It started today. I walked into the gym from the parking lot and they almost immediately hooked me up to an EKG. My heart rate was 147, and I had done nothing but walk about 100 feet. So, the nurse decided to be super-watchful over me; I was put on a seated step machine, but I did only two minute intervals, after which my heart rate was checked.
I am nothing if not consistent. Each time I rode the machine, my heart rate went up to 140-147, and each time I stopped, the rate slowed fairly quickly afterward. That was reassuring.
After the step machine, I rode the recumbent bike; also two minute intervals, also the same results. At one point I began to feel a tightness in my chest, and I stopped riding - which I had been told to do. As soon as I stopped, the tightness went away. I think, all told, I did about 22 minutes of exercise, plus about five minutes of cool-down stretches. I was tired, but I am none the worse for the wear. I look forward to the day when I can do all that and not be tired afterward. I pray that day comes.