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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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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99
Mar ’25
How to run HKWorkoutSession on watch without affecting activity rings?
My research group is using watch sensors (accelerometers, gyroscopes) to track wrist motion to detect and measure eating. https://cecas.clemson.edu/ahoover/bite-counter/ We are running an HKWorkoutSession on the watch so that the app can run for an extended period of time (up to 12 hr) and continue to sense and process motion data. Our app is adding to the activity rings, making it look like the user is exercising the entire time our app is running. Is there a method to prevent our app from contributing to the activity ring measures?
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110
Apr ’25
HealthKit Authorization Requests Immediately Denied in iOS 18.5 - No Permission Dialog Shown
I am experiencing a critical issue with HealthKit authorization in iOS 18.5 where requestAuthorization() calls are immediately denied without showing the user permission dialog. Problem Description: HealthKit authorization requests immediately return .sharingDenied status No system permission dialog is displayed to the user Authorization status changes from .notDetermined to .sharingDenied in <0.1 seconds This occurs for all HealthKit data types (step count, heart rate, sleep analysis, etc.) Technical Details: iOS Version: 18.5 (22F76) Xcode Version: 16F6 Device: iPhone (tested on both simulator and physical device) Bundle IDs tested: com.hereforyou.test2024, com.hereforyou.app Entitlements: com.apple.developer.healthkit = true Code Implementation: let healthStore = HKHealthStore() let stepType = HKObjectType.quantityType(forIdentifier: .stepCount)! // Status before request: .notDetermined try await healthStore.requestAuthorization(toShare: [], read: [stepType]) // Status after request: .sharingDenied (immediate, <0.1 seconds) Evidence this is not a code issue: Other HealthKit apps from App Store work correctly on the same device Proper entitlements are configured and verified HKHealthStore.isHealthDataAvailable() returns true Same code worked in previous iOS versions Multiple Bundle IDs tested with same result Expected Behavior: System should display HealthKit permission dialog allowing user to grant/deny access Actual Behavior: Authorization is immediately denied without user interaction Steps to Reproduce: Create new iOS app with HealthKit entitlements Call requestAuthorization() for any HealthKit data type Observe immediate denial without permission dialog Is this a known issue in iOS 18.5? Are there any workarounds or timeline for a fix? Best regards
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105
Jun ’25
Sleep Score API access
New in iOS 26 and WatchOS 26 is a Sleep Score calculation for users based on Duration, Bedtime and Interruptions. Unfortunately I can't find any APIs for developers to tap into this metric. Yes, in theory it's all created off the same Sleep Analysis data already available with HealthKit but that makes it very hard to recreate in our apps. If the numbers don't match up exactly, users will understandably complain. Can anyone confirm that this is the case and I've not missed a Sleep Score API? I'll then file feedback. Hopefully this doesn't go the way of Heart Rate Zones where the Apple Watch iPhone app has generated them for years and provided no way for third party apps to access these values (yes many feedbacks provided previously).
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202
Sep ’25
How to accurately query HKWorkout segment data
Hello, In my application, I need to obtain precise workout segment data from HKWorkout in order to calculate per-kilometer metrics such as heart rate and pace. My current approach is: 1.Use HKWorkout to fetch the associated HKWorkoutEvents. 2.Take the end time of one event as the start time of the next event to derive per-kilometer segment ranges. The issue I’m facing: •If a user sets Apple Watch to notify every 5 kilometers, then at 5 km, 10 km, 15 km, etc., I see overlapping event times. •From the HKWorkoutEvents data alone, I cannot distinguish between events that represent “per-kilometer splits” and those that represent “5-kilometer notifications.” •As a result, my per-kilometer heart rate and pace calculations can be inaccurate. My question is: Is there a recommended way to reliably differentiate per-kilometer splits from custom distance notifications and ensure accurate segment data retrieval? For example, should I instead reconstruct segments using HKWorkoutRoute and distance samples, rather than relying on HKWorkoutEvents? STEPS TO REPRODUCE 1.On Apple Watch, start an Outdoor Run using the Workout app. 2.In workout notifications, set distance alerts to every 5 kilometers. 3.During the run, when reaching 5 km, 10 km, 15 km, etc., the watch triggers notifications. 4.Query the corresponding HKWorkout from HealthKit and inspect its HKWorkoutEvents. 5.Notice that some event start times are duplicated, and it is unclear which events represent “per-kilometer splits” and which represent “5-kilometer notifications.” Expected Result: Be able to differentiate between per-kilometer splits and custom distance alerts, so that heart rate and pace per kilometer can be calculated accurately. Actual Result: The HKWorkoutEvents data contains duplicated event times without a way to distinguish event types, leading to inaccurate per-kilometer statistics.
