Lactate Threshold not auto updating from 7 july

Did you check, if by hazard, your Max HR did not change in that time? If you have the auto-detection enabled, it can easily happen. And when your Max HR is too high for you, the watch will have problems to detect the LTHR. Not telling there is no bug, but just to exclude this possibility, I'd check the max HR, and set it right (best after doing a true Max HR test).

My max heart rate has not changed, I have disabled max HR detection.

I have doble check and it still is correctly set at 184bpm, max HR from race, no changes in this year.

I use HRM run band too that I forgot to mention it.

Thanks for answer anyways, it could have been a possible solution.

Another possibility is that your HR was simply just too steady (which is what the first screenshot indeed looks like). The documentation tells:

Auto detection works best on runs that you spend some time in each zone as you increase the intensity of the activity.  

The best way to see whether the auto-detection works, or whether there is really a bug, is by conducing the Self-Guided LT Test as found in the Training option of the Running activity menu.

JordiGT said:

Last workout that trigered auto detection threshold:
05 july workout
Firmware: 13.26
Detected Theshold: Yes at 165.

I wouldn't trust too much auto detection, in particular if your workout was based on intervals. Although your workout looks actually pretty good to give you an estimate, I have had plenty of occurences where an interval workout would give me an FTP update that ended up too low. The guided test however, which uses a ramp, is much more accurate and consistent with the typical field test (95% of your best maximal steady 20mn effort).

In addition, this auto-detection gave you 165 bpm...

JordiGT said:

15/oct 10k at theshold zone

Firmware: 14.68
Detected Threshold: No

You ran a 10k at 90% of your HR Max on average. A10k is typically run at threshold, and the threshold is typically at 90-92% of HR Max for well trained athlete. It is not a rule, and some may get higher. In your case, 165bpm/0.90= 183bpm so it looks like your HR metrics are copacetic.

Nothing here is a rule or a solution for sure. In my case, my LTHR is 90% of my HR Max and I still get some VO2 Max workout labels for some threshold workouts, although I havet to admit I always tend to go at the higher range of the target pace, and it is easy to dabble in VO2 Max pace range.

According to Firstbeat white papers, there could be several reasons why the TE might be off:

If you have been training for your 10k, you could be in the "overtraining" response.

Anyway, there is nothing that indicates there is a software issue with your watch. 

My recommendation is to:

- perform a guided test to verify your LT values

- disable auto-detection or ignore the auto-detected values if you didn't perform a steady maximal effort for at least 20mn,

- once a month, try to complete a 20mn steady effort at your FTP/0.95 pace to verify that your estimations are good.

Could it be that your 10K further validated you current LTHR as 165, and thus no updated value (up/down) needed to be given?

Your graphic is much more erratic than mine :

But I can't tell if I am improving or getting worst based on that graph...

5646821 said:

But I can't tell if I am improving or getting worst based on that graph..

I'd tell it is rather stable - HR improved by 2 bpm (around +1%), while the pace slowed down by some 3 or 4 seconds per km (around -1%), compensating so each other. That's a completely negligible change, far beyond the expected accuracy. That's within +/-5% of laboratory measurements, according to the documentation at Firstbeatanalytics, at VO₂max values, and I expect it should be around the same at LTHR too.