It is important to develop a breathing pattern and try to stick with it during your entire run. But, every now and then, a deeper inhale and exhale will help you recharge, especially during a long distance run. Inhaling extra air will stretch the lungs a little in order to receive more oxygen during your normal breathing pattern. Expansion of the lungs will also improve oxygen and blood circulation. It is important to do this just a few times during a run, but not as a regular breathing pattern. Also, as mentioned previously, make sure that you do not exhale these larger breaths when the feet hit the ground as it may increase the risk of injury.