Did a 3 x 20 min at ftp. The first interval was ok but towards the second interval my diaphragm started to hurt. During a recovery it abated but returned in the middle of the third interval and was worse than the leg pain or mental fatigue.
It happened to me once already during a 20 min uphill race last year. It felt like spasms in the diaphragm and took a while after to recover. I am mindful of breathing, exhale deeply and breath normally (not hyperventilating or shallow breath). I didn’t have similar experience during my ramp tests, although during the last one I was wheezing pretty bad.
Does someone have a similar experience? Is there something I can do to improve my breathing? I searched only briefly on found an article on respiratory muscles fatigue that I will look into but personal experience might be useful too!