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Device didn't ask me to accept detected lactate threshold.

JoseR
8 months ago

Did Garmin remember the prompt to accept (or not) auto detected lactate threshold? I normally OK with Auto detection but I want to have control over it, last run it was updated but the option to accept it didn't pop up. Not sure if it is a new feature (it won't be very stupid) or a bug. 

Thanks!

  • 0 8 months ago in reply to JoseR

    LT is auto-detected only with an external HRM strap, so the peripheral vasoconstriction due cold temperatures should be of no concern. At least that's what the Epix 2 manual still claims, so unless it changed recently, and the manual was not updated, I assume it is still valid:

    epix (Gen 2) Standard/Pro Series Owner's Manual - Performance Measurements

    Lactate threshold

    Lactate threshold requires a chest heart rate monitor. Lactate threshold is the point where your muscles start to rapidly fatigue. Your watch measures your lactate threshold level using heart rate data and pace (Lactate Threshold).

  • 0 8 months ago in reply to trux

    That's the point, it seems with the last update (19.34) chest strap is no longer required.

    https://the5krunner.com/2024/10/26/garmin-changes-lactate-threshold-measurement-deep-dive/

  • 0 8 months ago in reply to JoseR

    I do not see anything in that direction been posted on the Epix 2 Beta Program forum yet. The only reference to "Lactate Threshold" or "LTHR" on the Epix 2 Beta Program forum is a note on the changelog about a fix of the missing Guided LT Test in the Track Run activity:

    https://forums.garmin.com/beta-program/fenix-7-series/f/announcements/320460/alpha-version-11-19 

    Fixed issue causing no Lactate Threshold test in Track Run.

    So it looks like at least in 2024 there is no such change pending for Epix 2.

  • 0 8 months ago in reply to trux

    I just did a threshold guided test today and my past experience was not really confirmed: the last auto-detection I received and discarded yielded the same LTHR but the pace was 8s/mile slower than today's guided test. Therefore, the auto-detection was slower by 2%. It doesn't seem a lot again, but this is a 9s/mile difference in my target 5k pace, which is a significant.

    For those who don't have the threshold guided test any longer, they can create a custom workout with the table below. Using their previous lactate threshold LTHR and pace @ threshold (yellow cells) to determine the higher limit of the fifth interval, they can turn auto-detect on, perform the workout and see if the watch detects a new threshold.

    In my case, I used the target paces from the right column to hit the HR targets of the test and it worked just great. My LTHR was detected just as I started the last interval.

    Observed Garmin test protocol My recommended target pace as % of previous lactate threshold pace
    Step # Duration  HR target as % of LTHR Target HR zone
    0 10-15mn N/A Warm up 80%
    1 4mn 86% Zone 2 85%
    2 4mn 86% Zone 2 85%
    3 4mn 94% Zone 3 95%
    4 4mn 100% Zone 4 100%
    5 3mn 105% Zone 5 110%
  • 0 7 months ago in reply to Etupes25

    I upgraded to the last firmware, performed a complete reset of the watch.

    Yesterday, after a long easy run where my heart rate remained well below Zone 3, I got an LTHR detection.

    This was a surprise to me as it is the first time I get one after a well-below threshold effort. It tells me that the LTHR detection algorithm is now able to predict the LTHR without reaching it.

    That would be nice if it were accurate. This auto-detection is highly suspicious to me. My LTHR was increased by 5bpm, and my lactate threshold pace was 10s/mile shorter than my typical lactate threshold pace.

    I am going to have high intensity ramp-like intervals this week, so I am eager to see if these will trigger a more accurate LTHR set of data...

  • 0 7 months ago in reply to Etupes25

    Almost exact the same scenario happened to me. A slow zone 2 run and LTHR  increased by 5BPM and pace 18s/km.... wow.

  • 0 7 months ago in reply to Etupes25
    Etupes25 said:
    I will run a new test in the next days, and I have a 5k coming up in a months. So I guess I will get a new data set to confirm my past experience...

    With the new approach with lactate threshold detection, I have had mixed results.

    I have an auto-detection on an easy run, with the LTHR value 10 bpm above my previous LTHR, and the pace about 20sec/mile faster.

    I had another easy run a couple of days later where another auto-detection happened with LTHR down 5bpm, but same pace.

    The following week, I had a nice ramp progressive tempo run with another auto-detection with the same LTHR, and a slight drop of 5s/mile in the pace (slower)

    Today I completed my 5k race, got an auto-detection with a +1 bpm in LTHR and the pace the same as the first 2 easy-runs.

    So, so far so good. Except for the single LTHR outlier, the new auto-detection seems pretty stable.

    Compared with the previous algo, my LTHR is higher by about 5bpm, and my pace is faster by about 12s/mile.

    However, with my last race, all the race predictions were updated towards more aggressive time and paces and are now copacetic with my threshold pace. My 5k prediction is also within 10s of my actual performance and the pace 5s faster. So this is pretty good at this point.

  • 0 7 months ago in reply to Etupes25

    Very interesting, thanks. So you would recommend leave auto detection on?

  • 0 7 months ago

    I had the same results... I don't think they should auto apply the values.  I did a recovery run and it received a value that was way off my previous Lactate threshold.  I should be able to discard this result, so that i don't have a constantly changing value. And only accept values for runs which meet the appropriate intensity.  

  • 0 7 months ago in reply to JoseR
    JoseR said:
    So you would recommend leave auto detection on?

    Because I don't use HR zones for workout benefit targeting, and because the pace estimates are good enough for training in my short experience, I would leave it on.

    If you avoid threshold and above workouts, I'd recommend to leave it on as well.

    If you aim at achieving a balanced training load, I would turn it on only for long tempo, longish threshold intervals and harder workouts on the flat.