It counts the highest drop anywhere in the activity, providing the parameters are met. It is not the same as Garmin which is after the activity, and for 2 minutes.
Stephen_Worrall:
When I have looked at my efforts though it looks at the biggest drop of HR (assuming some thresholds have been passed). In my case my HR stays at the same rate for about 10 to 20 seconds following the end of the effort/interval. Intervals only recognises the recovery period when my HR starts to drop. So my HRRc is shown as being higher than what it really is, since the recovery period is actually 70 or 80 seconds in length.
David explains it here:
The activity detail pages now show HRR (heart rate recovery) and the fitness stats.
HRR measures how quickly you recover after a hard effort. It is the largest drop in HR over 60 seconds starting from a HR of at least Z5 (threshold). It is shown in the heartrate trace on the chart. Recovery sections in activities with power are ignored if the average power is more than 1/3 of FTP or 5s power is more than 1/2 of FTP. So it is best to freewheel. The general idea is that, the faster or greater you…