--- title: "AIFitnessAPI" canonical: "https://aifitnessapi.com" description: "Verified guides, comparisons, pricing, and CI-tested code for fitness, wearable, nutrition, and AI motion APIs — pick the right stack and ship it." publisher: "AIFitnessAPI — funded by KinesteX; first-party pages disclose it" license: "Content readable and quotable with attribution" llms_txt: "https://aifitnessapi.com/llms.txt" --- # AIFitnessAPI > Verified guides, comparisons, pricing, and CI-tested code for fitness, wearable, nutrition, and AI motion APIs — pick the right stack and ship it. 276 verified pages across 21 clusters. Every page also exists as markdown at its own URL with `.md` appended. ## Fitness APIs — https://aifitnessapi.com/fitness-apis - [The Best Exercise Database APIs for Developers (2026)](https://aifitnessapi.com/fitness-apis/exercise-database-apis.md): exercise database API - [The Best Wearable Fitness & Health-Data APIs (2026)](https://aifitnessapi.com/fitness-apis/wearable-data-apis.md): wearable fitness API - [The Best Health-Data Aggregator APIs (2026)](https://aifitnessapi.com/fitness-apis/health-data-aggregator-apis.md): health data aggregator API - [The Best AI Workout & Motion-Tracking APIs (2026)](https://aifitnessapi.com/fitness-apis/ai-workout-tracking-apis.md): AI workout tracking API - [The Best Nutrition & Food Database APIs (2026)](https://aifitnessapi.com/fitness-apis/nutrition-apis.md): nutrition API - [Free & Open-Source Fitness APIs (2026)](https://aifitnessapi.com/fitness-apis/free-fitness-apis.md): free fitness API - [Apple HealthKit vs Google Health Connect (2026)](https://aifitnessapi.com/fitness-apis/apple-healthkit-vs-google-health-connect.md): HealthKit vs Health Connect - [Terra vs Vital (Junction): Health-Data APIs Compared (2026)](https://aifitnessapi.com/fitness-apis/terra-vs-vital.md): Terra vs Vital - [Fitbit API vs Garmin API (2026)](https://aifitnessapi.com/fitness-apis/fitbit-api-vs-garmin-api.md): Fitbit API vs Garmin API - [Fitness API vs Building Your Own: How to Decide (2026)](https://aifitnessapi.com/fitness-apis/fitness-api-vs-build-your-own.md): build or buy fitness API ## Guides — https://aifitnessapi.com/guides - [Camera Pose Tracking for Fitness Apps: A Practical Guide](https://aifitnessapi.com/guides/camera-pose-tracking.md): camera pose tracking - [How to Add Rep Counting to Your Fitness App](https://aifitnessapi.com/guides/add-rep-counting.md): how to add rep counting - [How to Add Real-Time Form Feedback to a Workout App](https://aifitnessapi.com/guides/add-form-feedback.md): how to add form feedback - [How to Track Workouts Without a Wearable (Camera-Only)](https://aifitnessapi.com/guides/track-workouts-without-wearables.md): track workouts without a wearable - [How to Add AI Workout Tracking to an iOS App (Swift)](https://aifitnessapi.com/guides/ai-workout-tracking-ios-swift.md): AI workout tracking iOS Swift - [How to Add AI Workout Tracking to an Android App (Kotlin)](https://aifitnessapi.com/guides/ai-workout-tracking-android-kotlin.md): AI workout tracking Android Kotlin - [How to Add AI Workout Tracking to a React Native App](https://aifitnessapi.com/guides/ai-workout-tracking-react-native.md): AI workout tracking React Native - [How to Add AI Workout Tracking to a Flutter App](https://aifitnessapi.com/guides/ai-workout-tracking-flutter.md): AI workout tracking Flutter - [How to Add AI Workout Tracking to a Web App (JavaScript)](https://aifitnessapi.com/guides/ai-workout-tracking-web.md): AI workout tracking web - [How to Improve Pose-Detection Accuracy in Your App](https://aifitnessapi.com/guides/improve-pose-detection-accuracy.md): improve pose detection accuracy - [How to Evaluate AI Motion Tracking SDKs](https://aifitnessapi.com/guides/evaluate-motion-sdks.md): how to evaluate motion tracking sdk ## Build Guides — https://aifitnessapi.com/build - [How to Build a Home Workout App (2026)](https://aifitnessapi.com/build/home-workout-app.md): how to build a home workout app - [How to Build an AI Fitness Coaching App (2026)](https://aifitnessapi.com/build/ai-fitness-coaching-app.md): how to build an AI fitness coaching app - [How to Build a Strength Training App (2026)](https://aifitnessapi.com/build/strength-training-app.md): how to build a strength training app - [How to Build a Running App (2026)](https://aifitnessapi.com/build/running-app.md): how to build a running app - [How to Build a Yoga App (2026)](https://aifitnessapi.com/build/yoga-app.md): how to build a yoga app - [How to Build a Personal Training App (2026)](https://aifitnessapi.com/build/personal-training-app.md): how to build a personal training app - [How to Build a Physical Therapy / Rehab App (2026)](https://aifitnessapi.com/build/rehab-physical-therapy-app.md): how to build a physical therapy app - [How to Build a Corporate Wellness App (2026)](https://aifitnessapi.com/build/corporate-wellness-app.md): how to build a corporate wellness app - [How to Build a Nutrition Tracking App (2026)](https://aifitnessapi.com/build/nutrition-tracking-app.md): how to build a nutrition tracking app - [How to Choose a Tech Stack for a Fitness App (2026)](https://aifitnessapi.com/build/fitness-app-tech-stack.md): fitness app tech stack - [How to Build a Weight Loss App (2026)](https://aifitnessapi.com/build/weight-loss-app.md): how to build a weight loss app - [How to Build a Meal Planning App (2026)](https://aifitnessapi.com/build/meal-planning-app.md): how to build a meal planning app - [How to Build a Sleep Tracking App (2026)](https://aifitnessapi.com/build/sleep-tracking-app.md): how to build a sleep tracking app - [How to Build a Recovery App (2026)](https://aifitnessapi.com/build/recovery-app.md): how to build a recovery app - [How to Build a Meditation App (2026)](https://aifitnessapi.com/build/meditation-app.md): how to build a meditation app - [How to Build a Cycle Tracking App (2026)](https://aifitnessapi.com/build/cycle-tracking-app.md): how to build a cycle tracking app - [How to Build a Step Challenge App (2026)](https://aifitnessapi.com/build/step-challenge-app.md): how to build a step challenge app - [How to Build a Senior Fitness App (2026)](https://aifitnessapi.com/build/senior-fitness-app.md): how to build a senior fitness app - [How to Build a Cycling App (2026)](https://aifitnessapi.com/build/cycling-app.md): how to build a cycling app - [How to Build a Swimming App (2026)](https://aifitnessapi.com/build/swimming-app.md): how to build a swimming app - [How to Build a Hiking App (2026)](https://aifitnessapi.com/build/hiking-app.md): how to build a hiking app - [How to Build a HIIT App (2026)](https://aifitnessapi.com/build/hiit-app.md): how to build a hiit app - [How to Build a Triathlon App (2026)](https://aifitnessapi.com/build/triathlon-app.md): how to build a triathlon app - [How to Build a Kids Fitness App (2026)](https://aifitnessapi.com/build/kids-fitness-app.md): how to build a kids fitness app ## Integration Guides — https://aifitnessapi.com/integrate - [How to Integrate Apple HealthKit (2026)](https://aifitnessapi.com/integrate/healthkit.md): how to integrate Apple HealthKit - [How to Integrate Google Health Connect (2026)](https://aifitnessapi.com/integrate/google-health-connect.md): how to integrate Google Health Connect - [How to Integrate the Fitbit API (2026)](https://aifitnessapi.com/integrate/fitbit-api.md): how to integrate the Fitbit API - [How to Integrate the Strava API (2026)](https://aifitnessapi.com/integrate/strava-api.md): how to integrate the Strava API - [How to Integrate the Garmin API (2026)](https://aifitnessapi.com/integrate/garmin-api.md): how to integrate the Garmin API - [How to Integrate the Oura API (2026)](https://aifitnessapi.com/integrate/oura-api.md): how to integrate the Oura API - [How to Integrate the WHOOP API (2026)](https://aifitnessapi.com/integrate/whoop-api.md): how to integrate the WHOOP API - [How to Integrate Terra (Health-Data Aggregator) (2026)](https://aifitnessapi.com/integrate/terra-api.md): how to integrate Terra - [How to Integrate the Nutritionix API (2026)](https://aifitnessapi.com/integrate/nutritionix-api.md): how to integrate the Nutritionix API - [How to Integrate the ExerciseDB API (2026)](https://aifitnessapi.com/integrate/exercisedb-api.md): how to integrate ExerciseDB - [How to Integrate the Polar API (2026)](https://aifitnessapi.com/integrate/polar-api.md): how to integrate the Polar API ## Troubleshooting — https://aifitnessapi.com/fix - [Why Is My Fitness API Returning 401 Unauthorized?](https://aifitnessapi.com/fix/fitness-api-401-unauthorized.md): fitness api 401 unauthorized - [How to Fix the OAuth redirect_uri Mismatch Error](https://aifitnessapi.com/fix/oauth-redirect-uri-mismatch.md): oauth redirect_uri mismatch - [Why Is My Fitness API Refresh Token Not Working?](https://aifitnessapi.com/fix/refresh-token-not-working.md): fitness api refresh token not working - [How to Fix Fitbit API 429 (Rate Limit) Errors](https://aifitnessapi.com/fix/fitbit-api-429-rate-limit.md): fitbit api 429 rate limit - [Why Is HealthKit Returning No Data?](https://aifitnessapi.com/fix/healthkit-no-data.md): healthkit returns no data - [Why Is Google Health Connect Returning No Data?](https://aifitnessapi.com/fix/health-connect-no-data.md): health connect returns no data - [Why Is My Strava Webhook Not Firing?](https://aifitnessapi.com/fix/strava-webhook-not-firing.md): strava webhook not firing - [Why Is Wearable Data Missing or Delayed?](https://aifitnessapi.com/fix/wearable-data-delayed.md): wearable data missing or delayed - [Can't Get Garmin API Access? Here's What's Going On](https://aifitnessapi.com/fix/garmin-api-approval.md): garmin api access approval - [Google Fit API Is Deprecated — What to Use Instead](https://aifitnessapi.com/fix/google-fit-api-deprecated.md): google fit api deprecated - [Oura Personal Access Tokens Are Deprecated — Here's the Fix](https://aifitnessapi.com/fix/oura-personal-access-token-deprecated.md): oura personal access tokens deprecated - [Fitbit Error Code 401: What It Means and How to Fix It](https://aifitnessapi.com/fix/fitbit-error-code-401.md): fitbit error code 401 - [HealthKit Authorization Denied: What It Means and What It Hides](https://aifitnessapi.com/fix/healthkit-authorization-denied.md): healthkit authorization denied - [Strava API 401 Unauthorized: What It Means and How to Fix It](https://aifitnessapi.com/fix/strava-api-401-unauthorized.md): strava api 401 unauthorized - [HealthKit Background Delivery Not Working: Why Your Observer Never