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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Icon Composer - Icon not visible in Fitness App
Hi everyone, we’re developing an app that lets users export selected bike rides to the HealthKit ecosystem. We created our app icon using the Apple Icon Composer and referenced the composer file in Xcode. Everything works fine, except that the logo doesn’t appear correctly in the Fitness app. Has anyone experienced this issue or knows how to fix it?
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340
Nov ’25
Can a 3rd party app use WorkoutKit to store interval details?
I am the developer of a workout app that allows users to create interval programs (e.g. Warm Up, Fast, Cool Down). It is possible for me to store the data for the intervals along with the workout in the Health system by using WorkoutKit (or any other method)? My aim is to make it so that the Fitness app shows the interval details when users view workouts created by my app. Thanks in advance.
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180
Nov ’25
How to monitor heart rate in background without affecting Activity Rings?
I'm developing a watchOS nap app that detects when the user falls asleep by monitoring heart rate changes. == Technical Implementation == HKWorkoutSession (.mindAndBody) for background execution HKAnchoredObjectQuery for real-time heart rate data CoreMotion for movement detection == Battery Considerations == Heart rate monitoring ONLY active when user explicitly starts a session Monitoring continues until user is awakened OR 60-minute limit is reached If no sleep detected within 60 minutes, session auto-ends (user may have abandoned or forgotten to stop) App displays clear UI indicating monitoring is active Typical session: 15-30 minutes, keeping battery usage minimal == The Problem == HKWorkoutSession affects Activity Rings during the session. Users receive "Exercise goal reached" notifications while resting — confusing. == What I've Tried == Not using HKLiveWorkoutBuilder → Activity Rings still affected Using builder but not calling finishWorkout() (per https://developer.apple.com/forums/thread/780220) → Activity Rings still affected WKExtendedRuntimeSession (self-care type) (per https://developer.apple.com/forums/thread/721077) → Only ~10 min runtime, need up to 60 min HKObserverQuery + enableBackgroundDelivery (per https://developer.apple.com/forums/thread/779101) → ~4 updates/hour, too slow for real-time detection Audio background session for continuous processing (suggested in https://developer.apple.com/forums/thread/130287) → Concerned about App Store rejection for non-audio app; if official approves this technical route, I can implement in this direction Some online resources mention "Health Monitoring Entitlement" from WWDC 2019 Session 251, but I could not find any official documentation for this entitlement. Apple Developer Support also confirmed they cannot locate it? == My Question == Is there any supported way to: Monitor heart rate in background for up to 60 minutes WITHOUT affecting Activity Rings or creating workout records? If this requires a special entitlement or API access, please advise on the application process. Or allow me to submit a code-level support request. Any guidance would be greatly appreciated. Thank you!
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322
2d
Is it possible to distinguish real vs manually added running data in HealthKit?
I am developing an iOS application that utilizes running workout data from the iOS Health app / Fitness app via HealthKit, with explicit user permission. Before finalizing the app design, I would like to clarify several technical aspects related to data reliability, manual entry, record modification, and GPS route availability in HealthKit. My questions are as follows: 1. Identifying manually added (non-physical) running workouts When a running workout is created in the Health app without actual physical movement (for example, a workout manually added by the user), is there any metadata, flag, or key in HealthKit that allows developers to distinguish these records from workouts generated through actual motion tracking (iPhone or Apple Watch)? 2. Editing existing running workout records Is it possible for users, or for third-party apps with HealthKit write permission, to edit an existing running workout (e.g., distance, duration, calories) after it has been saved? • If edits are allowed, are the original values preserved in any way, or are they fully overwritten? 3. Detecting modified workout records If a running workout (whether originally auto-recorded or manually created) has been edited after creation, is there any identifier, metadata field, source revision, or versioning mechanism in HealthKit that allows developers to detect that the workout has been modified? 4. Access to GPS route / running path data For outdoor running workouts recorded with location services enabled: • Does HealthKit provide access to GPS route data (running paths / location traces) associated with a workout? • Is this route data accessible to third-party apps with user permission? • Is route data available only for workouts recorded on Apple Watch, or also for iPhone-only recordings? • Is there a way to determine programmatically whether a running workout includes valid GPS route data? The overall goal is to understand whether, when building an app that relies on HealthKit running data, it is technically possible to differentiate motion-based workouts from manually added or edited records, and to assess the availability of route information for outdoor runs. Any clarification or references to official documentation would be greatly appreciated. Thank you
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195
Dec ’25
Bug apple Health
Hello everyone, I’m experiencing a visual issue when dismissing a sheet on iOS 26. I’m using the same implementation shown in the official Apple documentation. While testing, I noticed that some apps do not exhibit this behavior. However, when running this code on iOS 26, the issue consistently occurs. Issue description: The sheet dismisses abruptly A white screen briefly appears for a few milliseconds and then disappears This results in a noticeable visual glitch and a poor user experience I tested the exact same code on iOS 18, where the sheet dismisses smoothly and behaves as expected, without any visual artifacts. Has anyone else encountered this issue on iOS 26? Is this a known bug, or is there a recommended workaround? Any insights would be greatly appreciated. Thank you.
