A scientific analysis by the American College of Sports Medicine released at its annual meeting in Indianapolis ranked San Francisco as the fittest city in the United States.

The ACSM American Fitness Index report, called “Health and Community Fitness Status of 16 Large Metropolitan Areas,” analyzed U.S. Census, CDC’s Behavioral Risk Factor Surveillance System and other government data on America’s 15 most populous metropolitan areas plus Indianapolis.

The findings are based on a number of health indicators, such as the percentage of residents who are obese, who smoke, who exercise regularly, who maintain a healthy weight and diet (eat the recommended daily servings of fruits and vegetables), who have health insurance and access to health care. The analysis also took into consideration community and environmental indicators like the number of recreation centers, parks, and other green spaces. Important for the study was the number of health care providers as well.

Out of a possible 432 points a city could achieve, San Francisco scored the best, 403 points, thus becoming the fittest city involved in the analysis. Just two points separated San Francisco from Seattle which ranked second with a score of 401 points.

Next on top were: Boston with 370 points; Washington, D.C. with 369 points; Atlanta with 285 points; Philadelphia with 268 points; Chicago with 267 points; Dallas with 261 points; New York City with 260 points; Miami with 235 points; Phoenix with 233 points; Indianapolis with 231 points; Houston with 209 points; Los Angeles with 208 points; Riverside, California (score not available) and Detroit with 149 points.

The authors of the reports recommended new national guidelines for physical activity, which should be regularly developed, updated and promoted. It is already known that physical activity keeps us fit and away from various health problems like obesity and other conditions that results from it such as diabetes, heart disease and several forms of cancer. According to government statistics, 66 percent of adults and 32 percent of children and teens in the U.S. are overweight or obese.

"This epidemic of obesity is catching up with us, and one way we can combat it is to provide an environment where kids and families can exercise," says Walt Thompson, chairman of the panel that created the new index and a professor of exercise physiology at Georgia State University in Atlanta, the USA Today reports.

To prevent all these, ACSM recommends that all healthy adults need moderate-intensity aerobic physical activity for at least 30 minutes on five days each week or vigorous-intensity aerobic physical activity for at least 20 minutes on three days each week.