Heart Rate Variability (HRV) Chart by Age
Heart rate variability (HRV) is a measure of the variation in time between consecutive heartbeats, reflecting autonomic nervous system function. HRV naturally declines with age as parasympathetic tone decreases. This chart presents normal RMSSD and SDNN ranges by age group based on large-scale population studies.
Reference Data
| Age Range | RMSSD Normal Range (ms) | SDNN Normal Range (ms) |
|---|---|---|
| 20–25 | 25–105(25–105) | 40–120(40–120) |
| 25–30 | 22–95(22–95) | 38–115(38–115) |
| 30–35 | 19–85(19–85) | 35–110(35–110) |
| 35–40 | 17–78(17–78) | 32–105(32–105) |
| 40–45 | 15–70(15–70) | 30–100(30–100) |
| 45–50 | 13–62(13–62) | 28–95(28–95) |
| 50–55 | 11–55(11–55) | 25–90(25–90) |
| 55–60 | 10–48(10–48) | 22–85(22–85) |
| 60–65 | 9–42(9–42) | 20–80(20–80) |
| 65–70 | 8–38(8–38) | 18–75(18–75) |
| 70–75 | 7–34(7–34) | 16–70(16–70) |
| 75+ | 5–30(5–30) | 14–65(14–65) |
Source: Nunan et al., 2010, Scandinavian Journal of Medicine & Science in Sports; Framingham Heart Study normative data; ESC/NASPE Task Force on HRV, 1996, Circulation.
How to Interpret This Data
HRV is one of the most accessible biomarkers of autonomic nervous system health. RMSSD (Root Mean Square of Successive Differences) primarily reflects parasympathetic (vagal) tone and is the most commonly used short-term HRV metric. SDNN (Standard Deviation of NN intervals) captures overall autonomic variability including both sympathetic and parasympathetic contributions and is the gold standard for 24-hour recordings.
The decline in HRV with age is a well-documented physiological phenomenon. Between ages 20 and 70, average RMSSD decreases by approximately 50–60%, reflecting progressive reduction in vagal modulation of heart rate. This decline accelerates after age 55 in most individuals. However, individual variation is substantial — physically active older adults may maintain HRV values comparable to sedentary younger individuals.
These ranges represent approximately the 10th–90th percentile for healthy individuals without cardiovascular disease. Values below the lower range may indicate autonomic dysfunction and warrant medical evaluation, particularly in younger individuals. Factors including fitness level, medications (especially beta-blockers), chronic stress, sleep quality, and alcohol consumption significantly influence HRV. Always interpret HRV in the context of the individual's health status and trends over time rather than relying on a single measurement.
Frequently Asked Questions
What is a good HRV for my age?
A 'good' HRV is one that falls in the upper half of the normal range for your age group. For example, a 35-year-old with an RMSSD above 45 ms would be considered above average. However, your personal trend over time is more meaningful than any single reading. Consistently improving HRV with lifestyle changes (exercise, sleep optimization, stress management) is more important than hitting a specific number.
Why does HRV decrease with age?
HRV decreases with age primarily due to reduced parasympathetic (vagal) nervous system activity, structural changes in the sinoatrial node, increased arterial stiffness, and decreased baroreflex sensitivity. These are normal physiological changes, but the rate of decline is modifiable through regular exercise, stress management, adequate sleep, and cardiovascular risk factor control.
Should I be worried if my HRV is below the normal range?
A single low HRV reading is not cause for alarm, as HRV fluctuates with stress, sleep, hydration, and daily activity. However, consistently low HRV relative to your age group may indicate autonomic dysfunction, cardiovascular risk, or chronic stress. Consult a healthcare provider if your HRV is persistently below the 10th percentile for your age, especially if accompanied by symptoms like fatigue, dizziness, or exercise intolerance.