Fewer than half of US adults get enough physical activity for their health, said a US government study released Tuesday.
In a country where two thirds of the population is overweight or obese, just 48 percent get enough exercise, said the US Centers for Disease Control and Prevention.
Current US guidelines call for at least two and a half hours per week of moderate-intensity aerobic physical activity, such as brisk walking, in periods of at least 10 minutes each.
The CDC report found that walking as exercise is increasing, with about six in 10 US adults getting active through walking.
"More than 145 million adults are now getting some of their physical activity by walking," said a statement by CDC director Thomas Frieden.
"People who are physically active live longer and are at lower risk for heart disease, stroke, type 2 diabetes, depression and some cancers."
Joan Dorn, branch chief of the Physical Activity and Health Branch in CDC's Division of Nutrition, Physical Activity and Obesity, said she was encouraged by the increase in adults who walk for exercise.
"But there is still room for improvement. People need more safe and convenient places to walk. People walk more where they feel protected from traffic and safe from crime," she said.
"Communities can be designed or improved to make it easier for people to walk to the places they need and want to go."