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387
Dec ’25
HealthKit backgroundDelivery is only triggering in the background while charging
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.
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339
Jan ’26
Extended Runtime API - Health Monitoring
In the WWDC 2019 session "Extended Runtime for WatchOS apps" the video talks about an entitlement being required to use the HR sensor judiciously in the background. It provides a link to request the entitlement which no longer works: http://developer.apple.com/contect/request/health-monitoring The session video is also quite hard to find these days. Does anyone know why this is the case? Is the API and entitlement still available? Is there a supported way to run, even periodically, in the background on the Watch app (ignoring the background observer route which is known to be unreliable) and access existing HR sensor data
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37m
HKObserverQuery not working in background
I'm developing a single target watchOS app that obtains HealthKit information. I have the "Background Delivery" option checked under "Signing & Capabilities" for the watch target. The app does HKObserverQueries in the foreground that work as I would expect. But when I click the Digital Crown to return to clock face, the HKObserverQuery activity stops. I'm using Xcode 15.4, on Mac 14.5 and a Apple Watch Series 4 running 10.5.
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864
Mar ’25
HealthKit returns different values depending on the OS the request is made on
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) }
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1.2k
Jun ’25
Location of indoor workouts
In the fitness app under iOS 18, the location of all workouts is displayed on a small map. For workouts with routes, I can already successfully read out the route and thus also determine the starting point. So that works. For indoor workouts such as yoga or indoor rowing, the exact location is also displayed in the fitness app. I would now also like to read out this location for these indoor workouts in my app. Does anyone know how to do this?
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848
Apr ’25
How to Save Heart Rate in HKCategoryTypeIdentifier.mindfulSession
I’m trying to associate heart rate (HR) data with a mindfulness session (HKCategoryTypeIdentifier.mindfulSession) in HealthKit, but I can’t find any documentation on how to do this. I’ve seen third-party apps (like Medito) successfully log HR within Mindful Minutes, even when the session takes place on an iPhone (not an Apple Watch). However, when I try saving HR in the metadata, it does not appear in the Health app's Mindful Minutes section. Code snippet: func logMindfulnessSession(start: Bool, heartRate: Double? = nil) { let mindfulType = HKCategoryType.categoryType(forIdentifier: .mindfulSession)! let now = Date() let endTime = now.addingTimeInterval(Double(selectedDuration)) var metadata: [String: Any]? = nil if let hr = heartRate { let heartRateUnit = HKUnit.count().unitDivided(by: HKUnit.minute()) let hrQuantity = HKQuantity(unit: heartRateUnit, doubleValue: hr) metadata = ["heartRate": hrQuantity] // ❓ Is there a correct key for HR? } let sample = HKCategorySample( type: mindfulType, value: 0, start: now, end: endTime, metadata: metadata ) healthStore.save(sample) { success, error in if let error = error { print("HealthKit session save error: \(error.localizedDescription)") } else { print("Mindfulness session saved successfully.") if let hr = heartRate { print("Saved with HR: \(hr) BPM") } } } } Questions: What is the correct metadata key for associating heart rate with a mindful session? Does HealthKit require a specific format (e.g., HKQuantitySample) for HR? 0 Are there additional permissions needed to allow HR to appear in Mindful Minutes? Does HR need to be stored separately in HKQuantityTypeIdentifier.heartRate, and if so, how do third-party apps ensure it appears in the same entry as the mindful session? thank you!
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810
Mar ’25
Healthstore read only in objective-C ?
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 ?
