Female athletes are 4-6 times more likely to tear their ACL than male athletes participating in the same sports. Research has demonstrated that there are neuromuscular differences between males and females that explain this disparity in ACL injury rates. This study is being done to determine whether a specially designed exercise program (KIPP) can lower a female teenager’s chances of having a knee injury or knee pain while playing sports. The study is also being done to see if the exercise program can improve a teenager’s fitness or athletic performance.