Three generations ago, a majority of Americans walked to get where they were going. Cars were rare and some roads were little more than dirt paths.
Fast forward to America today, which struggles with rising obesity and cardiovascular health issues - and fewer than 25 percent of Americans walk, bike or use any other form of "active" transportation.
Could there be a connection?
"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," said lead study author Gregg Furie, M.D. 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 noted. He set out to measure the effects of activity as part of a daily routine. Active transportation is one of the main ways people do that.
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."
The study found that most Americans don't even walk 10 minutes a day.
"That's a pretty low rate," said Furie, "and we need to increase that level."
There are many good reasons to walk whenever possible. The study found that 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.
Not surprisingly, the U.S. has one of the lowest rates of active transportation in the world, according to James F. Sallis, Ph.D., of 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. 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."
The study is reported in the American Journal of Preventive Medicine.