HRV (RMSSD)
Variation in time between heartbeats measured in milliseconds; indicates autonomic nervous system balance
Why HRV (RMSSD) matters
Higher HRV indicates better cardiovascular fitness and stress resilience. Lower HRV associated with higher mortality risk. Key marker of recovery and overall health.
Reference Range
Short-term (5-min) RMSSD in healthy adults: mean 42 ms, study range 19-75 ms
Sourced reference
Compare to your own baseline on the same device
Targets by source
Each position below is attributed and linked to the document that states it. Several are population percentiles or averages rather than targets; the note says which. How we verify ranges.
- Healthy-adult mean 42 ms (SD 15); study range 19-75 msNunan 2010 systematic review, Pacing Clin Electrophysiol (44 studies, 21,438 adults); values as tabulated in Shaffer & Ginsberg 2017, Table 6Short-term 5-minute resting ECG values, not a target. Wearables compute RMSSD overnight with their own algorithms, so absolute numbers are device-dependent: compare each reading to your own 7-day baseline on the same device.
Experts discussing HRV (RMSSD)
- Heart Rate Variability and Recovery OptimizationDisclosure: Huberman Lab has been sponsored by Function Health, which appears in our blood-test comparisons.
- Dr. Andy Galpin: Maximize Recovery To Achieve Fitness & Performance GoalsDisclosure: Huberman Lab has been sponsored by Function Health, which appears in our blood-test comparisons.
Devices that measure this
Devices in our comparisons whose published specs list this metric:
Track Your Heart Rate Variability
Monitor HRV (RMSSD) with wearables and health tracking devices
Health Disclaimer
This information is for educational purposes only. Consult a healthcare provider for personalized health recommendations.
Last reviewed Sep 23, 2026 · First published Oct 1, 2025