Polar and Garmin activity graphs using detailed sample data (e.g.: data recorded every few seconds) are accessible in AthleteMonitoring for up to 30 days after the data has been recorded and transferred to AthleteMonitoring.
After this period, sample data is automatically removed from AthleteMonitoring, and can still be accessed via Polar Flow or Garmin Connect.
Recorded session summary data (total distance, average heart rate, etc.) stays in AthleteMonitoring and remains accessible without time limitation.