Side Stitch

Annoying for sure.  I went 3 years without getting one and then I got a couple in the same week this Spring.  What I do is really focus on my exhale but pushing hard but tightening my lips like I'm blowing out of a small straw.  What this does is gets your diaphragm to contract and relax.  Somewhere I read that one of the causes of a side stitch is that the diaphragm is spasming vs. contracting and relaxing (I guess a cramp).  Give it a try and see if it helps, it does me.

The main cause for these are shallow breathing. You may not think you are but you are. When going hard it's easy to forget to breath deep in the gut.
When you feel one coming on, focus on the breath. Breath all the way down into the gut and push out. But not to fast . Slower controlled breath.

I'll give it a try...thanks.  Strange that I'd be a shallow breather as I'm a wind player (I've played brass and woodwind instruments my whole life!)  But maybe I am while running!  Deep breathing here I come...    Thx!

x2 on the deep, controlled breathing.  This has always worked for me.