I've been getting sick of doing the elliptical at the gym, and I've kind of been getting into running. Breathing-wise, I'm OK, but I've been getting shin splints. My shins will start to ache while I'm running, and then they really kill when I slow back down to walking. Do you have any suggestions for things I could do to help? Kinds of shoes, kinds of stretches to do, shoe inserts, etc?