Both sports and studies go hand in hand. There is no point in having the physical aspect down if you can not properly read and write, and do the math that would be required to keep track of your score and points during the sport. Just like studying all the time is not good if you are not getting exercise.
I believe keeping sports in school not only gives kids some much needed exercise, it allows allows them to participate in a team competition, much like they will encounter throughout life. The competition pushes kids to work hard and develop their work ethic. I personally feel that I owe a lot to my school's wrestling program. I have the strength to push through difficult tasks, another valuable aspect of participating in organized sports.