Your answer is well informed and I am glad you agree with me on the Metformin issue.
Regarding the Metoprolol, yes, going by the HR of the cardio watch may not be an accurate way to determine effort or my body’s aerobic efficiency, but I also go by the perceived effort level, which is an unmistakable indicator of improved efficiency, as I am now able to do many more lapses. Or perhaps is this still the effect of Metformin?
Regarding the possibility that Metoprolol prevent me from going into Afib when exercising, therefore triggering physiological processes resulting in a perceived higher efficiency, I have to say that, based on my medical history, I would not expect A Fib to occur that frequently, even less during each running session.
In fact, I had it for the first time about three years ago, and, again, two weeks ago, in both cases without any untoward symptoms (difficulty in breathing, chest pains or other.) except for an abnormally high pulse, between 100-130, briefly peaking, occasionally, to 160.
It lasted a few days, but when I finally decided to go to E.R., it was back to normal and the ECG did not show any problems. I am sure that if it happened again, I’d certainly pick it up from my cardio watch or by taking my pulse, which I frequently do.
Thank you so much for your comments