Pair with your wearable
HRV Breathe for every wearable.
We don't measure HRV. We train it. Pair with whichever device you already use — Apple Watch directly, or any HealthKit-compatible HRV source via its iOS app.
Other supported wearables
RMSSD · Ring PPG, whole-night integration
Oura Ring
Oura measures overnight RMSSD on your finger. HRV Breathe trains it during the day. Pairing flow via Apple Health.
Read
RMSSD · Strap PPG, final sleep cycle
Whoop
Whoop reads RMSSD from the last sleep cycle of the night. We read the day-by-day breath-trained reflection of that same vagal tone.
Read
RMSSD · Wrist PPG, overnight + on-demand
Garmin
Garmin's Body Battery, HRV Status, and stress score all derive from one underlying RMSSD reading. We’re the protocol that moves it.
Read
RMSSD · Wrist PPG, overnight
Fitbit
Fitbit's Sense and Charge devices report nightly HRV. We pair via Apple Health on iOS for the daily breath-training side.
Read
Both · Chest ECG, real-time
Polar H10
The chest-strap ECG that researchers use. Gold-standard HRV accuracy when you want to calibrate or troubleshoot a wrist reading.
Read
Don’t see your device? If it writes HRV to Apple Health on iOS, HRV Breathe reads it the same way — no integration needed. Tell us which device and we’ll add a guide.