What's a good HRV score? Heart rate variability for people who train

What is a good HRV score? The honest answer: one that's normal for you, and steady or rising over time. Heart rate variability varies so much between people that comparing your number with a friend's, or with a chart online, tells you almost nothing. Comparing today's number with your own last few weeks tells you quite a lot.

That's the whole post in two sentences. The rest covers what HRV actually measures, what average HRV and "normal" HRV look like in published data, why your number is mostly not your fault, and how to use the trend to train smarter instead of panicking at your watch every morning. If you'd rather not read the tea leaves yourself, an app that plans the whole week can do the planning part.

One ground rule first: this is about HRV as a training-readiness signal. It is not a health test. If you're worried about your heart, your HRV, or anything clinical, see a doctor, not a blog.

What HRV actually is

Your heart doesn't beat like a metronome. The gap between one beat and the next keeps changing by a few milliseconds, speeding up slightly as you breathe in and slowing as you breathe out. Heart rate variability is the measure of that beat-to-beat variation (Shaffer & Ginsberg, 2017).

Why should someone who trains care? Because that variation is shaped largely by the parasympathetic ("rest and digest") side of your nervous system. When you're well recovered, variation tends to be higher. After hard training, poor sleep, alcohol, illness or stress, it tends to drop. So a morning HRV reading is a cheap, daily, non-invasive glimpse of how much stress your body is currently dealing with.

It's a glimpse, not a verdict. HRV reflects all stress, not only training stress, which matters later. It's one input among several, which is why it belongs inside a structured plan, such as a hybrid training template, rather than replacing one.

The number your watch shows

Most wearables and apps report a version of RMSSD (root mean square of successive differences), in milliseconds. It's the most common short-term HRV metric for athletes because it's mostly driven by parasympathetic activity and is less dependent on breathing rate than some alternatives (Altini & Plews, 2021). Some apps then convert it into a 1–100 "score" with their own formula. Those scores aren't comparable between brands, and sometimes not between devices from the same brand.

Measurement context changes the number too. Overnight averages, a one-minute reading on waking, and a five-minute lab recording are all "HRV" and all give different values. Published norms for 24-hour, short-term and ultra-short-term recordings are explicitly not interchangeable (Shaffer & Ginsberg, 2017).

What is a normal HRV? Average HRV in the data

People search for a single "normal HRV" number. There isn't a useful one, but here's what the data looks like, with the caveats attached.

Look at how wide those spreads are. In the app dataset, a standard deviation of 37 ms on a mean of 69 means plenty of perfectly healthy, active people sit far above or below "average". The Nunan review also flagged very large differences between individuals in some HRV measures (Nunan et al., 2010).

So, average HRV is a real statistic. It's just not a target.

So what is a good HRV score?

A good HRV is:

1. ›Within your normal range. Today's value close to your own recent baseline.
2. ›Stable day to day, without wild swings.
3. ›Holding steady or drifting up across weeks of consistent training.

That's it. A 35 ms runner who's stable and rising is in better shape, readiness-wise, than a 90 ms runner whose number has slid for ten days straight.

Why your number is mostly not your fault

In the large app dataset, the population factors everyone fixates on (sex, age, BMI and physical activity level) together explained only about 15% of the variance in RMSSD (Altini & Plews, 2021). The rest is individual: genetics, measurement setup, and things nobody's identified.

Age does matter. HRV declined with age in that data, with a moderate correlation (Altini & Plews, 2021). Which is another reason a 50-year-old shouldn't benchmark against a 25-year-old's screenshot.

Training doesn't give you a guaranteed high number either. More active people did have slightly higher HRV on average, but the link was small, and stronger for resting heart rate than for HRV (Altini & Plews, 2021).

Conclusion: you can't out-train your genetics on a single reading. Stop trying. Track your own trend.

What moves HRV day to day

In the same free-living data, here's how people's morning readings shifted after common stressors (Altini & Plews, 2021):

Two things stand out. First, a hard session nudges HRV down a little; a night of heavy drinking hits it four times harder. Your watch is not only judging your intervals. Second, the authors describe HRV as a sensitive but not specific marker of stress. It tells you something is loading the system. It doesn't tell you what.

That's why reading HRV in isolation goes wrong. A low morning after a wedding means something different from a low morning after three hard training days, even if the number is identical.

How to use HRV in training

The useful version of HRV is boring: consistent measurement, a rolling baseline, and a bias toward ignoring single days.

Measure the same way every time

Same time (on waking is the standard), same position, same device, before coffee and before checking your work email. Change the method and you change the number. Better still, let a device that measures overnight do it consistently.

