yo aron, it took me about 3 to 4 months. I wasn't very active before I started training in boxing. As a result, frequent running and skipping or a pick up game of hoops was something that my underdeveloped shins were not prepared for. I'm close to 30 and you're 17 so it shouldn't take as long as I did to get accustomed to the roping. Sorry bro, I know the pain of shin splints can be unbearable, but once you're over the hump it won't be an issue. Hopefully you'll update us with good news within a few weeks.