We are developing a health app that relies on HKObserverQuery and BackgroundDelivery to monitor Heart Rate data. On watchOS 10.6 and 11.6 , these data updates are typically delivered reliably every 8–12 minutes, occasionally exceeding 12 minutes, but generally not longer than 15 minutes. This frequency has been sufficient for the real-time data requirements of our app.
However, after adapting our app to watchOS 26, we noticed that HKObserverQuery triggers much less frequently, with longer and very inconsistent intervals. This issue has had a major impact on our product: data collection for essential features is unreliable, resulting in a greatly diminished user experience on watchOS 26 and making the app essentially useless from the user’s perspective.
Observed Behavior:
HKObserverQuery and BackgroundDelivery are extremely unstable, with trigger intervals frequently exceeding 15 minutes, and sometimes even 20 minutes.
When the user is sedentary, intervals become even longer; there are cases where no heart rate or active energy updates are delivered for 30 minutes, or even over 1 hour.
Request for Support and Guidance:
Have there been any changes to the HKObserverQuery background delivery mechanism on watchOS 26, specifically for Heart Rate and Active Energy data?
If these changes are intentional system optimizations, could you provide guidance or recommended practices to ensure our app can reliably retrieve updates and maintain a smooth experience for users?
Thank you for your support.
Health & Fitness
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Ever since upgrading to OS 26.1, I've noticed that HealthKit anchored object queries seem to be much slower-updating than normal. I was curious if Apple stated anything explicitly changed on this front? I use anchored object queries to update some of the workout metrics that HKLiveWorkoutBuilder doesn't report (like stepCount).
I am using this below code since WatchOS 10 to set the user steps observer and get the callback of steps whenever changes.
This is still working perfectly fine till watchOS 11 but when i updated to watchOS 26.1, I am not getting the callback of steps, like the observer is not working at all. I should get a callback inside query block whenever user take steps, but it is not working in watchOS 26.1.
func setupStepCountObserver(completion: @escaping (Double, Double) -> Void) {
let stepCountType = HKObjectType.quantityType(forIdentifier: .stepCount)!
let query = HKObserverQuery(sampleType: stepCountType, predicate: nil) { [weak self] _, completionHandler, error in
if let error = error {
print("Error setting up observer query: \(error.localizedDescription)")
return
}
// Fetch the latest step count data
self?.getLast20SecTodaysSteps(completion: completion)
// Call the completion handler to let HealthKit know you have processed the update
completionHandler()
}
// Execute the query
healthStore.execute(query)
// Enable background delivery of updates
healthStore.enableBackgroundDelivery(for: stepCountType, frequency: .immediate) { success, error in
if let error = error {
print("Error enabling background delivery steps: \(error.localizedDescription)")
} else if success {
print("Background delivery enabled for steps.")
}
}
}
Hi,
I've had trouble for a while now with HealthKit giving me different values if I make the request on iOS and WatchOS.
I am using the exact same method on both with the same parameters but I get vast differences in the results.
The code I am using to call HealthKit on both devices is:
let dateRange = HKQuery.predicateForSamples(withStart: Date().removeMonths(numberOfMonths: 1), end: Date().endOfDay())
let predicate: NSPredicate
predicate = NSCompoundPredicate(type: .and, subpredicates: [dateRange])
let query = HKStatisticsQuery(quantityType: HKQuantityType(.stepCount), quantitySamplePredicate: predicate, options: .cumulativeSum) { _, result, error in
if error != nil {
//print("Error fetching step count, or there is no data: \(error.localizedDescription), \(startDate) -> \(endDate)")
onComplete(0)
return
}
if let result, let sum = result.sumQuantity() {
let stepCount = sum.doubleValue(for: HKUnit.count())
DispatchQueue.main.async {
onComplete(Int(stepCount))
}
}
}
healthStore.execute(query)
}
Platform & Version:
iOS Version: 18.3.1
Development Environment: Xcode 16.2, macOS 14.6.1
Description of the Issue:
We're exploring ways to better integrate Apple Fitness+ workouts into our app. We've noticed that some third-party apps, such as Strava and HealthFit, now display Fitness+ workout details, including the title, trainer, and an image.
I’ve been investigating how this is possible, and the only relevant change I’ve found is that HKMetadataKeyAppleFitnessPlusCatalogIdentifier is now being set for Fitness+ workouts. However, I can’t find any public API or official documentation that explains how to use these identifiers to retrieve the associated workout details.
