Physically Active People May, Biologically, Be a Decade Younger

By Miranda Hitti

WebMD Health News
Reviewed by Louise Chang, MD

Jan. 29, 2008 -- Being physically active may shave 10 years off your biological age, a new study shows.

The finding "provides a powerful message" about the potential antiaging effects of regular exercise, write the researchers, who support the following CDC guidelines:
Get at least 30 minutes of moderate-intensity physical activity (such as brisk walking) at least five days per week or get at least 20 minutes of vigorous-intensity physical activity (such as jogging) at least three days a week.








The researchers -- who included Lynn Cherkas, PhD, of Kings College London -- report their findings in the Archives of Internal Medicine.

Cherkas and colleagues studied some 2,400 adult British twins who provided blood samples and completed surveys about their physical activity, smoking, and health history.

The researchers used the blood samples to measure the length of telomeres -- chromosome tips -- on the participants' white blood cells.

Telomeres shorten a bit each time a cell divides, making them a possible marker of aging.

The study shows that physically active people had longer telomeres than sedentary people, regardless of age, sex, smoking, BMI (body mass index), or socioeconomic status.
10 Years Younger?

The telomere length difference "suggests that inactive subjects may be biologically older by 10 years compared with more active subjects," the researchers write.

But the study doesn't prove that. Participants weren't followed over time, so it's not clear who lived longest.

"Persons who exercise are different from sedentary persons in many ways," writes Jack Guralnik, MD, PhD, of the National Institute on Aging, in an editorial published with the study.

The importance of telomere length is controversial and may prove valuable, but it isn't "the sought-after Holy Grail that measures in a single number exactly where any individual is in relation to eventual life span," Guralnik writes.

Telomeres aside, plenty of studies have linked physical activity to better health. For instance, physical activity was recently named one of four steps to living 14 years longer. If you're ready to become more active, check in with your doctor first. But, remember, there is no better time than the present to become more active - so, get moving....