A study by Stessman and colleagues from Hadassah Hebrew University in Jerusalem found that initiating physical activity over the age of 70 years leads to a 12% increase in longevity. This study was published in the September issue of the Archives of Internal Medicine.

This study also found that physically active persons between 70 to 85 years not only were less likely to die, but also had increased function and less loneliness. In addition, the physically active considered themselves to be more healthy than the inactive group. The findings of this study were similar to the British Heart Study and the Zutphen Elderly Study, both of which showed that physical activity was associated with longer lifespan in older persons.

Another study in the Archives of Internal Medicine found that in postmenopausal women increasing the amount of exercise improved both the mental and physical aspects of quality of life. 

A study from the University of North Carolina in Chapel Hill reported that young people who actively commuted (walked or rode a bicycle to work)  had a reduced risk of developing cardiovascular risk factors. The risk factors they looked at were obesity, fitness, blood pressure, triglycerides and blood insulin levels.

The BOTTOM LINE : Taking up exercise at any age will increase your chances of living longer.