Exercise Has Anti-aging Benefits and Makes You Years Younger on a Cellular Level

Updated | It's not quite eternal youth but scientists have discovered how humans can slow down the aging process and shave almost a decade off their biological age—vigorous exercise. In a study of more than 5,000 adults in the U.S., a researcher found those who exercise regularly are younger on a cellular level than those who lead sedentary or moderately active lifestyles.

Research published in the journal Preventative Medicine in April considered data on 5,823 people who had participated in the National Health and Nutrition Examination Survey between 1999 and 2002. The participants were asked demographic and lifestyle questions, including how often they exercised.

They also looked at telomere length. Telomeres are protective caps found at the ends of chromosomes that help keep them stable—not unlike how the plastic sheath at the end of shoelaces stops them from fraying. Every time a cell divides, telomeres get shorter. Eventually they become too small to protect the chromosomes and cells get old and die—resulting in aging.

Shorter telomeres are related to many age-related diseases, including cancer, stroke and cardiovascular disease.

In the study, exercise science professor Larry Tucker from Brigham Young University compared telomere length with levels of physical activity. His findings showed significant differences between those who did regular, vigorous exercise and those who did not.

"Just because you're 40, doesn't mean you're 40 years old biologically," he said in a statement. "We all know people that seem younger than their actual age. The more physically active we are, the less biological aging takes place in our bodies."

He discovered adults with a high level of physical activity had a "biological aging advantage" of nine years compared to sedentary adults. When compared with those who did a moderate amount of exercise, the difference for highly active adults was seven years.

A high level of physical activity was constituted as running between 30 and 40 minutes per day, at least five days per week.

"Overall, physical activity was significantly and meaningfully associated with telomere length in U.S. men and women," he wrote. "Evidently, adults who participate in high levels of physical activity tend to have longer telomeres, accounting for years of reduced cellular aging compared to their more sedentary counterparts."

He said exactly why exercise appears to preserve telomere length is not known, but added it could be linked with inflammation and oxidative stress—exercise is known to suppress inflammation and stress over time.

"If you want to see a real difference in slowing your biological aging, it appears that a little exercise won't cut it. You have to work out regularly at high levels," he said. "We know that regular physical activity helps to reduce mortality and prolong life, and now we know part of that advantage may be due to the preservation of telomeres."

This article has been updated with the name of the university where Larry Tucker works.