Health & Fitness

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Explore the technical aspects of health and fitness features, including sensor data acquisition, health data processing, and integration with the HealthKit framework.

Health & Fitness Documentation

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HKAnchoredObjectQuery ignores "no correlation" predicate in updateHandler
Hello, I'm seeing an inconsistency in how HKAnchoredObjectQuery applies predicates between its initial results handler and its update handler. Specifically, predicates that filter quantity samples by correlation membership - using either HKQuery.predicateForObjectsWithNoCorrelation() or NSPredicate(format: "%K == nil", HKPredicateKeyPathCorrelation) - are respected in the resultsHandler but silently ignored in the updateHandler. Setup I have three long-running HKAnchoredObjectQuery instances: One for HKCorrelationType(.bloodPressure) - no predicate One for HKQuantityType(.bloodPressureSystolic) - predicate: HKQuery.predicateForObjectsWithNoCorrelation() One for HKQuantityType(.bloodPressureDiastolic) - predicate: HKQuery.predicateForObjectsWithNoCorrelation() The intent of the predicate on the systolic/diastolic queries is to capture only standalone quantity samples written directly by third-party apps - not the constituent sub-samples of an HKCorrelation. The correlation query handles correlated samples. Expected behavior When a BloodPressure correlation is saved to the store, only the correlation query's updateHandler should fire, with 1 new sample. The systolic and diastolic updateHandlers should not fire, since those samples have correlation != nil which is excluded by the predicate. Actual behavior After saving one BloodPressure correlation, all three updateHandlers fire with 1 new object each. The systolic and diastolic update handlers receive the correlated sub-samples despite the predicateForObjectsWithNoCorrelation() predicate. The same predicate correctly filters those kinds of samples out of the initial resultsHandler. Additionally, the same predicate applied in a one-shot HKSampleQuery for the systolic or diastolic type correctly returns 0 results when only correlated readings exist. The problem is only experienced in updateHandler of a long-running HKAnchoredObjectQuery. Tested iOS versions iOS 26.3 iOS 18.7.6 Workaround When an HKAnchoredObjectQuery updateHandler fires with systolic or diastolic samples, I fire a one-shot HKSampleQuery with a compound predicate using the sample UUIDs and predicateForObjectsWithNoCorrelation. Any samples that are part of a correlation are not returned in the HKSampleQuery resultsHandler.
1
0
123
1w
Clarification on HealthKit Observer Delivery Frequency and BGTaskScheduler Behavior
Hi Team, We are implementing HealthKit data sync using HKObserverQuery along with enableBackgroundDelivery and BGTaskScheduler for fallback processing. However, we are observing inconsistent behavior and would like clarification on expected system behavior: For HKObserverQuery: When using enableBackgroundDelivery with frequency .immediate, we sometimes receive updates promptly, but other times we do not receive any trigger at all. Similarly, when using .hourly, our expectation was that updates would be delivered approximately once per hour, but in practice, triggers are delayed, batched, or skipped. For BGTaskScheduler: We are scheduling BGAppRefreshTask with earliestBeginDate set (e.g., 1 hour), but tasks are sometimes delayed by several hours or not triggered predictably. In some cases, tasks are not executed even after extended periods. We would like to understand: Are HKObserverQuery delivery frequencies (.immediate, .hourly, .daily) strictly best-effort hints rather than guaranteed intervals? Under what conditions can observer updates be skipped or significantly delayed? Is there any recommended approach to ensure more reliable periodic syncing of HealthKit data? For BGTaskScheduler, what factors most strongly influence scheduling delays or missed executions? Our goal is to design a reliable sync mechanism, but the lack of deterministic behavior is making it difficult to define expected system behavior. Any clarification or recommended best practices would be greatly appreciated. Thanks in advance!
1
0
113
1w
State of Mind and the free text: Can it be fetched?
Has anyone actually managed to read the free-text note/context from Apple Health State of Mind entries? I’m building an iOS app that reads HKStateOfMind data from HealthKit. I can get the expected stuff fine: valence labels associations But in the Health app, users can also add extra context text to a mood entry, like: Tasks, Weather - Great work-life balance From my app, I can read Tasks and Weather, but I can’t find the Great work-life balance part anywhere. I already checked: public HKStateOfMind properties metadata debug description / object description attachment-ish routes Nothing so far. So before I spend more time chasing this: is that text just not exposed to third-party apps? Or is there some weird HealthKit path I’m missing? If anyone has actually pulled this off, I’d love to know how.
