I have noticed the same issue but cannot find documentation on this. I have previously exported Workout Data using RunGap and these files show the full resolution of the heart rate data, but the very same workouts on my iPhone older than 3 months now have only abbreviated heart rate data available when you do a query. At some point the iPhone appears to have cleared-out the HKSamples associated with workouts older than a certain time, and which were available in the past when I did those rungap exports which is very frustrating. If anyone knows how to restore these missing data I would be grateful to know how.
Topic:
App & System Services
SubTopic:
Health & Fitness
Tags: