Max Heart Rate Updated Without Meeting the "New" Max Heart Rate During the Activity [FR255, bug]

Agreed, I just turned 59 and my max rate hovers in the mid 180s. Right now I am only using the wrist hrm but when I was using the hrm pro chest strap it was also consistently at the same level (which is why I stopped wearing it when I realized the 255 was basically matching). Admittedly I've been running marathons for over 25 years, roughly two a year but I don't consider myself to be overly fit (as I see my times continue to slide :( ) so I don't think the number of older athletes who can reach that heart rate to be 'insanely' low. I would imagine most runners who are going to invest in a 255 (rather than a more entry level watch) probably hae a good amount of fitness already as a base.

I have also done the lactate test, and I did not really come all that close to my maximum heart rate. I would need a very special workout to get close to it, by repeatedly sprinting closer and closer without getting muscle fatigue. My watch estimates close to 190 as maximum heart rate, but in a hard run I rarely get over 170, since my lactate threshold is just over 160. I am 52 years old, with VO2Max 54. 

I know my maximum heart rate is far beyond 180, but it is nearly impossible to verify exactly what it is.

First, let's not confuse me being in the best shape of my life with me being super fit. I was 45yo when I started running, and I did not take care of myself when I was young. It's just that now, after running for 15 years, I am running more consistently 6 days a week usually, and taking the suggested workouts Garmin provides.

I have a chest strap and have found it provides the same readings I expect to see as the 255, once any spurious spikes are cancelled out, which happen occasionally and are easy to identify.

In my experience the 255 and my previous 245 are as accurate if not more so than the strap. I do snug up the watch strap a notch when I run, especially for a hard run.

I considered trying a different strap but after reading reviews of different brands decided against it. I have not attempted the LT test as I have been using the Race Widget to train since I got the 255.

I have the same issue as discussed in this thread. For some reason my watch wants to set the max HR to 196 after every activity I record. Even if the max HR in that activity was 150. This happens after every running activity of I set it to 186-188 manually. 

I don't even understand where this number comes from. The problems is not that it overrides my manual entry (it should do it), but rather that it is most probably this is an incorrect number and it does this even if that activity did not push me to max... fl

If go to reports I can get all the running max HRs of the past year:

Heart Rate

2022-12-1 180 bpm

2023-1-1 188 bpm

2023-2-1 184 bpm

2023-3-1 188 bpm

2023-4-1 184 bpm

2023-5-1 188 bpm

2023-6-1 185 bpm

2023-7-1 182 bpm

2023-8-1 202 bpm

2023-9-1 185 bpm

2023-10-1 183 bpm

2023-11-1 178 bpm (this is based on two activities one of which was an easy run)

It includes all types of running like hard intervals with close to max effort. The 202 is probably just an error as the rest is consistent. Any way at my age (36) and my training the 196 seems excessive especially if one looks at max HRs from the past (which by the way seemingly consistent with my expectation and my age and training).

I gave up on the auto-detect feature. I couldn't get mine to play nice with the auto-detect, so I had to set it to manual and instead use the data from the HRM Pro-Plus to set it to an appropriate number (max from hard interval runs)

But do you really think you could reach your maximum possible heart rate? Wouldn't you be able to push even harder if your life depended on it (chased by something dangerous), or with a start number on your chest, fighting for an olympic medal? Or wouldn't you be able to push even a little harder or longer if you were more rested? Did you pass out after the effort, or vomit?

I think even 95 percent of max is very hard to reach.

Good question and sure, it might be able to be higher, but if you do the field test right, it seems you'll get to max. You don't just run once and see how high it gets, you have to do multiple intervals so you're body is already rev'ed up and then you push it for multiple minutes. Don't do it at random, google field tests for getting your max. Here is one of the articles:  https://marathonhandbook.com/how-to-calculate-max-heart-rate/#:~:text=Warm%20up%20by%20running%201,is%20your%20maximum%20heart%20rate.

That article would not work for me. I would reach muscle fatigue long before my max heart rate. I am more of a sprinter type that would need a series of short sprints going faster and faster with rest in between. I can not hold my maximum effort for more than 5 seconds or so, and I need to be extremely motivated to do my best. I can definitely not do it alone. I need to compete with someone, and it must be important to win.

I noticed another odd thing. I have my HR zones set to %LTHR. The % are set to defaults, like above 102% of the LTHR for maximum effort.

Now, when I reset my Max HR manually (lets say to 188 from 196) and go for an easy run (where I dont come even close to my maxHR) and a new Max HR is detected (goes back to 196) then, my heart rate zone %-es are changed as well like the max effort changes to above 108% of the LTHR. I dont see any reason for the HR zone % to change. That is the point of a % that it is variable by default...

Has any of you encountered/noticed this before?