What is a good HRV? The published numbers by age, and why they only go so far
People want a target. The research gives ranges that fall steadily with age and vary enormously between individuals. Here are the numbers and how to use them.
"Is my HRV good?" is the most common question people ask about their wearable. The honest answer has two parts. There are population values, and they are useful for context. But HRV differs so much between healthy people, and between devices, that your own baseline is a far better reference than anyone else's number.
Values by age and sex
One of the clearest age breakdowns comes from the KORA S4 cohort in Germany. Voss and colleagues analysed five-minute resting ECG recordings from 1,906 healthy adults (782 women, 1,124 men) aged 25 to 74.
| Age | RMSSD women, ms | RMSSD men, ms | SDNN women, ms | SDNN men, ms |
|---|---|---|---|---|
| 25 to 34 | 42.9 (22.8) | 39.7 (19.9) | 48.7 (19.0) | 50.0 (20.9) |
| 35 to 44 | 35.4 (18.5) | 32.0 (16.5) | 45.4 (20.5) | 44.6 (16.8) |
| 45 to 54 | 26.3 (13.6) | 23.0 (10.9) | 36.9 (13.8) | 36.8 (14.6) |
| 55 to 64 | 21.4 (11.9) | 19.9 (11.1) | 30.6 (12.4) | 32.8 (14.7) |
| 65 to 74 | 19.1 (11.8) | 19.1 (10.7) | 27.8 (11.8) | 29.6 (13.2) |
Three things stand out. RMSSD roughly halves between the late twenties and the late fifties. The standard deviations are large: at 25 to 34, a woman one standard deviation below the mean has an RMSSD of about 20 ms and one a standard deviation above has about 66 ms, and both are healthy. And differences between men and women narrow with age and had disappeared in the oldest two decades.
The wider picture
| Study | Year, journal | Who and how many | Design | Main result |
|---|---|---|---|---|
| Nunan et al. | 2010, Pacing and Clinical Electrophysiology | 44 studies, 21,438 healthy adults | Systematic review of short-term (about 5 minute) ECG HRV | Pooled RMSSD 42 ms (SD 15), SDNN 50 ms (SD 16); very large differences between individuals |
| Voss et al. | 2015, PLoS One | 1,906 healthy adults aged 25 to 74 | Cross-sectional, 5-minute resting ECG | RMSSD fell from about 40 to 43 ms at 25 to 34 to about 19 ms at 65 to 74 |
| Natarajan et al. | 2020, Lancet Digital Health | 8,203,261 Fitbit users | Cross-sectional, wrist PPG over one 24-hour period | HRV fell with age; high-frequency power fell about 80 percent from 20 to 60; RMSSD did not differ significantly by sex; more activity linked to higher HRV |
The Fitbit analysis is the largest HRV dataset published. It found a strong daily rhythm in HRV, which is why the time of measurement matters, and it published benchmark tables by age and sex at two times of day. Its authors suggested these distributions could act as a framework for interpreting individual readings. It was funded by Fitbit, used one randomly chosen day per user and is cross-sectional.
Why your device shows a different number
None of the tables above will match your app exactly, for three reasons.
- Timing. The reference values are mostly short daytime recordings. Wearables usually average across the night, when vagal activity is higher. Overnight values tend to sit above daytime ones.
- Method. Oura reports the average of five-minute samples taken through the night. WHOOP reports RMSSD during sleep. Garmin's HRV status uses a seven-day average of overnight readings. Apple Health stores SDNN, a different metric altogether.
- Sensor. Optical sensors estimate beat timing. In a 2022 laboratory study against ECG, the mean overnight RMSSD bias ranged from about minus 4.5 ms to minus 22 ms depending on the device and how it sampled. See wearable accuracy.
Oura's own help pages say typical values range from under 20 to over 200 milliseconds and advise comparing your HRV only with your own history. Garmin's manual says HRV varies with sex, age and fitness and judges your status against your own baseline range.
So what is "good"?
A workable answer:
- Good is stable or rising against your own baseline when training, sleep and health are steady.
- A value in the middle of the age range for your sex is unremarkable. A value low for your age is not a diagnosis, but it is a reason to look at sleep, alcohol, fitness and weight, and to mention it at your next check-up if it persists.
- A sudden drop of a large amount over several nights usually has a cause you can name: a hard week, travel, a cold, drinking, a new medicine. See reading wearable trends.
- An unusually high, erratic HRV with palpitations can be a rhythm problem rather than fitness. That is one for a clinician.
What raises HRV over time
The changes with the most consistent evidence are the ordinary ones. Regular aerobic exercise is associated with higher HRV at every age in the Fitbit data. Diet and exercise weight loss tends to shift autonomic balance towards the parasympathetic side, according to a 2019 meta-analysis, although the authors rated the evidence low quality. Less alcohol helps on the nights you skip it. Enough sleep matters too: the sleep guide has the trial data. There is no good evidence that chasing a higher HRV number in itself improves health; it is a gauge, not a target.
Comparing yourself fairly
If you want to compare with the tables, use the same type of measurement. A five-minute seated or lying reading first thing in the morning with an ECG chest strap and an app that reports RMSSD is the closest match to the Nunan and Voss methods. Comparing an overnight ring average with a daytime ECG table will mislead you in one direction or the other.
Logging it
Peptide AI brings in overnight HRV from Oura, WHOOP, Garmin, Apple Health and Health Connect through wearable integrations and builds your own baseline from it. The trend sits next to the dose log and the training log, which is where a change in HRV usually finds its explanation.
Questions people ask
What is a normal HRV for my age?
In 1,906 healthy German adults, mean five-minute resting RMSSD was about 40 to 43 ms at ages 25 to 34, 32 to 35 ms at 35 to 44, 23 to 26 ms at 45 to 54, 20 to 21 ms at 55 to 64 and 19 ms at 65 to 74. Standard deviations were large, so a wide range is normal.
Do women have higher HRV than men?
In the KORA S4 data, women had slightly higher mean RMSSD in younger age groups, and the difference disappeared in the oldest two decades. In 8.2 million Fitbit users, RMSSD did not differ significantly by sex.
Why is my ring HRV higher than the published norms?
Most published norms are five-minute daytime ECG recordings. Rings and straps average across the night, when vagal activity is higher, and each company uses its own method.
What is a bad HRV?
There is no single cut-off. A value persistently low for your age and sex, or a sustained drop from your own baseline, is worth investigating. One low night usually reflects sleep, alcohol, training or illness.
Can I raise my HRV?
Regular aerobic activity, weight loss through diet and exercise, enough sleep and less alcohol are all associated with higher HRV, though most of the evidence is observational or low quality.
Sources
- Short-term heart rate variability: influence of gender and age in healthy subjects (Voss et al.), PLoS One, 2015
- A quantitative systematic review of normal values for short-term heart rate variability in healthy adults (Nunan et al.), Pacing and Clinical Electrophysiology, 2010
- An overview of heart rate variability metrics and norms (Shaffer and Ginsberg), Frontiers in Public Health, 2017
- Heart rate variability with photoplethysmography in 8 million individuals: a cross-sectional study (Natarajan et al.), Lancet Digital Health, 2020
- A validation of six wearable devices for estimating sleep, heart rate and heart rate variability in healthy adults (Miller et al.), Sensors, 2022
- Effects of weight changes in the autonomic nervous system: a systematic review and meta-analysis (Costa et al.), Clinical Nutrition, 2019
- Heart Rate Variability, Oura Help Center
- Forerunner 970 Owner's Manual: Heart Rate Variability Status, Garmin
- heartRateVariabilitySDNN, Apple Developer Documentation, HealthKit
