Heart rate zones update

runny said:

It seems that if max HR change, the % of zones will change to adhere to the new BPM's ?

Which watch model do you use? Some older models indeed did it in this way. You best move the thread to the forum dedicated to your watch model, since the handling differs from one model to another. Recent models update the absolute values, not the percentage. If yours does it in the wrong way, all you can do is reporting the problem to the Support, and resetting the zone table - it then recalculates the zones with the default percentages, using the new Max HR.

BTW, be wary of any new Max HR detections. Max HR does not really evolute with fitness. And when it does, it surprisingly rather slightly drops (because the heart is stronger, and may slightly increase its effective working volume). And it also drops with age. So it is rather advisable disabling the auto-detection, and updating it manually once a year, after doing a lab or a field test.