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Mar ’25
HKAnchoredObjectQuery Stops Receiving Updates
I implemented this to receive updates for specific data types and keep the latest daily information up to date. However, for some reason, it only works for a while before stopping completely. Background Delivery internal func backgroundDeliveryForReadTypes(enable: Bool, types: Set<HKQuantityType>) async { do { if enable { try await statusForAuthorizationRequest(toWrite: [], toRead: types) for type in types { try await healthStore.enableBackgroundDelivery(for: type, frequency: .daily) } } else { for type in types { try await healthStore.disableBackgroundDelivery(for: type) } } } catch { debugPrint("Error enabling background delivery: \(error.localizedDescription)") } } HKQueryAnchor internal var walkingActivityQueryAnchor: HKQueryAnchor? { get { if let anchorData = UserDefaults.standard.data(forKey: "walkingActivityAnchor") { return try? NSKeyedUnarchiver.unarchivedObject(ofClass: HKQueryAnchor.self, from: anchorData) } return nil } set { if let newAnchor = newValue { let anchorData = try? NSKeyedArchiver.archivedData(withRootObject: newAnchor, requiringSecureCoding: true) UserDefaults.standard.set(anchorData, forKey: "walkingActivityAnchor") } else { UserDefaults.standard.removeObject(forKey: "walkingActivityAnchor") } } } HKAnchoredObjectQuery internal func observeWalkingActivityInBackground( _ start: Bool, toRead: Set<HKQuantityType>, completion: @escaping @Sendable (Result<WalkingActivityData?, Error>) -> Void ) { if start { guard (walkingActivityQuery == nil) else { return } let predicate = getPredicate(date: Date()) let queryDescriptors = toRead.map { HKQueryDescriptor(sampleType: $0, predicate: predicate) } let handleSamples: @Sendable (HKAnchoredObjectQuery, [HKSample]?, [HKDeletedObject]?, HKQueryAnchor?, Error?) -> Void = { [weak self] _, samples, _, newAnchor, error in guard let self = self else { return } if let error = error { completion(.failure(error)) return } guard let samples = samples, !samples.isEmpty else { completion(.success(nil)) return } Task { self.walkingActivityQueryAnchor = newAnchor let activity = await self.getWalkingActivity(date: Date()) completion(.success(activity)) } } let query = HKAnchoredObjectQuery( queryDescriptors: queryDescriptors, anchor: walkingActivityQueryAnchor, limit: HKObjectQueryNoLimit, resultsHandler: handleSamples ) query.updateHandler = handleSamples healthStore.execute(query) walkingActivityQuery = query } else { if let query = walkingActivityQuery { healthStore.stop(query) walkingActivityQuery = nil } } } WalkingActivityData private func getWalkingActivity(date: Date) async -> WalkingActivityData { async let averageHeartRate = try await self.getAverageHeartRate(date: date) async let steps = try self.getStepCount(date: date) async let durationMinutes = try self.getTotalDurationInMinutes(date: date) async let distanceMeters = try self.getDistanceWalkingRunning(date: date, unit: .meter()) async let activeCalories = try self.getActiveEnergyBurned(date: date) return await WalkingActivityData( date: date, steps: try? steps, activeCalories: try? activeCalories, distanceMeters: try? distanceMeters, durationMinutes: try? durationMinutes, averageHeartRate: try? averageHeartRate ) } Example of getAverageHeartRate func getAverageHeartRate(date: Date) async throws -> Double? { let type = HKQuantityType(.heartRate) _ = try checkAuthorizationStatus(for: type) guard let heartRate = try await getDescriptor( date: date, type: type, options: .discreteAverage ).result(for: healthStore) .statistics(for: date)? .averageQuantity()?.doubleValue(for: HKUnit.count().unitDivided(by: HKUnit.minute())) else { return nil } return Double(String(format: "%.2f", heartRate)) ?? 0.0 } Descriptor & predicate internal func getPredicate(startDate: Date, endDate: Date) -> NSCompoundPredicate { let predicateForSamples = HKQuery.predicateForSamples(withStart: startDate, end: endDate) let excludeManual = NSPredicate(format: "metadata.%K != YES", HKMetadataKeyWasUserEntered) return NSCompoundPredicate(andPredicateWithSubpredicates: [predicateForSamples, excludeManual]) } internal func getDescriptor(startDate: Date, endDate: Date, type: HKQuantityType, options: HKStatisticsOptions) -> HKStatisticsCollectionQueryDescriptor { let calendar = Calendar(identifier: .gregorian) let anchorDate = calendar.date(bySetting: .hour, value: 0, of: startDate)! var interval = DateComponents() interval.day = 1 return HKStatisticsCollectionQueryDescriptor( predicate: HKSamplePredicate.quantitySample(type: type, predicate: getPredicate(startDate: startDate, endDate: endDate)), options: options, anchorDate: anchorDate, intervalComponents: interval ) } Implementation public func observeWalkingActivityInBackground(_ start: Bool, toRead: Set<HKQuantityType>, memberID: String) { observeWalkingActivityInBackground(start, toRead: toRead) { [weak self] result in guard let self = self else { return } } }
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345
Mar ’25
Querying heart rate samples hangs for some users
