Too Much Sitting, Not Enough Physical Activity Accelerates Biological Aging

Older women taking part in the Women’s March on January 21 weren’t just exercising their democratic right to protest—they were also protecting the length of their telomeres.

Researchers at University of California report that older women who sit for more than 10 hours a day, with less than 30 to 40 minutes of moderate-to-vigorous physical activity per day, have cells that are biologically older by eight years compared to women who are less sedentary.

They found that these women have shorter telomeres—tiny caps found on the ends of DNA strands, like the plastic tips of shoelaces—that protect chromosomes from deterioration and progressively shorten with age.

As a cell ages, its telomeres naturally shorten and fray, but health and lifestyle factors, such as obesity and smoking, may accelerate that process.

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

“Our study found cells age faster with a sedentary lifestyle. Chronological age doesn’t always match biological age,” said study author Dr. Aladdin Shadyab.

Nearly 1,500 women, ages 64 to 95, participated in the study.

“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,” said Dr. Shadyab. “Physical activity should continue to be part of our daily lives as we get older, even at 80 years old.”

Shadyab said future studies will examine how exercise relates to telomere length in younger populations and in men.

The research was published in the American Journal of Epidemiology.