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107
Oct ’25
Apple Watch Ultra exercise app and activity rings won’t connect after charging
Since upgrading to iOS 26 beta on my Apple Watch Ultra and iPhone 16 Pro Max, my exercise app and activity rings have sporadically not connected after charging. Several recent mornings, when I’ve put my watch on, the activity rings are grayed out and when I click on them, they will show no activity, even though I have been active. Similarly, when I attempt to select the activity app, it will open, but when I select an activity, it will not start the workout. I’ve tried starting and restarting the watch and phone. I’ve checked permissions, and both the watch and phone are running the latest iOS. The only fix seems to be unpairing and repairing the watch and phone which is an absolute pain. Any assistance on how to permanently fix this would be greatly appreciated.
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122
4w
HKAnchoredObjectQuery updateHandler stops working with error
Hi! I am using the HKAnchoredObjectQuery to first get a snapshot of the initial results, and then trigger an updateHandler. I need to handle the initial results and the updates separately, which is why I implemented two completions. When I test the code, it works for a while. New and deleted samples trigger the updateHandler. However, after a while there appears an error: [connection] nw_read_request_report [C2] Receive failed with error "Software caused connection abort" Followingly, the updateHandler will stop getting triggered when I add updates in Apple health. Anyone have experience with this? func getMostRecentSample(for sampleType: HKSampleType, anchorKey: String, completion: @escaping (HKQuantitySample?, Error?) -> Swift.Void, updateHandler: @escaping (HKQuantitySample, Error?) -> Swift.Void) {     // If it is the first initialization, anchor is passed as nil     var anchor: HKQueryAnchor? = nil // Check for previous saved anchor in userdefaults     if UserDefaults.standard.object(forKey: anchorKey) != nil {       let data = UserDefaults.standard.object(forKey: anchorKey) as! Data       do {         guard let newAnchor = try NSKeyedUnarchiver.unarchivedObject(ofClass: HKQueryAnchor.self, from: data) else {           print("Could not parse anchor to HKQueryAnchor type")           return         }         anchor = newAnchor       } catch {         print("Error retreiving anchor from UserDefaults")       }     }     let query = HKAnchoredObjectQuery(type: sampleType,                      predicate: nil,                      anchor: anchor,                      limit: HKObjectQueryNoLimit                       ) { (query, samplesOrNil, _, newAnchor, errorOrNil) in       guard let samples = samplesOrNil as? [HKQuantitySample] else {         fatalError("*** An error occurred during the initial query: \(errorOrNil!.localizedDescription) ***")       }       if let anchor = newAnchor {         do {           let data = try NSKeyedArchiver.archivedData(withRootObject: anchor as Any, requiringSecureCoding: false)           UserDefaults.standard.set(data, forKey: anchorKey)         } catch {           print("Error retreiving anchor from UserDefaults")         }       }       completion(samples.last, nil)     }           // Setting up long-running query     query.updateHandler = { (query, samplesOrNil, _, newAnchor, errorOrNil) in       guard let samples = samplesOrNil as? [HKQuantitySample] else {         fatalError("*** An error occurred during an update: \(errorOrNil!.localizedDescription) ***")       }       if let anchor = newAnchor {         do {           let data = try NSKeyedArchiver.archivedData(withRootObject: anchor as Any, requiringSecureCoding: false)           UserDefaults.standard.set(data, forKey: anchorKey)         } catch {           print("Error retreiving anchor from UserDefaults")         }       }       if let sample = samples.last {         updateHandler(sample, nil)       }     }     self.healthStore.execute(query)   }
