"Physical activity is a modifiable behavior associated with health, functional status and longevity, and encouraging a physically active lifestyle has become an accepted public health goal," the authors write as background information in the article.

However, most research on the benefits of physical activity has focused on middle-aged populations.

Jochanan Stessman, M.D., and colleagues at Hebrew University Medical Center and Hebrew University Hadassah Medical School, Jerusalem, studied 1,861 individuals born in 1920 and 1921. Participants underwent assessments in their homes at ages 70, 78 and 85 years, during which they were asked about their physical activity levels.

Those who performed less than four hours per week of physical activity were considered sedentary, while those who exercised about four hours weekly, performed vigorous activities such as jogging or swimming at least twice weekly or who engaged in regular physical activity (for example, walking at least an hour daily) were considered physically active.

The proportion of participants who were physically active was -
    ● 53.4 percent at age 70,
    ● 76.9 percent at age 77 and
    ● 64 percent at age 85.

When compared with those who were sedentary, individuals who were physically active were -
    ● 12 percent less likely to die between ages 70 and 78,
    ● 15 percent less likely to die between ages 78 and 85 and
    ● 17 percent less likely to die between ages 85 and 88.

They were also more likely to remain independent and experienced fewer declines in their ability to perform daily tasks.

These active seniors also reported fewer new instances of loneliness -
    ● 12.2 percent vs. 22.6 percent from ages 70 to 78 and
    ● 26.5 percent vs. 44.1 percent from ages 78 to 85.

They also were less likely to have poor self-rated health -
    ● 77.3 percent vs. 63.3 percent from ages 70 to 78 and
    ● 63.8 percent vs. 82.6 percent from ages 78 to 85.

The benefits associated with physical activity were observed not only in those who maintained an existing level of physical activity, but also in those who began exercising between ages 70 and 85.

"Although the mechanism of the survival benefit is most likely multifactorial, one important finding was the sustained protective effect of physical activity against functional decline," the authors write.

Physical activity may delay the spiral of decline that begins with inability to perform daily activities and continues through illness and death by improving cardiovascular fitness, slowing loss of muscle mass, reducing fat, improving immunity and suppressing inflammation.

"Despite the increasing likelihood of comorbidity, frailty, dependence and ever-shortening life expectancy, remaining and even starting to be physically active increases the likelihood of living longer and staying functionally independent," the authors write.

"The clinical ramifications are far reaching. As this rapidly growing sector of the population assumes a prominent position in preventive and public health measures, our findings clearly support the continued encouragement of physical activity, even among the oldest old. Indeed, it seems that it is never too late to start."