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0
89
1w
No Response for Family Controls Distribution Entitlement Request for 2 Weeks
Hello, I have submitted multiple requests for the Family Controls Distribution Entitlement through this form: https://developer.apple.com/contact/request/family-controls-distribution After submitting my requests, I waited for about 1 week but did not receive any response. Since I heard nothing, I contacted Apple Developer Support by email. After that, I finally received a response from an advisor asking for additional information, including my follow-up number. I replied with all the requested information immediately, but it has now been 5 more days and I still have not received any further response. In total, I have been waiting for about 2 weeks for this entitlement request. My app is a Screen Time control / digital wellbeing application that helps users reduce screen time through exercise-based challenges and healthy habits. My app uses the FamilyControls, ManagedSettings, and DeviceActivity frameworks and requires the Distribution Entitlement for App Store release. Here are my details: Case Number: 102866460896 Request Type: Family Controls Distribution Entitlement I understand the team may be busy, but I would appreciate any help checking the status of my request or escalating it if possible. Thank you very much.
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40
1w
Clarification on HealthKit Background Access While Device Is Locked
Hello Apple Developer Support / Community, I would like clarification regarding HealthKit data access behavior when an iPhone is locked. We are building an app that uses: HKObserverQuery enableBackgroundDelivery HKAnchoredObjectQuery Background execution to sync HealthKit data to our server Our specific question is: When the device is locked with passcode/Face ID protection enabled, can an app launched in the background through HKObserverQuery or other background mechanisms reliably access and read HealthKit data? We would like to understand the expected Apple-supported behavior for the following scenarios: If new HealthKit samples are written while the phone is locked, will HKObserverQuery still trigger immediately? If the observer callback is invoked while locked, can HKAnchoredObjectQuery successfully read the new samples? Is HealthKit data inaccessible while locked due to Data Protection / encrypted store behavior? Should developers expect delivery or data reads to be deferred until the user unlocks the device? We are trying to set correct expectations for background syncing and would appreciate official clarification on whether near real-time HealthKit sync is possible while the device remains locked. Relevant documentation mentions HealthKit store encryption, but we would appreciate direct confirmation for production behavior. Thank you.
0
0
67
6d
Clarification on HealthKit Observer Behavior in Flutter App vs Native iOS App
Hello Apple Developer Support / Community, I would like clarification regarding HealthKit observer behavior when comparing a Flutter-based iOS app with a fully native iOS app. We are using HealthKit background delivery with: HKObserverQuery enableBackgroundDelivery HKAnchoredObjectQuery We have observed that in a Flutter-based app, HKObserverQuery callbacks appear to execute multiple times or more frequently than expected for a single data update. In comparison, a native iOS implementation using similar HealthKit logic appears more stable and predictable. We would like to understand the expected platform behavior and whether there are any known considerations from Apple’s perspective. Specific questions: Does iOS treat HealthKit observer delivery differently for apps built with Flutter versus fully native UIKit / Swift apps? Are there known issues where app lifecycle handling, Flutter engine initialization, method channels, isolates, or plugin architecture could cause repeated observer callbacks? Can repeated HKObserverQuery executions occur if queries are registered multiple times during app launches or engine restarts? Does Apple recommend any specific observer management pattern for cross-platform frameworks such as Flutter? From the HealthKit system side, should observer callback frequency be identical regardless of whether the app is Flutter or native, assuming the same iOS code is used? We are trying to determine whether this behavior is due to HealthKit delivery semantics, duplicate observer registration, Flutter lifecycle integration, or framework-related limitations. Any guidance from Apple or developers who have implemented HealthKit successfully in Flutter would be appreciated. Thank you.