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1.1k
Mar ’25
HealthKit quantity types are not documented when generated by the system and on which Apple Watch models
Finally at last Apple Health supports saving .distancePaddleSports, .distanceCrossCountrySkiing, .distanceRowing, .distanceSkatingSports, and much more. The backstory. In the land of 10,000 lakes, there hasn't been a way to save 'canoe' or 'kayak' distance and I've been asking for it for years. Thank you health team for adding it this year! FB7807993 - Add HKQuantityTypeIdentifier.paddleDistance for canoeing, kayaking, etc type workouts (June 2020) Prior we could just save the totalDistance to a workout, but since the HKWorkout initializers were deprecated we no longer have a supported way to save these distances in our workouts. The iOS 18 / watchOS 11 introduction addresses this. If you want to know more why you can't do this in earlier versions you can check these feedback titles: FB10281482 - HealthKit: Deprecation of totalDistance on a workout session of paddleSports breaks apps that used that to save distance to the workout because there is no "paddleDistance" type available to save as sample data (June 2022) FB12402974 - HealthKit: Deprecation of HKWorkout completely breaks support for third party fitness apps from saving non-standard workout distance (June 2023) Great, so there is new support that solves all of these requests and issues for the new version of the OSes. However, the downside is now that there is not much for documentation. Unlike the .runningSpeed and .runningPower introduced in iOS 16 / watchOS 9, none of the new iOS 18 / watchOS 11 types have documentation, at all. To some degree this is understandable, but types from last year still remain undocumented too. Without this information for the data types introduced in both iOS 17/18 and watchOS 10/11 it makes building and integrating with these new types difficult to say the least. We can't make assumptions about anything. Can we get a documentation update for new (and existing) quantity types for when Apple Watch will automatically generate samples? FB14236080 - Developer Documentation / HealthKit: Update documentation for HKLiveWorkoutDataSource typesToCollect for which sample types are automatically collected by watchOS 10 and 11 (July 2024) FB14942555 - HealthKit / Documentation: App Update Release Issue - HKQuantityTypeIdentifiers are missing documentation describing when the system automatically adds data (today) I know that the behavior has changed from release to release for some of these types, so documentation would be based on OS version. If you didn't catch it, watchOS 11 will now associate .cyclingSpeed for cycling workouts both indoor and outdoor. FB12458548 - Fitness: Connected cycling speed sensor did not save samples to health via cycling workout (June 2023 - received reply that only saved for indoor cycling, but not documented otherwise) FB14311218 - HealthKit: Expected outdoor cycling to include .cyclingSpeed quantity type as a default HKLiveWorkoutDataSource type to collect (July 2024) To the other third party fitness apps out there, how are you managing the knowledge of which devices collect which data types on which versions of the OS? Sure, we could look at the HKLiveWorkoutDatSource and inspect the typesToCollect property across a bunch of devices, but again that is trial by error not 'as documented'. Is the behavior of simulators guaranteed to match the behavior of real devices? Maybe, but also maybe not. Fingers crossed for a nice documentation update to spell out all of the behavioral details. Apple folks / DTS, many of the above feedbacks are addressed and I plan to update or close them after the releases this fall. Some are still outstanding. P.S. I hope that .paddleSports gets deprecated and split into individual activity types like skiing did years ago. Their MET scores are different according to the research on the physical activity compendium site. FB7807902 - Split HKWorkoutActivityType.paddleSports into their own activity types (June 2020)
