Mary Brittin, 77, of Decatur, Ga., is cheered on while approaching the finish line in the half-mile walk competition in the Dekalb County Senior Olympics in Decatur, Ga., on May 16, 2014. (David Goldman/AP)

A moderate program of regular physical activity can keep older people walking without assistance, one key to maintaining independence in old age, a new study shows.

A clinical trial by researchers at the University of Florida, Gainesville and Jacksonville, followed 1,635 sedentary men aged 70 to 89 who could walk a quarter-mile in 15 minutes but were at risk of losing that ability. The subjects, who came from urban, suburban and rural communities across the United States, participated for an average of 2.6 years.

Half followed a regimen of walking 150 minutes per week and doing strength, flexibility, and balance exercises. The other half attended health education classes and did stretching exercises. By the end, those who followed the first program were better able to walk without assistance for 400 meters, or around a quarter-mile.

Research has shown that older people who lose their mobility have higher rates of disease and disability; and regular physical activity is known to be beneficial to people of all ages and health conditions.

The trial, called the Lifestyle Interventions and Independence for Elders and funded by the National Institute on Aging and the National Heart, Lung, and Blood Institute, was the first of its kind to test a specific regimen of regular physical activity for sedentary older people.