Dear TEACHER_NAME I agree with you're choice to not allow students to participate in sports and other activities because it will both encourage the students who are already working hard to keep doing so and it will urge the students who are not doing well to try harder . I think that as a result of your choice more students will try harder in all of their classes , but I also see why you should not make that choice based on the effect it will have on the students . For the students who are doing well they might turn into bullies and start to pick on the students who are not doing so well .For the students who are not doing well it may depress them in two ways one way it could effect them is making them a target for bullies and that ties into the second effect sadness which can lead to the even greater plummet into them failing and then depression and lack of confidence. my stance is that you should change the policy .