Action Points
· As the proportion of people living in the suburbs increases in the U.S., so do average commuting distances and time by private vehicle, which increase time spent in sedentary behavior.
· Point out that this study suggests that commuting distance is adversely associated with moderate to vigorous physical activity, adiposity, and blood pressure.
The longer you drive to work, the more likely you are to be overweight and have high blood pressure, researchers reported.
And the daily commute was also negatively associated with high levels of physical activity and cardiorespiratory fitness, according to Christine Hoehner, PhD, of Washington University in St. Louis, and colleagues.
On the other hand, a long commute had no associations with some other measures of health, including glucose metabolism and lipid levels, Hoehner and colleagues reported in the June issue of the American Journal of Preventive Medicine.
"This study yields new information about biological outcomes and commuting distance, an understudied contributor to sedentary behavior that is prevalent among employed adults," Hoehner said in a statement.
The findings come from a cross-sectional analysis of a host of clinical factors in 4,297 people who commuted to work in the Dallas-Fort Worth and Austin areas of Texas.
While commuting on foot or by bicycle has known health benefits, it's not possible for many adults. Instead, many commuters drive, especially in large urban areas, the researchers noted.
And the average time spent commuting and the average distance traveled has been increasing, as more people choose to live in the suburbs. Yet there has been little study on the health effects of so-called passive commuting, Hoehner and colleagues added.
To help fill the gap, they turned to the Cooper Center Longitudinal Study, which involves people referred to the Cooper Clinic in Dallas for a preventive medical examination, which included a maximal treadmill test.
The researchers used the treadmill test to establish a level of cardiorespiratory fitness, and also recorded details of body composition and laboratory measurements.
Participants provided a detailed medical history, including information on demographics, health habits, and health history. They were also asked to report on the amount of time a week they spent in moderate to vigorous physical activity.
Finally, the length of their daily commute was estimated by geocoding home and work addresses. Potential participants who worked at home or were unemployed were excluded.
In a multiple linear regression analysis, they reported, commuting distance was negatively associated with moderate to vigorous physical activity and cardiorespiratory fitness.
And it was positively associated with body mass index, waist circumference, and diastolic blood pressure.
When the model was adjusted to account for physical activity and cardiorespiratory fitness, commuting distance remained associated with body mass index, waist circumference, and diastolic blood pressure, although the link with the first two was attenuated.
But in addition, systolic blood pressure and risk of metabolic syndrome became significant, the researchers noted.
Those who commuted more than 15 miles to work were less likely to meet recommendations for moderate to vigorous physical activity, the researchers found, possibly because time spent commuting is time not spent in the gym.
Those whose daily trip was 15 miles or more also were more likely to be obese, while those who traveled at least 10 miles had a greater risk of high blood pressure.
There might be several reasons for the latter link, the researchers noted, including the stress of battling congested roads day in and day out.
The researchers cautioned that the study excluded such other important contributors to a sedentary lifestyle as sitting down at work and TV viewing.
They also cautioned that the study was a snapshot and that the study population was primarily white and well-off, so that the findings may not apply to other groups.
