Vital ms (RMSSD or SDNN)
HRV
Heart rate variability as a stress and recovery marker
Also known as
heart rate variability HRV score RMSSD SDNN
Definition
HRV measures the variation in time intervals between heartbeats as an indicator of autonomic nervous system function. High HRV signals good adaptability; low HRV indicates physiological stress or overtraining. HRV is captured via wearables (Apple Watch, Garmin, Oura, WHOOP) and is considered a central daily biohacking metric for recovery and training load management.
| Parameter | Value |
|---|---|
| Unit | ms (RMSSD or SDNN) |
| Reference Range | Highly age- and individual-dependent; typical RMSSD baseline: 20–80 ms |
| Optimal Range (lab2go) | Personal baseline +10% as daily readiness indicator |
Last Reviewed: 17 April 2026 · maritta