I actually don't know myself. I was a very active person and was a sportperson and I was not excellent in studies. My main school exams were approaching and I really wanted to score well but I couldn't sit in one place and study for an hour without feeling feverish. I did meditation, yoga and I studied really hard. I guess I became more mindful and less physically active in those few months. All these things really helped me stutter less. It is all about finding a balance. If you're a person who is generally less active, I would suggest you to start a sport and get a balance. Trying to excel in new things and being more mindful really does help with stammering.