Modesty in Sportswear and Athletics

Today's question says, "How do Christian parents justify their girls wearing revealing clothes in extracurricular activities such as ballet, cheer, volleyball? I don't find it consistent that Christian families should allow it, and if we shouldn't allow it, how do we go about exposing our girls to these sports without having them reveal their bodies? I don't want to seem legalistic, but it just doesn't seem that the Bible justifies dressing like this simply because it's a sport. Please share your opinion."