The 30-Minute Advantage
Glen E. Duncan, PhD, an assistant professor of epidemiology at the University of Washington in Seattle, agrees that moderate amounts of physical activity can make a big difference in health. He and his colleagues recently conducted a study, published in the Archives of Internal Medicine, in which they counseled nearly 500 sedentary adults on the value of walking for 30 minutes a day. Those who walked at a higher intensity, and those who walked at moderate intensity and more often, achieved greater health benefits. But all showed some improvement except those who walked infrequently, and at less intensity.
"It was about people in the real world," Duncan says. "We let people choose when and where they would walk. We tailored exercise descriptions, gave them heart rate monitors and pedometers."
However, despite the health benefits and the sense of well-being they achieved, some of the study participants cut back on their exercise regimen.
"Ultimately it was up to them to comply with their exercise prescriptions," says Duncan, "but their compliance diminished over time. Exercise is like medicine -- it only works if you do it."
That's why Duncan would like to see urban environments changed in ways that would encourage people to walk more, climb stairs, and ride bicycles.
"It's hard to be active in our society," said Duncan. "How many streets have dedicated bike lanes? Some areas don't even have sidewalks."
Those who make a minimal effort, however, can find a way to burn a few extra calories a day. It's hard to believe that after spending hours watching the Super Bowl, fans can't find 30 minutes for a brisk walk to help them win their battle against weight gain.