Dec. 1, 2005 - More than half of U.S. adults still do not get a minimum amount of daily exercise recommended to help stave off obesity and chronic disease, according to government figures released Thursday.
The report shows that Americans were only slightly more likely to exercise regularly in 2003 than in 2001. That's troubling to public health experts, who have long pegged Americans' inert lifestyles as a major factor in rates of obesity that now top 30%.
Government health recommendations call for adults to engage in at least 30 minutes of moderate physical activity five days or more per week. That includes walking or bicycling, but also minimally exertive household chores like gardening or vacuuming.
Just under 46% of Americans surveyed in 2003 said they get that amount of exercise, up 0.6% from 2001, the CDC reported Thursday. One-sixth of adults reported that they participate in moderate physical activity for less than 10 minutes per week.
Obesity and Exercise
Lack of regular exercise is closely intertwined with obesity, and both factors are known risks for the leading killers of American adults, including heart disease, diabetes, and several forms of cancer.
Sixty-four percent of Americans over 20 years old now qualify as overweight, while 30% are classified as obese, according to government figures.
Sanjeeb Sapkota, MD, a CDC epidemiologist who co-authored the physical activity report, called the 2001 to 2003 results frustrating. But he pointed out that states where physical activity rates improved outnumbered those where they declined, suggesting some progress in approaching national public health goals.
"The frame we looked at is two years, and two years is not a lot of time to change behavior," he tells WebMD.
The Role of Environment
Still, overall exercise rates remain low in a nation where daily suburban highway commutes and office cubicles long ago replaced farm and factory work, and television, computers, and video games now overwhelmingly dominate leisure time.
Those forces have largely overwhelmed messages extolling the benefits of regular exercise, says Tegan Boehmer, PhD, an epidemiologist at the St. Louis University School of Public Health.
While almost all adults know exercise is a good idea, many spend too much time commuting to and from work to set aside time. Public health researchers have turned increasing attention to the large number of suburban communities with no bike paths, open spaces, or even sidewalks.
"There's just not access to the things that even make you think about being physically active. We've almost transitioned it out of our lives and our daily thinking," says Boehmer, who conducts research on the connection between obesity and the made-made environment.
"Right now there's conflicting messages between the public health messages we send people and the opportunities to actually do it," she says.
Nebraska Gets Active
Just 34% of adults in Nebraska reported regular physical activity in 2001, putting the state among the worst in the nation. But activity rates jumped more than 10% by 2003, far more than in any other state. At the same time, the number of the state's sedentary adults dropped by half, according the CDC's report.
State health officials said they were pleasantly surprised by the drastic improvement and could not point to any specific cause.
Money from states' multibillion settlement with tobacco companies helped extend public health departments to 20 locations around the state. Public campaigns urging adults to be more active with their kids may also have helped, says said Joann Schaefer, MD, Nebraska's chief medical officer.
"It is a constant message that we send, I'm not kidding you. We harp on it," she says.
Schaefer speculates that part of the reported improvement may also come from experts' redefinition of what constitutes exercise. Adults who spend enough time gardening or walking through shopping centers -- and not necessarily on a gym stair climber -- now qualify as physically active.
"I think the whole idea of act vs. exercise has been introduced and sold," she says.
Neither Nebraska nor the CDC yet has evidence that increases in mild activity will translate to lower disease or obesity rates.