Vigorous Exercise Reduces Cell Aging by 9 YearsVigorous exercise can reduce aging at the cellular level by nine years, a new study claims. "Just because you're 40, doesn't mean you're 40 years old biologically," said Brigham Young University exercise science professor Larry Tucker. "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." The study, which was published in the journal Preventive Medicine, found that people who have “consistently high levels of physical activity” have younger cells as measured through the length of telomeres. Telomeres are “protein endcaps of our chromosomes,” which shorten as we age because each time a cell replicates, they shorten a tiny bit. Exercise appears to stave this off. Tucker said adults with higher levels of exercise have telomeres that are nine years “younger” than people who don’t exercise and seven years younger than those who exercise moderately. In order to count as highly active, women have to jog 30 minutes five times a week, while men need to jog for 40 minutes. "If you want to see a real difference in slowing your biological aging, it appears that a little exercise won't cut it," Tucker said. "You have to work out regularly at high levels." Tucker arrived at his conclusions after looking at data from 5,823 adults who took part in the U.S. Centers for Disease Control National Health and Nutrition Examination Survey, which measured the telomere length of participants. The survey also had information about subjects’ activity levels. The shortest telomeres were observed in subjects with a sedentary lifestyle, and the difference in telomere length among sedentary subjects and subjects who exercised moderately was not very different. Tucker said we still don’t know the reasons why exercise prevents telomeres from shortening. "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," he said.