Fires](https://aifitnessapi.com/fix/healthkit-background-delivery-not-working.md): healthkit background delivery not working - [HealthKit errorDatabaseInaccessible: Reads Fail While the Device Is Locked](https://aifitnessapi.com/fix/healthkit-database-inaccessible.md): healthkit errordatabaseinaccessible - [HealthKit errorHealthDataUnavailable: The Device Does Not Support HealthKit](https://aifitnessapi.com/fix/healthkit-health-data-unavailable.md): healthkit errorhealthdataunavailable - [HealthKit errorHealthDataRestricted: An MDM Profile Turned HealthKit Off](https://aifitnessapi.com/fix/healthkit-data-restricted-mdm.md): healthkit errorhealthdatarestricted mdm - [HealthKit errorNoData: The Query Ran and Found Nothing](https://aifitnessapi.com/fix/healthkit-error-no-data.md): healthkit errornodata - [HealthKit errorInvalidArgument: Finding the Argument HealthKit Rejected](https://aifitnessapi.com/fix/healthkit-invalid-argument.md): healthkit errorinvalidargument - [HealthKit errorAuthorizationNotDetermined: You Called Before You Asked](https://aifitnessapi.com/fix/healthkit-authorization-not-determined.md): healthkit errorauthorizationnotdetermined - [HealthKit errorRequiredAuthorizationDenied: Clinical Records Are a Separate Class](https://aifitnessapi.com/fix/healthkit-required-authorization-denied.md): healthkit errorrequiredauthorizationdenied - [HealthKit Workout Session Errors: Four Cases, Two of Them Undocumented](https://aifitnessapi.com/fix/healthkit-workout-session-errors.md): healthkit workout session errors - [HealthKit errorNotPermissibleForGuestUserMode: Writes Blocked in a Guest Session](https://aifitnessapi.com/fix/healthkit-guest-user-mode.md): healthkit errornotpermissibleforguestusermode - [Undocumented HealthKit Errors: Handling a Case Apple Never Described](https://aifitnessapi.com/fix/healthkit-undocumented-errors.md): undocumented healthkit error codes ## Concepts — https://aifitnessapi.com/learn - [What Is a Fitness API?](https://aifitnessapi.com/learn/what-is-a-fitness-api.md): what is a fitness API - [What Is a Health-Data Aggregator?](https://aifitnessapi.com/learn/what-is-a-health-data-aggregator.md): what is a health data aggregator - [On-Device vs Cloud Health Data: What's the Difference?](https://aifitnessapi.com/learn/on-device-vs-cloud-health-data.md): on-device vs cloud health data - [What Is OAuth 2.0 (and How Health APIs Use It)?](https://aifitnessapi.com/learn/what-is-oauth-for-health-data.md): OAuth for health data - [What Are Webhooks (and Why Fitness APIs Use Them)?](https://aifitnessapi.com/learn/what-are-webhooks.md): what are webhooks - [What Is Pose Estimation (for Fitness Apps)?](https://aifitnessapi.com/learn/what-is-pose-estimation.md): what is pose estimation - [What Is HRV (Heart Rate Variability)?](https://aifitnessapi.com/learn/what-is-hrv.md): what is HRV - [What Is VO2 Max (and How Do Wearables Estimate It)?](https://aifitnessapi.com/learn/what-is-vo2-max.md): what is VO2 max - [What Are Sleep Stages (Awake, Light, Deep, REM)?](https://aifitnessapi.com/learn/what-are-sleep-stages.md): what are sleep stages - [How Do Fitness Apps Estimate Calories Burned?](https://aifitnessapi.com/learn/how-fitness-apps-estimate-calories.md): how fitness apps estimate calories - [Webhooks vs. Polling for Fitness Data: How to Decide](https://aifitnessapi.com/learn/webhooks-vs-polling-for-fitness-data.md): webhooks vs polling for fitness data - [What Are OAuth Scopes (and How Health APIs Grant Them)?](https://aifitnessapi.com/learn/what-are-oauth-scopes.md): what are oauth scopes - [What Is RPE (Rating of Perceived Exertion)?](https://aifitnessapi.com/learn/what-is-rpe.md): what is RPE ## Alternatives — https://aifitnessapi.com/alternatives - [The Best Fitbit API Alternatives (2026)](https://aifitnessapi.com/alternatives/fitbit-api-alternatives.md): Fitbit API alternatives - [Google Fit API Alternatives (It's Deprecated) (2026)](https://aifitnessapi.com/alternatives/google-fit-api-alternatives.md): Google Fit API alternatives - [Garmin API Alternatives When You Can't Get Access (2026)](https://aifitnessapi.com/alternatives/garmin-api-alternatives.md): Garmin API alternatives - [The Best Strava API Alternatives (2026)](https://aifitnessapi.com/alternatives/strava-api-alternatives.md): Strava API alternatives - [The Best Oura API Alternatives (2026)](https://aifitnessapi.com/alternatives/oura-api-alternatives.md): Oura API alternatives - [The Best WHOOP API Alternatives (2026)](https://aifitnessapi.com/alternatives/whoop-api-alternatives.md): WHOOP API alternatives - [Apple HealthKit Alternatives (2026)](https://aifitnessapi.com/alternatives/healthkit-alternatives.md): HealthKit alternatives - [The Best Terra (tryterra.co) Alternatives (2026)](https://aifitnessapi.com/alternatives/terra-alternatives.md): Terra alternatives - [The Best Nutritionix Alternatives (2026)](https://aifitnessapi.com/alternatives/nutritionix-alternatives.md): Nutritionix alternatives - [The Best ExerciseDB Alternatives (2026)](https://aifitnessapi.com/alternatives/exercisedb-alternatives.md): ExerciseDB alternatives - [KinesteX Alternatives, From the Team Behind KinesteX (2026)](https://aifitnessapi.com/alternatives/kinestex-alternatives.md): kinestex alternatives ## Compliance — https://aifitnessapi.com/compliance - [Does My Fitness App Need to Be HIPAA Compliant?](https://aifitnessapi.com/compliance/hipaa-compliance-fitness-app.md): does my fitness app need to be hipaa compliant - [GDPR for Fitness Apps: What Developers Need to Know](https://aifitnessapi.com/compliance/gdpr-fitness-app.md): gdpr for fitness apps - [Is Fitness Data PHI? PII, PHI, and Health Data Untangled](https://aifitnessapi.com/compliance/is-fitness-data-phi.md): is fitness data phi - [Does the FDA Regulate Fitness Apps?](https://aifitnessapi.com/compliance/fda-fitness-app-regulation.md): does the fda regulate fitness apps - [Apple App Store Health Data Rules: What You Need to Ship a HealthKit App](https://aifitnessapi.com/compliance/app-store-health-data-rules.md): apple app store health data rules - [What does Google Play's health data policy require?](https://aifitnessapi.com/compliance/google-play-health-data-policy.md): google play health data policy - [How to Store Health Data Securely](https://aifitnessapi.com/compliance/store-health-data-securely.md): how to store health data securely - [How to Get Valid User Consent for Health Data](https://aifitnessapi.com/compliance/health-data-user-consent.md): user consent for health data - [What Does a Fitness App Privacy Policy Need to Include?](https://aifitnessapi.com/compliance/health-app-privacy-policy.md): fitness app privacy policy - [Health Data Retention and Deletion: A Developer's Guide](https://aifitnessapi.com/compliance/health-data-retention-deletion.md): health data retention and deletion ## Migrations — https://aifitnessapi.com/migrate - [How to migrate from Google Fit to Health Connect](https://aifitnessapi.com/migrate/google-fit-to-health-connect.md): migrate google fit to health connect - [Migrating from the Fitbit Web API to the Google Health API](https://aifitnessapi.com/migrate/fitbit-web-api-to-google-health.md): fitbit web api google migration - [Adding Android to a HealthKit app](https://aifitnessapi.com/migrate/add-android-to-healthkit-app.md): add android support healthkit app - [Consolidate wearables: replace direct integrations with one aggregator](https://aifitnessapi.com/migrate/consolidate-wearables-with-aggregator.md): replace direct integrations with aggregator - [Migrate from an aggregator to direct provider integrations](https://aifitnessapi.com/migrate/aggregator-to-direct-integration.md): move from aggregator to direct api - [How to switch from one health data aggregator to another](https://aifitnessapi.com/migrate/between-health-data-aggregators.md): switch health data aggregator - [Migrate from polling to webhooks for a fitness API](https://aifitnessapi.com/migrate/polling-to-webhooks.md): migrate polling to webhooks fitness api - [Adapting Your Integration to Strava's API Changes](https://aifitnessapi.com/migrate/adapt-to-strava-api-changes.md): strava api changes 2024 migration - [Keep Users Connected During a Fitness API Migration](https://aifitnessapi.com/migrate/keep-users-connected-during-migration.md): migrate fitness api without losing users - [Migrate off a deprecated fitness API](https://aifitnessapi.com/migrate/migrate-off-a-deprecated-fitness-api.md): migrate off deprecated fitness api ## Pricing — https://aifitnessapi.com/pricing - [Fitbit API Pricing: What Does It Actually Cost?](https://aifitnessapi.com/pricing/fitbit-api-pricing.md): fitbit api pricing - [Garmin API Pricing: What Does It Actually Cost?](https://aifitnessapi.com/pricing/garmin-api-pricing.md): garmin api pricing - [Strava API Pricing: What Does It Actually Cost?](https://aifitnessapi.com/pricing/strava-api-pricing.md): strava api pricing - [Oura API pricing: what it actually costs](https://aifitnessapi.com/pricing/oura-api-pricing.md): oura api pricing - [WHOOP API Pricing: What Does It Actually Cost?](https://aifitnessapi.com/pricing/whoop-api-pricing.md): whoop api pricing - [Health data aggregator API pricing: how Terra, Junction, Rook, and Spike charge](https://aifitnessapi.com/pricing/health-data-aggregator-pricing.md): health data aggregator api pricing - [What does a nutrition API cost?](https://aifitnessapi.com/pricing/nutrition-api-pricing.md): nutrition api pricing - [Exercise Database API Pricing: What Does It Cost?](https://aifitnessapi.com/pricing/exercise-database-api-pricing.md): exercise database api pricing - [Are Fitness APIs Free? An Honest Overview](https://aifitnessapi.com/pricing/are-fitness-apis-free.md): are fitness apis free - [How Much Does a Fitness API Cost?](https://aifitnessapi.com/pricing/how-much-does-a-fitness-api-cost.md): how much does a fitness api cost - [Fitness API Free Tiers Compared: What Free Actually Includes](https://aifitnessapi.com/pricing/fitness-api-free-tiers-compared.md): fitness api free tier comparison ## Comparisons — https://aifitnessapi.com/compare - [Oura vs WHOOP: Which API for Your App?](https://aifitnessapi.com/compare/oura-vs-whoop.md): oura vs whoop api - [Fitbit vs Apple Watch: Which for Your App?](https://aifitnessapi.com/compare/fitbit-vs-apple-watch.md): fitbit vs apple watch api - [Strava vs Garmin: Which API for Your App?](https://aifitnessapi.com/compare/strava-vs-garmin-connect.md): strava vs garmin api - [Fitbit vs Oura API: Which for Your