1
0
126
5d
Health permissions problem with watchOS 10.6.2
In the last few weeks 5 users have reported my workout watch app being unable to read health data despite the permissions being enabled in the iPhone Settings app. This has been a common complaint over the years and is usually fixed by disabling the permissions; rebooting both devices; and then enabling them again. This usually nudges iOS into sending the permissions to watchOS. However that procedure doesn't work for these users, all of whom are using watchOS 10.6.2. They are using various versions of iOS 18 or 26 so it seems to be a problem with that version of watchOS, which users are usually limited to because their hardware won't support anything more up to date. It seems that unpairing and re-pairing the watch can fix the problem but not always. I looked around and it seems that other apps are having the same problem: https://www.reddit.com/r/runna/comments/1rhhs2n/runna_wont_start_an_outdoor_run_on_apple_watch/ Does anyone know a way to fix this? My current advice is to repeatedly unpair / re-pair until it works, which isn't really practical! Thanks in advance.
0
0
52
4d
HealthKit Background Sync: How Close to Real-Time Can We Reliably Get?
I am building an iOS mobile application using Flutter, with native Swift integration for accessing Apple HealthKit instead of a Flutter plugin. The primary goal is to capture and sync specific HealthKit data types, namely Respiratory Rate and Sleeping Wrist Temperature, and send this data to a backend API as close to real-time as possible after it is written to HealthKit. The application needs to support both foreground and background syncing. Data should be synced when the app is opened, but also in the background when the device is locked. Additionally, there are reliability constraints to consider: the user may not open the app for extended periods, the device may remain locked, and Low Power Mode or other system restrictions may impact background execution. I have explored a few possible approaches. One option is using BGTaskScheduler to periodically fetch and sync data. However, based on my understanding, background tasks are not guaranteed to execute frequently and may be throttled or stopped by the system after some time. Another approach is to use HKObserverQuery along with HKAnchoredObjectQuery. In this setup, observer queries would be registered for the required data types, background delivery would be enabled, and whenever triggered, anchored queries would fetch incremental updates which would then be sent to the backend. This seems closer to a real-time model, but I am unsure how reliable and timely these background updates are in practice. I have also looked into newer APIs like HKQueryDescriptor, but it is not clear whether they provide any advantage over the observer plus anchored query approach for this use case. My main questions are: what is the recommended architecture for achieving near real-time syncing of HealthKit data for these metrics? Does HealthKit background delivery provide any guarantees or expectations around delivery timing, or can updates be significantly delayed depending on system conditions? How should edge cases be handled, such as when the device remains locked for long durations or when Low Power Mode is enabled? Would it be advisable to combine observer queries with BGTaskScheduler as a fallback mechanism? Finally, apps like Athlytic appear to show updated data immediately when opened. I am curious whether this is primarily achieved through background delivery or by fetching data on demand when the app becomes active. The goal is to design a system that is as close to real-time as possible while remaining reliable and compliant with iOS background execution constraints. Any recommended patterns, best practices, or references would be greatly appreciated.
0
0
55
23h
WorkoutKit: pre-roll alert / lead time before IntervalStep transition (FB22708659)
Hi all, I'm building a coaching app for runners on top of WorkoutKit and would like to confirm a missing API — or learn that I overlooked something. The gap IntervalStep transitions deliver a haptic at T0 of the next step. The available alerts (HeartRateRangeAlert, SpeedRangeAlert, PaceRangeAlert, PowerRangeAlert, CadenceRangeAlert) are reactive — they activate when the measured value leaves the target range, not ahead of a planned step. There is no API for a "pre-roll" haptic at, say, T-15s before a high- effort step. On watchOS today, the only signal arrives exactly at step start. What I checked The WorkoutAlert protocol and concrete types — all metric-driven, no scheduling primitive. IntervalStep initializer — (.work, step: WorkoutStep). No leadTime, warning, countdown, or prepareDuration parameter. CustomWorkout — no per-step pre-roll knob. WorkoutScheduler and the rest of the surface in iOS/watchOS 26.4 SDK. If I missed something obvious, please point me at it. Filed with Apple Feedback ID: FB22708659 Has anyone here found a cleaner workaround, or seen any signal from the WorkoutKit team about pre-roll cues being on the roadmap? Thanks!
