Workout Session
A single workout / exercise session pulled from the device's health store (HealthKit HKWorkout on iOS, ExerciseSessionRecord on Android Health Connect).
Aggregate counterpart to HealthData (which is per-day steps + distance + calories): a workout is a discrete bounded activity with a start/end and a typed activityType.
Properties
Normalized activity identifier — e.g. "running", "cycling", "yoga", "walking", "hiit". Lowercased and underscore-joined; falls back to "other" when the platform type has no mapping.
Precomputed duration in minutes; may differ slightly from endTime - startTime when the source recorded paused intervals.
Workout end as Unix epoch seconds.
Workout end as an ISO-8601 UTC string.
Human-friendly source label (e.g. "Apple Watch", "Strava"), or null when unavailable.
Workout start as Unix epoch seconds — convenient for building a Swift Date(timeIntervalSince1970:) directly.
Workout start as an ISO-8601 UTC string (e.g. "2026-05-17T07:30:00Z"). Parse with kotlinx.datetime.Instant.parse(...) when you need a typed value.
Distance covered in meters, when available (running, walking, cycling, etc.); null for stationary activities or when not recorded.
Active energy burned in kilocalories, or null when the source did not record it.