I understand perfectly. I noticed the same thing when I was between ablations...I had to monitor my HR closely while out for a walk. When it got near 119, I would slow right down to a plodding pace or stop for a few minutes. But things can change quickly, depending on where one is in the cycle of AF. I was actually going pretty well in late January of 2023, despite having been told that I was now two weeks away from a needed second ablation, and was able to literally jog up a long flight of outdoor steps near a sandy cliffside at the ocean. We're talking about 160 risers, with a short 30 meters between them and the next flight which was not as steep, but had the same number of risers in a longer path. Looking back on that experience wistfully, but with a heart happily in NSR, I don't do more now than to plod up those stairs....but I do it regularly.

I would urge you to just do what you know you can do, and what you 'think' your heart can do. In time, with healing, you may find yourself 80% of the way back, and that might have to be 'it' for now. Or, you may find yourself back to your old self in about a year's time, and still happily in NSR.