According to the latest research it's never too late to get fit. Researchers in the United States say the benefits of a healthy, active lifestyle which includes regular exercise last well into old age.
The scientists from Brigham and Women's Hospital in Boston say that 70-year-olds who take regular exercise, eat well, and do not smoke greatly increase their chance of living until 90.
They believe that longevity is at the most only influenced to the tune of 30% by our genes and after that it is lifestyle factors which determine a long life.
The researchers arrived at this conclusion by studying 2,357 male doctors whose average age was 72 when they joined the study between 1981 and 1984.
The doctors provided data on their health which included high blood pressure and exercise habits, and completed regular questionnaires each year until 2006.
Of the group a total of 970, which equates to 41%, lived to 90 or longer and the research team found that it was those who exercised two to four times per week, did not smoke, maintained normal body weight and blood pressure, and avoided diabetes, who had a 54% chance of living to 90.
Those who failed on each count had only a 4% chance of living to see their tenth decade.
The researchers say the key to enjoying longevity is down to the individual and looking after one's health and exercising regularly is three times more important than a person's genes when it comes to leading an active life well into your 90s.
They say those who avoid smoking and being overweight and lead active lives are likely to be in better shape in later life than men decades younger who are destined to die prematurely; smoking they say is also associated with a significant decrease in mental function.
The researchers estimate that a 70-year-old man who does not smoke, has normal blood pressure and weight, does not have diabetes and exercises two to four times a week, has a 54 per cent probability of living to be 90.