New research reveals that middle-aged people who do 30 minutes of vigorous activity three times a week are half as likely to suffer physical decline and impaired mobility as they age compared to those who do nothing.

“We have clear evidence now that fitness is the most important predictor of longevity and, more importantly, quality of life,” says sports scientist Aaron Coutts, a member of Fernwood’s Scientific Advisory Board. “For every hour you exercise, you can expect to live an additional two hours!”

Based on our reputation as the sluggish country, that sort of advice has not exactly provided a stimulus for Australians. A recent survey published in Melbourne’s Age newspaper showed that one in five of us doesn’t even manage one 10-minute walk a week.

Interestingly, it is fitness rather than fatness that will dictate the type of health future we face. Consider some of the facts advanced by Coutts: Women who are fit are 20% less likely than their sedentary counterparts to catch colds or flu. They are also 34% less likely to suffer fractures and falls and, for those who walk 1.5km a day, they manage to reduce their risk of mental decline by 13%.

“Being fit is much more important than being a certain size,” says Coutts. “Being overweight and unfit elevates your risk of death remarkably. But being fat and fit doesn’t necessarily make an impact on your longevity.”

The benefits to be gained from exercise were put to the test in a collaborative study between the US and the UK where the data obtained from more than 10,000 people aged between 50 and 69 were studied. Their findings, published in the Journal of the American Geriatrics Society, showed that those who maintained a reasonable level of physical activity were more likely to be able to walk distances, climb stairs, maintain their sense of balance and sustain their hand grip as they got older. Those who were less physically active were significantly more likely to suffer from decreased physical ability in later life.

Being overweight or obese has been linked to an increased risk of heart disease, diabetes, high blood pressure, stroke and some cancers. However, if you are fat but fit, your life expectancy seems to be higher than if you are fat and unfit.