Ab exercises! I have a tendency to get side stitches when I run and what really helped was strengthening my ab muscles. I still get them occasionally, but not nearly as much as I used to.
I did get one when I was running this weekend. I was trying to run six miles and really wanted to finish. The side stitch started in mile 1. For the first three miles, I toughed it out. I used my hand to press on the area where the pain was, which decreased the pain to a point where I could continue to run. If the pain got too bad, I walked until it diminished enough that I could run again. It was clear that strategy wasn't going to work for the second half of the run, so I tried something different and it did actually work. I was able to eliminate the side stitch for the remainder of the run. Here is what worked:
- I stopped a rested after mile 3. Really, completely recovered from the first three miles. I even sat down for a little while. I made sure all the pain from the side stitch was completely gone before starting up again.
- I did a few ab stretches (basically just stretching my hands above my head and reaching up as high as a I could), before I started running again.
- When I started to run again, I concentrated on really sucking in my gut. I also concentrated on taking very deep, rhythmical breaths.
- I slowed my pace down.
I could feel that the stitch was there, ready to flair up at a moment's inattention, but by concentrating on sucking in my abs and breathing deeply, and running a little slower than normal, I kept it at bay.
Also, I've found that being dehydrated triggers them for me. I suspect that's why I had a problem this weekend. I had a couple glasses of wine on both Friday and Saturday nights, which probably dehydrated me for my Sun morning run. So making sure you are properly hydrated might help too.