New research on the negative effects of a sedentary lifestyle have shown that too much sitting and not enough physical activity can age cells by up to eight years.
Previous research has already linked too much sitting to health problems such as obesity, higher levels of "bad" cholesterol, and an increased risk of cardiovascular disease.
The new study, carried out by researchers at University of California San Diego School of Medicine, has now found that elderly women with a low level of physical activity who sit for more than 10 hours a day have cells that are biologically older by eight years compared to women who are less sedentary.
The research team believe that they are the first to objectively measure how the combination of sedentary time and exercise can affect biological aging.
For the research the team looked at nearly 1,500 women ages 64 to 95 from the Women's Health Initiative (WHI), a national longitudinal study studying the chronic diseases in postmenopausal women.
Participants were asked to complete questionnaires as well as wear an accelerometer for seven consecutive days while both awake and asleep to track their movements.
The team found that women who carried out less than 40 minutes of moderate-to-vigorous physical activity per day and who also remain sedentary for more than 10 hours per day have shorter telomeres.
Like the plastic tips of shoelaces, telomeres are found on the ends of DNA strands. They protect chromosomes from deterioration but as cells age they naturally shorten and fray, with shortened telomeres linked with cardiovascular disease, diabetes and major cancers.
Health and lifestyle factors, such as obesity and smoking, can also speed up the shortening.
However the team also found that women who sat for long periods of time did not have a shorter telomere length if they exercised for at least 30 minutes a day, which is the national recommended guideline.
Commenting on the findings lead author Aladdin Shadyab added that, "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."
"Chronological age doesn't always match biological age,"
Shadyab also added that future studies will look at how exercise could affect telomere length in younger populations and in men.
The study can be found published online in the American Journal of Epidemiology.