Glossary · Definition
HRV (Heart rate variability)
HRV (Heart Rate Variability) is the variation in milliseconds between consecutive heartbeats. Higher = better adapted, more parasympathetic tone, generally fitter.
Definition
HRV (Heart Rate Variability) is the variation in milliseconds between consecutive heartbeats. Higher = better adapted, more parasympathetic tone, generally fitter.
What it means
Measured in milliseconds, typically as rMSSD (root mean square of successive differences). Genetics + age set baseline; lifestyle moves it 10-20%. Typical adult ranges: 20s = 60-90 ms, 30s = 50-80, 40s = 40-70, 50+ = 30-60. Athletes typically run 20-30% above peers. Compare to YOUR baseline, not absolute numbers.
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Why it matters
HRV is a useful proxy for recovery + readiness — it drops with overtraining, illness, alcohol, poor sleep, and chronic stress. Used to time hard workouts vs recovery days. The biggest single intervention that raises HRV is consistently good sleep; the biggest single drop is alcohol within 3 hours of bed.
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Frequently asked questions
Best wearable for HRV?
Oura Ring 4 (most accurate consumer HRV at the wrist/finger). Whoop is close. Apple Watch Series 9+ shows HRV trends but less granular.
How do I raise it?
Sleep quality, Zone 2 cardio, strength training, hydration, lower alcohol. Avoid late meals + alcohol within 3h of bed.