Many people in the U.S. don't walk, bike, or engage in other forms of active transportation, missing an important opportunity to improve their cardiovascular health, concludes a new study in the American Journal of Preventive Medicine.

Active transportation refers to any form of human-powered transportation, most commonly walking and cycling, but also using a wheelchair, in-line skating, or skateboarding. The study's researchers suggest active transportation is "an untapped reservoir of opportunity for physical activity for many U.S. adults."

"We knew that many studies have demonstrated that physical activity can help prevent a variety of conditions like high blood pressure, obesity, diabetes, and serum lipid abnormalities—all risk factors for developing cardiovascular disease," says lead study author Dr. Gregg Furie, of the Yale School of Medicine, who specializes in adult primary care medicine. However, the majority of previous studies done on physical activity primarily focused on its use in recreational activity or leisure time activity, he says.

Using cross-sectional data from the 20072008 and 20092010 cycles of the National Health and Nutrition Examination Survey (NHANES), Furie and his colleague, Mayur M. Desai, associate professor at the Yale School of Public Health, were surprised to find that less than one quarter of U.S. adults in a nationally representative sample reported walking or bicycling for transportation for more than 10 minutes continuously in a typical week.

"That's a pretty low rate," says Furie, "and we need to increase that level." People who engaged in active transportation on average had lower body mass indexes and lower odds of hypertension, compared to those who didn't.

The study identified reasons why government policies and infrastructure, along with "built environment interventions," should allow and encourage active transportation. Communities that do so may promote dedicated bicycle lanes and routes, educate residents about bike and motor vehicle road-sharing, provide bicycle storage, and integrate public transportation for both pedestrians and cyclists.

The U.S. has one of the lowest rates of active transportation in the world, says James F. Sallis, chief of the division of behavioral medicine at the University of California, San Diego.

"This is not an accident. U.S. transportation policies and funding prioritize travel by car, unwittingly discouraging active travel," says Sallis, who also is director of active living research at UCSD. "This situation is made worse by land use and zoning policies that separate residential and commercial zones to the extent that it is not feasible to walk for daily needs. These new findings point out how transportation policy is health policy."

He calls the study "powerful evidence from a large national sample that active transportation is just as beneficial to health as leisure-time physical activity."

Not surprisingly, Sallis says, "The findings highlight that transportation policies that essentially ignore walking and cycling appear to be contributing to the major chronic diseases that account for 80 percent of health care costs."

There's a need for better understanding of the overall benefits of active transportation, Furie says, adding, "This information adds to the weight of evidence that suggests more work is necessary to develop environmental policies that make it safer, easier, and more desirable for people to walk and bike for transportation."