Related
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Lactate Threshold Test, MaxHR - Questions About HR Settings

ZombieSloth
over 1 year ago

Can someone help provide clarity about some of the settings on the watch, and whether I have them configured properly? I have a HRM-Pro+ strap which I obtained a few weeks ago and I use that on all runs.

  • Automatic MaxHR and LTHR turned ON
  • MaxHR is 186bpm (which conforms to the default age-based calculation, and is decently accurate based on the actual max HR I have observed during some short sprints)
  • LTHR is 167bpm (discussion below)
  • HR Zones are based on %LTHR with default percentage bins
  • SW/FW 15.19

The LTHR of 167bpm was "guesstimated" by the watch before I got the HRM strap and it is 90% of the MaxHR. When I got the HRM strap, I did the LTHR test (15 min warmup, then a series of 4 minute intervals of increasing HR: 139, 153, 163, 172bpm) and at the end it said that LTHR was calculated as 167bpm. So it could be that I fall well into the middle of the distribution of human physiology and default values are representative for me.

But, I have never seen the MaxHR or LTHR values change. Connect (app and website) say that LTHR is a manually set value of 167bpm.

Questions

  1. Some forum posts here say that the automatic MaxHR and LTHR will only ever increase, and never decrease, as far as I can understand. So if one suspects that their true values are lower than the presently set ones, they should manually set artificially low values and then go on a run which hits all 5 HR zones in order to have new automatic values populate (if they are lower than the old max values). Is this correct?

  2. I am planning to re-run the LTHR Test this afternoon, and throw in some max-effort intervals afterward in order to try to double-check my MaxHR. What should I set my HR Zones to before this test, and are there any other HR-related settings that I need to have set a specific way before/after in order to have things work correctly?
    1. Based on posts here, it is sounding like I should set the HR Zones to be based on %MaxHR and manually adjust LTHR to something low like 150bpm if I want the test to make an accurate estimate if I suspect that it will be less than 167bpm.

  3. During the LTHR test, should automatic MaxHR and/or LTHR be left on or off?

  4. I have never seen a Lactate Threshold Pace value be given. It is always blank ("--:--"), despite having a LTHR. What could be causing this?

  5. Up until the start of the year, I had a Vivoactive3 and some health data was imported from that I think. Could there be some issue related to that which I may need to do a hard-reset to clear out? I can live with losing all of my health/performance data since should only take ~1 month to get things up to date again, but obviously I'd prefer to avoid this.

Thanks!

  • 0 over 1 year ago

    At the first point, I can tell you I got a lower max. heartrate yesterday (from 194 to 192). Automatically, and also updated in GC. After my first LTHR test I did not have any intensive training which could cause a change, but I have no reason for doubts.Somewhere upcoming weeks it will show in the training scheme.

    2a: that are the settings I used for my first LTHR test. Lowered my MaxHR from 196 (manually) to 176, and set LTHR manually to 150. Then set the system to auto-update. First had an easy run, after which my max heart rate was automatically updated to 194 (pretty close to what i used to have set manually). A week later I ran the LTHR test, which brought me the 158 LTHR detection. After that, I accepted the LTHR, and set the heart rate zones to %LTHR. Although I think my detected LTHR is still to low, I see a leap forward in my training intensity. Probably because of my shifted zones. I expect it to improve more coming weeks.

    3: I had both switched on

    4. I do not know. I had a 4m37s paces together with the 158hr after my test.

    5. I had a 645m before, and also imported some data. Never had an issue with that.

  • 0 over 1 year ago in reply to DaKo

    how do you see in the GC app if LTHR is set manually? It seem I do not have that information in it.

  • +1 over 1 year ago

    I decided to mess with a bunch of settings and then go and re-run the LTHR test this evening. The results were definitely different, that is for sure.

    Before the LTHR test I:

    • Turned OFF automatic MaxHR, LTHR, and FTP
    • Set Max HR to 170 (from 186)
    • Set LTHR to 150 (from 167)
    • Set the HR Zones to manual BPM values which corresponded to what they were when LTHR was 167
    • Turned automatic HR detection and FTP back on

    Then I went out and ran the test. It was definitely easier than before, in that it stopped me after much lower HR targets. The resulting LTHR estimate was 151, versus 167 previously (which seemed to be "stuck" and never update), and my MaxHR was estimated to be 184, versus 186 previously. Also, for the first time ever I was given a LT Pace value.

    This is, I assume, good because it hopefully means that the automatic estimates are able to function now. However I do question the correctness of the LTHR value, and I wonder if the artificially low MaxHR value present during the test did in fact have an impact on the ranges in which the test would look for HRV signals.

    I am going to take tomorrow off to rest and then do the LTHR test again on Thursday just to see if it is repeatable. It seems reasonable that it might be a bit off due to me messing about with things that may in fact be influencing the test program. For reference, here are the differences in LTHR test targets.

    • When MaxHR/LTHR earlier in the month were set to 186/167, the test HR targets were: 139, 139, 153, 163, 172
    • When MaxHR/LTHR today were set to 170/160, the HR test targets were: 140, 128, 140, 149, 157

    In both cases, the highest target was 92% of the set value for MaxHR at the time. So with MaxHR back up at 184, my hypothesis is that on Thursday the highest target will be 170bpm. Whether or not the calculated LTHR value changes is anyone's guess. We shall see!