Question:
Is there an official API available to fetch metadata for Fitness+ workouts using these identifiers? Or are these third-party apps potentially accessing private APIs? If no API exists, is the only option to create a manual mapping of these identifiers—something that seems impractical given the constantly evolving Fitness+ workout catalog?
Any guidance on this would be greatly appreciated. Thanks!
Topic:
App & System Services
SubTopic:
Health & Fitness
Tags:
Health and Fitness
HealthKit
WorkoutKit
The background deliver works perfectly when the app is in the background or suspended states. However, when the app is killed (terminated state), the background task does not execute
Hello Apple Community,
What does approach use the Fitness app for swimming distance calculation per set (segment)?
I've tried 2 options but all of them have different values than in the Fitness app.
Calculation like that: pool length * number of laps = swimming distance BUT the Fitness app sometimes shows other values for distance per set (segment).
Fetch all distance values via HKQuantityTypeIdentifier.distanceSwimming (HKSampleQuery`) and than try to match distance values with set (segment) duration. Again I got other values for swimming distance per set, values are bigger than in the Fitness app.
let healthStore = HKHealthStore()
let distanceType = HKQuantityType.quantityType(forIdentifier: HKQuantityTypeIdentifier.distanceSwimming)!
let predicate = HKQuery.predicateForSamples(withStart: startDate as Date, end: endDate as Date?, options: .strictStartDate)
let query = HKSampleQuery(sampleType: distanceType, predicate: predicate, limit: HKObjectQueryNoLimit, sortDescriptors: [.init(keyPath: \HKSample.startDate, ascending: true)], resultsHandler: { (query, results, error) in
if let error {
Logger.e("\(error)")
continuation.resume(returning: nil)
}
continuation.resume(returning: results)
})
healthStore.execute(query)
Is it possible to get the same swimming distance like in the Fitness app per set via HealthKit?
Topic:
App & System Services
SubTopic:
Health & Fitness
Looking for help with our Apple HealthKit integration. We've successfully pulled steps, distance, active energy, glucose and heart rate. However, the data pulled for sleep duration is incorrect. Not sure what we're doing wrong.
HealthKit background delivery only triggers when charging. I have set step monitoring to hourly frequency. Despite step changes, callbacks fail to arrive after 3-4 hours on battery, but trigger immediately upon connecting power. Observed for 2 days: background updates are only received when charging. The device is not in Low Power Mode, and Background App Refresh is enabled for the app in Settings.
I'm trying to hook into the new workoutEffort score supported in iOS 18, I am collecting this information from users when they submit their workout and trying to add a sample to the HKWorkout in the same manner as I've been adding other samples like bodyweight, calories burned, etc.
I'm receiving the error:
HKWorkout: Sample of type HKQuantityTypeIdentifierWorkoutEffortScore must be related to a workout
I tried adding the samples using HKWorkoutBuilder.add([samples]) as which has been working perfectly for calories burned & bodyweight, but I am receiving the above error for workoutEffortScore
As a second approach, I tried adding the sample after I called finishWorkout on the HKWorkoutBuilder and received back the HKWorkout object using HKHealthStore.add([samples], to: HKWorkout) and am still receiving the same error!
I don't know otherwise how to relate a sample to a workout, I thought those were the APIs to do so? I'm using Xcode 16.0 RC (16A242) and testing on an iOS 16 Pro simulator
I have an App in objective-c that is using Health data (walk/run, cycling) to give advice to users . I do not want/need to write any data in the Healtkit.
If i do (with the 3 values in the plist / .info :
self.healthStore requestAuthorizationToShareTypes:nil readTypes:readDataTypes
My request crashes.
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Must request authorization for at least one data type'
*** First throw call stack:
(
0 CoreFoundation 0x00000001804b910c __exceptionPreprocess + 172
1 libobjc.A.dylib 0x0000000180092da8 objc_exception_throw + 72
2 CoreFoundation 0x00000001804b901c -[NSException initWithCoder:] + 0
3 HealthKit 0x000000019da034d4 -[HKHealthStore _validateAuthorizationRequestWithShareTypes:readTypes:] + 92
4 HealthKit 0x000000019da03670 -[HKHealthStore requestAuthorizationToShareTypes:readTypes:shouldPrompt:completion:] + 292
BUT in swift :
healthStore.requestAuthorization(toShare: nil, read: readTypes)
is working, présents only my 2 datas to read... in the same IOS , same phone without crashing. What is the difference ?
Nil object in objective-c and Nil object in swift are not the same ? how do i make readonly requests in objective C ?
Hi everyone!
I'm trying to get the total sleep time for a given day, but users report that there's a difference between what my app reports and what the Apple Health app reports. In particular, we're off by 2 minutes less on average.
