Exercise helps to keep one young – even at the cellular level, according to new research. A study conducted at the University of California San Diego School of Medicine found that older women who do little physical activity, sitting for more than 10 hours a day, have cells that are biologically older by eight years compared to women who are more active.
Nearly 1,500 women, ages 64 to 95, participated in the study as part of the larger Women’s Health Initiative, a national, longitudinal study investigating the factors that contribute to chronic diseases in postmenopausal women. Participants both completed questionnaires and wore an accelerometer on their right hips for seven consecutive days during waking and sleeping hours in order to track their movements.
The study found that participants who had fewer than 40 minutes of moderate to vigorous physical activity per day, or who were sedentary for more than 10 hours per day, also had shorter telomeres – tiny caps that are found on the ends of DNA strands and function like the plastic tips of shoelaces. Telomeres protect chromosomes from deterioration and get progressively shorter with age. Shortened telomeres are a natural consequence of aging, but health and lifestyle factors, such as obesity and smoking, may accelerate that process, contributing to 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 Aladdin Shadyab, Ph.D., lead author of 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. 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.” The current study was published in the American Journal of Epidemiology.