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high aerobic / heart rate zones / training load

Heilrath
11 months ago

I set my heart rate zones in my Fenix 7 based on the lactate threshold value. I feel that it works very well.

Strangely, however, the assignment to the training zones in the respective activities is often different from the representation in the training load. Even if, for example, I spent an entire run in Zone 2, it might be rated as high aerobic in the training load view. How can this be?

  • +1 11 months ago

    The training effect and the training load estimation don't use your training zones. They are based on the Excess Post Exercise Oxygen Consumption: after a workout, the body continues consuming more O2 than normal to recuperate, rebuilt energy stores, heal micro tears in muscles, etc. While EPOC is happening after the workout, the watch estimates EPOC during the workout, based on intensity, duration and on/off patterns and repetitions.

    Only the dynamics of EPOC estimates during the workout lead to TE and its classification. Your heart rate zones are only for you, to help target certain outcomes.

    If the metrics of your watch are well aligned, a workout designed to be a threshold workout will be recognized as such, etc. If not, it shows some misalignement. Possible areas:

    - the Max HR is off. This is the most crucial data input to the watch. All training and fitness metrics depend on the accuracy of Max HR. Wear a chest strap, leave the auto-detection on, and run a variety of efforts. If you are a well trained runner, run your best 5k ever and add 5bpm to the peak HR during the race for a manual test.

    - the LTHR is off. LTHR and pace at LTHR is used to differentiate some labels depending on EPOC dynamics (for example tempo vs threshold). If you have a new Max HR, run a guided hreshold test since one influences the detection of the other. Do not trust blindly the LTHR auto-detection.

    - the rest HR is off. Wear the watch during the night and use the average resting HR

    - the HR data during your trianing is off. You should wear a chest strap if you care about accuracy and your training metrics. No way around it.

    - less likely, the pace data is off. Could be bad GPS data or a poorly calibrated pod/ HRM etc.

  • 0 11 months ago in reply to Etupes25

    Thanks a lot! That's very helpful!

  • 0 11 months ago in reply to Etupes25

    Thank you, sounds very useful! I just did a performance diagnostic at a medical doctor to get accurate LTHR and MaxHR. Interestingly, LTHR was much lower than the auto discovery of Garmin. As I did the diagnostics riding a bike, I set LTHR and MaxHR +10 heart beats higher for all other sports than biking. 

    My issue still remains, Garmin shows very low "high aerobic" Focus. What can I do to get more exposure in that area? Is this the area just exactly below my LTHR? This is totally independent of the heart beat zones, right?

  • 0 11 months ago in reply to 2377468
    2377468 said:
    As I did the diagnostics riding a bike, I set LTHR and MaxHR +10 heart beats higher for all other sports than biking. 

    I know there is plenty of content about biking metrics being lower than running. The reasons are not well understood, but weight bearing and mass of muscles involved are often quoted.

    If you have not run lab tests for other activities like running, don't make assumptions. Keep it simple and use the same LTHR and Max HR as for biking.

    2377468 said:
    This is totally independent of the heart beat zones, right?

    "Totally" is a bit radical. To be accurate, the watch is using LTHR and Threshold pace for a couple of the various tests and checks it uses to choose the sentence that describes the benefit of the workout. But, yes, TE is independent of zones.

    2377468 said:
    What can I do to get more exposure in that area?

    VO2 Max: 4 to 5mn run/bike maximum steady pace/power,, 1:1 rest ratios, 15-30mn total across intensity intervals

    Threshold: 10-20mn maximum steady pace/power, 4mn rest, total 30-90mn total across intensity intervals, or 1h of maximum steady pace/power (FTP definition)

    Tempo. This is a tricky one because it is a label bestowed to workouts that "fail" some of the tests for "Threshold", "VO2 Max", or even "Anaerobic", "Sprints". Otherwise a run with intervals of 5-10mn in zone 3, 4 or 5 is likely to end up as tempo (for example the FTP test itself ends up qualified as tempo).

    All of the above should be classified as high aerobic for running or biking. For other activities, you would choose the longer intervals, keep the intensity steady, and target your average HR in the corresponding Tempo (zone 3), Threshold (zone 4) and VO2 Max (Zone 5).

  • 0 11 months ago in reply to Etupes25

    For reference here is a table with other specific examples, although they might be less easy to implement:

    https://www.firstbeatanalytics.com/en/features/workout-labels/

  • 0 11 months ago in reply to Etupes25

    Thank you very much, this is very helpful, I'm wondering why Garmin hasn't such a nice documentation like this!?

  • 0 11 months ago in reply to Etupes25

    Thanks a lot also for this helpful answer!

    The setting of LTHR and MaxHR +10 for other sports than biking was a recommendation of the lab. They say it's because only the leg muscles are used, whereas in other sports the upper body is also used. 

  • 0 11 months ago in reply to 2377468
    2377468 said:
    They say it's because only the leg muscles are used, whereas in other sports the upper body is also used. 

    Yes, this is the typical explanationfor the common scenario to have Max HR measurements with a lower value for swimiing than for cycling than for running. Many sources quote about a 5% difference in bpm.

    Research has found plenty of nuances though: differences in VO2 Max, Max HR and Treshold vary depending on what your specialty is and your level of training.

    "Maximal heart rate (HRmax) is generally re-ported to be slightly (~5%) higher when obtained from an incremental treadmill test as comparedwith an incremental cycle test in untrained sub-jects.[7,23,103]In addition, the relationshipbetween HR and exercise intensity or.VO2 is exercise dependent [14,104,105] and is influenced by training mode, postural position [106] or labora-tory environment [107]. In triathletes, the HRmax observed in cycling is often lower by 6–10beats/min than that obtained during running. [62,78,79,103] Longitudinal investigations haved emonstrated HRmax to remain relatively stable over the course of a season,[98] with higher values (~5 beats/min) observed in running than in cycling.[62] In contrast, there is also evidence suggesting that HR max is similar between cycling and running modes.[53,67,72,88,99]

    https://www.researchgate.net/publication/24205037_Physiological_Differences_Between_Cycling_and_Running

    2377468 said:
    The setting of LTHR and MaxHR +10 for other sports than biking was a recommendation of the lab.

    I would not go higher than 5 for Max HR. A difference of 10 for LTHR may be OK.

    In both cases, I recommend you start with these values for running, but then run a guided threshold test and keep Max HR auto-detection. Im all cases, use a chest strap when running or biking.

    Getting your Max HR as accurate as possible for running is important as the error in VO2 Max estimates increases with errors in Max HR.

    https://assets.firstbeat.com/firstbeat/uploads/2017/06/white_paper_VO2max_30.6.2017.pdf