This is an ongoing issue that I haven't been able to solve: I am querying different types of HealthKit data over the past year. While this works fine for HRV, it hangs for some users when I'm trying to get heart rate data. Here's the relevant query func initialRead(from startDate: Date) async throws -> [HKSample] { let endDate = anchorStart let interval: TimeInterval = .days(7) var currentStartDate = startDate var currentEndDate = Date(timeInterval: interval, since: currentStartDate) var samples: [HKSample] = [] while currentStartDate <= endDate { let datePredicate = SampleType.datePredicate(start: currentStartDate, end: currentEndDate) let predicate = NSCompoundPredicate(andPredicateWithSubpredicates: [datePredicate,HKQuery.predicateForObjects(withMetadataKey: HKMetadataKeyHeartRateMotionContext, allowedValues: [HKHeartRateMotionContext.sedentary])]) do { let result = try await withCheckedThrowingContinuation { continuation in let completionQuery = HKSampleQuery(sampleType: HKQuantityType.heartRate, predicate: predicate, limit: HKObjectQueryNoLimit, sortDescriptors: [.init(key: HKSampleSortIdentifierStartDate, ascending: true)]) { query, samples, error in if let samples { continuation.resume(returning: samples) } else { if let error { continuation.resume(throwing: error) } else { continuation.resume(returning: []) } } } healthStore.execute(completionQuery) } samples = samples.merge(from: result) } catch { Logger.general.error("Reading failed for dates \(currentStartDate) to \(currentEndDate): \(error)") } currentStartDate = currentEndDate currentEndDate = Date(timeInterval: interval, since: currentStartDate) } return samples } extension HKSampleType { static func datePredicate( start:Date?, end:Date?) -> NSPredicate { HKQuery.predicateForSamples(withStart: start, end:end, options: .strictStartDate) } } For reference, I expect about 1000 sedentary samples per week. Basically what happens for these users is when they start reading the HR data, the app hangs. They start each read manually via a special TestFlight build with buttons for starting the different data type readings. Any advice on how to proceed with this bug would be great since it only affects some users. I am able to create test builds for this audience to test different options. One theory is the motion context predicate is screwing something up. If any apple dev can enlighten me how to narrow down the issue, that would be great.
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229
Mar ’25
Recording a HeartbeatSeries
I need to be able to create and store a HeartbeatSeries for a given time-period from an Apple Watch, to then retrieve that data from HealthKit to be processed. I have working code which allows me to begin a workout session, which is being used to determine how long a session has been running for. I also have working code for retrieving HeartbeatSeries data from HealthKit. The issue is that no HeartbeatSeries data is being stored into HealthKit as a result of the workout session running. Whether that session is running for as little as 30 seconds or as long as 20 minutes, nothing is stored. However, when I use the the Apple "Meditation" app (formerly known as "Breathe"), I can query HealthKit afterwards and retrieve a list of individual heartbeat timings during that 2 minute period. Therefore, it IS possible to store a HeartbeatSeries from within an app on the Apple Watch. What I would like to know is, how can I use the pulse sensor built-in to the Apple Watch to be able to record a HeartbeatSeries similar to how the Meditation app does it.
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154
Mar ’25
Has HealthKit Changed GPS Standards in iOS 18.4 Beta 4?
I am a developer from mainland China. Today, I noticed that the HKWorkoutRoute data stored by my app in HealthKit shows significant discrepancies when viewed on the workout route map in the Health and Fitness apps on iOS 18.4. Instead of displaying the actual movement path, the route appears to be offset by several hundred meters. I collected this data using my app on watchOS 11.3.1, and all CLLocation data comes directly from Core Location. I did not convert WGS84 standard data to GCJ02. Reviewing historical data, all workout routes before March 17, 2025, appear correct, but every record after that date exhibits the offset issue.
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121
Mar ’25
Synchronization Timing Between Apple Watch HealthKit Store and iPhone HealthKit Store
Hi, I’m currently working on an app that utilizes sleep data from HealthKit to provide users with meaningful insights about their sleep. To ensure a smooth user experience, I’d like to understand when sleep data collected by the Apple Watch is saved to the HealthKit store and when it gets synced to the iPhone. Ideally, I want to fetch sleep data right after the user wakes up and opens our app. However, to do this reliably, I need to know the timing of how and when this data becomes available in the iPhone’s HealthKit store. I’ve looked through the official documentation and relevant WWDC sessions but couldn’t find clear information on this topic. If anyone has insights or experience with how and when the Apple Watch syncs HealthKit data—especially sleep records—to the iPhone, I’d greatly appreciate your input. Thanks!
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126
Apr ’25
Incorrect Step Count from Apple HealthKit Data
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); } };
6
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264
Jul ’25