0
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6
14h
HKAnchoredObjectQuery ignores "no correlation" predicate in updateHandler
Hello, I'm seeing an inconsistency in how HKAnchoredObjectQuery applies predicates between its initial results handler and its update handler. Specifically, predicates that filter quantity samples by correlation membership - using either HKQuery.predicateForObjectsWithNoCorrelation() or NSPredicate(format: "%K == nil", HKPredicateKeyPathCorrelation) - are respected in the resultsHandler but silently ignored in the updateHandler. Setup I have three long-running HKAnchoredObjectQuery instances: One for HKCorrelationType(.bloodPressure) - no predicate One for HKQuantityType(.bloodPressureSystolic) - predicate: HKQuery.predicateForObjectsWithNoCorrelation() One for HKQuantityType(.bloodPressureDiastolic) - predicate: HKQuery.predicateForObjectsWithNoCorrelation() The intent of the predicate on the systolic/diastolic queries is to capture only standalone quantity samples written directly by third-party apps - not the constituent sub-samples of an HKCorrelation. The correlation query handles correlated samples. Expected behavior When a BloodPressure correlation is saved to the store, only the correlation query's updateHandler should fire, with 1 new sample. The systolic and diastolic updateHandlers should not fire, since those samples have correlation != nil which is excluded by the predicate. Actual behavior After saving one BloodPressure correlation, all three updateHandlers fire with 1 new object each. The systolic and diastolic update handlers receive the correlated sub-samples despite the predicateForObjectsWithNoCorrelation() predicate. The same predicate correctly filters those kinds of samples out of the initial resultsHandler. Additionally, the same predicate applied in a one-shot HKSampleQuery for the systolic or diastolic type correctly returns 0 results when only correlated readings exist. The problem is only experienced in updateHandler of a long-running HKAnchoredObjectQuery. Tested iOS versions iOS 26.3 iOS 18.7.6 Workaround When an HKAnchoredObjectQuery updateHandler fires with systolic or diastolic samples, I fire a one-shot HKSampleQuery with a compound predicate using the sample UUIDs and predicateForObjectsWithNoCorrelation. Any samples that are part of a correlation are not returned in the HKSampleQuery resultsHandler.
Replies
1
Boosts
0
Views
123
Activity
1w
Clarification on HealthKit Observer Delivery Frequency and BGTaskScheduler Behavior
Hi Team, We are implementing HealthKit data sync using HKObserverQuery along with enableBackgroundDelivery and BGTaskScheduler for fallback processing. However, we are observing inconsistent behavior and would like clarification on expected system behavior: For HKObserverQuery: When using enableBackgroundDelivery with frequency .immediate, we sometimes receive updates promptly, but other times we do not receive any trigger at all. Similarly, when using .hourly, our expectation was that updates would be delivered approximately once per hour, but in practice, triggers are delayed, batched, or skipped. For BGTaskScheduler: We are scheduling BGAppRefreshTask with earliestBeginDate set (e.g., 1 hour), but tasks are sometimes delayed by several hours or not triggered predictably. In some cases, tasks are not executed even after extended periods. We would like to understand: Are HKObserverQuery delivery frequencies (.immediate, .hourly, .daily) strictly best-effort hints rather than guaranteed intervals? Under what conditions can observer updates be skipped or significantly delayed? Is there any recommended approach to ensure more reliable periodic syncing of HealthKit data? For BGTaskScheduler, what factors most strongly influence scheduling delays or missed executions? Our goal is to design a reliable sync mechanism, but the lack of deterministic behavior is making it difficult to define expected system behavior. Any clarification or recommended best practices would be greatly appreciated. Thanks in advance!
Replies
1
Boosts
0
Views
113
Activity
1w
State of Mind and the free text: Can it be fetched?
Has anyone actually managed to read the free-text note/context from Apple Health State of Mind entries? I’m building an iOS app that reads HKStateOfMind data from HealthKit. I can get the expected stuff fine: valence labels associations But in the Health app, users can also add extra context text to a mood entry, like: Tasks, Weather - Great work-life balance From my app, I can read Tasks and Weather, but I can’t find the Great work-life balance part anywhere. I already checked: public HKStateOfMind properties metadata debug description / object description attachment-ish routes Nothing so far. So before I spend more time chasing this: is that text just not exposed to third-party apps? Or is there some weird HealthKit path I’m missing? If anyone has actually pulled this off, I’d love to know how.
Replies
0
Boosts
0
Views
89
Activity
1w
No Response for Family Controls Distribution Entitlement Request for 2 Weeks
Hello, I have submitted multiple requests for the Family Controls Distribution Entitlement through this form: https://developer.apple.com/contact/request/family-controls-distribution After submitting my requests, I waited for about 1 week but did not receive any response. Since I heard nothing, I contacted Apple Developer Support by email. After that, I finally received a response from an advisor asking for additional information, including my follow-up number. I replied with all the requested information immediately, but it has now been 5 more days and I still have not received any further response. In total, I have been waiting for about 2 weeks for this entitlement request. My app is a Screen Time control / digital wellbeing application that helps users reduce screen time through exercise-based challenges and healthy habits. My app uses the FamilyControls, ManagedSettings, and DeviceActivity frameworks and requires the Distribution Entitlement for App Store release. Here are my details: Case Number: 102866460896 Request Type: Family Controls Distribution Entitlement I understand the team may be busy, but I would appreciate any help checking the status of my request or escalating it if possible. Thank you very much.
Replies
1
Boosts
0
Views
40
Activity
1w
Clarification on HealthKit Background Access While Device Is Locked
Hello Apple Developer Support / Community, I would like clarification regarding HealthKit data access behavior when an iPhone is locked. We are building an app that uses: HKObserverQuery enableBackgroundDelivery HKAnchoredObjectQuery Background execution to sync HealthKit data to our server Our specific question is: When the device is locked with passcode/Face ID protection enabled, can an app launched in the background through HKObserverQuery or other background mechanisms reliably access and read HealthKit data? We would like to understand the expected Apple-supported behavior for the following scenarios: If new HealthKit samples are written while the phone is locked, will HKObserverQuery still trigger immediately? If the observer callback is invoked while locked, can HKAnchoredObjectQuery successfully read the new samples? Is HealthKit data inaccessible while locked due to Data Protection / encrypted store behavior? Should developers expect delivery or data reads to be deferred until the user unlocks the device? We are trying to set correct expectations for background syncing and would appreciate official clarification on whether near real-time HealthKit sync is possible while the device remains locked. Relevant documentation mentions HealthKit store encryption, but we would appreciate direct confirmation for production behavior. Thank you.
Replies
0
Boosts
0
Views
67
Activity
6d
Clarification on HealthKit Observer Behavior in Flutter App vs Native iOS App
Hello Apple Developer Support / Community, I would like clarification regarding HealthKit observer behavior when comparing a Flutter-based iOS app with a fully native iOS app. We are using HealthKit background delivery with: HKObserverQuery enableBackgroundDelivery HKAnchoredObjectQuery We have observed that in a Flutter-based app, HKObserverQuery callbacks appear to execute multiple times or more frequently than expected for a single data update. In comparison, a native iOS implementation using similar HealthKit logic appears more stable and predictable. We would like to understand the expected platform behavior and whether there are any known considerations from Apple’s perspective. Specific questions: Does iOS treat HealthKit observer delivery differently for apps built with Flutter versus fully native UIKit / Swift apps? Are there known issues where app lifecycle handling, Flutter engine initialization, method channels, isolates, or plugin architecture could cause repeated observer callbacks? Can repeated HKObserverQuery executions occur if queries are registered multiple times during app launches or engine restarts? Does Apple recommend any specific observer management pattern for cross-platform frameworks such as Flutter? From the HealthKit system side, should observer callback frequency be identical regardless of whether the app is Flutter or native, assuming the same iOS code is used? We are trying to determine whether this behavior is due to HealthKit delivery semantics, duplicate observer registration, Flutter lifecycle integration, or framework-related limitations. Any guidance from Apple or developers who have implemented HealthKit successfully in Flutter would be appreciated. Thank you.