App?](https://aifitnessapi.com/compare/fitbit-vs-oura.md): fitbit vs oura api - [WHOOP vs Garmin: Which for Your App?](https://aifitnessapi.com/compare/whoop-vs-garmin.md): whoop vs garmin api - [Terra vs ROOK: Which Aggregator API for Your App?](https://aifitnessapi.com/compare/terra-vs-rook.md): terra vs rook - [Terra vs Spike Health: Which Aggregator for Your App?](https://aifitnessapi.com/compare/terra-vs-spike.md): terra vs spike health - [Nutritionix vs Edamam: Which Nutrition API to Use?](https://aifitnessapi.com/compare/nutritionix-vs-edamam.md): nutritionix vs edamam - [Edamam vs Spoonacular: Which Nutrition API?](https://aifitnessapi.com/compare/edamam-vs-spoonacular.md): edamam vs spoonacular - [ExerciseDB vs wger: Which Exercise API for Your App?](https://aifitnessapi.com/compare/exercisedb-vs-wger.md): exercisedb vs wger - [KinesteX vs Sency: Which Motion Tracking SDK?](https://aifitnessapi.com/compare/kinestex-vs-sency.md): kinestex vs sency - [KinesteX vs QuickPose: Decide by How Much You Want to Build](https://aifitnessapi.com/compare/kinestex-vs-quickpose.md): kinestex vs quickpose - [KinesteX vs MediaPipe: Which Layer Do You Want to Own?](https://aifitnessapi.com/compare/kinestex-vs-mediapipe.md): kinestex vs mediapipe - [Apple Watch vs WHOOP: Which for Your App?](https://aifitnessapi.com/compare/apple-watch-vs-whoop.md): apple watch vs whoop api - [Apple Watch vs Garmin: Which Should You Build On?](https://aifitnessapi.com/compare/apple-watch-vs-garmin.md): apple watch vs garmin api - [Rook vs Spike: Which Health-Data API Fits Your Build?](https://aifitnessapi.com/compare/rook-vs-spike.md): rook vs spike health data api - [USDA FoodData Central vs Open Food Facts: Which Free Food Data?](https://aifitnessapi.com/compare/usda-fooddata-central-vs-open-food-facts.md): usda fooddata central vs open food facts ## Health Data — https://aifitnessapi.com/data - [Heart Rate API: How to Get Heart-Rate Data Into Your App](https://aifitnessapi.com/data/heart-rate-api.md): heart rate api - [HRV API: How to Get Heart Rate Variability Data](https://aifitnessapi.com/data/hrv-api.md): hrv api - [VO2 Max API: How to Get VO2 Max Data](https://aifitnessapi.com/data/vo2-max-api.md): vo2 max api - [Blood Oxygen (SpO2) API: How to Get SpO2 Data](https://aifitnessapi.com/data/blood-oxygen-api.md): blood oxygen spo2 api - [Sleep Tracking API: How to Get Sleep Data Into Your App](https://aifitnessapi.com/data/sleep-tracking-api.md): sleep tracking api - [Step Counting API: How to Get Step Data](https://aifitnessapi.com/data/step-counting-api.md): step counting api - [Workout Detection API: Get Recorded Workout Sessions](https://aifitnessapi.com/data/workout-detection-api.md): workout detection api - [GPS Activity API: How to Get Route Data from Workouts](https://aifitnessapi.com/data/gps-activity-api.md): gps activity route api - [Calorie Tracking API: How to Get Calorie Data](https://aifitnessapi.com/data/calorie-tracking-api.md): calorie tracking api - [Body Composition API: Weight, Body Fat, and Lean Mass Data](https://aifitnessapi.com/data/body-composition-api.md): body composition api - [Menstrual Cycle API: How to Get Cycle Tracking Data](https://aifitnessapi.com/data/menstrual-cycle-api.md): menstrual cycle api - [Blood Glucose API: How to Get Glucose Data Into Your App](https://aifitnessapi.com/data/blood-glucose-api.md): blood glucose api - [Blood Pressure API: How to Read BP Data In Your App](https://aifitnessapi.com/data/blood-pressure-api.md): blood pressure api - [Respiratory Rate API: How to Get Breathing-Rate Data](https://aifitnessapi.com/data/respiratory-rate-api.md): respiratory rate api ## AI Motion — https://aifitnessapi.com/motion - [Pose Estimation Models Compared: MediaPipe, MoveNet, YOLO and More](https://aifitnessapi.com/motion/pose-estimation-models-compared.md): pose estimation models compared - [2D vs 3D Pose Estimation for Fitness Apps](https://aifitnessapi.com/motion/2d-vs-3d-pose-estimation.md): 2d vs 3d pose estimation - [Pose Estimation Accuracy: What It Means and What Drives It](https://aifitnessapi.com/motion/pose-estimation-accuracy.md): pose estimation accuracy - [Multi-Person Pose Tracking: Top-Down vs Bottom-Up](https://aifitnessapi.com/motion/multi-person-pose-tracking.md): multi person pose tracking - [On-Device vs Cloud Pose Estimation: Which to Choose](https://aifitnessapi.com/motion/on-device-vs-cloud-pose-estimation.md): on device vs cloud pose estimation - [Real-Time Pose Estimation: Frame Rate, Latency, and Model Trade-offs](https://aifitnessapi.com/motion/real-time-pose-estimation.md): real time pose estimation - [Pose Estimation Hardware Requirements: What You Actually Need](https://aifitnessapi.com/motion/pose-estimation-hardware-requirements.md): pose estimation hardware requirements - [How Rep Counting Works: The Algorithm Explained](https://aifitnessapi.com/motion/how-rep-counting-works.md): how does rep counting work - [How Camera-Based Form Feedback Works](https://aifitnessapi.com/motion/how-form-feedback-works.md): how does form feedback work - [Build vs Buy: AI Motion Tracking](https://aifitnessapi.com/motion/build-vs-buy-ai-motion-tracking.md): build vs buy motion tracking - [MediaPipe vs MoveNet: Decide by What You Compute