Summary:
The Daily Suggested Workouts (DSW) feature does not use the user's custom heart rate zones when the workout target is set to "Heart Rate." Instead, it appears to revert to a default zone structure, likely based on Max HR, providing workout targets that are incorrect and actively detrimental to the user's training plan across multiple activity types.
My User Configuration:
My heart rate zones are carefully configured based on my Lactate Threshold Heart Rate (LTHR) and are applied to both my Running and Cycling profiles:
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Based on: %LTHR
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LTHR: 168 bpm
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Zone 1 (Recovery): 120 - 142 bpm
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Zone 2 (Base/Easy): 143 - 150 bpm
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Zone 3 (Tempo): 151 - 159 bpm
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Zone 4 (Threshold): 160 - 168 bpm
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Zone 5 (Maximal): > 168 bpm
Steps to Reproduce:
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Configure custom heart rate zones based on LTHR, as detailed above.
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Ensure these zones are used for both the Running and Cycling activity profiles.
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Navigate to the activity settings and set the Daily Suggested Workout target type to "Heart Rate."
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View the suggested workout for a "Base" run.
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View the suggested workout for a "Base" bike ride.
Expected Result:
For any "Base" workout suggestion, the target heart rate should fall squarely within my custom Zone 2 range, which is 143 - 150 bpm.
Actual Result:
The DSW feature completely ignores my custom zones and provides different, incorrect targets for each sport:
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For a "Base" run, the watch suggests a target of 137 bpm.
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For a "Base" bike ride, the suggested target is even lower and worse: 130 bpm.
Both of these targets fall into my Zone 1 (Recovery) and are significantly below my actual Base training zone. This proves that the DSW feature is ignoring my custom zone configuration across multiple activity types.
Critical Impact on Training:
This bug has severe negative consequences that make the feature unusable:
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Systematic Undertraining: If I follow the workout as suggested (e.g., run at 137 bpm or bike at 130 bpm), I am not getting the intended training stimulus. Over time, this leads to a decrease in fitness and VO2 Max, as I am consistently training at too low an intensity.
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Incorrect Exercise Load and Workout Labeling: If I ignore the flawed suggestion and run at my correct Base pace (e.g., 146 bpm), the watch misinterprets the effort. It sees a heart rate higher than its incorrect target and often labels the workout as a "Tempo" effort, assigning an inflated Exercise Load score.
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Corrupted Training Plan: This misclassification completely breaks the adaptive nature of the DSW plan. After the watch incorrectly labels my proper Base run as "Tempo," it will then alter the following day's suggestion to something easier, like "Rest" or "Recovery," preventing me from doing the scheduled high-intensity work. The entire weekly plan becomes disrupted.
In its current state, this bug renders the heart-rate-based Daily Suggestions feature not just useless, but actively harmful to a user's training goals.
Firmware: 23.18
Garmin-Chris Garmin-Laurie