Apple HealthKit Explained: What It Is and How Steply Uses It
Apple HealthKit is one of the most important but least understood features of the iPhone. It sits behind the scenes, quietly acting as a central repository for all your health and fitness data. Understanding how it works — and how Steply interacts with it — helps you make better decisions about your data and your health.
What HealthKit Actually Is
HealthKit is not an app — it's a secure, on-device database built into iOS. Apple designed it as a neutral hub where different apps and devices can share health data without any single company having access to everything. Your step data from Steply, your heart rate from Apple Watch, your sleep data from a third-party app, and your nutrition logs from a food tracker all live in HealthKit in a standardized format. Each app only accesses the specific data types you explicitly permit.
Central Repository
One source of truth
All health data from apps and devices flows into HealthKit. The Health app is the front-end that displays it.
Permission-Based
You control access
Each app must request specific data types. You approve or deny each request individually in iOS Settings.
On-Device Only
Never transmitted by Apple
HealthKit data never leaves your device unless you explicitly share it or enable iCloud Health backups.
What Steply Reads and Writes to HealthKit
Steply's HealthKit integration is carefully scoped. On first setup, you'll be asked to grant permissions for specific data types. Steply can read step count data from HealthKit (allowing it to incorporate steps counted by Apple Watch when your phone isn't present) and write step data back to HealthKit when Steply has detected steps that aren't yet recorded. This two-way sync ensures your Apple Health app always has a complete picture of your daily activity.
Steply's HealthKit Permissions
- ✓Read: Step Count — to incorporate Watch steps and other sources into Steply's count
- ✓Write: Step Count — to record Steply-detected steps into HealthKit
- ✓Read: Distance Walking/Running — for distance calculations in analytics
- ✓All permissions can be revoked at any time in Settings → Privacy → Health → Steply
Controlling Your HealthKit Data
You have complete control over which apps access your HealthKit data. Navigate to Settings → Health → Data Access & Devices to see a full list of every app with HealthKit access, along with exactly which data types they can read or write. You can revoke individual permissions or all permissions for any app at any time without losing the data already stored in HealthKit.
HealthKit Privacy Tips
- •Regularly audit which apps have Health access in Settings → Health → Data Access
- •Remove access for apps you no longer use — their data permissions remain active until revoked
- •Enable iCloud Health backup if you want your health data to restore on a new iPhone
- •You can export all your HealthKit data as an XML file: Health app → Profile → Export All Health Data
- •Steply stores its own data locally independent of HealthKit — revoking HealthKit access does not delete your Steply history
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