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872
Dec ’24
Sleep Analysis inBed sample not recorded on Apple Watch in iOS 18
In this link, Apple states we can know when a user is in bed vs sleeping and compare their quality of sleep by it. Only, in iOS 18, Apple no longer reports inBed time samples for the Apple Watch. I get why they stopped doing this for the phone, but why the watch? Bug? My app was using the inBed times for this very purpose and now only works for Garmin and Oura who still report inBed times. https://developer.apple.com/documentation/healthkit/hkcategoryvaluesleepanalysis
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1.4k
Dec ’24
car accident detect API
https://support.apple.com/zh-cn/104959 Our application provides car insurance services. Does Apple have any API related to car accident detection exposed to developers? We want to do something when an iPhone detects a car accident
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419
Jan ’25
Deprecated: HKCategoryValueMenstrualFlow
We currently use the HKCategoryValueMenstrualFlow enum to determine the type of menstrual flow: light, medium, etc. a user is having. We also use this enum in determining if it's an actual period day. The Problem I see HKCategoryValueMenstrualFlow was recently deprecated but has not been replaced by another data type. Are there plans to replace/update it with another data type? When or at what point in the future will this deprecation cause a problem in my code?
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944
Dec ’24
When does appleExerciseTime update or change?
I've been trying to figure out what the bare minimum is required for HKWorkoutBuilder to create a workout that adds time the appleExerciseTime. I couldn't find the documentation for this. This is my code so far. func createWorkoutSample( expectedActiveEnergyData: [Double], expectedExerciseMinutesData: [Double], calendar: Calendar, startDate: Date ) async throws -> [HKSample] { var testData: [HKSample] = [] let workoutConfiguration = HKWorkoutConfiguration() workoutConfiguration.activityType = .running workoutConfiguration.locationType = .outdoor let results = try await withThrowingTaskGroup(of: HKSample?.self) { group in for (index) in 0..<expectedActiveEnergyData.count { guard let date = calendar.date(byAdding: .day, value: index, to: startDate) else { continue } group.addTask { let builder = HKWorkoutBuilder( healthStore: self.manager.healthStore, configuration: workoutConfiguration, device: .local() ) let endDate = date.addingTimeInterval(expectedExerciseMinutesData[index] * 60) try await builder.beginCollection(at: date) let energyType = HKQuantityType.quantityType( forIdentifier: .activeEnergyBurned )! let energyQuantity = HKQuantity( unit: HKUnit.kilocalorie(), doubleValue: expectedActiveEnergyData[index] ) let energySample = HKQuantitySample( type: energyType, quantity: energyQuantity, start: date, end: endDate ) return try await withCheckedThrowingContinuation { continuation in builder.add([energySample]) { (success, error) in if let error = error { continuation.resume(throwing: error) return } builder.endCollection(withEnd: endDate) { (success, error) in if let error = error { continuation.resume(throwing: error) return } builder.finishWorkout { (workout, error) in if let error = error { continuation.resume(throwing: error) return } continuation.resume(returning: workout) } } } } } } for try await workout in group { if let workout = workout { testData.append(workout) } else { print("Skipping nil workout result.") } } return testData } print("Total samples created: \(results.count)") return results } When I query appleExerciseTime, there are no results. I've looked at the HKWorkoutBuilder documentation, and most of the information expands on adding samples related to the deprecated HKWorkout.
