Recovery Heart Rate is your heart's ability to return to a normal rate after an activity within a specific amount of time. In general, a faster heart rate (HR) recovery (HR slowing down) from an activity is an indication of an improved fitness level. It is suggested to consult a physician if you continuously see your HR dropping less than 12 beats-per-minute (BPM) within one-minute of stopping an activity.
The Forerunner 910XT, 610, or 310XT will display your recovery heart rate (as shown below) two minutes after the Start/Stop button is pressed. The number outside the parenthesis is your current HR, while the number in parenthesis is the difference between your HR at the end of your activity and your Recovery HR.
The below picture shows the runner's HR was 154 BPM at the end of the activity. Two minutes later the HR was 125 BPM, which was a 29 BPM drop after two minutes.
Update the Forerunner's 310XT or 910XT operating software using Garmin Express, if the Recovery Heart Rate message does not appear.
Garmin Express - https://connect.garmin.com/en-US/start/