Good article, Carole. I've saved it for reference.
As for breathing, it's wierd how we have to think about breathing sometimes, isn't it??? LOL When I began running, I didn't think too much about it until I started with the side stitches as well. I concentrated on longer and more 'regular' controlled breathing until I was running pain-free. Every now and then during a long run, I would feel the NEED for a deep, deep breath. That's when I would take a deep inhale and slowly let it out. Now, when running, breathing is second nature again.
BUT...my breathing is different between my long runs (trianing for my half) and my races (recent 4 miler, 5K, etc). My short races where I am going for speed, I breath quicker and shallower. My longer runs for the marathon have more controlled longer breaths. I am able to breath in and out of my nose during long steady state runs now, and I find that incredible! LOL
I hope I've helped some!
Gayle