HRV measures timing, not speed
Even when your heart rate appears steady, the time between beats naturally varies. Wearables often use pulse signals to estimate these beat-to-beat timing differences and summarize them with a metric such as RMSSD.
A single HRV number has limited meaning
HRV varies between individuals and can change with sleep, training, stress, illness, alcohol, travel, measurement timing, and more. Comparing your reading to an internet “normal” is usually less useful than observing a consistent personal baseline.
Use HRV as one piece of context
A shift in HRV does not identify its cause or diagnose a condition. Consider it beside how you feel, sleep, training, and resting heart rate. Consult a qualified clinician for symptoms or health concerns.
A note on health information
This article is for general education, not medical advice. GRND is not a medical device. For symptoms, diagnosis, treatment, or urgent concerns, contact a qualified healthcare professional or local emergency service.