What kind of lives are the most inactive people living? "I think they're living the typical life. They drive their children to school, they sit at a desk all day long, they may play some video games and they go to sleep," Archer said.
John Jakicic, chair of the department of health and physical activity at the University of Pittsburgh, praised the study but cautioned that its definition of "vigorous" is limited and not based on a person's fitness level. For some very obese people, for instance, just general walking could be considered vigorous, he explained.
What to do?
As little as 30 minutes of exercise five days a week can stop weight gain and improve health, study author Archer said. "People don't understand that [you] don't have to go to the gym and lift weights and run marathons to have dramatic impacts on your body. Standing rather than sitting, walking rather than taking your car, they have huge impacts on your health over time."
Jakicic agreed that little changes can have a big difference. "Traditional exercise approaches are not the way to try to get obese people active -- the barriers are just too great," he said. "However, we showed a number of years ago that encouraging multiple brief periods -- five to 10 minutes two to three times per day -- was an effective way to get individuals active initially. Once they started to become more active in this way, they started to add even more activity."
The study appeared recently in the Mayo Clinic Proceedings.