What we're doing is:
Get all the samples that are either core, deep, rem or unspecified
Cut-off time at 3 PM previous day
Merge overlapping intervals
Add all the remaining intervals
For debugging purposes I'm storing and sending all the raw samples to a server, and I have run tests and I don't find anything wrong. It looks like the number we come up with is correct according to our own rules. I wonder, how is Apple adding up all the samples to arrive at a number that's slightly off to our number.
Any insight would be appreciated. Thanks.
When I set the distanceFilter = 5 (5 meters) in the GPS CLLocationManager
I can't display the workout routes in the Apple Fitness app after writing the recorded GPS data to HealthKit via HKWorkoutRouteBuilder.
The smaller distanceFilter, Fitness will displays the route.
Should I consider setting up a small distanceFilter when developing a workout app on watchOS?
Hi, i'm trying to get the number of step counts a person has taken. I decided to pull the data from health kit and the number of steps are incorrect. Come to find out apple health recommends an app called pedometer++ for the number of steps counted and after testing I realized that they are getting the correct number of steps a person is taking. How can I pull the correct number of steps a person has taken? I want to be able to merge the data from watch and phone to make sure we are getting the correct number of steps but not double counting the steps either.
any guidance on this would be appreciated!
Here's the code snippet that i'm using right now:
permissions: {
read: [AppleHealthKit.Constants.Permissions.StepCount],
write: [],
},
};
AppleHealthKit.initHealthKit(permissions, error => {
if (error) {
console.log('Error initializing HealthKit: ', error);
return;
} else {
dispatch(setAllowHealthKit(true));
getHealthKitData();
console.log('HealthKit initialized successfully');
}
});
const getHealthKitData = async () => {
try {
const today = new Date();
const options = {
startDate: new Date(today.setHours(0, 0, 0, 0)).toISOString(),
endDate: new Date().toISOString(),
};
const steps = await new Promise((resolve, reject) => {
AppleHealthKit.getStepCount(options, (error, results) => {
if (error) reject(error);
resolve(results?.value);
});
});
setStepsCount(steps);
} catch (error) {
console.error('Error fetching HealthKit data:', error);
}
};
Are there any HealthKit related changes to be aware of in the new update that enables SPO2 / Blood Oxygen Saturation measurements on certain Apple Watch models within the US?
I’m aware of processing happening on the phone…. But beyond that:
Does this mean values are then saved to Apple Health?
Do these models still take background SPO2 measurements in the same way as other models do?
Are these values then visible in third party iOS apps as normal through HealthKit?
Do these values sync back to the paired Apple Watch HealthKit store for third party apps to access on the Watch?
For reference I have an iOS and WatchOS app that, amongst other features, provides the ability to see your SPO2 values in the Watch app, complications and in the iOS app.
Topic:
App & System Services
SubTopic:
Health & Fitness
Tags:
WatchKit
Health and Fitness
watchOS
HealthKit
Hello,
I’m building a health-related app for both watchOS and iOS, which needs to monitor certain health data (e.g., heart rate, active energy).
Before updating to watchOS 26, the queries worked reliably without any issues. However, after adapting to watchOS 26, some users have reported that health data updates stop being delivered.
What I’ve observed:
HKObserverQuery with enableBackgroundDelivery is set up normally.
On WatchOS 26, the query sometimes stops delivering updates entirely after a certain point, and once an update is missed, it may stop delivering further updates completely.
Restarting the Apple Watch temporarily restores delivery, but the problem reoccurs after some time.
This makes background health data monitoring unreliable for my app.
Here’s a simplified version of the code we are using:
guard let heartType = HKObjectType.quantityType(forIdentifier: .heartRate) else { return }
let query = HKObserverQuery(sampleType: heartType, predicate: nil) { query, completionHandler, error in
if let error = error {
logEvent("Observer error: \(error.localizedDescription)")
return
}
logEvent("Heart rate changed")
MyNotificationManager.shared.sendNotification() // Send a local notification
completionHandler()
}
healthStore.execute(query)
healthStore.enableBackgroundDelivery(for: heartType, frequency: .hourly) { success, error in
if success {
logEvent("Background heart rate delivery enabled")
} else {
logEvent("Failed to enable background heart rate delivery: \(error?.localizedDescription ?? "Unknown error")")
}
}
Could you please clarify:
Is this a known issue with HKObserverQuery and enableBackgroundDelivery on watchOS 26?
Are there any recommended workarounds or best practices to ensure continuous background delivery of health data?
Thank you in advance for your help.
