New research suggests that people whose office are 15 miles away from their home get insufficient exercise and are at greater risk of obesity.

PROBLEM: Though plenty of studies have shown the harmful effects of sedentary behavior, little is known about the specific association of long car commutes to adverse health outcomes.

METHODOLOGY: Researchers led by Christine M. Hoehner studied 4297 adults who had a comprehensive medical exam between 2000 and 2007 and geocoded home and work addresses in 12 Texas metropolitan counties. They measured their cardiorespiratory fitness, body mass index, and metabolic risk variables, including waist circumference, high-density lipoprotein cholesterol level, and blood pressure. Every week for three months, they also asked the participants to report on their physical activities.

RESULTS: On the whole, people who drove longer distances tended to participate less frequently in moderate to vigorous physical activities. They had lower cardiorespiratory fitness and greater body mass indices, waists, and blood pressures. More precisely, those who commuted more than 15 miles to work were at greater risk of obesity and were less likely to meet recommended standards for physical activity, while those who drove more than 10 miles tended to have high blood pressure.

CONCLUSION: Farther commutes to and from work may compromise cardiorespiratory fitness, weight, and physical activity.

IMPLICATION: Since driving to work is only one of many forms of inactivity, Hoehner says studies are needed to assess sedentary time across multiple behaviors to zero in on the independent health effects of commuting.

SOURCE: The full study, "Commuting Distance, Cardiorespiratory Fitness, and Metabolic Risk," (PDF) is published in the American Journal of Preventive Medicine.

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