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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Statistics collection query first result returned is wrong
I'm reading hourly statistics from HealthKit using executeStatisticsCollectionQuery (code below). Expectation What I expect is to get back the list with one row per hour, where each hours has the same cumulative sum value. Actual result In results, first hour always contains less calories than next hours, which all have the same value. Example: Start: 2025-06-02T00:00:00+03:00, anchor: 2025-06-02T00:00:00+03:00, end: 2025-06-02T12:00:00+03:00 🟡 2025-06-02T00:00:00+03:00 Optional(50.3986 kcal) 🟡 2025-06-02T01:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T02:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T03:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T04:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T05:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T06:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T07:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T08:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T09:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T10:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T11:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T12:00:00+03:00 Optional(14.0224 kcal) As you can see, here we have 2025-06-02T00:00:00+03:00 Optional(50.3986 kcal) Now, if I add one more hour to the request (from beginning of time window), the same hour has proper calories count, while newly added hour, has wrong value): 2025-06-01T23:00:00+03:00, anchor: 2025-06-01T23:00:00+03:00, end: 2025-06-02T12:00:00+03:00. 🟡 2025-06-01T23:00:00+03:00 Optional(50.3986 kcal) 🟡 2025-06-02T00:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T01:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T02:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T03:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T04:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T05:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T06:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T07:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T08:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T09:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T10:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T11:00:00+03:00 Optional(64.421 kcal) 🟡 2025-06-02T12:00:00+03:00 Optional(14.0224 kcal) And now first hour of the day, magically has more calories burned: 2025-06-02T00:00:00+03:00 Optional(64.421 kcal) I suspect similar things happen with other quantity types, but haven't yet found a way to reproduce it. Am I doing something wrong or is it a bug in HealthKit? Code let anchorDate = startDate let predicate = HKQuery.predicateForSamples(withStart: startDate, end: endDate, options: [.strictStartDate]) healthStore.executeStatisticsCollectionQuery( quantityType: .basalEnergyBurned, quantitySamplePredicate: predicate, options: [.separateBySource, .cumulativeSum], anchorDate: anchorDate, intervalComponents: DateComponents(hour: 1), initialResultsHandler: { statistics, error in if let error = error { log(.error, "Error retrieving steps: \(error.localizedDescription)") continuation.resume(throwing: SpikeException("Error retrieving steps: \(error.localizedDescription)")) return } if let statistics { let f = ISO8601DateFormatter() f.timeZone = TimeZone.current for s in statistics { log(.debug, "\(f.string(from: s.startDate)) \(s.sumQuantity())") } } continuation.resume(returning: statistics ?? []) } )
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Jul ’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
Launch companion Watch App without Health Kit
How to launch companion Watch App without relying on Health Kit? I need my companion watch to launch automatically in some specific cases. What I'm doing to achieve that is to call "startWatchApp" in HKHealthStore(). This worked flawlessly for well over a year but AppReview is now giving me a hard time about using HealthKit without actually using health related data. Is there a way to do the same without using HealthKit? Seems silly that this is bundled only with the HealthKit... If I don't find another solution I will probably be forced to start reading heart rate data and reporting it to the user just so that AppReview will stop saying that I have no reason to use HealthKit... But ideally I'd love to learn about a way to open the companion Watch app without HealthKit and do things the right way...
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64
Jun ’25
Health app and Activity Data are gone?
Hi y’all! This is my first post but I wanted to ask if anyone else has had this happen and fixed it. But I have lost 3 years of fitness and health data upon upgrading to iOS 26 beta 1. I have about 2 gigs of health data in iCloud which I’m praying to Tim is my data lol. But I was wondering if anyone else went through this issue on their test device and yeah.
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25
Jun ’25
Sensor and Feature Issues on watchOS 26 Beta
Hi all, I’m currently running watchOS 26 beta and have been experiencing several sensor-related issues since updating: • Raise to Wake function doesn’t activate reliably or at all. • Heart rate sensor fails to measure or shows inconsistent readings. • Location services are not working properly, affecting workout tracking and apps that rely on GPS. • Blood oxygen (SpO2) measurements are failing or missing completely. I’m not sure exactly when these issues began, but they started after installing the latest beta. I’ve tried restarting and resetting but the problems persist. Has anyone else encountered similar issues? Any insights or fixes would be appreciated! Thanks!
