis-St. Paul has very low rates of diabetes, heart disease, and asthma and fewer disease-caused deaths than most other big cities.