This is quite a specific one. There seem to be a number of different versions of “side stitch”, and from personal experience, they seem to correlate to how much and how hard you are breathing.
Previously we have posted about the possibility of psoas being implicated in stitch as it is a considerable hip flexor and gets stretched when running at higher speeds and greater exertion.
A few weeks ago I decided that I would start running with a Heart Rate Monitor (HRM) again. You might be able to tell where this is going.
Strapped on the HR monitor around my chest and went off for a run. It wasn’t all that fast or exciting, but by the end of it, I was having considerable difficulty breathing in without pain.
A bit of a problem, you might say, but I thought it was nothing too worrisome.
However, I went out again a couple of days later, same routine, and again, the pain in my abdomen came back… but not really the same deep pain as I have got with diaphragmatic pain previously. This was really specific and in between my ribs – yet undeniably a stitch.
Now, there are muscles in between the ribs called intercostals, they work pretty much all the time, but they work a lot harder to help expand the chest to gain more lung capacity when under exertion. Although I had been running a fair amount recently, it was the additional compression around my ribs from the HRM that meant my intercostals were working overtime as I ran. They were getting tired faster than normal having had to work harder (though for less amount of time) – and hence started hurting, essentially asking me to stop running while they recovered.
Now I have been running with the HRM for the last month or so, I have got used to the slight restriction around my chest, my intercostals have got a bit stronger, and there is no longer any indication of stitch as I run.
The upshot of this is that the intercostal muscles that I use for breathing were not strong enough to cope with the increased demand of running with a Heart Rate Monitor, and for a few runs, I really knew about it – because they ended up hurting. Soon they became stronger, and now I don’t get the stitch.
Note – I didn’t stretch it out. I couldn’t foam roller it, nothing like that – I simply tapered my exercise to gradually increase my exposure, and pretty soon, the muscles were strong enough to not give me pain.