London, Jan 6 (IANS): Debunking the common assumption that ageing results in one becoming progressively frail, researchers have found that physical activity could help extend the strength and health of youth.

The study of amateur older cyclists found that many possessed levels of physiological function that would place them at a much younger age bracket compared with the general population.

With similar levels of exercise, the researchers found little physical difference between people aged 79 and those aged 55.

"Inevitably, our bodies will experience some decline with age, but staying physically active can buy you extra years of function compared to sedentary people," said Norman Lazarus from King's College London in Britain.

"A sedentary lifestyle causes physiological problems at any age. Hence, the confusion as to how much the decline in bodily functions is due to the natural ageing process and how much is due to the combined effects of ageing and inactivity," lead author Ross Pollock added.

The study recruited 84 male and 41 female cycling enthusiasts aged 55 to 79 to explore how the ageing process affects the human body, and whether specific physiological markers can be used to determine age.

Men and women had to be able to cycle 100 km in under 6.5 hours and 60 km in 5.5 hours, respectively, to be included in the study.

Smokers, heavy drinkers and those with high blood pressure or other health conditions were excluded from the study.

The researchers found that people of different ages could have similar levels of function such as muscle strength, lung power and exercise capacity.

The study was published in The Journal of Physiology.