    I had some commentary on the impact of this new, much lower LTHR value since it has some potentially wide-ranging impacts, but I'll save that until Thursday!

    I am marking this post as the answer since it seemed to "un-stick" the automatic estimated values and suddenly the full functionality of things seems to be working. Just a note to anyone who reads this, if you set both MaxHR and LTHR to low values, you may want to re-do the LTHR test again in a day or two since the test stops at ~92% of MaxHR and it may not test you much past your LTHR. I hope that this post is helpful to someone. See my later follow-up posts below for more info.

  • 0 over 1 year ago in reply to DaKo

    In the phone app it was indicating the manual value under Performance Stats > Lactate Threshold down at the bottom where the numeric value is. At least that is where I think I remember it being. It may have been on the report page in the Connect webpage. Either way, it doesn't say it anymore. I suspect that the value was "stuck" due to something I probably did in the past when messing with settings, or maybe it is a bug involving manual LTHR values and firmware updates. Not sure...I just really hope that things work correctly going forward! I can deal with a couple of days of odd performance measurements as I sort this out.

  • 0 over 1 year ago in reply to DaKo

    Thanks for the thoughtful responses. I suppose that we will see how the automatic adjustments go from here since (hopefully!) they are actually working now.

    As for the manual adjustments to HR values, it is looking like the MaxHR value may impact how the LTHR test works. We'll see when I do the test again in a couple of days.

  • 0 over 1 year ago

    I was feeling well rested today so I redid the LTHR Test this afternoon, just to see what the behavior and results would be.

    As expected, the HR targets were a lot higher since my MaxHR was back up to 184, with the highest HR target being 170 or 92% of max.

    The result of the test was a LTHR of 155 (up from 151 yesterday) and a slightly slower LT Pace, which in a way makes sense since the test today went well above the calculated LTHR whereas yesterday it barely asked me to get above the resulting value of 151 with a high target of 157. Aside from the artificially low MaxHR value I had put in before yesterday's test, I was out on a gravel service road with 15-25mph winds blowing which wasn't going to help. Today I found a flat, straight, paved stretch of road where there was a lot less wind. So, LTHR is sitting at ~84% of MaxHR today. I'll redo the test in a week or two maybe, if some of the workout suggestions don't make for any changes between now and then. After yesterday's LTHR test run, I did the assigned anaerobic workout, so I wasn't 100% fresh today.

    Interestingly, it seems that the HR target value for suggested workout runs is derived from MaxHR and seems to have little to do with LTHR. For all 3 of the MaxHR values I have had recently (186, 170, 184), the base run target HR has always been 75% of max. As it stands now, the target HR for my upcoming base runs is at the very top edge of Z2 when using %LTHR and the default percentages. With the original "stuck" HR values, the LTHR was exactly 90% of MaxHR, and I am definitely not an elite runner lol. Today it is 84%, so if suggested workouts are based on MaxHR mostly then I guess I'll be operating a bit higher within the currently calculated HR zones. It is all "just numbers" in the end, but for the foreseeable future it looks like I am going to be spending a lot of time in top-Z2 and bottom-Z3.

    One thing that I am quite pleased about now that the automatic calculations seem to be working fully is that my workout suggestions are longer, harder, and more varied. For more than a month with the "stuck" MaxHR and LTHR values (with "--:--" for LT Pace) the suggestions were almost all base runs of 30-40 minutes, with Tempo or Anaerobic ones coming up once every 2 weeks. If my LTHR value was stuck way too high, maybe the algorithm was expecting me to have a much higher aerobic capacity than I actually have at present and was having issues figuring out what to be suggesting. Under the Load Focus bar graphs, the light blue Low Aerobic line is sitting at around 2X the upper limit of the optimal range thanks to all those base run assignments. Now, I am seeing longer base runs, sprints, tempo, and threshold suggestions coming up. My VO2Max has started decreasing slightly on the graph in the watch, but that is to be expected since I have been messing with settings, and I am going to be running slower during workout assignments. It'll take time to adapt as always, but I am hopeful that the training will be more effective now.

    Whatever the case, I am going to stick with the suggestions and see how things go. I have some historical run data that has me doing half marathon distances with an average HR of 163 at a pace of ~8:00 per mile, although that was with the optical HR from the watch which I have found to be subject to cadence lock at times. I would not call them max-effort runs, but I was definitely out of stamina at the end. So the current estimate LTHR of 155 at a pace  of 7:52 per mile is reasonably believable.

  • 0 over 1 year ago in reply to ZombieSloth

    Woke up this morning and interestingly the workout suggestions all came up looking a bit different in that the base runs are now at 128bpm (versus 137bpm yesterday) which is ~low Z2, and the threshold run now targets 152bpm (versus 162bpm yesterday) which is 98% of LTHR (instead of 105%). Based on the current LTHR value and HR zones based off of it, the numbers seem to make sense now (when yesterday they seemed a little odd). So it seems like it can sometimes take 12+ hours for the suggestions to update from a new input.

    It would be nice if Garmin published a bit more information about how the stuff works or maybe what to expect as far as how/when suggestions will change when a user has an update to a critical input. But I suppose that Garmin also rightly wants to be guarded about the exact algorithm since it is part of their secret sauce that really differentiates them from Apple and other fitness watches.