Watch the rolling average, not the daily number

Elite endurance research leans on rolling averages for exactly this reason. In a case study of two elite triathletes, the 7-day rolling average of HRV declined steadily in the athlete who became non-functionally overreached, while it stayed stable in the other; day-to-day variability in HRV also changed in the athlete who struggled (Plews et al., 2012). Two athletes is not a law of nature, but it's a good illustration of why one low reading is noise and a week-long slide is signal.

A practical approach:

• ›Baseline: your average over the last few weeks.
• ›Normal range: the band your daily readings usually sit in.
• ›Signal: the 7-day average drifting out of that band and staying there, especially alongside poor sleep, heavy legs or rising effort for the same sessions.

Fit it into the plan, don't let it replace the plan

HRV is most useful when it modifies a plan that already has structure: hard days, easy days, and training phases that build and recover on purpose. Within that, a sustained low trend might mean swapping a hard session for an easy one, or bringing your next deload forward a week. If you've never planned one, start with how to deload properly. A single low day usually means nothing, or at most taking the planned hard session a notch easier.

High readings aren't always green lights either. Research in elite athletes found that both increases and decreases in HRV have been associated with poor adaptation, and that very fit athletes can see HRV drop even as resting heart rate falls, an effect called saturation (Plews et al., 2013). The authors' fix was long-term monitoring to learn each athlete's individual pattern. In other words: baseline and trend, again.

HRV, heart rate zones and easy running

HRV is about recovery between sessions. Heart rate zones are about intensity during them. They're related but separate tools.

The connection is easy training. In the app data, low-intensity training days were followed by slightly higher HRV the next morning, and high-intensity days by lower HRV (Altini & Plews, 2021). That's one more argument for keeping easy days genuinely easy, which is the whole idea behind a guide to zone 2 heart rate. If you're not sure where your easy ceiling sits, start with heart rate zones explained, and if your zone 2 pace feels insultingly slow, our guide to zone 2 running covers why that's normal.

When low HRV means something

A sustained drop below your normal range, together with declining performance, poor sleep and low mood, is worth acting on: train easier, sleep more, and look at what else in life is piling on. Whether you're overtrained or just tired is a separate question with its own signs, and HRV alone can't answer it. Researchers haven't found a single marker that reliably diagnoses overtraining syndrome, HRV included (Meeusen et al., 2013).

What to do about low HRV mostly comes down to context. After a big training block or a short night, it's expected and usually passes within days. If it stays low for no obvious reason, or you feel unwell, stop treating it as a training question and see a doctor.

Should HRV decide your workouts?

This is where HRV-guided training comes in: adjusting each day's session based on the morning reading. A meta-analysis comparing HRV-guided with predefined training found HRV-guided plans were better at improving HRV itself, while showing small, not statistically significant advantages for aerobic fitness and endurance performance (Manresa-Rocamora et al., 2021). The authors also noted fewer negative responders with HRV guidance, and that best practices for baselines and daily thresholds still need more research.

Translation: HRV guidance seems at least as good as a fixed plan, possibly a little better, and probably safer for people prone to overdoing it. It isn't magic, and a well-structured plan with honest easy days already captures much of the benefit.

Tracking HRV without obsessing

The short version of how to monitor HRV properly:

• ›Pick one device and one measurement method and stick with them.
• ›Measure daily, or let an overnight device do it.
• ›Ignore single readings. Watch the 7-day average against your normal range.
• ›Log the obvious confounders: alcohol, late meals, bad sleep, illness, travel, menstrual cycle.
• ›Act on trends that agree with how you feel and perform. Investigate trends that don't.
• ›Never compare your number with someone else's.

How exrsz fits in

exrsz doesn't diagnose anything from your heart. It builds a periodized plan from your goal, schedule, level and equipment, balances running and lifting in one plan, and adapts each week to how you actually trained, so a rough week leads to a sensible next week instead of the same plan on repeat.

FAQ

What is a good HRV score?

A good HRV score is one that sits within your own normal range and holds steady or trends up over weeks. HRV varies hugely between healthy people, so your baseline matters far more than any universal number.

What is the average HRV?

It depends on how it's measured. A review of short-term recordings in healthy adults reported an average RMSSD of 42 ms (Nunan et al., 2010), while a large dataset of morning smartphone readings averaged 69 ms (Altini & Plews, 2021), both with wide spreads.

What is a normal HRV for my age?

HRV tends to decline with age, but individual differences are large, so age-based charts are a rough guide at best. Track your own baseline over a few weeks and compare against that.

Why is my HRV lower than my friend's?

Mostly because you're different people. In a dataset of over 28,000 users, sex, age, BMI and activity level together explained only about 15% of the differences in HRV between people (Altini & Plews, 2021).

Should I skip training if my HRV is low?

Not for a single low reading. If your 7-day average has dropped below your normal range and you feel and perform worse, make the day easier. If it stays low without an obvious reason, or you have symptoms, see a doctor.