I did an outdoor ride on my gravel bike, which doesn’t have a power meter. The ride is uploaded from Garmin to Xert but the XSS seems to be set to 0. How can I manually update the XSS so it reflects the effort I did?
You could activate the Heart Rate Derived Metrics in settings under profile (last tab). That way Xert will estimate your power and all derived metrics like XSS from heart rate (and cadence) if you have those on record for both activities with power and without power data. Can be fairly accurate if the activities are similar.
Ah! Great! Exactly what I was looking for. Big thanks for your help.