Muscles: Use 'Em or Lose 'Em

Exercise alters DNA molecules and appears to help prep the body for benefits of activity

(RxWiki News) Exercise does more than stretch and work your muscles - it actually alters the molecules in your muscles' DNA, prepping those muscles to reap the benefits of exercise.

A recent study looked at changes in the molecular DNA of healthy but inactive men and women and then replicated them in the laboratory, learning about the chemical changes that show how profoundly exercise can alter the human body.

"Make exercise part of your daily routine."

A study led by Romain Barrès, of the Novo Nordisk Foundation Center for Basic Metabolic Research at the University of Copenhagen in Denmark, and his colleagues found that both exercise and caffeine produced these tiny changes in DNA molecules.

Although the genetic code - the As, Gs, Ts and Cs - were not changed, the chemical changes the researchers did observe may be part of the body's response to exercise as it prepares to build strength.

"Our muscles are really plastic," said co-author Juleen Zierath of Karolinska Institutet in Sweden. "Muscle adapts to what you do. If you don't use it, you lose it, and this is one of the mechanisms that allows that to happen."

For the study, 14 healthy, sedentary men and women, who were 25 years old on average, exercised intensely for a short period of time. Then Barrès, Zierath and their colleagues took biopsies of the participants' muscle.

They found fewer "chemical marks" in the participants' DNA than they had before the exercise, and the differences occurred in the same parts of the DNA that are related to a gene's ability to turn "on" and adapt to exercise.

The scientists found the same reaction in the molecules of the DNA when they caused muscle cells to to contract in a lab.

The scientists aren't sure how the mechanism occurs, but the research provides clues to understanding how the body adapts to take advantage of the benefits offered by exercise.

Zierath called exercising a form of medicine and said this research appears to hint at the idea that physical activity might actually give the body an opportunity to alter its genome to become healthier starting from some of the tiniest building blocks in human bodies.

In the same study, the scientists found a similar reaction in the muscles' molecular DNA when they were exposed to caffeine.

Zierath said their study doesn't mean drinking coffee is just as good as a morning workout, but further research may reveal that combining the two can offer benefits at that molecular level.

The biggest take-away from the study is that the body can change in response to what a person does with it in more dramatic ways than researchers may have previously realized. Incorporating exercise into a daily routine may alter the body in tiny ways to gain more benefit from that exercise.

The study appears in the March issue of Cell Metabolism. No conflicts of interest were noted in the paper.

The research was funded by The European Research Council Advanced Grant Ideas Program, The European Foundation for the Study of Diabetes, Swedish Research Council, the Swedish Diabetes Association, Stockholm County Council, Strategic Research Foundation, Knut and Alice Wallenberg Foundation, The Strategic Diabetes Program at Karolinska Institutet, and the Australian Research Council.

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Review Date: 
March 6, 2012