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897
Jan ’25
Read Workout Effort Scores
Is there documentation on how to read workout effort scores from a HealthKit workout? I'm interested in reading workoutEffortScore and estimatedWorkoutEffortScore. I have not been successful trying to read them using the same method that I do other workout HKQuantityTypes (heartRate, stepCount, etc). I'm using Swift and I do have authorization for those types requested and granted. I have found documentation on setting these values (https://developer.apple.com/forums/thread/763539) but not reading them. Thank You
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919
Jan ’25
Workouts fail to register on Fitness activity rings
Hello, My app syncs workout data from a third-party device and records workouts with HealthKit as follows: let builder = HKWorkoutBuilder(healthStore: healthStore, configuration: hkConf, device: hkDevice) try await builder.beginCollection(at: startDate) try await builder.addSamples(samples) try await builder.endCollection(at: endDate) let workout = try await builder.finishWorkout() let workoutRouteBuilder = HKWorkoutRouteBuilder(healthStore: healthStore, device: hkDevice) try await workoutRouteBuilder.insertRouteData(filteredLocations) try await workoutRouteBuilder.finishRoute(with: workout, metadata: nil) However, I’m encountering two issues: The workouts appear in Apple Fitness but do not contribute to the activity rings. The workout includes a route (visible in the raw workout data in Apple Health) but does not display on Apple Fitness. Is there any way to fix this? I’d appreciate any suggestions you might have. __
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755
Jan ’25
Extended Runtime Session vs HKWorkoutSession Issues
I am working on an Apple Watch companion app to an existing live iOS app. I am utilizing the heart rate tracking for an active 'self-care' sauna session. I say self-care in quotes because it's more self-care than a workout activity, but it is closely blurring the lines between the two. I have come to understand that if a session truly isn't a workout, then you should not use workoutSession.startActivity. However the app needs to function entirely like a workout would. This is not a meditation application. Sauna is actually just one of many activity types supported in the app. I have tried using extended runtime session, and there have been numerous issues with doing so. It is not nearly as robust for the user. For example, the active session is not prioritized by the watch's CPU. Now playing is no longer functional. Heart rate is far more inconsistent, and this variable is as critical as if it were in a workout. I have tried using HKWorkoutSession, however I worry the app will be rejected by doing so. This method works most accurately to collect the right data for the user, and prioritizes system resources as expected. The app can be moved to the background as expected and continue to communicate with the iOS app. What is the best way to move forward here. It almost feels like I am operating in a grey area with no real solution in place. Any assistance is greatly appreciated as we would like to follow all guidelines while producing a high quality experience for our users.
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802
Jan ’25
Can't create energy goals in WorkoutKit
I can create WorkoutGoals of all kinds except .energy, but I can't find any indication of the conditions under which energy goals can be used. No matter what I try, the response from supportsGoal is always false e.g. CustomWorkout.supportsGoal(.energy(10, .kilojoules), activity: .running, location: .outdoor) CustomWorkout.supportsGoal(.energy(10, .calories), activity: .cycling, location: .outdoor) CustomWorkout.supportsGoal(.energy(10, .kilocalories), activity: .running, location: .outdoor) For any combination I've tried, I get Not supported due to unsupportedGoal Has anybody managed to successfully create energy goals?
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805
Jan ’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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809
Apr ’25
Walking/Running Distance not included in daily total
Hi, I have an iPhone/watch app that measures walking/running distance. It starts a workout session records data successfully into healthkit and then ends the workout session. I can see the data in the Health app from my app and it all appears to be correct. The issue I'm having is that the Health app doesn't use my app's data in its total distance for the day. For example, I can add 1 mile of fake data (I know that's not allowed per policy) for testing and it gets successfully added but not used in the total. The health app is only using distances collected by the watch and the phone for calculating the total distance for the day and is ignoring the distance provided by my app. What could I be missing?
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675
Feb ’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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92
Mar ’25
怎样读取健康记录心理状态的情境,并将自己APP的数据传入进去
读取是不是解析 metadata 的对应键来获取值对吧~但我看了相关开发文档好像没找到这个的键是什么~于是也没法写入到对应的,现在只能自定义键来进行写入 但是这样写入后无法显示在心情下方的影响因素后面~ 这个 key 是没公开的吗还是说我方法弄错了~请各位大大指教
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74
May ’25