Seems that after 50 years of running my doctor thinks I may have developed
Exercise Induced Bronchoconstriction. This comes after weeks if not months of increasing chest congestion and breathing problems while running. It all culminated last Saturday when I was only able to run to the first control at the Bon Tempe O event before walking back with overwhelming chest pain. It also coincided with a diagnosis and treatment of Sleep Apnia. I think these two conditions are interrelated and will try sort them out over the next few weeks.
So later today one hour before my run, I will use for the first time an asthma inhaler. Let's see how it works.