Message from Preston – March

You don’t have to be a Harvard University graduate to know that obesity results from energy imbalance: too many calories in, too few calories burned.

But according to a recent study by the Harvard School of Public Health, a number of factors influence how many calories people burn each day, among them, age, body size, and genes. But the most variable factor—and the most easily modified—is the amount of activity people get each day.

Keeping active can help people stay at a healthy weight or lose weight. It can also lower the risk of heart disease, diabetes, stroke, high blood pressure, osteoporosis, and certain cancers, as well as reduce stress and boost mood. Inactive lifestyles do just the opposite.

Despite all the health benefits of physical activity, people worldwide are doing less of it—at work, at home, and as they travel from place to place. The World Health Organization, the U.S. Dept. of Health and Human Services, and other authorities recommend that for good health, adults should get the equivalent of two and a half hours of moderate-to-vigorous physical activity each week.

There’s been some debate among researchers, however, about just how much activity people need each day to maintain a healthy weight or to help with weight loss, and the most recent studies suggest that a total of two and a half hours a week is simply not enough.

Though people often use “physical activity” and “exercise” interchangeably, the terms have different definitions. “Physical activity” refers to any body movement that burns calories, whether it’s for work or play, daily chores, or the daily commute. “Exercise,” a subcategory of physical activity, refers to “planned, structured, and repetitive” activities aimed at improving physical fitness and health. Researchers sometimes use the terms “leisure-time physical activity” or “recreational physical activity” as synonyms for exercise.