Why data with high anaerobic values when cross country skiing?

Why does Garmin show most anaerobic training when I’m cross-country skiing at an easy pace, and my heart rate is well within the aerobic range compared to when I’m running?

  • Maybe a long shot:

    - if you have sport-specific heart rate zones defined for XC country skiing, and the Max HR is off? what about LTHR for this sport?

    - did you check the FTP value for cross country skying?

    I suspect that if any of these value is off, it could affect how the watch calculates the training effect...