Is 40 ms HRV Good? What HRV Values From 20 to 100 ms Mean

Is 40 ms HRV good? For most adults, yes. In large wearable studies, 40 ms is close to the median for people in their mid-thirties to early forties, below the median in your twenties and above it from your mid-forties. Whether it is good for you depends on how it compares with your own usual range, measured the same way.

Find your number below for where it sits by age, what it might mean and what to do.

How to read the values on this page

The ages below come from the reference studies in our HRV by age chart. The main yardstick is the Fitbit study of 8 million people, which reports median RMSSD between 6am and 7am, plus the middle half of users (the 25th to 75th percentile). We also mention 5-minute lying-down tests from the KORA study by Voss and colleagues and 24-hour recordings from Umetani and colleagues.

These figures are RMSSD. If your app shows SDNN, the numbers run higher and the sections below do not apply. To judge any value, measure the same way every time, give it about two weeks to see your normal range, and read a rolling average of several days alongside your resting heart rate and how you feel.

Is high or low HRV good?

In general, higher resting HRV reflects stronger parasympathetic (rest and recover) activity, and lower HRV reflects more strain. Across populations, low HRV is linked with risk: a meta-analysis of 21,988 people without known heart disease found that low HRV was associated with a 32% to 45% higher risk of a first cardiovascular event. That research used clinical recordings, mostly SDNN, and describes groups, not individuals.

Higher is not always better. A review of HRV metrics and norms by Shaffer and Ginsberg describes an optimal level of HRV, and notes that some heart rhythm problems can push HRV readings up rather than down.

Is 20 ms HRV good?

Where it sits: in the Fitbit morning data, 20 ms is below the middle half at every age up to the mid-fifties. At 60 it sits right at the bottom edge of the middle half (21 ms for women, 20 ms for men). In 5-minute lying-down tests, it is close to the average for people aged 55 to 74 (19.1 to 21.4 ms), and in 24-hour recordings the average from the 50s onwards was 21 to 25 ms.

What it might mean: in your late fifties or older, 20 ms can be entirely ordinary. In your twenties or thirties it is unusual as a baseline, but a single low night after alcohol, a hard session, broken sleep or a cold is common.

What to do: if 20 ms is your normal and you feel well, nothing needs to change. If it is a sharp fall from your usual range, ease off hard training, protect your sleep and watch the next few nights. Low numbers also occur in healthy people: in Umetani's study, 12% of healthy people over 65 fell below 15 ms on 24-hour recordings.

Is 30 ms HRV good?

Where it sits: 30 ms is close to the median at 50 to 55 in the Fitbit data (31 ms at 50, 29 ms at 55). It sits inside the middle half from about 35 for women and 40 for men, through to 60. At 30 it is just below the middle half, and in your twenties it is below it. In 5-minute tests it is above the average for everyone aged 45 and over.

What it might mean: from your forties onwards, a typical reading. For a younger adult it is on the low side as a baseline, though within the range of healthy people.

What to do: if 30 ms is your settled baseline, use it as your reference point and watch for changes against it. If you normally sit at 45 ms and see 30 ms for several days, look at what changed: sleep, alcohol, training load, stress or a coming illness. Regular aerobic exercise, consistent sleep and less alcohol are the foundations covered in our guide to what a good HRV is.

Is 40 ms HRV good?

Where it sits: 40 ms is close to the median at 35 to 40 in the Fitbit data (41 to 43 ms at 35, 37 to 38 ms at 40). It falls inside the middle half from age 25 to 50 for both women and men, and for women at 20. It is above the middle half from about 55 for men and from 60 for women, and below it for men at 20. In 5-minute tests, it matches the average for women aged 25 to 34 (42.9 ms), and a systematic review by Nunan and colleagues put the pooled short-term average for healthy adults at 42 ms.

What about 39 ms? The same reading for practical purposes: a 1 ms gap is far smaller than the normal night-to-night swing.

What it might mean: for most adults, an average to good reading, and above the typical range in your late fifties or sixties.

What to do: nothing, if it matches your normal. If you usually sit at 55 to 65 ms and wake to 40 ms, treat it as a sign of strain and consider an easier day.

Is 50 ms HRV good?

Where it sits: 50 ms is close to the median at 25 to 30 in the Fitbit data (45 to 54 ms). It sits inside the middle half from 20 to 40 and above it from about 45 onwards.

What it might mean: in your twenties or thirties, a typical healthy reading. From your mid-forties, it puts you in the top quarter of people your age on this measure, which often goes with good aerobic fitness.

What to do: keep judging it against your own baseline. A fall from 50 ms to 38 ms may still look average on a chart, but for you it is a meaningful change.

Is 60 ms HRV good?

Where it sits: 60 ms is near the median at age 20 (56 ms for women, 66 ms for men). It stays inside the middle half up to about 35, and from 40 onwards it is in the top quarter.

What it might mean: young adults often sit here, and in the Fitbit data more daily activity went with higher HRV. In your fifties or older it is high for your age, which is usually fine if it has been steady for weeks.

What to do: if it is your stable baseline, use it as your reference. In very fit people, HRV does not always rise with fitness: a review of elite endurance athletes by Plews and colleagues found HRV can even dip as fitness improves, and recommends averaging across days rather than reacting to one reading.

Is 80 ms HRV good?

Where it sits: in the Fitbit data, 80 ms is inside the middle half only at age 20 (up to 85 ms for women and 96 ms for men). From 25 onwards it is in the top quarter. On 24-hour recordings it falls inside Umetani's 95% limits at 20 (21 to 87 ms) but above them at 30 (18 to 74 ms).

What it might mean: often normal in young, fit people. In your forties or older it is unusual, though it can still be genuine.

What to do: look at the trend. A stable 80 ms over weeks is your normal. A jump from 45 ms to 80 ms overnight can reflect poor signal, movement or irregular beats rather than a sudden gain in fitness. Shaffer and Ginsberg note that just two artefacts in a 5-minute segment can distort RMSSD.

Is 100 ms HRV or more good?

Where it sits: above the middle half at every age in the Fitbit data, where the highest upper edge is 96 ms (men at 20). It is also above Umetani's 24-hour RMSSD limits for healthy people at every age from 20.

What it might mean: some young endurance athletes do read this high. But first check which metric your app shows. Over 24 hours, SDNN is a different scale altogether: Shaffer and Ginsberg cite 24-hour SDNN above 100 ms as the healthy range. For RMSSD, readings this high are uncommon, and the same review notes that heart rhythm problems such as atrial fibrillation can raise HRV figures.

What to do: if 100 ms or more is your long-standing baseline and you feel well, it is likely your normal. If it has appeared suddenly or jumps around from night to night, and especially if you notice a fluttering, pounding or irregular heartbeat, speak to a doctor.

When is low HRV or a sudden change worth discussing with a doctor?

A wearable HRV number cannot diagnose a heart condition, and one low reading is not a reason to worry. It is worth talking to your GP or doctor if:

• Your HRV stays well below your usual range for more than a week or two with no obvious cause, especially with a raised resting heart rate or feeling run down.
• Your readings become erratic or suddenly very high, and you notice an irregular or racing heartbeat.
• You take medicines that affect heart rate. Reference studies such as KORA excluded people on these medicines, so the charts may not apply to you.

Symptoms matter more than numbers. The NHS advice on heart palpitations (UK guidance) says to see a GP if palpitations keep coming back, last longer than a few minutes, or you have a heart condition or a family history of heart problems. Call 999, or your local emergency number, if palpitations come with chest pain, shortness of breath or fainting.

Frequently asked questions

Is 40 ms HRV good?

For most adults, yes. In data from millions of wearable users, 40 ms RMSSD is close to the median at 35 to 40, inside the typical range from 25 to 50, and above the typical range from your mid-fifties. The more useful question is whether 40 ms is normal for you, measured the same way each time.

What does low HRV mean?

A low HRV reading usually means your body is under more strain than usual, from short sleep, alcohol, hard training, stress or illness. HRV also falls naturally with age, so a low number for a 25 year old can be typical for a 60 year old. A sustained drop below your own baseline matters more than the number itself.

Is 30 HRV good?

From your forties onwards, 30 ms RMSSD is a typical reading and close to the median at 50 to 55 in large wearable data. For people in their twenties it is on the low side as a baseline, though still within the range seen in healthy adults. Compare it with your own usual range before drawing conclusions.

Can HRV be too high?

Researchers describe an optimal level of HRV rather than a maximum. Very high readings can be genuine in young, fit people, but a sudden jump can also come from poor signal or irregular beats. If very high or erratic readings come with palpitations or an irregular heartbeat, speak to a doctor.

This article is for general information and is not medical advice. PulseRing Pro is a wellness device, not a medical device, and does not diagnose or treat any condition. If you are worried about your health, speak to your GP or a qualified clinician.