Downstream](https://aifitnessapi.com/motion/mediapipe-vs-movenet.md): movenet vs mediapipe - [MediaPipe Pose Landmarker Models: Lite vs Full vs Heavy](https://aifitnessapi.com/motion/mediapipe-pose-landmarker-models.md): pose landmarker lite vs full vs heavy - [Apple Vision Framework Body Pose: The Native iOS Option](https://aifitnessapi.com/motion/apple-vision-body-pose.md): apple vision framework body pose ## AI Features — https://aifitnessapi.com/ai - [AI Workout Plan Generation: How to Build One That Ships](https://aifitnessapi.com/ai/ai-workout-plan-generation.md): ai workout plan generator - [AI Food Logging: Text and Photo Nutrition Entry That Actually Works](https://aifitnessapi.com/ai/ai-nutrition-logging.md): ai food logging api - [Personalizing Your App With a User's Own Wearable Data](https://aifitnessapi.com/ai/personalize-with-wearable-data.md): personalize app with wearable data ai - [Grounding an LLM in Your Exercise Database](https://aifitnessapi.com/ai/ground-llm-in-exercise-database.md): rag exercise database llm - [Writing the System Prompt for an AI Fitness Coach](https://aifitnessapi.com/ai/ai-fitness-coach-prompts.md): ai fitness coach system prompt - [AI vs Rules-Based Coaching: Where a Language Model Actually Helps](https://aifitnessapi.com/ai/ai-vs-rules-based-coaching.md): ai vs rule based fitness app - [How to Evaluate an AI Fitness Feature](https://aifitnessapi.com/ai/evaluating-ai-fitness-features.md): how to evaluate ai fitness feature - [Guardrails for an LLM That Gives Fitness Advice](https://aifitnessapi.com/ai/llm-safety-fitness-advice.md): llm safety fitness advice guardrails - [Choosing an LLM for a Fitness App: Pick by Job, Not by Leaderboard](https://aifitnessapi.com/ai/choosing-an-llm-for-fitness-apps.md): which llm for fitness app - [What Does an AI Fitness Feature Cost to Run?](https://aifitnessapi.com/ai/ai-fitness-app-cost.md): how much does an ai fitness feature cost - [Structured Output for Workout Plans: Constraining What the Model Returns](https://aifitnessapi.com/ai/structured-output-for-workout-plans.md): llm structured output json schema workout plan ## Architecture — https://aifitnessapi.com/architecture - [Incremental Sync: Reading Only What Changed Since Last Time](https://aifitnessapi.com/architecture/incremental-sync.md): how to sync only new health data since last sync - [Backfilling Years of Wearable Data Without Hitting Rate Limits](https://aifitnessapi.com/architecture/historical-backfill.md): backfill years of wearable data rate limit - [Background Sync That Does Not Depend on the Phone Waking Up](https://aifitnessapi.com/architecture/background-sync.md): healthkit background delivery not firing - [Webhook ingestion for health data: making at-least-once delivery safe](https://aifitnessapi.com/architecture/webhook-ingestion.md): health api webhook idempotency duplicate events - [Mapping Users to Wearable Provider Accounts and Devices](https://aifitnessapi.com/architecture/identity-and-account-linking.md): map users to wearable provider accounts multiple devices - [Deduplicating Health Data From Multiple Sources](https://aifitnessapi.com/architecture/deduplicate-health-data.md): healthkit duplicate steps multiple sources - [Normalizing wearable data across providers](https://aifitnessapi.com/architecture/normalize-wearable-data.md): normalize wearable data across providers - [Timezones and Day Boundaries: Whose Midnight Defines the Day?](https://aifitnessapi.com/architecture/timezones-and-day-boundaries.md): fitness app daily totals timezone local midnight - [Missing Data and Gaps in Health Metrics](https://aifitnessapi.com/architecture/missing-data-and-gaps.md): missing days step data fill gaps health app - [How Should You Store Health Time-Series Data?](https://aifitnessapi.com/architecture/time-series-storage.md): database schema for storing heart rate time series app - [Resolving Sync Conflicts in an Offline-First Workout Log](https://aifitnessapi.com/architecture/offline-first-conflict-resolution.md): offline first workout logging sync conflict - [Versioning Derived Metrics and Recomputing Health History](https://aifitnessapi.com/architecture/metric-versioning-and-recompute.md): recalculate derived metrics after algorithm change backfill - [Monitoring a Health Data Pipeline for Silent Failures](https://aifitnessapi.com/architecture/data-quality-monitoring.md): monitor health data pipeline anomaly detection - [Deleting and Exporting a User's Health Data](https://aifitnessapi.com/architecture/data-deletion-and-export.md): implement delete user health data across backend - [Caching Fitness API Responses Without Serving Stale Health Data](https://aifitnessapi.com/architecture/caching-fitness-api-responses.md): cache fitness api responses health data ## Testing — https://aifitnessapi.com/test - [How to Test a HealthKit Integration](https://aifitnessapi.com/test/healthkit-integration.md): how to test healthkit integration - [Test Data for Health Connect: Fakes, the Toolbox, and the Generators You Write](https://aifitnessapi.com/test/health-connect-test-data.md): health connect test data - [Mock Wearable Data That Is Ugly Enough to Find Bugs](https://aifitnessapi.com/test/mock-wearable-data.md): mock wearable data for testing - [Testing Background Sync: Three Tests, and Only One Is Real](https://aifitnessapi.com/test/background-sync.md): test healthkit background delivery - [Testing an OAuth Integration: The Token Lifecycle, Not the Login Screen](https://aifitnessapi.com/test/oauth-flows.md): how to test oauth integration third party api - [Provider Sandboxes: Build the Fake, Keep One Real Account](https://aifitnessapi.com/test/provider-sandboxes.md): fitbit api sandbox - [Testing Webhooks Locally: Replay Signed Payloads, Not Just the Handshake](https://aifitnessapi.com/test/webhooks-locally.md): test strava webhook locally - [Testing 429 Rate-Limit and Outage Handling in a Health Backfill](https://aifitnessapi.com/test/rate-limits-and-outages.md): test api rate limit handling 429 - [Testing Camera Features When You Have No Camera](https://aifitnessapi.com/test/camera-features-without-a-device.md): test camera app ios simulator - [Testing Pose Estimation Accuracy with a Regression Corpus](https://aifitnessapi.com/test/pose-detection-accuracy.md): how to test pose estimation accuracy - [How to Test a Rep Counting Algorithm](https://aifitnessapi.com/test/rep-counting.md): test rep counting algorithm - [CI for an App That Needs a Real Device](https://aifitnessapi.com/test/device-lab-and-ci.md): ci for app that needs real device - [Testing Offline Sync and Conflict Resolution](https://aifitnessapi.com/test/offline-sync.md): test offline sync conflict mobile app - [Testing That a User's Health Data Is Actually Deleted](https://aifitnessapi.com/test/data-deletion.md): how to verify user data deleted ## Cookbook — https://aifitnessapi.com/cookbook - [Recipe: Single-Flight Refresh-Token Rotation](https://aifitnessapi.com/cookbook/refresh-rotation.md): oauth refresh token rotation code example - [Recipe: A Replay-Safe Health Webhook Receiver](https://aifitnessapi.com/cookbook/webhook-receiver.md): idempotent webhook receiver code example - [Recipe: A Rate-Limit-Aware Fetch Wrapper](https://aifitnessapi.com/cookbook/rate-limit-fetcher.md): retry after 429 exponential backoff fetch wrapper - [Day-Boundary Rollup: Grouping Samples by Civil Date](https://aifitnessapi.com/cookbook/day-boundary-rollup.md): group health samples by local day code example - [Rep Counter: A State Machine and the Scorer That Guards It](https://aifitnessapi.com/cookbook/rep-counter.md): rep counting state machine code example javascript - [Backfill Checkpointer: A Resumable Window Walker](https://aifitnessapi.com/cookbook/backfill-checkpointer.md): resumable backfill checkpoint 429 retry code example ## Connected Devices — https://aifitnessapi.com/devices - [Connect a Bluetooth Heart Rate Monitor to Your App (2026)](https://aifitnessapi.com/devices/bluetooth-heart-rate-monitor.md): connect a bluetooth heart rate monitor to an app - [Reading Cycling Power, Cadence, and Speed Sensors in an App](https://aifitnessapi.com/devices/cycling-sensors-power-cadence.md): read cycling power meter cadence sensor app - [What Is FTMS? The Bluetooth Fitness Machine Service (2026)](https://aifitnessapi.com/devices/ftms-fitness-machine-service.md): what is FTMS fitness machine service - [Treadmill App Integration: Reading FTMS Treadmill Data](https://aifitnessapi.com/devices/treadmill-app-integration.md): connect treadmill data to fitness app - [Smart Bike Trainer Integration: FTMS and Cycling Power](https://aifitnessapi.com/devices/indoor-bike-trainer-integration.md): integrate smart bike trainer app - [Getting Rowing Machine Data Into an App (2026)](https://aifitnessapi.com/devices/rowing-machine-data.md): get rowing machine data into app - [Live Heart Rate From Apple Watch in Your App (2026)](https://aifitnessapi.com/devices/apple-watch-live-heart-rate.md): get live heart rate from apple watch in app - [Wear OS Health Services for Live Workout Data (2026)](https://aifitnessapi.com/devices/wear-os-health-services.md): wear os health services live workout data - [ANT+ vs Bluetooth for Fitness Sensors (2026)](https://aifitnessapi.com/devices/ant-plus-vs-bluetooth.md): ant+ vs bluetooth fitness sensors - [Web Bluetooth for Fitness Apps in the Browser (2026)](https://aifitnessapi.com/devices/web-bluetooth-fitness.md): web bluetooth fitness app browser - [Core Bluetooth for Fitness Devices on iOS (2026)](https://aifitnessapi.com/devices/ios-ble-fitness-devices.md): ios core bluetooth fitness devices - [Testing Bluetooth Fitness Device Integrations (2026)](https://aifitnessapi.com/devices/testing-ble-fitness-devices.md): test bluetooth fitness device integration ## Engagement & Retention — https://aifitnessapi.com/engagement - [Push Notifications for a Fitness App: Permissions and Payload](https://aifitnessapi.com/engagement/push-notifications-fitness-app.md): push notifications for fitness app - [Live Activities for Workout Tracking on iOS](https://aifitnessapi.com/engagement/live-activities-workout-tracking.md): live activity workout tracking ios - [Fitness App Widgets and Watch Complications](https://aifitnessapi.com/engagement/widgets-and-complications.md): fitness app widget complication - [Wear OS Ongoing Activity for Workout Tracking](https://aifitnessapi.com/engagement/wear-os-ongoing-activity.md): wear os ongoing activity workout - [Engagement SDKs for Fitness Apps: The