HeartRateVariabilityRmssdRecord: Health Connect heart rate variability data

What Google says HeartRateVariabilityRmssdRecord is

Captures user's heart rate variability (HRV) as measured by the root mean square of successive differences (RMSSD) between normal heartbeats.

Quoted from Google’s HeartRateVariabilityRmssdRecord Jetpack reference, last updated 2026-06-24, read 2026-10-03.

Class

androidx.health.connect.client.records.HeartRateVariabilityRmssdRecord

Google's category

Vitals

Record type

Instantaneous

Unit class

none named in Google's table

Mandatory fields

heartRateVariabilityMillismetadatatime

Added in (Jetpack)

1.1.0

Permissions

The exact strings Google’s data-types table declares for HeartRateVariabilityRmssdRecord. Google’s page: “Before requesting any permissions, your app must declare them in the manifest.”

<uses-permission android:name="android.permission.health.READ_HEART_RATE_VARIABILITY" />
<uses-permission android:name="android.permission.health.WRITE_HEART_RATE_VARIABILITY" />

import androidx.health.connect.client.permission.HealthPermission
import androidx.health.connect.client.records.HeartRateVariabilityRmssdRecord

val permissions = setOf(
    HealthPermission.getReadPermission(HeartRateVariabilityRmssdRecord::class),
    HealthPermission.getWritePermission(HeartRateVariabilityRmssdRecord::class),
)

The 4 fields of HeartRateVariabilityRmssdRecord

Types and descriptions as Google’s reference prints them. The range column quotes Google’s own range annotation or sentence; a dash means Google states none, which is not the same as no validation.

Read HeartRateVariabilityRmssdRecord in Kotlin

The shape of Google’s own read example, with HeartRateVariabilityRmssdRecord and its names filled in. Get the client with HealthConnectClient.getOrCreate(context) after checking getSdkStatus.

import androidx.health.connect.client.HealthConnectClient
import androidx.health.connect.client.records.HeartRateVariabilityRmssdRecord
import androidx.health.connect.client.request.ReadRecordsRequest
import androidx.health.connect.client.time.TimeRangeFilter
import java.time.Instant

suspend fun readHeartRateVariabilityRmssd(
    client: HealthConnectClient,
    startTime: Instant,
    endTime: Instant,
): List<HeartRateVariabilityRmssdRecord> {
    val response = client.readRecords(
        ReadRecordsRequest(
            HeartRateVariabilityRmssdRecord::class,
            timeRangeFilter = TimeRangeFilter.between(startTime, endTime),
        )
    )
    // One page of up to pageSize records (default 1000); follow
    // response.pageToken for the rest.
    return response.records
}

Setting up the client, the permission flow and Play Console declaration: integrating Health Connect step by step.

HealthKit counterpart

The metric on other platforms

This guide lists HeartRateVariabilityRmssdRecord beside the types on the other platforms this site covers whose own descriptions name the same metric, each quoted, with how each one is read.

• HRV API: How to Get Heart Rate Variability Data

Questions

What permission does HeartRateVariabilityRmssdRecord need?

Google's Health Connect data-types table (read 2026-10-03) declares android.permission.health.READ_HEART_RATE_VARIABILITY for reading HeartRateVariabilityRmssdRecord and android.permission.health.WRITE_HEART_RATE_VARIABILITY for writing it, and says apps must declare permissions in the manifest before requesting them.

Can you aggregate HeartRateVariabilityRmssdRecord with AggregateRequest?

Not directly. As read on 2026-10-03, Google's Jetpack reference defines no AggregateMetric constants on HeartRateVariabilityRmssdRecord, so there is no metric to put in an AggregateRequest. Read the records with readRecords and a ReadRecordsRequest, and compute any summary yourself.

What values does HeartRateVariabilityRmssdRecord.heartRateVariabilityMillis accept?

Google's reference types heartRateVariabilityMillis as Double. Its description reads: "Heart rate variability in milliseconds. Required field. Valid Range: 1-200."

What is the HealthKit equivalent of HeartRateVariabilityRmssdRecord?

This site's verified cross-platform matrix pairs HeartRateVariabilityRmssdRecord with HKQuantityTypeIdentifier.heartRateVariabilitySDNN in its HRV row. The caveat recorded with that pairing: The big one: the HRV Apple Watch records into HealthKit is SDNN, while Health Connect's record is RMSSD. They are different measures and are not interconvertible — do not normalize one into the other. iOS 27 added HKQuantityTypeIdentifier.heartRateVariabilityRMSSD, but as of October 2, 2026 Apple's documentation gives it no description, so it is not paired with Health Connect's record here: what it holds, how it is computed and whether Apple Watch writes it are not stated.