Genes and Responses to Exercise

In the field of exercise science, the principle of individual differences has been well established. This principle simply states that because of human uniqueness, all individuals will have a varying response to an exercise stimulus and the ability to increase fitness. The Heritage Family Study and others have demonstrated that heredity plays a major role in determining to what degree an individual responds to and adapts to an exercise stimulus. Physical performance phenotypes—cardiorespiratory endurance and muscle strength—and other muscle performance traits and health-related fitness pheno-types—exercise heart rate, blood pressure, body composition, and insulin and glucose metabolism—have moderate to high heritability values of 25% to 80%. Therefore, given the individual variation observed in these phenotypes and considering that apart from identical twins, no 2 people share ...