(Bizuayehu Tesfaye ~ Associated Press)
In what may be the first large U.S. study of health and commuting, the researchers found only about 17 percent of workers walked or bicycled any portion of their commute.
Those active commuters did better on treadmill tests of fitness, even when researchers accounted for their leisure-time physical activity levels, suggesting commuter choices do make a difference.
"There are numerous health benefits that can be gained any time you increase your physical activity," said HealthPoint Plaza fitness manager Amy Sutherlin in an e-mail interview. "You will burn more calories, gain more lean muscle tissue and burn fat, improve your heart and lung function, and arrive to work in a great, awake state of mind."
For men in the study, but not women, the active commuters also had healthier numbers for body mass index, blood pressure, insulin and blood fats called triglycerides. Women walked or biked shorter distances and they may have done so less vigorously, the authors speculated.
Crumbling sidewalks, lack of bike paths and sheer distances all keep American commuters in their cars, experts said.
"I do live 20 miles away, so walking to work would be a little extreme," Sutherlin said. She is currently plotting routes that would make it safer for her to ride her bike to work.
"In this area we are limited by lack of shoulders on the sides of the back roads and no bike paths located along the sides of the major streets," she said. "Right now I feel much safer riding in a group rather than by myself. The back road between Jackson and Cape is very winding and there are some blind spots and no shoulder, so caution is the key."
Patrick Koetting bikes to his job at Cape Bicycle Cycling & Fitness Inc., and he's in good company. The "employee bike rack" outside the business has roughly the same amount of bikes as the store has workers. He said he barely breaks a sweat now on his two-mile ride to or from work.
"Really the only reason any of us drive to work is because we have somewhere else to be," he said.
Koetting said traffic probably keeps potential cyclists in their vehicle for the work commute.
The new study is based on tests and questionnaires from 2,364 workers who were part of a larger federally funded study on heart disease risk. The participants lived in Chicago, Minneapolis, Birmingham, Ala., and Oakland, Calif. They were asked in 2005 and 2006 about their commuting habits in the past 12 months.
The study has a chicken-and-egg problem: The already-active people could be the ones leaving their cars at home.
Penny Gordon-Larsen of the University of North Carolina at Chapel Hill, who led the study, acknowledged that fitness contributes to wanting to walk to work, but she said the reverse also is probably true.
Prior research has found that the countries with the highest levels of walking and biking also have the lowest levels of obesity. But little research has looked at the health of Americans who walk or bike to work, said James Sallis of San Diego State University, who studies environmental factors and policies that influence physical activity. He wasn't involved in the new study.
"I'm really glad to see people starting to take a look at this in the U.S.," Sallis said.
Zoning in many U.S. cities separates workplaces from homes, lengthening commutes, he said.
"You're building in the impossibility of actively commuting to work," Sallis said. Cities that build bike paths like Portland, Ore., see higher rates of cycling, he said, and companies can provide showers, changing areas and secure bike parking to encourage active commuting.
Sutherlin said she has seen an increase of cyclists on main roads in Cape Girardeau and that she thinks the Share the Road signs around town have helped increase awareness.
Koetting said a helmet, lights on the bicycle and bright clothes can help cyclists feel safer.
The study was published in Monday's Archives of Internal Medicine.
Southeast Missourian features editor Chris Harris contributed to this report.