Washington, Sep 18 (IANS) Older adults who exercise seem to live longer and have a lower risk of disability, says a new study.

Jochanan Stessman and colleagues at Hebrew University Medical Centre and its 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.

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 (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.

Compared to sedentary individuals, those 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.

Seventeen percent were less likely to die between ages 85 and 88. They were more likely to remain independent and experienced fewer declines in their ability to perform daily tasks.

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 of 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 study authors write.

Physical activity arrested the decline by improving cardiovascular fitness, slowing loss of muscle mass, reducing fat, improving immunity and suppressing inflammation, says a Hebrew University release.

These findings appeared in the current issue of Archives of Internal Medicine.