It is more than theoretical, according to scientists who say they have discovered a way to mimic the effects of exercise on muscles.
“We’re not trying to put the health clubs out of business, we’re just trying to extend the benefits of exercise to people who can’t exercise or won’t,” said Dr. R. Sanders Williams, dean of the medical school at Duke University in North Carolina.
Writing today in the journal Science, Williams and his co-authors said their findings could lead to the development of drugs that could produce the health benefits of exercise, especially for those who cannot exercise because of medical conditions.
“It has the potential to improve the lives of patients with heart failure, pulmonary disease, renal failure, diabetes and other chronic diseases,” said Williams, a cardiologist whose research was funded by the National Institutes of Health.
Research was conducted on mice, but Williams said he is confident the same effect can be duplicated in humans. The “fundamental effects of exercise are similar in animals and humans,” he said.
“We’ve used a gene to produce effects in a mouse that would be similar to what would happen if a mouse went on an exercise program,” he said.
“We know that mice will run on a wheel for several miles a day and doing that yields positive effects. We also know that we can use a gene to mimic the effects of a running stimulus. And that then creates the distinct possibility that if you could discover a drug that would mimic the effect of the gene, you would produce that result.”
Williams said there is a genetic component to exercise. “Most people don’t think of jogging as having anything to do with genetics, but in fact it does. When you are jogging, you are switching your genes on and off.”
Although the development of a pill is perhaps years away, Williams envisions a therapy that, unlike most exercise activities would not be selective to certain muscles; rather, it would provide benefits throughout the skeletal structure.
The science starts with the premise that stimulating the protein in muscle increases a person’s endurance or capacity for physical activity and helps metabolize fats and sugar, helping control weight and improve cardiovascular health. In the study, Williams and his research team identified a protein enzyme called calmodulin-dependent protein kinase (CaMK) that controls the production of cells that help transform oxygen and other molecules into energy. The activation of CaMK stimulates the production of structures called mitochondria, which are especially plentiful in those who are fit.
“Activation of CaMK recapitulated the effects of exercise indicating that this is a central pathway by which exercise modifies the metabolic properties of skeletal muscles. Until now scientists did not suspect that this particular enzyme was involved in that control,” Williams said.
Williams acknowledged the development of a pill to enhance exercise capacity and make muscles more efficient raises the possibility of it being used to enhance athletic performance.
“It is conceivable it could become a drug of abuse in athletes, but that doesn’t deter us because we have in mind the societal good — the elimination of human suffering and improving quality of life — which would justify the effort,” he said.