Apple Watch heart rate data delayed and inconsistent compared to other devices

[umityilmazz]

I’m using the health plugin in my iOS app to read heart rate data from Apple Health after users connect their watches. With non-Apple devices (e.g., Garmin, Fitbit), the heart rate data seems to sync regularly and the values match what users see in their workouts.

However, with Apple Watch I notice two issues:

The data does not sync in a regular/timely way (it looks delayed or irregular).

Even after a workout is completed, the max heart rate values stored in Apple Health can be different from what is shown on the watch during the workout.

Is this an expected limitation of how Apple Health syncs Apple Watch data, or is there something I should configure differently in order to get more accurate and consistent values from Apple Watch?

[marcos-abreu]

Hey,

Not part of the health plugin team, but (my 5 cents) from what I have researched this is how Apple HealthKit works on some data types, specially if it is part of a workout, where it takes time collect and the system does some post processing of the data before making it available. On top of that the watch itself goes through the same process, where it collects data to a certain point to include some context before sharing it back with HealthKit.

The understanding works similar to the workout routes: You can read a bit about it here (even though is about the workout route, it explains it better than what I could)

vhttps://developer.apple.com/documentation/healthkit/reading-route-data

[umityilmazz]

Thanks for the detailed explanation, that makes a lot of sense.

My main goal here is to get real-time heart rate data from Apple Watch (similar to what we can get from non-Apple devices). From what you described, it seems like HealthKit only exposes Apple Watch heart rate samples after some post-processing and syncing, so it’s not truly real-time.

Just to confirm — if I want to access live heart rate updates directly from the Apple Watch while a workout is in progress, is the only reliable approach to build a companion watchOS app that communicates with the iOS app (for example, using WatchConnectivity)?

Or is there any other way to stream real-time heart rate data from Apple Watch without having to build a separate companion app?

If you happen to have any knowledge or experience regarding this part, I’d really appreciate your insight.