Walking and biking raise health and fitness levels

Trying to get fit but can't work it into your daily schedule? Incorporating even relatively short bouts of exercise into a daily commute appears to deliver significant rewards, according to a new study from the University of North Carolina at Chapel Hill.

Researchers looked at the health and fitness levels of active commuters " people who walk or ride a bike to work at least part of the way " compared to those who drive or take public transportation.

Men and women who were active commuters performed better on a fitness test, according to the study published in the July 13, 2009, issue of Archives of Internal Medicine.

And men who walk or bike have lower obesity rates as well as healthier triglyceride levels, blood pressure and insulin levels, said study author Penny Gordon-Larsen, Ph.D., nutrition associate professor in UNC's Gillings School of Global Public Health.

"We don't know why women don't reap all the same health benefits as men," said Gordon-Larsen, an obesity epidemiologist. "We can speculate " women may not be exercising as intensely or it may be that they are commuting shorter distances. But for both sexes, we see significant health benefits to walking or biking to work."

For most adults, 60 minutes of brisk walking per day is sufficient to meet physical activity guidelines for avoiding weight gain, Gordon-Larsen said, and walking is an activity most people can do.

"Walking or biking to work is one way to increase physical activity," said Janne Boone-Heinonen, Ph.D., a postdoctoral nutrition researcher at UNC and co-author of the study. And while the benefits of exercise in general have been studied quite a bit, she noted, not much research has been conducted on the cardiovascular and overall health benefits of "non-leisure" activities like active commuting.

Gordon-Larsen and colleagues studied 2,364 adults in the Coronary Artery Risk Development in Young Adults (CARDIA) study who worked outside the home. At examinations conducted between 2005 and 2006, participants reported the length of their commute in minutes and miles, including details on the percentage of the trip taken by car, public transportation, walking or bicycling. Researchers also recorded participants' height, weight and other health variables, including blood pressure and fitness levels as assessed by a treadmill test. In addition, subjects wore an accelerometer to measure their levels of physical activity during at least four days of the study period.

The average length of active commuters' trips was 20 minutes for men and 17 minutes for women. However, fewer than two in 10 (16.7 percent) of the participants used any means of active commuting to reach their workplace.

The results add to existing evidence that walking or biking to work is beneficial, the authors noted.

"Ultimately it would be wonderful to see more people walking and biking to work, but towa make this happen, we need to make walking and biking safe and accessible by reducing environmental barriers to activity," Gordon-Larsen said.

Additional research is needed to determine other potential benefits of active commuting and unravel the relationship between walking or biking to work and other health-promoting behaviors that people may engage in, the authors concluded.