Walking, Biking Commutes Narrow Exercise Gap Among Californians

Newswise — Some California residents who walk or bike to work or errands may not be as inactive as previous studies — which focused on leisure-time physical activity —have suggested.

When active transportation is taken into account, the "exercise gap" that separates low-income Californians from richer residents shrinks dramatically, according to the new report in the American Journal of Preventive Medicine.

More Latinos and more people with only a high school education also meet the national standards for physical activity when biking and walking for transportation are included in their daily exercise tally, according to David Berrigan, Ph.D., of the National Cancer Institute and colleagues.

"It can be very challenging for people with physically demanding jobs, inflexible work schedules or lack of easy access to a car to participate in leisure-time physical activity," Berrigan said.

However, the study indicates that these barriers may not reduce overall levels of physical activity as much as previous studies of leisure-time activity have suggested.

Younger people, men, people with higher education and incomes and white people are the most likely to meet daily physical activity recommendations, the researchers found. But when active transportation was added to the daily total, the gap between the most active groups and other groups shrank.

For instance, there is an 18 percent difference in the number of white versus Latino Californians who meet physical activity recommendations through leisure-time activity. This difference narrows to 7 percent when biking and walking for transportation are considered, Berrigan and colleagues show.

For people with incomes reaching at least four times the poverty level (about $18,000 for a family of four in 2001, when the study data were collected) and those living below poverty level, the gap shrank from 25 percent to 11 percent after including walking and biking for transportation.

The researchers say public health researchers should be mindful of these results when they consider interventions to help people get more physical activity in their lives. People who walk or bike more for transportation may be more tired or have less time to start up a traditional exercise program, Berrigan said.

In the end, public transportation works best if "it goes where you want to go," said Andrew J. Dannenberg, a community health researcher at the National Center for Environmental Health. "If it's two buses and transfers, and any trip you can drive in 20 minutes takes you two hours, you're not going to take it."

The survey by Berrigan and colleagues also suggests it may be easier to be an active commuter in cities, since walking and biking for transportation were more prevalent in urban areas.

But some cities are better-suited to active transport than others, Dannenberg said. For instance, Philadelphia's hub-and-spoke commuter rail lines that bring people from the suburbs into a central business district may encourage more walking than the less-compact transportation system in Los Angeles, "where the destinations don't line up very well and there are too many people wanting to go to many different places."

The study data come from a statewide telephone survey of more than 55,000 Californians. The survey was conducted in English, Spanish, Mandarin, Cantonese, Vietnamese, Korean and Khmer.

The California Health Interview Survey 2001 was supported by the California Department of Health Services, California Endowment, the National Cancer Institute, California Children's and Family Commission, Centers for Disease Control and Prevention and the Indian Health Service.

Berrigan D, et al. (2006) Active transportation increases adherence to activity recommendations. Am J Prev Med 31(4), 2006.