Replies
1
Boosts
0
Views
126
Activity
5d
Health permissions problem with watchOS 10.6.2
In the last few weeks 5 users have reported my workout watch app being unable to read health data despite the permissions being enabled in the iPhone Settings app. This has been a common complaint over the years and is usually fixed by disabling the permissions; rebooting both devices; and then enabling them again. This usually nudges iOS into sending the permissions to watchOS. However that procedure doesn't work for these users, all of whom are using watchOS 10.6.2. They are using various versions of iOS 18 or 26 so it seems to be a problem with that version of watchOS, which users are usually limited to because their hardware won't support anything more up to date. It seems that unpairing and re-pairing the watch can fix the problem but not always. I looked around and it seems that other apps are having the same problem: https://www.reddit.com/r/runna/comments/1rhhs2n/runna_wont_start_an_outdoor_run_on_apple_watch/ Does anyone know a way to fix this? My current advice is to repeatedly unpair / re-pair until it works, which isn't really practical! Thanks in advance.
Replies
0
Boosts
0
Views
52
Activity
4d
HealthKit Background Sync: How Close to Real-Time Can We Reliably Get?
I am building an iOS mobile application using Flutter, with native Swift integration for accessing Apple HealthKit instead of a Flutter plugin. The primary goal is to capture and sync specific HealthKit data types, namely Respiratory Rate and Sleeping Wrist Temperature, and send this data to a backend API as close to real-time as possible after it is written to HealthKit. The application needs to support both foreground and background syncing. Data should be synced when the app is opened, but also in the background when the device is locked. Additionally, there are reliability constraints to consider: the user may not open the app for extended periods, the device may remain locked, and Low Power Mode or other system restrictions may impact background execution. I have explored a few possible approaches. One option is using BGTaskScheduler to periodically fetch and sync data. However, based on my understanding, background tasks are not guaranteed to execute frequently and may be throttled or stopped by the system after some time. Another approach is to use HKObserverQuery along with HKAnchoredObjectQuery. In this setup, observer queries would be registered for the required data types, background delivery would be enabled, and whenever triggered, anchored queries would fetch incremental updates which would then be sent to the backend. This seems closer to a real-time model, but I am unsure how reliable and timely these background updates are in practice. I have also looked into newer APIs like HKQueryDescriptor, but it is not clear whether they provide any advantage over the observer plus anchored query approach for this use case. My main questions are: what is the recommended architecture for achieving near real-time syncing of HealthKit data for these metrics? Does HealthKit background delivery provide any guarantees or expectations around delivery timing, or can updates be significantly delayed depending on system conditions? How should edge cases be handled, such as when the device remains locked for long durations or when Low Power Mode is enabled? Would it be advisable to combine observer queries with BGTaskScheduler as a fallback mechanism? Finally, apps like Athlytic appear to show updated data immediately when opened. I am curious whether this is primarily achieved through background delivery or by fetching data on demand when the app becomes active. The goal is to design a system that is as close to real-time as possible while remaining reliable and compliant with iOS background execution constraints. Any recommended patterns, best practices, or references would be greatly appreciated.
Replies
0
Boosts
0
Views
55
Activity
23h
WorkoutKit: pre-roll alert / lead time before IntervalStep transition (FB22708659)
Hi all, I'm building a coaching app for runners on top of WorkoutKit and would like to confirm a missing API — or learn that I overlooked something. The gap IntervalStep transitions deliver a haptic at T0 of the next step. The available alerts (HeartRateRangeAlert, SpeedRangeAlert, PaceRangeAlert, PowerRangeAlert, CadenceRangeAlert) are reactive — they activate when the measured value leaves the target range, not ahead of a planned step. There is no API for a "pre-roll" haptic at, say, T-15s before a high- effort step. On watchOS today, the only signal arrives exactly at step start. What I checked The WorkoutAlert protocol and concrete types — all metric-driven, no scheduling primitive. IntervalStep initializer — (.work, step: WorkoutStep). No leadTime, warning, countdown, or prepareDuration parameter. CustomWorkout — no per-step pre-roll knob. WorkoutScheduler and the rest of the surface in iOS/watchOS 26.4 SDK. If I missed something obvious, please point me at it. Filed with Apple Feedback ID: FB22708659 Has anyone here found a cleaner workaround, or seen any signal from the WorkoutKit team about pre-roll cues being on the roadmap? Thanks!
Replies
0
Boosts
0
Views
6
Activity
14h