Stream HRV4Training data. No HRV4Training API needed.
HRV4Training writes heart rate variability and resting heart rate to Apple Health and Health Connect — and Sahha’s SDK reads them into your app as normalized biomarkers and readiness scores, alongside every other source.
- On-device
- Apple Health + Health Connect
- HIPAA
- GDPR
- SOC 2
Free for 30 days · No credit card
- HRV (SDNN)
- 64 ms
- Resting heart rate
- 52 bpm
Identical schema across 500+ sources
Your users connect HRV4Training. Sahha does the rest.
This is your user’s side of the story — one screen, once. Sahha ingests every HRV4Training signal, normalizes, deduplicates, and delivers it to your service — raw, or as refined intelligence your product can act on.
A Allow "your app"
On-device and permissioned
HRV4Training data is read on the user’s own device, only after they grant Apple Health or Health Connect permission — nothing syncs without consent.
One integration, every source
Permission is per data type, not per brand. Anything that writes to Apple Health or Health Connect — HRV4Training today, a new watch next year — flows through the same SDK with no extra prompt and no new code.
What HRV4Training syncs through Apple Health & Health Connect.
Request only what you need
You choose exactly which of these signals to request from Apple Health / Health Connect — users are only ever prompted for those, which keeps opt-in rates high.
One schema, every source
HRV4Training, Apple Watch, and Oura all return the same fields and units.
What crosses the bridge
Heart rate variability and resting heart rate pass through the platform; some device-exclusive metrics may not.
Heart & HRV
2
HealthKit / Health ConnectSahha- heartRateVariabilitySDNNheart_rate_variability_sdnnms
- restingHeartRateresting_heart_ratebpm
See a real payload
{
"type": "HKQuantityTypeIdentifierHeartRateVariabilitySDNN",
"value": 64,
"unit": "ms",
"startDate": "2026-06-03T06:41:00Z",
"sourceRevision": { "source": { "name": "HRV4Training" } }
}[
{
"category": "vitals",
"type": "heart_rate_variability_sdnn",
"value": 64,
"unit": "millisecond",
"periodicity": "daily",
"aggregation": "avg",
"startDateTime": "2026-06-03T06:41:00Z",
"endDateTime": "2026-06-03T06:42:00Z"
}
// …resting heart rate log
]HRV4Training measures HRV from your phone camera each morning and writes SDNN and resting heart rate to Apple Health and Health Connect. Apple Health exposes HRV as SDNN, which Sahha reads as heart_rate_variability_sdnn.
Missing a metric you need? Talk to us in the Sahha Slack — if HRV4Training captures it, we can usually add support.
Get more than just raw data
Sahha turns these signals into biomarkers, scores, archetypes, and insights — the modeling done for you.
Reading Apple Health and Health Connect yourself? Here’s the to-do list.
Everything on the left is yours to write, test, and maintain across two platforms. Everything on the right, Sahha already did.
- Integrate Apple Health.
- Then Health Connect, separately.
- Then reconcile the two.
One SDK covers Apple Health, Health Connect, and every cloud source.
- Write the HealthKit queries.
- Write the Health Connect queries.
- Wire up background delivery.
The SDK handles queries, permissions, and background sync.
- Dedupe apps writing the same metric.
- Map dozens of platform types.
- Normalize iOS against Android.
Deduped, typed, one schema — one stream per user.
- Build a sleep model.
- Build an activity model.
- Hire a data scientist.
Scores, archetypes, and insights — built in.
- Apple or Google changes an API.
- You find out in production.
We version the SDK. You never notice.
No HRV4Training developer account needed — Sahha reads what HRV4Training already writes to Apple Health and Health Connect.
Live in an afternoon, not a sprint.
- # Add the Sahha SDKnpm install sahha-react-native01
Add the Sahha SDK
Drop the Sahha SDK into your iOS or Android app — or React Native or Flutter. One dependency covers both Apple Health and Health Connect.
- A
Allow “your app”
ConnectSleepActivityHeart rate02Prompt for health permissions
Call the SDK to show the native Apple Health or Health Connect consent sheet. The user chooses what to share — under your brand. It’s one prompt, ever: permission is per data type, not per brand, so every future source is already covered.
- Your app LIVESleep7h 12mReadiness82Heart rate62 bpm03
Sahha reads and delivers
Once permission is granted, the SDK reads HRV4Training data from Apple Health / Health Connect in the background, normalizes it to one schema, and streams it to your app by webhook or API.
Most teams read live HRV4Training data the same day they add the SDK. The only per-source prerequisite: your user has HRV4Training’s Apple Health / Health Connect sync switched on — most source apps enable it by default.
Route it into your stack.
Sahha streams every update to your webhook — and a step-by-step guide takes it the rest of the way into your database, CDP, or messaging tool.
HRV4Training integration questions
How does Sahha get HRV4Training data?
HRV4Training writes HRV and resting heart rate to Apple Health and Health Connect, and Sahha reads them from there with its mobile SDK — no HRV4Training API to integrate.
Is HRV reported as SDNN or RMSSD?
Apple Health stores HRV as SDNN, so Sahha receives HRV4Training’s HRV as heart_rate_variability_sdnn. Cloud sources like Oura and WHOOP report RMSSD instead — Sahha keeps them under distinct field ids so the numbers are never compared apples-to-oranges.
Do I need a mobile app to use the HRV4Training integration?
Yes. Because HRV4Training data lands in Apple Health / Health Connect on the user’s device, you embed the Sahha mobile SDK to read it. Cloud-only sources like Oura don’t need the SDK, but on-device sources like HRV4Training do.
Does it work on both iOS and Android?
Yes. The same Sahha SDK reads Apple Health on iOS and Health Connect on Android, and normalizes both to one schema.
Is the HRV4Training integration HIPAA and GDPR compliant?
Yes. Sahha is HIPAA and GDPR compliant and SOC 2 certified, and HRV4Training data flows through the same compliant pipeline as every other source.
One API for every other source, too.
Add another wearable or app and the schema, webhooks, and scores are identical — no new pipeline to build.
Start streaming HRV4Training data today.
Connect once. Sahha handles consent, normalization, and real-time delivery — for HRV4Training and every other source.
Free for 30 days · No credit card
- One API for HRV4Training and every other source
- Real-time webhooks + on-demand REST, one normalized schema
- Scores, archetypes & insights — no modeling required
- HIPAA, GDPR & SOC 2 · your brand on the consent screen