What is a good HRV on Apple Watch?

Is 20, 30, 40 or 100 ms a good HRV?

At 35, an Apple Watch SDNN of 20 ms or less is below typical, 30–60 ms is typical and 70 ms or more is above typical — the typical range for 35–44, women and men combined, is about 26–64 ms.

Each cell compares one value with the resting ECG range for that age group (Voss et al. 2015). It follows the age and sex set in the checker above.

Above typical isn’t automatically better, and below typical isn’t a diagnosis. Apple Watch reads about 8 ms lower than a chest strap on average, so treat this as a rough guide and compare mostly with your own baseline.

What does Apple Watch actually measure?

Apple Watch measures HRV as SDNN — the standard deviation of the intervals between normal heartbeats — in short readings taken while you are still.

• When: in the background when you are still, by default about every four hours (more often with irregular rhythm notifications or AFib History on), and after every Breathe session in the Mindfulness app.
• Where to see it: Health → Browse → Heart → Heart Rate Variability.
• Accuracy: against a chest strap, Apple Watch read HRV about 8 ms lower on average, with sizeable individual errors (O’Grady 2024). Trends are more reliable than single readings.

Apple Watch HRV vs Recovery HRV

Since September 2026, Apple Watch Series 12 and Ultra 4 show two kinds of HRV: Recovery HRV for daily stress and recovery, and overall HRV for broader health trends.

• How often: Apple measures HRV up to 24 times more often than before. According to DC Rainmaker’s review, that is every five minutes overnight, averaged over your sleep.
• Which formula: the same review reports that Recovery HRV and all values in the Vitals app are now RMSSD — the metric WHOOP, Oura and Garmin use. Apple’s own announcement doesn’t name it.
• Baseline: overnight values are compared with your personal baseline; daytime values with your own history for the same time of day, at rest only.
• Readiness: a 0–10 score (Recover, Pace yourself, Ready, Go for it) from activity, vitals and sleep. It needs at least seven nights of sleep tracked with the watch.

No Series 12? See how to get a readiness read on an older Apple Watch from your HRV, resting heart rate and sleep.

Normal HRV by age and gender

HRV falls with age: in a population study of 1,906 adults, average SDNN dropped from about 50 ms at 25–34 to about 29 ms at 65–74.

Mean ± standard deviation from 5-minute resting ECGs lying down (KORA S4, Voss et al. 2015). A one-minute wrist reading uses a different sensor, window and posture, so it isn’t directly comparable. Differences between women and men are small and inconsistent across studies.

Why is Apple Watch HRV lower than WHOOP or Oura?

Because they measure different things at different times: Apple Watch takes SDNN readings while you are still, often during the day; WHOOP and Oura average RMSSD over your sleep, when HRV is highest.

HRV follows a daily rhythm — highest early in the morning, lower in the evening (Fitbit data from 8 million people). Longer recordings also produce higher values. Recovery HRV on Series 12 and Ultra 4 is an overnight RMSSD too, so it lands much closer to WHOOP and Oura. Compare each device only with itself.

Keep in mind that WHOOP, Oura, Garmin, Polar and Fitbit don’t write their HRV to Apple Health at all — so the HRV you see in Health usually comes from Apple Watch. See what each tracker syncs to Apple Health.

Why is my HRV low or dropping?

The usual causes are poor or short sleep, alcohol, illness, hard training without recovery, stress and the time of day.

• Alcohol: even small amounts lowered overnight HRV recovery in a study of 4,098 people, more with higher doses.
• Training load: in athletes, a falling 7-day average is an early sign of accumulated fatigue.
• Illness and stress: HRV often dips when your body is fighting something or under pressure.

How to raise your HRV

Regular aerobic exercise, enough regular sleep, less alcohol and slow breathing are the best-supported ways to raise HRV — and a lasting change takes weeks to months, not days.

• Aerobic training: in a meta-analysis of 16 randomised trials in healthy adults, exercise training raised resting RMSSD and SDNN compared with no training (Amekran 2024). Mostly easy, conversational-pace sessions are a sustainable way to train often — find your range with the Zone 2 calculator.
• Sleep, at regular times: in a meta-analysis of 11 randomised trials, sleep deprivation lowered RMSSD (Zhang 2025), and in 557 students tracked with Fitbit, going to bed 30 minutes or more later than usual raised heart rate during sleep (Faust 2020). Direct evidence that a fixed schedule itself raises HRV is still limited, but a steady routine also makes your readings comparable.
• Alcohol: in 4,098 Finnish employees, alcohol lowered overnight HRV and recovery in a dose-dependent way — even low doses had a measurable effect (Pietilä 2018).
• Slow breathing, about six breaths per minute: this is the “resonance” rate used in HRV biofeedback, where heart-rate swings are largest (Lehrer & Gevirtz 2014). A meta-analysis of 223 studies found slow breathing raised vagally mediated HRV during a session, right after it, and after multi-session programmes (Laborde 2022). On Apple Watch, set Settings → Mindfulness → Breath Rate to 6 for Breathe sessions. Readings taken during or right after slow breathing are higher than passive ones, so keep the same routine if you compare days.
• Body weight: in a systematic review, losing excess weight through diet and exercise tended to raise vagal markers such as RMSSD, though the evidence is of low quality and the pooled change in SDNN was not significant (Costa 2019).
• Illness: infection lowers HRV — in health-care workers wearing Apple Watch, SDNN patterns changed in the week before a COVID-19 diagnosis (Hirten 2021). Rest and let it come back rather than chasing the number.
• How long it takes: the exercise trials lasted from 4 weeks to 8 months, about 10 weeks on average. Alcohol, a short night or a cold can lower HRV within a night or a few days. Judge progress by your 30-day average.

How to get a consistent reading

Do a one-minute Breathe session at the same time every morning, sitting still, and look at the weekly trend instead of single numbers.

When should I talk to a doctor?

If your HRV stays well below your normal for more than a week without an obvious reason, or comes with symptoms such as chest pain, dizziness or palpitations.

Apple Watch HRV is a wellness metric, not a diagnosis, and it can be distorted by irregular heart rhythms such as AFib.