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Resting heart rate: your quietest fitness signal

A deep look at the resting heart rate Strathlon reads from Apple Health: what it genuinely tells you, why we draw one band and not a colour-coded ladder, why the age-and-sex table that dominates search results is not a clinical source, and how to read your own trend without frightening yourself.

Resting heart rate is the most informative number you will never feel yourself produce. It is measured while you do nothing, it moves slowly, and over months it tracks your training honestly in a way the scale does not. It is also the number most likely to be over-read: because a single figure in beats per minute looks like a verdict, and it is not one. This page is about getting the signal without the anxiety.

On this page

  1. What the number actually is
  2. Why it moves with fitness at all
  3. The 60–100 band, and what it is not
  4. The table you will find online, and why we don't use it
  5. Your own baseline is the better reference
  6. What moves it that has nothing to do with fitness
  7. Why a wrist reading sits below a clinic reading
  8. Age and sex, honestly
  9. How to read it well
  10. What it cannot tell you
  11. Practical takeaways
  12. References

What the number actually is

Your resting heart rate is how many times your heart beats per minute when you are awake, still and relaxed. Strathlon does not measure it. It reads the figure your iPhone or Apple Watch has already written to Apple Health, which your watch estimates from long stretches of inactivity: most of it overnight and in quiet periods of the day.

If you have no watch, you can type a figure into your profile instead. If you have given us neither, the app falls back to a typical adult value so the rest of the maths still runs, and it says so wherever that figure is used. It never presents a stand-in as if it were a reading of you.

One reading is not the story. A single day's resting heart rate is close to meaningless on its own. It is the direction across weeks that carries the information, which is exactly why Strathlon draws it as a line and not as a score.

Why it moves with fitness at all

Your heart's job at rest is to push a fixed amount of blood around your body each minute. It can do that with many small beats or fewer large ones. Endurance training makes the heart a more effective pump (it fills better and ejects more per beat), so the same delivery needs fewer beats. Your nervous system's resting balance also shifts with training toward the calmer, rest-and-digest side.

The practical consequence: as aerobic fitness improves over months, resting heart rate tends to drift down. It is a slow signal that plays out over weeks rather than days. Anyone promising you a resting heart rate change from one week of training is selling something.

The 60–100 band, and what it is not

The shaded region behind your line is 60 to 100 beats per minute. That is the range published for healthy adults by the American Heart Association, and the same two thresholds appear in the guidance of NHS inform, the British Heart Foundation and the Mayo Clinic.[4]

It is worth being precise about what that band is. It is a rough orientation: the span within which most healthy adults fall. It is not a target. It is not a score. And it is not a judgement about you. Two things follow from that, and Strathlon is deliberately built around both.

  • Being below it is common and usually unremarkable. Fit people, and particularly endurance athletes, routinely sit in the forties and fifties. Some people sit low without training at all. A number under 60 is not a problem by itself.
  • Being above it on one reading means very little. See what moves it that has nothing to do with fitness: the list is long, and most of it is mundane.
Why the band has no colours. A green-to-red ladder would turn a physiological measurement into a verdict on your body, and it would do it on a product that says plainly it is a guide and not medical advice. The band is one flat, quiet tint for exactly that reason, your line stays a single colour whether it is inside or outside, and nothing on the screen behaves differently because of where you fall.

The table you will find online, and why we don't use it

Search for resting heart rate and you will quickly meet a table: rows for Athlete, Excellent, Good, Above average, Average, Below average, Poor, split by age band and by sex, with tidy ranges in each cell. It is reproduced by wearable companies, health sites and hundreds of fitness blogs. It looks authoritative.

We went looking for its source before considering drawing it, because a banded chart is only as honest as the numbers behind it. We could not find a clinical one. The earliest and most stable carrier we could trace is a consumer fitness website, whose archived copies going back more than a decade carry the same figures with no citation of any study, author or publication anywhere on the page. From there it has been re-published widely, in at least one case under a physician's byline, and the numbers had already drifted in the copying. That re-publication is what makes it read as medical.

The clinical literature is candid about the gap. A 2018 editorial in Heart, the journal of the British Cardiovascular Society, states it directly: "there is still no established recommendation for healthy RHR values in adults."[1]

So we don't draw it. Putting a cell labelled Poor on your chart, sourced from a page that cites nobody, is not a feature. It is a made-up medical-looking judgement, and it would be the single most damaging thing we could put on this screen.

Your own baseline is the better reference

Here is the more useful fact, and it is the one the population tables obscure: an individual's resting heart rate is remarkably stable over time, and the spread between people is much wider than the movement within one person. A study of 92,457 wearable users published in PLOS ONE in 2020 found exactly this pattern[2], and its authors note that population reference ranges are rarely a helpful measure of an individual's health.

Which is why the primary reference line on your chart is your own rolling average. The population band isn't the reference line here. A four-beat drift below your own 28-day average tells you something. Sitting at 71 when the population band runs from 60 to 100 tells you almost nothing. The same logic already runs quietly under the bonnet: your readiness score compares today's resting heart rate against your own recent baseline, never against anybody else's.

What moves it that has nothing to do with fitness

Before reading a rise as a training signal, work through this list. Most single-day jumps are on it.

  • Alcohol: one of the most reliable overnight elevators, often visible the night after.
  • Being unwell: a rise frequently precedes you noticing symptoms.
  • A warm room, or a warm night.
  • Dehydration: less blood volume means more beats to deliver the same amount.
  • Poor or short sleep, and travel across time zones.
  • Stress and anxiety, including the ordinary work kind.
  • Caffeine, particularly late in the day.
  • Altitude, for the first days at height.
  • Medication. Beta blockers lower it substantially. Thyroid medication, decongestants, stimulants and some inhalers raise it. If you take any of these, your number is telling you about your prescription as much as your training.
  • A hard session the day before: a normal, temporary response to training load, rather than a warning.

