Study reveals how exercise turns back the clock in aging muscles

•  Doctors call physical exercise a "polypill," because it can prevent and treat many of the chronic diseases that are associated with aging.

• A new study of muscle fibers from mice and humans shows how exercise affects gene expression.

• The exercise-induced changes “reprogram” the epigenetic expression of the fibers to a more youthful state.

• The findings could provide leads for the development of drugs to mimic these benefits in people who are unable to exercise.

Research shows that people who exercise regularly not only strengthen their muscles but also improve their overall health, regardless of how late in life they start.

For example, recent studies have found that exercise reduces the risk of cardiovascular disease, as well as Alzheimer's and Parkinson's in older people.

Conversely, reductions in muscle mass and strength are associated with lower quality of life and higher mortality from all causes.

As a result of its proven ability to prevent and treat several chronic diseases at low cost, doctors have called exercise a drug-free "polypill" that can benefit almost everyone.

"Exercise is the most powerful drug we have," says Dr. Kevin Murach, assistant professor at the Exercise Science Research Center, University of Arkansas, Fayetteville, AR.

He believes that exercise should be considered a health-enhancing, potentially life-extending treatment, alongside medications and a healthy diet.

Scientists hope that a better understanding of how exercise rejuvenates aged muscle at a molecular level will provide clues for future anti-aging therapies.