Have you ever had that feeling that there was something about your feet or shoes but could not put your finger exactly on it? There was some slight discomfort about your feet, maybe your shoes felt slightly tight but no blisters or soreness. You have discovered that your running shoes need to be at least a half or maybe a whole size bigger than your street shoes. This is because your feet swell as your run, this is normal and occurs more in hot weather than in cold. If you get properly sized shoes you will be surprised what difference it will make in your times.