Chicago ? Even in the “oldest old,” a little physical activity goes a long way, extending life by at least a few years for people in their mid- to late 80s, Israeli researchers found.

The three-year survival rate was about three times higher for active 85-year-olds compared with those who were inactive. Getting less than four hours of exercise weekly was considered inactive; more than that was active.

The results “clearly support the continued encouragement of physical activity, even among the oldest old. Indeed, it seems that it is never too late to start,” the researchers wrote in Monday’s Archives of Internal Medicine, which published the study.

They noted that exercise reaped benefits even for previously sedentary 85-year-olds; their three-year survival rate was double that of inactive 85-year-olds.

Oldsters didn’t have to be super-athletes to live longer; walking at least four hours weekly counted, even if it was just in 15-minute strolls a few times daily.

Active octogenarians also reported less depression and loneliness and a greater ability to perform daily tasks.

Similar benefits have been shown in people in their 60s and 70s, but there has been little research about exercise benefits in people in their 80s.