Im 17 I have been running through this winter on a tread mill. I understand that a tread mill is harder on your body but the weather. Well the middle of my feet and the left side of my left foot hurts. I ran in nike free run 3s but i now run in saucony glide 5 its better on my feet but the left side of my left foot still hurt. Is it normal to just have pain while running do i need arch supports should i see a doctor? Does anyone have a similar problem.