As we reported last week, only 52 percent of Americans get the recommended amount of aerobic exercise, but a new study in the American Journal of Cardiology suggests getting just half is better than nothing at all.
The U.S. government recommends that every week adults get two-and-a-half hours of moderate-intensity physical activity, like brisk walking or even active household chores.
Researchers on a grant by the National Institutes of Health decided to test whether they could tease out health differences between different “doses” of weekly activity based on the official recommendations—what’s known as a dose-response study.
Isolating their subjects to post-menopausal women with metabolic syndrome—a combination of risk factors for cardiovascular disease and diabetes, including obesity, high cholesterol and high blood sugar—the scientists compared a sedentary control group with three exercise groups. These groups were tiered at 50 percent (the equivalent of 75 minutes a week), 100 percent (150 min/wk) and 150 percent (225 min/wk) of the recommended amount of activity.
After six months, researchers found a similarly tiered effect on a composite score, zMS, used to measure the overall severity of metabolic syndrome. Those women who were active for only half the recommended time saw an overall improvement in their zMS and even shaved a few statistically significant centimeters off their waistlines. For each step up in activity, the score improved.
Dr. Conrad Earnest, a professor in the Department for Health at the University of Bath in England and a co-author of the study, said via email that it would be reasonable to say there may be a similar dose-effect for the general population as well.
“The strength of our study is that simply moving on a regular basis is much better for your health than sitting remaining sedentary,” he said, adding that “moving regularly and throughout the day even if divided up will work toward improving your health.”