Why a wrist reading sits below a clinic reading

Published reference figures come from clinic measurements: seated, after several minutes of rest, taken by a person. Your watch estimates from long inactive stretches, much of it while you are asleep, and heart rate falls during sleep. The two are not the same measurement.

The PLOS ONE wearable cohort above sits roughly ten beats per minute below the clinic-measured[2] population figures. That reflects a difference of method. It says nothing about a difference in health. It is another reason we treat the published band as loose orientation rather than a scale to score you against, and another reason your own trend beats any comparison.

Age and sex, honestly

Two real, well-replicated observations, stated at their actual size.

Sex: women's resting heart rates average a few beats per minute higher than men's, largely because of differences in heart size. It is one of the better-replicated findings in the area. It is also small: a few beats against a band forty beats wide.

Age: across adult life, less than you would think. The US National Center for Health Statistics published age-and-sex resting-pulse percentiles from a national survey (Ostchega Y, Porter KS, Hughes J, Dillon CF, Nwankwo T. Resting Pulse Rate Reference Data for Children, Adolescents, and Adults: United States, 1999–2008. National Health Statistics Reports no. 41, 2011)[3]. Where the middle half of adults sit (the 25th to 75th percentile) looks like this:

  • Men: 61–76 (ages 20–39) · 61–77 (40–59) · 60–75 (60–79) · 61–78 (80+)
  • Women: 66–82 (ages 20–39) · 64–79 (40–59) · 64–78 (60–79) · 64–77 (80+)

Read those rows across. Over four decades of adult life the band shifts by one to three beats per minute: smaller than your own swing after a bad night's sleep. That is why Strathlon draws one band for every adult rather than an age-graded one: an age-graded band would promise a precision the evidence does not contain.

Note what those numbers are. Percentiles describe how common a value is. Whether it is healthy is a separate question. "Half of men in their thirties sit between 61 and 76" is a statement about a population. It is not a statement about you, and it is not a target.

How to read it well

  • Read the trend line, and ignore the last point. Direction over weeks is the signal.
  • Compare yourself to yourself. Your own rolling average is the only reference that means anything at your resolution.
  • Expect it to be noisy. Day-to-day scatter of several beats is normal and carries no information.
  • Treat a sustained rise as a question worth investigating. Several days up, with no obvious cause from the list above, is worth noticing: usually as "am I under-recovered, unwell, or drinking more than I think?"
  • Give a training change a month. Adaptation shows up over weeks.

What it cannot tell you

Resting heart rate is a single number produced by a great many systems, so it is inherently ambiguous. It cannot tell you why it moved. It cannot separate under-recovery from a virus, or a warm bedroom from a stressful week. It is not a measure of cardiovascular disease risk at the individual level, and it is not a diagnostic of anything.

Strathlon is a general fitness and wellbeing tool rather than a medical device. If your resting heart rate is persistently very high or very low for you, or if it comes with symptoms (breathlessness, chest discomfort, dizziness, fainting, or a heartbeat that feels irregular), that is a conversation with a doctor, and it is a conversation worth having regardless of what any app draws on a chart.

Practical takeaways

  • The band is orientation. It isn't a target. Below it is common. Above it on one day means little.
  • Your own trend is the real signal, tracked over weeks rather than days.
  • The age-and-sex "Athlete to Poor" table is not a clinical source. We do not use it, and neither should you.
  • Age moves the population band by one to three beats across adult life. Your own bad night moves you more.
  • A wrist figure sits below a clinic figure. The gap reflects how each is measured, and nothing about your health.
  • Alcohol, illness, heat, dehydration, poor sleep, stress, caffeine and medication all move it. Rule those out first.
  • Symptoms beat charts. Always.

References

Every figure and threshold above is sourced below. Strathlon is not affiliated with, and not endorsed by, any of these organisations.

  1. Cooney MT, Mayr A. Resting heart rate: what is normal? Heart. 2018;104(13):1048–1049. An editorial in the journal of the British Cardiovascular Society, and the source of the quoted line that "there is still no established recommendation for healthy RHR values in adults". PubMed 29382691 · doi:10.1136/heartjnl-2017-312731
  2. Quer G, Gouda P, Galarnyk M, Topol EJ, Steinhubl SR. Inter- and intraindividual variability in daily resting heart rate and its associations with age, sex, sleep, BMI, and time of year: retrospective, longitudinal cohort study of 92,457 adults. PLOS ONE. 2020;15(2):e0227709. Nearly 33 million daily readings. Mean daily resting heart rate was 65 bpm with a range of 40–109 bpm across individuals, and the authors conclude that "individuals have a daily RHR that is normal for them but can differ from another individual's normal by as much as 70 bpm", while "within individuals, RHR was much more consistent over time". That gap between the two is the whole argument for reading your own baseline. PubMed 32023264
  3. Ostchega Y, Porter KS, Hughes J, Dillon CF, Nwankwo T. Resting pulse rate reference data for children, adolescents, and adults: United States, 1999–2008. National Health Statistics Reports no. 41. National Center for Health Statistics, 2011. The source of the age-and-sex percentiles quoted above. In the public domain. cdc.gov/nchs
  4. The 60–100 beats-per-minute adult range is published by the American Heart Association (United States), and the same two thresholds appear in the guidance of NHS inform (Scotland), the British Heart Foundation (United Kingdom) and the Mayo Clinic (United States). It is a rough orientation for healthy adults rather than a target: reference 1 above is the cardiology literature saying so directly.

Last checked 17 August 2026.