Topic:
App & System Services
SubTopic:
Health & Fitness
Tags:
Health and Fitness
watchOS
HealthKit
Observation
I have a watchOS app with a connected iOS app using Swift and SwiftUI. The watchOS app should read heart rate date in the background using HKOberserQuery and enableBackgroundDelivery(), send the data to the iPhone app via WCSession. The iPhone app then sends the data to a Firebase project.
The issue I am facing now it that the app with the HKObserverQuery works fine when the app is in the foreground, but when the app runs in the background, the observer query gets triggered for the first time (after one hour), but then always get terminated from the watchdog timeout with the following error message:
CSLHandleBackgroundHealthKitQueryAction scene-create watchdog transgression: app<app.nanacare.nanacare.nanaCareHealthSync.watchkitapp((null))>:14451 exhausted real (wall clock) time allowance of 15.00 seconds
I am using Xcode 16.3 on MacOS 15.4
The App is running on iOS 18.4 and watchOS 11.4
What is the reason for this this issue? I only do a simple SampleQuery to fetch the latest heart rate data inside the HKObserverQuery and then call the completionHandler. The query itself takes less than one second.
Or is there a better approach to read continuously heart rate data from healthKit in the background on watchOS? I don't have an active workout session, and I don't need all heart rate data. Once every 15 minutes or so would be enough.
Hi,
I have a workout app in the App Store which mirrors workout data between the phone and watch.
Since iOS 26.x I've been having issues and received reports of the mirroring no longer working. Users in iOS 18 have no problems with this functionality.
Bug description: A workout session is started from the phone app and starts mirroring to the watch companion device. The watch starts the workout session and then the mirroring session is disconnected / lost. Sending data to the companion device fails and ending the session on the phone doesn't end the session on the watch...essentially they become completely disconnected.
Please note I am testing this on physical devices...not simulators.
As a sanity check I've also tried the "Building a multidevice workout app" sample code and it has the same problem.
To re-create on the sample app, I start a workout from the phone, the watch workout starts and then the mirroring session seems to disconnect and is unable to send data.
This is the log from the "Building a multidevice workout app" sample code.
Successfully started workout
Type: Notice | Timestamp: 2025-10-17 06:57:07.341401+02:00 | Process: MirroringWorkoutsSample Watch App | Library: MirroringWorkoutsSample Watch App.debug.dylib | Subsystem: com.example.apple-samplecode.MirroringWorkoutsSampleABC123.watchkitapp | Category: MirroringWorkoutsSampleForWatch | TID: 0x1b2ca7
-[SPRemoteInterface _appRecoverAnyExtendedRuntimeSession:]_block_invoke:4350: Got no sessions back from -[CSLSSessionService existingRunningSessions:] or -[CSLSSessionService existingScheduledSessions:] after receiving a PUICInitializeSessionServiceAction
Type: Error | Timestamp: 2025-10-17 06:57:07.641571+02:00 | Process: MirroringWorkoutsSample Watch App | Library: WatchKit | Subsystem: com.apple.watchkit | Category: default | TID: 0x1b2ca7
Session state changed from 1 to 2
Type: Notice | Timestamp: 2025-10-17 06:57:07.647883+02:00 | Process: MirroringWorkoutsSample Watch App | Library: MirroringWorkoutsSample Watch App.debug.dylib | Subsystem: com.example.apple-samplecode.MirroringWorkoutsSampleABC123.watchkitapp | Category: MirroringWorkoutsSampleForWatch | TID: 0x1b2e87
Failed to send data: Error Domain=com.apple.healthkit Code=100 "Failed to send data to remote session." UserInfo={NSLocalizedDescription=Failed to send data to remote session.}
Type: Notice | Timestamp: 2025-10-17 06:57:07.669922+02:00 | Process: MirroringWorkoutsSample Watch App | Library: MirroringWorkoutsSample Watch App.debug.dylib | Subsystem: com.example.apple-samplecode.MirroringWorkoutsSampleABC123.watchkitapp | Category: MirroringWorkoutsSampleForWatch | TID: 0x1b2ca7
Would appreciate any help with this problem as it's affecting customers.
Thank you
WorkoutKit WorkoutScheduler seems broken with the first beta of iOS 18.2.
I have tested using my app from Xcode and the one that is on the App Store (and working properly on other devices), and it's not working with this new beta of iOS.
They appears in WorkoutScheduler.shared.scheduledWorkouts, but not on the watch.
I even tried with other apps that do the same with
Manual add to Apple Watch with SwiftUI workoutPreview work.
Xcode 16.0
iOS 18.2 Beta 1
WatchOS 11.1