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98
Jul ’25
HealthKit - HKWorkoutRouteBuilder never returns from insert when created from newly added iOS HKLiveWorkoutBuilder API on Simulator
Has anyone had success using the HKWorkoutRouteBuilder in conjunction with the new iOS support for HKLiveWorkoutBuilder? I was running my watchOS code that worked now brought over to iOS and when I call insertRouteData the function never returns. This happens for both the legacy and closure based block patterns. private var workoutSession: HKWorkoutSession? private var workoutBuilder: HKLiveWorkoutBuilder? private var serviceSession: CLServiceSession? private var workoutRouteBuilder: HKWorkoutRouteBuilder? private func startRouteBuilder() { Task { @MainActor in self.serviceSession = CLServiceSession(authorization: .whenInUse) self.workoutRouteBuilder = self.workoutBuilder?.seriesBuilder(for: .workoutRoute()) as? HKWorkoutRouteBuilder self.locationUpdateTask = Task { do { for try await update in CLLocationUpdate.liveUpdates(.fitness) { if let location = update.location { self.logger.notice(#function, metadata: [ "location": .stringConvertible(location) ]) try await self.workoutRouteBuilder?.insertRouteData([location]) self.logger.notice("Added location") } } } catch { self.logger.error(#function, metadata: [ "error": .stringConvertible(error.localizedDescription) ]) } } } } I did also try CLLocationManager API with delegate which is what my current watch code uses (a bit old). Same issue. Here is what I've found so far: If the workout session is not running, and if the builder hasn't started collection yet, inserting route data works just fine I've tried different swift language modes, flipped from main actor to non isolated project settings (Xcode 26) Modified Apple's sample code and added location route building to that and reproduced the error, modified sample attached to feedback This issue was identified against Xcode 26 beta 2 and iPhone 16 Pro simulator. Works as expected on my iPhone 13 Pro beta 2. FB18603581 - HealthKit: HKWorkoutRouteBuilder insert call within CLLocationUpdate task never returns
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154
Jul ’25
Some swimming activities are not fetched by combined predicate
I'm using following filters to fetch swimming activities from HealthKit. For some users it fetches all workouts (pool && open water) but for other it skips some open water activities. See screenshot, all those swimming activities are not fetched by following code. let startDate = Calendar.current.date(byAdding: .month, value: -1, to: Date())! let endDate = Date() let swimmingPredicate = HKQuery.predicateForWorkouts(with: .swimming) let timePredicate = HKQuery.predicateForSamples(withStart: startDate, end: endDate, options: .strictStartDate) let predicate = NSCompoundPredicate(andPredicateWithSubpredicates: [swimmingPredicate, timePredicate]) let query = HKSampleQuery(sampleType: .workoutType(), predicate: predicate, limit: HKObjectQueryNoLimit, sortDescriptors: [.init(keyPath: \HKSample.startDate, ascending: false)], resultsHandler: { [weak self] query, samples, error in ... Could someone help with ideads what is missing in this case?
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52
Jul ’25
HKLiveWorkoutBuilder get wrong calorie data for iOS 26
In iOS 26, HKLiveWorkoutBuilder is supported, which we can use like HKWorkoutSession in watchOS - this is very exciting. However, it currently seems to have a bug in calculating calories. I tested it in my app, and for nearly 6 minutes with an average heart rate of 134, it only calculated 8 calories consumed (80 calories per hour), including basal consumption, which is obviously incorrect. (I used Powerboats Pro 2 connected to my phone, which includes heart rate data, and HKLiveWorkoutBuilder correctly collected the heart rate, which is great.) I think my code is correct. func workoutBuilder(_ workoutBuilder: HKLiveWorkoutBuilder, didCollectDataOf collectedTypes: Set<HKSampleType>) { for type in collectedTypes { guard let quantityType = type as? HKQuantityType else { return // Nothing to do. } let statistics = workoutBuilder.statistics(for: quantityType) if let statistics = statistics { switch statistics.quantityType { case HKQuantityType.quantityType(forIdentifier: .heartRate): /// - Tag: SetLabel let heartRateUnit = HKUnit.count().unitDivided(by: HKUnit.minute()) let value = statistics.mostRecentQuantity()?.doubleValue(for: heartRateUnit) let roundedValue = Double( round( 1 * value! ) / 1 ) if let avg = statistics.averageQuantity()?.doubleValue(for: heartRateUnit) { self.avgHeartRate = avg } self.delegate?.didUpdateHeartBeat(self, heartBeat: Int(roundedValue)) case HKQuantityType.quantityType(forIdentifier: .activeEnergyBurned): let energyUnit = HKUnit.kilocalorie() let value = statistics.sumQuantity()?.doubleValue(for: energyUnit) self.totalActiveEnergyBurned = Double(value!) print("didUpdate totalActiveEnergyBurned: \(self.totalActiveEnergyBurned)") self.delegate?.didUpdateEnergyBurned(self, totalEnergy: self.totalActiveEnergyBurned + self.totalBasalEneryBurned) return case HKQuantityType.quantityType(forIdentifier: .basalEnergyBurned): let energyUnit = HKUnit.kilocalorie() let value = statistics.sumQuantity()?.doubleValue(for: energyUnit) self.totalBasalEneryBurned = Double(value!) print("didUpdate totalBasalEneryBurned: \(self.totalBasalEneryBurned)") self.delegate?.didUpdateEnergyBurned(self, totalEnergy: self.totalActiveEnergyBurned + self.totalBasalEneryBurned) return default: print("unhandled quantityType=\(statistics.quantityType) when processing statistics") return } } I think I've found the source of the problem: let workoutConfiguration = HKWorkoutConfiguration() workoutConfiguration.activityType = .traditionalStrengthTraining //walking, running is ok workoutConfiguration.locationType = .outdoor When I set the activityType to walking or running, the calorie results are correct, showing several hundred calories per hour. However, when activityType is set to traditionalStrengthTraining or jumprope, the calculations are incorrect. PS: I'm currently using Xcode 26 beta3 and iOS 26 beta3. Hope this issue can be resolved. Thanks.
