I created a manual activity and my avg bpm does not show up even though i was wearing my watch

I created a manual activity and my avg bpm does not show up even though i was wearing my watch and my HR was recorded.  Any reason why? 

  • HR data will be visible in the activity only if you record the activity with your Garmin device. All-day HR data contains only averages over 2 minutes samples, which is insufficient for activities, and no performance metrics can be derived from it anyway.