Molecular Proof: Exercise Keeps You Young
Intense Activity Keeps Telomeres Long
Dec. 1, 2009 -- People who exercise regularly tend to stay healthier as they
age, and now new research may explain why at a cellular level.
Compared to people who did not exercise, elite runners in the study had
cells that looked much younger under a microscope.
Specifically, investigators measured the length of telomeres -- the DNA on
either end of thread-like chromosomes.
Just as the plastic tips on the ends of shoelaces keep the laces from
fraying, telomeres protect the chromosomes that carry genes during cell
Each time a cell divides, telomeres get shorter. When telomeres get too
short, cells can no longer divide and they die.
Researchers now believe telomere shortening is critical to aging, making
people more vulnerable to diseases such as heart disease, diabetes, and
“Telomeres can be thought of as a biological clock,” lead researcher Ulrich
Laufs, MD, of Homburg, Germany’s Saarland University tells WebMD. “If they are
shorter than a critical length, the process of programmed cell death
Exercise and Telomeres
The new research involved animal and human studies designed to determine how
exercise impacts telomere length.
In the animal studies, mice that ran on a running wheel for as little as
three weeks showed evidence of increased production of telomere-stabilizing
proteins, which protected against cell death.
In the human studies, middle-aged professional athletes who ran about 50
miles a week and had done so for many years had longer telomeres than healthy,
age-matched non-athletes who did not exercise regularly.
Not surprisingly, the athletes also had slower resting heart rates, lower
blood pressures, and less body fat.
The study appears in the Dec. 15 issue of the American Heart Association
“This is the first time it has been shown at the molecular level that
exercising has an antiaging effect on the cardiovascular system,” Laufs
American Heart Association spokesman Barry Franklin, PhD, calls the new
“In many respects, I think this is a blockbuster study that complements
research in twins published last year,” he tells WebMD.
Exercise May Trump Genes
That study suggested exercise might trump genes when it comes to keeping
Researchers found that telomere length was related to activity level. People
who engaged in the most exercise had telomeres of similar length to inactive
people up to 10 years younger.
When one twin was largely sedentary and the other was active, the active
twin tended to have longer telomeres.
The most active people in the twin study engaged in just a few hours of
moderate to vigorous activity a week, suggesting that it is not necessary to
run 50 miles a week to achieve the antiaging benefits of exercise.
“In my own lab, I have seen a 3-month conditioning program raise oxygen
capacity significantly,” Franklin says.
He is director of cardiac rehabilitation and the exercise laboratories at
the William Beaumont Hospital in Royal Oaks, Mich.
“In both studies, active people had cells that were measurably younger than
inactive people,” he says. “This striking finding may explain how exercise
helps prevent heart attacks, diabetes and other degenerative diseases.”