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Jul ’25
Tax Category
Hi, My app concept features various sections; a) Personal development section: featuring exercises and guides, b) Coaches section: featuring coaching sessions offering virtual or in-person sessions related to yoga, fitness, lifestyle etc. (marketplace for coaches). c) Events section: hosting virtual or in-person events. Hence which "tax category" should I be selecting? Thanks, Gavin
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24
Aug ’25
Is it possible to get Workout intervals and data from third party app via HealthKit or WorkoutKit?
If a user selects custom structured workout in the apple watch Workout app and records a run with intervals, how can my third party app pull in that data? I can obviously get the workout and health stuff like heart rate, but I cannot find how to save the intervals and the relevant data. The workout events are not seemingly helpful - segments are not obviously related to this. Is it possible? Is it only possible to have the third party app create a customworkout with metadata and then our third party app parses the interval distance/time based on our own structure? I think this stuff should be able to be accessed.
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212
Aug ’25
What determines which suggested apps are listed in Health?
Hello - I'm wondering about the suggested apps listed by Apple in their Health app. For example, if you select the "Sleep" category there are a bunch of suggested apps like AutoSleep and Sleepzy. These are not Sleep apps that I installed on my own phone or ever shared sleep data with. Is there a way to request to have a relevant app shown there? Or is it more automatic, like you're an app that integrates with HealthKit in certain ways and Apple has a way of determining that app is suitable for the user (ex. App Store popularity, user behavior, etc.)
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105
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
watchOS: CoreMotion data, Watch goes to sleep and disconnects during tests
Hello, I am working on a Iphone app and companion Watch app that prompts the user to go through a few activities like walk, sit, etc and collects the CoreMotion data from the Watch. The phone app coordinates the actions and sends a command to the watch to start/stop the measurement. My problem is that the Watch keeps on disconnecting after a few seconds and that is messing up the data collection. Is there a way to keep the watch awake and not sleep during the duration of these tests? I also used a HealthKit session to try and keep the watch awake and measuring.. but none of these methods are reliable.. Can you please suggest how to keep the watch and phone connected and awake during the data collection? (The whole test takes about 4-5 minutes).. I have spent many days on this problem.
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Oct ’25
Feature Request: Expand HealthKit Body Composition Data Types to Support Smart Body Scanning Scales
Summary: Expanding HealthKit to support the full spectrum of smart scale metrics will allow Apple Health to remain the central hub for health data, align with user expectations, and future-proof the framework as body composition analysis evolves. Description: With the growing adoption of smart body composition scales (e.g. segmental impedance scanners, multi-frequency analyzers, and body pods), users are generating a wide variety of clinically relevant metrics that currently cannot be stored natively in HealthKit. At present, HealthKit supports a core set of body composition values (Body Mass, BMI, Body Fat %, Lean Mass, Height, Waist Circumference). While useful, these do not capture the full picture modern devices provide, leading to fragmentation: • Users can see dozens of metrics in the device app, but only a handful flow into Health. • Developers must resort to metadata fields, which are inconsistent across apps and not accessible in Apple’s Health app UI. This gap undermines HealthKit’s role as a central, standardized health record. ⸻ Proposed Additions: Expand HealthKit HKQuantityTypeIdentifier to include additional body composition and derived measurements commonly reported by smart scales: Core Body Composition • Visceral fat percentage / rating • Skeletal muscle mass • Segmental muscle mass (arms, legs, trunk) • Segmental fat mass (arms, legs, trunk) • Bone mineral mass • Total body water % / hydration Derived Health Metrics • Muscle-to-fat ratio • Phase angle (bioelectrical impedance) • Metabolic age • Basal metabolic rate (BMR) ⸻ Rationale: • User benefit: Health app would show a more complete health profile, not just weight and fat %. • Developer benefit: Creates standardized identifiers, eliminating the need for proprietary storage in metadata. • Industry alignment: Many leading health devices already provide these metrics; users expect them to sync into Health. • Future-proofing: As body scanning scales proliferate, HealthKit can remain the trusted central repository rather than ceding ground to siloed vendor apps. ⸻ Suggested Implementation: • Introduce new HKQuantityTypeIdentifier values for each metric. • Permit segmental values to be represented as discrete samples with metadata for body region. • Ensure values can be written by apps/devices and surfaced in Health app UI, just like existing body composition data.
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78
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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