The Genetics of Exercise

Have you ever had an experience like this: You and a friend start jogging together. Neither of you have been exercising much, but after a few days, your friend is easily striding along as you wheeze, gasp and hold onto your aching side. Do not feel bad about your performance; it may be your genes. Scientists have identified about 200 genes that play a role in our body's ability to become fitter, referred to as "adaptation to exercise." Mark Olfert of the University of California at San Diego and Claude Bouchard of the Pennington Biomedical Research Center explain. (Begins at 03:51)