From Health magazine
With the help of the International Health, Racquet & Sportsclub Associations annual listing of the largest gyms and health clubs worldwide, we assembled a list of U.S. clubs with more than 25 locations spread over at least three states, excluding those offering only personal or single-sport training.
Our experts reviewed information provided by the gyms in their individual areas of expertise, awarding them scores based on a broad range of criteria, including facilities and staffing, equipment and classes, healthy green practices, and nutrition. These scores were weighted and averaged, yielding our final results.