Thank you for your article on the positive impact of sports on the academic outcome of girls ["Racing to a Degree," August 6].
It made the important point that sports can help students develop, through practice, goal-oriented behavior. However, sports may also help academic performance in another way as exercise builds better brains. In animal experiments, exercise has been found to modify gene expression in the brain. In a study on children, high physical fitness was associated with better scores on indexes of attention and working memory.