When my son was having difficulties at school, the Manly psychologist he was seeing recommend that we get him more involved with sports. He said that our son had a lot aggression built up within him and no way to release it. We enrolled him in karate classes and that really seemed a great outlet for him. He’s since stopped seeing the psychologist and has improved in all areas of his life. While I don’t give karate all the credit, I do think it helped him with self discipline. I’ll forever be grateful to that psychologist for those words of advice though.