For the newbie runner it is a common thing - side cramps. Often, I have experienced those sharp streaks of pain in my sides that make me instantly want to wimp out. They will have me hunched over, barely running and considering that I should just call it a day. I figured that I was out of shape and that was my body letting me know that I wasn't ready to be a runner. My muscles crying out, "You don't have what it takes!" What changed for me is when I figured out what was causing the issue and it surprised me what I uncovered.
Side cramps or "stitches" are caused by a muscle spasm in the diaphragm. The diaphragm is the dome shaped muscle that separates the chest cavity from the abdominal cavity and it assists in the breathing process. It moves up when we inhale and moves down when we exhale. When we run, our internal organs are bouncing up and down and at the same time as we exhale our diaphragm is moving down. This act of the organs and diaphragm going in opposite directions is what causes the spasms.
How did I fix this problem? I began concentrating on taking deep breaths while I was running instead of taking short breaths. Now I have virtually eliminated my side stitches so that I can keep going!