A short walk just four times a week can reduce the risk of early death in older people by a staggering 40 per cent, a new study has claimed.

Each walk only needs to be a 15-minute stroll in the open air to give elderly a better chance of extending their longevity by a few years, said Italian researchers.

Allowing for a host of other factors from smoking to diet, the walking elderly had a 40 per cent better survival rate than those who did not, the study found.

For ten years, medical experts monitored over 200 residents of an old folks` home. Their average age was 80 and every aspect of their lifestyle, health and habits were noted, the `Daily Mail` reported.

This included their mental state, their diets, their weight, whether or not they smoked or drank coffee or were depressed, for instance. None had cancer or other terminal illness.

Most (around 80 per cent) of the subjects were physically active, said the researchers.

During the decade of study, two in three of the volunteers died, researchers reported in the journal Maturitas, allowing them to look at the differences between them and the survivors.

"Over-all survival was highest for subjects walking in the open air four times a week for at least 15 minutes in comparison to subjects walking less than four times a week," they wrote.

Walking is obviously an easier form of exercise for older people to take up but it also has the effect of holding back heart disease, stroke and other likely causes of death in the elderly.

The fresh air and exercise can increase the efficiency of the immune system to ward off viruses, strengthen bones and reduce obesity.

It can also lead to better physical health which in turn can mean a reduced risk of injuries from falls too.

There are also healthy side effects. Old folk who walked regularly were also more likely to eat healthily and less likely to be depressed, researchers said.

Although the figures were adjusted to take these factors into account, it does suggest that encouraging elderly to walk more would have a variety of benefits, they said.