According to this ^[1] article in USA Today Seattle is the second fittest city in the USA, following San Francisco.

Ranking was done by the American College of Sports Medicine whose considerations in ranking the cities were a variety of health indicators including the number of people who exercise regularly, maintain a healthy weight, follow a healthy diet, have access to health care and have health insurance, and don’t smoke. Other factors include the availability of parks, walking/bike trails and public transportation.

Coming in at number 3 was Boston; rounding out the top 10 were Washington, DC; Atlanta; Philadelphia; Chicago; Dallas/Ft. Worth; New York City; and Miami/Ft. Lauderdale.

The Seattle Parks Department ^[2] says that Seattle has over 400 parks and open areas that make up over 6200 square feet of park land.