Effects of Title IX and sports participation on girls' physical activity and weight.

In this study, we examined the association between girls' participation in high school sports and the physical activity, weight, body mass, and body composition of adolescent females during the 1970s when girls' sports participation was dramatically increasing as a result of Title IX. We found that increases in girls' participation in high school sports, a proxy for expanded athletic opportunities for adolescent females, were associated with an increase in physical activity and an improvement in weight and body mass among girls. In contrast, adolescent boys experienced a decline in physical activity and an increase in weight and body mass during the period when girls' athletic opportunities were expanding. Taken together, these results strongly suggest that Title IX and the increase in athletic opportunities among adolescent females it engendered had a beneficial effect on the health of adolescent girls.