A NEED FOR MORE EXPERIMENTAL STUDIES OF PHYSICAL ACTIVITY DURING CHILDHOOD: RESPONSE

Abstract

Dear Editor-in-Chief: We would like to thank Dr. Shephard for his comments on our recent article (1) but wish to clarify a few points raised in his letter. Although we agree that our data would support those who wish to increase school physical activity time, we did not specifically study this point. We looked at extracurricular activities. Our broad definition of organized childhood sports would include both competitive and noncompetitive activities and not just competitive activities as implied in his letter. We agree that confounding by a factor such as enjoyment of or skill at physical activity in childhood, as was mentioned in our article, may have influenced our findings. Although it is likely that sports participation in childhood is not random, increasing the extent to which children participate in sports by giving more children skills and exposure to a variety of sports may increase the level of adult participation in physical activity. We agree that an experimental study to investigate the “childhood intervention” hypothesis would be both difficult and costly. Allen Kraut, M.D. Samuel Melamed, Ph.D. Paul Froom, M.D.