Do you want to look younger? New study reveals a natural way to make your skin appear up to 40 years younger.

Forget expensive anti-aging creams, scientists have discovered that regular exercise may be the key to reversing the skin's aging process.

Researchers at McMaster University in Ontario found that even with people they studied who started working out later in life, younger looking skin could be achieved.

'I don’t want to over-hype the results, but, really, it was pretty remarkable to see,' Dr Mark Tarnopolsky, who oversaw the study, tells The New York Times.

The study started out with mice, when scientists noticed that depriving the furry critters of their exercise wheels led them to quickly become weak, bald and sick.

Those who had access to their wheels, however, were healthier overall, kept their fur longer and didn't even go gray.

Encouraged by their findings, the team went on to study a group of 29 male and female volunteers between the ages of 20 and 84.

Half the participants were instructed to partake in at least three hours of moderate to vigorous physical activity every week, while the other half remained mostly sedentary.

All the volunteers then surrendered a patch of skin on their buttocks - an area rarely exposed to the skin-damaging effects of the sun - and sure enough, the sample who had been working out displayed visibly younger looking skin.

Their final part of the study looked at over-65's who had previously not been exercise bunnies, but who adopted a fitness regime for three months.

'All they had done different was exercise,' concludes Dr Tarnopolsky.  'It is astonishing to consider all of the intricate ways in which exercise changes our bodies.'When comparing the before-and-after buttock skin samples, researchers say the results were startling, noting that both inner and outer layers of the skin looked like those of 20 to 40-year-olds.

While he admits the sample size is small and more research is needed, the findings are yet another score for exercise; which boasts a long list of other established health benefits, including a sharper brain and better cardiovascular health.

And all of us for whom vanity trumps all, it couldn't be a better reason to get on the treadmill.