Sitting for ten hours each day can age women by eight years, study finds

Sitting down for long periods of time without participating in regular exercise can accelerate biological ageing in women, according to new research published in the American Journal of Epidemiology.

The study found that those who kept to a sedentary position for ten hours or more a day and participated in less than 40 minutes of moderate physical activity had bodies of women eight years older.

Aladdin Shadyab, lead author of the study with the Department of Family Medicine and Public Health at UC San Diego School of Medicine, said: "Our study found cells age faster with a sedentary lifestyle. Chronological age doesn't always match biological age.

"Discussions about the benefits of exercise should start when we are young, and physical activity should continue to be part of our daily lives as we get older, even at 80-years-old."

Researchers at The University of California San Diego conducted a study of around 1,500 women aged between 64 and 95.

Participants completed questionnaires and wore an accelerometer on their right hip for seven consecutive days during waking and sleeping hours to track their movements.

They were discovered to have shorter telomeres - the tiny caps found on the ends of strands of DNA which protect chromosomes and which are associated with faster ageing.

As cells age, their telomeres naturally shorten and fray, but health and lifestyle factors, such as obesity and smoking, are believed to accelerate the process.

Shortened telomeres are also associated with cardiovascular disease, diabetes and cancers.

"We found that women who sat longer did not have shorter telomere length if they exercised for at least 30 minutes a day, the national recommended guideline," added Mr Shadyab.

Current NHS guidelines recommend adults aged 65 or older, who are generally fit and have no health conditions that limit their mobility, to do at least 150 minutes of moderate aerobic activity such as cycling or walking each week, and strength exercises on two or more days that work all the major muscles (legs, hips, back, abdomen, chest, shoulders and arms).

Older people are also advised to break up long periods of sitting with light activity, as sedentary behaviour is now considered an independent risk factor for ill health, no matter how much exercise is done.

Researchers say future studies will also examine how exercise relates to telomere length in younger populations and in men.