Some of the research into the genetics of exercise has focused on individual genes. Dr. Olfert has looked at thrombospondin, a gene that limits the growth of small blood vessels, known as capillaries, in the muscles. Removing the gene allows greater capillary growth. The more capillaries in the muscle, the more oxygen the muscle will have available during exercise.
In one study, Olfert compared sedentary mice that did not have the thrombospondin gene in their skeletal muscle to mice that did have the gene. He found the mice without the thrombospondin, as expected, could exercise at a much greater capacity compared to the normal sedentary mice with the gene. What's more, the mice without thrombospondin could exercise at almost the same level as the mice with thrombospondin that exercised regularly.
While this research is exciting, it has its limitations, Dr. Olfert said. Many genes play a role in exercise adaptation, most of these genes probably have a minor effect, and the way these genes work and interact with each other is quite complicated.
Dr. Bouchard has focused his research on gene patterns, using the power of computing to sift through thousands of genes. He has been involved with the Heritage Family Study, which began in 1992. In this program, family members undertake a standard exercise program while researchers measure changes in maximal oxygen uptake (a measure of aerobic fitness), blood pressure and glucose and insulin metabolism.
The researchers compared measures of adaptation to exercise on individuals within families and between families on a variety of measures, including maximum oxygen uptake. Because families share a similar genetic makeup, the research has helped uncover the role that genetics plays in exercise. For example, the researchers calculated th
|Contact: Christine Guilfoy|
American Physiological Society