Sedentary adults benefit from less than an hour of weekly exercise

In the journals

There's good news for seniors who have trouble reaching the recommended 150 minutes of exercise per week: a new study suggests that doing as little as 48 minutes can help some older adults.

The research, published online Aug. 18, 2017, by PLOS ONE, evaluated how different amounts of exercise benefited approximately 1,700 adults ages 70 to 89. Those chosen did less than 20 minutes of physical activity per week and were at a high risk for mobility issues.

Half of the group were randomly assigned to do a 20-minute exercise program twice a week, which consisted of 10 minutes of walking followed by 10 minutes of lower-body resistance training with ankle weights, balance exercises, and a stretching routine.

The exercise group also performed additional home workouts as they could, and wore an accelerometer to measure daily movements. The other half participated in regular health education workshops that covered topics like nutrition, travel safety, and negotiating the health care system.

After six months, the exercise group showed significant improvement in walking speed over 400 meters, scored higher on mobility and balance tests, and moved more during the day than the group who didn't do the workouts. The benefit also continued at the one- and two-year follow-ups. While all the participants who added some activity saw improvements, those who engaged in at least 48 minutes per week had the most benefit.