Low Heart Rate

Thanks for the link to see I'm within range. The doctor is not a cardiologist. She said she is very thorough and I replied that I am very active. To that she said that Lance Armstrong's resting heartrate was 40. I just shrugged and said as an active person mine is 57.

@lauramks If you'd like a bit of advice from a fellow athlete, and only if you don't already know of, or do, this, you can monitor your waking HR every morning before stirring. In fact, it's also a good time to assess your rested/resting BP. The idea is to take both measurements, say with a wearable (the Samsung Galaxy watch that I use does this, plus take SO2 sat measurements during sleep, HR during sleep, plus the usual stages of sleep and duration of each) so you don't have to sit up and get something out of a drawer. You want as little disturbance, hence the wearable that was already in place during the night.

Take a month's worth of measurements and chart them by hand so that you can see it at a glance. If you see a variation more than 10% it probably means 'something'. For example, your running average HR upon waking goes something like 55 BPM. One morning, the day after getting a flu or COVID booster, your measured HR is 64. Well, that's well above that 10% variation, so it would mean taking a day off training...or a 30 minute walk at an easy pace at most. No HIT, no stair workout, etc.

My main message is to be able to show a cardiologist, if you ever get in front of one's desk, your recent data. A steady climb, or FALL, of BP or HR, would suggest to both of you that something's changing, and it is probably not for the better this side of 50.