Categories, Honestly](https://aifitnessapi.com/engagement/engagement-sdks-compared.md): best engagement sdk for fitness app - [Streaks and Habit Loops in a Fitness App](https://aifitnessapi.com/engagement/streaks-and-habit-loops.md): how to build streaks in fitness app - [Leaderboards and Challenges in a Fitness App](https://aifitnessapi.com/engagement/leaderboards-and-challenges.md): fitness app leaderboard implementation - [Adding Social Features to a Fitness App](https://aifitnessapi.com/engagement/social-features-fitness-app.md): add social features to fitness app - [Gamification in Fitness Apps: Which Mechanics Fit Exercise](https://aifitnessapi.com/engagement/gamification-in-fitness-apps.md): gamification in fitness apps - [Does Camera Coaching Improve Retention?](https://aifitnessapi.com/engagement/camera-coaching-engagement.md): does camera coaching improve retention - [How to Measure Retention in a Fitness App](https://aifitnessapi.com/engagement/measuring-retention-fitness-app.md): how to measure retention fitness app - [A/B Testing an Engagement Feature](https://aifitnessapi.com/engagement/ab-testing-engagement-features.md): a/b test engagement feature app - [Fitness App Engagement Metrics That Matter](https://aifitnessapi.com/engagement/engagement-metrics-that-matter.md): fitness app engagement metrics - [Notification Fatigue and Opt-Out in Fitness Apps](https://aifitnessapi.com/engagement/notification-fatigue-and-optout.md): notification opt out rate fitness app ## Watch Apps — https://aifitnessapi.com/watch-apps - [Anatomy of a watchOS Workout App](https://aifitnessapi.com/watch-apps/watchos-workout-app-anatomy.md): build apple watch workout app - [HealthKit on Apple Watch: What Changes on the Wrist](https://aifitnessapi.com/watch-apps/healthkit-on-apple-watch.md): healthkit on apple watch - [Background Execution on Apple Watch: Two Mechanisms](https://aifitnessapi.com/watch-apps/apple-watch-background-execution.md): apple watch background execution workout - [WorkoutKit: Scheduling Workouts Into Apple's Workout App](https://aifitnessapi.com/watch-apps/workoutkit-scheduled-workouts.md): workoutkit scheduled workouts apple watch - [Mirroring an Apple Watch Workout to iPhone](https://aifitnessapi.com/watch-apps/mirroring-workouts-to-iphone.md): mirror apple watch workout to iphone - [Wear OS Fitness App Anatomy: Standalone or Not (2026)](https://aifitnessapi.com/watch-apps/wear-os-app-anatomy.md): wear os fitness app standalone - [Wear OS Exercise Tracking with Health Services (2026)](https://aifitnessapi.com/watch-apps/wear-os-exercise-tracking.md): wear os health services exercise tracking - [Wear OS Tiles for a Fitness App (2026)](https://aifitnessapi.com/watch-apps/wear-os-tiles.md): wear os tile fitness app - [Wear OS Phone Sync: The Data Layer and Its Limits (2026)](https://aifitnessapi.com/watch-apps/wear-os-phone-sync.md): wear os data layer sync phone - [watchOS vs Wear OS: Building the App That Runs on the Watch](https://aifitnessapi.com/watch-apps/watch-platform-differences.md): watchos vs wear os development fitness - [Watch App Battery: The Constraint That Decides Scope](https://aifitnessapi.com/watch-apps/watch-app-battery.md): watch app battery drain fitness - [Testing Watch Apps Without a Watch on Every Desk](https://aifitnessapi.com/watch-apps/testing-watch-apps.md): test watch app without device ## Accessibility — https://aifitnessapi.com/accessibility - [VoiceOver and the numbers that change during a set](https://aifitnessapi.com/accessibility/voiceover-live-workout-metrics.md): voiceover live workout metrics - [TalkBack and the Android workout screen](https://aifitnessapi.com/accessibility/talkback-workout-screens.md): talkback workout screen android - [What to call an exercise, a set and a rep range](https://aifitnessapi.com/accessibility/labelling-exercises-and-sets.md): accessible labels for exercises and sets - [Making a health chart readable without the chart](https://aifitnessapi.com/accessibility/accessible-health-charts.md): accessible health charts - [Dynamic Type on a workout screen: what breaks at 200 percent](https://aifitnessapi.com/accessibility/dynamic-type-workout-screens.md): dynamic type workout screen - [Touch targets when the hand is shaking](https://aifitnessapi.com/accessibility/touch-targets-during-a-workout.md): touch target size fitness app - [Colour contrast when the screen is in sunlight](https://aifitnessapi.com/accessibility/colour-contrast-outdoors.md): color contrast for outdoor fitness apps - [Reduce Motion in a coaching interface](https://aifitnessapi.com/accessibility/reduced-motion-coaching-ui.md): reduce motion fitness app - [Gestures and hands-free control during a workout](https://aifitnessapi.com/accessibility/gestures-and-hands-free-control.md): hands free controls fitness app - [Haptics when the audio channel is already busy](https://aifitnessapi.com/accessibility/haptics-when-audio-is-busy.md): haptic feedback fitness app - [Captions, subtitles and audio descriptions for workout video](https://aifitnessapi.com/accessibility/captions-for-workout-video.md): captions for workout videos - [Testing accessibility in a fitness app](https://aifitnessapi.com/accessibility/testing-accessibility-fitness-app.md): test accessibility fitness app