Heart Rate Variability
Also known as: HRV, Heart Rate Variation
The variation in time between consecutive heartbeats, a key indicator of autonomic nervous system function and overall health.
FULL EXPLANATION
Heart Rate Variability (HRV) measures the variation in the time intervals between heartbeats, known as R-R intervals. Unlike heart rate, which tells you how fast your heart is beating, HRV reveals how well your autonomic nervous system is regulating your heart.
Higher HRV generally indicates greater parasympathetic (rest-and-digest) activity and better cardiovascular fitness. Lower HRV may suggest stress, fatigue, or poor recovery. HRV is measured in milliseconds and commonly reported as RMSSD (root mean square of successive differences) or SDNN (standard deviation of NN intervals).
WHY IT MATTERS
HRV is one of the most reliable non-invasive indicators of autonomic nervous system balance. It correlates with stress resilience, recovery status, cardiovascular disease risk, and all-cause mortality.
HOW TO IMPROVE
Improve HRV through consistent sleep schedules, regular aerobic exercise, stress management techniques like meditation, limiting alcohol, and maintaining good hydration.
NORMAL RANGES
Normal HRV varies significantly by age and fitness level. Young adults typically have RMSSD values of 30-80ms, while athletes may exceed 100ms. Values tend to decrease with age.
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