Type Property

heartRateVariabilitySDNN

A quantity sample type that measures the standard deviation of heartbeat intervals.

Declaration

static let heartRateVariabilitySDNN: HKQuantityTypeIdentifier

Discussion

These samples use time units (described in HKUnit) and measure discrete values (described in HKStatisticsQuery).

Heart rate variability (HRV) is calculated by measuring the variation between individual heartbeats. While there are multiple ways of computing HRV, HealthKit uses SDNN heart rate variability, which is calculated using the standard deviation of the inter-beat (RR) intervals between normal heartbeats (typically measured in milliseconds).

See Also

Vital Signs

static let heartRate: HKQuantityTypeIdentifier

A quantity sample type that measures the user’s heart rate.

static let restingHeartRate: HKQuantityTypeIdentifier

A quantity sample type that measures the user’s resting heart rate.

static let walkingHeartRateAverage: HKQuantityTypeIdentifier

A quantity sample type that measures the user’s heart rate while walking.

static let oxygenSaturation: HKQuantityTypeIdentifier

A quantity sample type that measures the user’s oxygen saturation.

static let bodyTemperature: HKQuantityTypeIdentifier

A quantity sample type that measures the user’s body temperature.

static let bloodPressureDiastolic: HKQuantityTypeIdentifier

A quantity sample type that measures the user’s diastolic blood pressure.

static let bloodPressureSystolic: HKQuantityTypeIdentifier

A quantity sample type that measures the user’s systolic blood pressure.

static let respiratoryRate: HKQuantityTypeIdentifier

A quantity sample type that measures the user’s respiratory rate.

static let vo2Max: HKQuantityTypeIdentifier

A quantity sample that measures the maximal oxygen consumption during incremental exercise.