Exercise is key to good health and an essential tool in the fight against obesity, but new numbers suggest that many Americans don't get any physical activity at all.
In a checkup of the nation's health, the CDC found that fewer than two in 10 Americans get the recommended levels of exercise, and more than a quarter of U.S. adults do not devote any time to physical activity. The findings were published today in the agency's annual report on health statistics.
Regionally, the problems are even more pronounced. Inactivity runs rampant across the U.S. South and Appalachia, where nearly 30 percent of people reported that they do not get any physical exercise -- not even light activities such as golfing or gardening.
"That's probably even an underestimate of the real problem," said Dr. Antronette Yancey, a professor at UCLA who serves on a board that supports first lady Michelle Obama's "Let's Move" campaign. Yancey said that in self-reported data, participants often vastly overstate their actual activity.
In Alabama, Kentucky, Louisiana, Mississippi, Oklahoma and Tennessee, inactivity rates are at least 29.2 percent in more than 70 percent of counties. These states also have some of the highest levels of health problems, such as diabetes and obesity.
Areas of the country where residents are most likely to be active include parts of the Northeast, the West Coast, Colorado and Minnesota.
One factor that could account for regional variation is social norms.
"There's evidence to suggest that if people see people outside walking, then that makes them more likely to walk," she said. "If people feel that physical activity is the norm in their peer group, then they're more likely to be physically active."
Another difference, Yancey said, is that transit-rich cities such as New York and Chicago encourage more activity, even if it's just to climb stairs to a subway platform or walk to the bus stop.
The nation's poor health habits add to waistlines and shrink wallets. According to the latest government numbers, 34 percent of American adults are obese and another 34 percent are overweight. Obese individuals spend on average 40 percent more on health care every year compared with individuals of normal weight.
While exercise is nearly free, obesity-related health care costs total an estimated $147 billion annually. The cost of treating diabetes totals some $116 billion.
Federal guidelines call for 150 minutes of moderate to vigorous physical activity every week, including two days of full-body strengthening. But when so few people are meeting these guidelines, Yancey said, it may be time to consider more drastic measures, from employer-mandated exercise breaks for office workers to auto-free zones that encourage more walking.
"There really is no lower limit. Every step counts. Every calorie burned is one that doesn't end up around your waist," she said.