Never said they weren't multi-factorial. We were talking about the common causes of shin splints for MOST people. Of course there are people that will suffer more often even when running regularly due to things like overpronation. It only takes me about 2 weeks to get over my shin splints. I have a friend that would take almost 2 months of running regularly before they would subside. Neither one of use suffered any actual bone fractures, mostly just tendon irritation.