RHR: You Can Check This in 60 Seconds. Most People Are Misreading What it Tells Them.
We are one chapter away from finishing the dashboard.
Over the last four posts, we’ve covered VO2 max, grip strength, heart rate variability, and bone density — metrics that require lab tests, dynamometers, wearable devices, or clinical appointments. Each is worth the effort. Each tells you something about your body that you cannot learn any other way.
This metric requires none of that.
No equipment. No appointment. No device. Just your finger on your wrist and sixty seconds of stillness.
Resting heart rate is the most accessible number on this list, and it is one of the most underused.
What Resting Heart Rate Is
Resting heart rate — RHR — is simply the number of times your heart beats per minute when your body is at complete rest. Not during exercise. Not after climbing a flight of stairs. At rest — ideally first thing in the morning, before you get out of bed, before coffee, before the day begins.
It is the baseline rhythm of your cardiovascular system. Like all baselines, it tells you far more when you track it over time than when you check it once.
The clinical normal range is 60 to 100 beats per minute. But normal and optimal aren’t the same. For most healthy adults — and especially for those who train consistently — a resting heart rate in the 50s or even 40s reflects a cardiovascular system operating with genuine efficiency. The heart is a muscle. A stronger, more conditioned heart pumps more blood per beat, and therefore needs to beat fewer times per minute to do the same work.
A low resting heart rate, in a trained individual, is a sign of cardiovascular strength. The heart is doing more with less.
The Andy Weir Connection
In Project Hail Mary, Ryland Grace checks his instruments not once but continuously — because a single reading is a data point, while a trend is a story. The oxygen recycler reading that held steady for three days and then dropped on the fourth is not the same as one that was always low. The change is the signal.
Resting heart rate works exactly this way. A single reading tells you roughly where you are. But a resting heart rate that has been climbing for a week, while everything else in your life feels normal — that is your body sending a message through the instrument panel. Something is building up. Something needs attention.
This is why tracking matters more than measuring. The number on any given morning is interesting. The direction it’s moving in is the story.
Why It Matters More After 50
Resting heart rate tends to rise slightly with age as cardiac efficiency naturally declines. This is not inevitable — it is modifiable — but it is the default trajectory without intervention.
More practically, after age 50, the signals embedded in resting heart rate become more significant. Research consistently links elevated resting heart rate — particularly above 80 beats per minute — to increased risk of cardiovascular disease, all-cause mortality, and metabolic dysfunction. A large-scale study by Zhang et al. found that each 10-beat increase in resting heart rate was associated with a 9% higher risk of all-cause mortality and an 8% higher risk of cardiovascular mortality.
Conversely, a lower resting heart rate among older adults is linked to better cardiovascular outcomes, lower blood pressure, and longer life expectancy. The direction of the association is consistent across populations and study designs.
This is not a coincidence. Resting heart rate reflects how hard your cardiovascular system is working to maintain basic function. A system that works less hard at rest has more reserve capacity when demands increase — during exercise, during illness, and during the physiological stresses that become more consequential after 50.
What Elevation in RHR Signals
One of the most practical applications of resting heart rate tracking is as an early-warning system — the same role we discussed for HRV in Chapter 3.
A resting heart rate that rises meaningfully above your personal baseline — without a change in training load — is often one of the earliest physiological signs of:
Oncoming illness — RHR often rises 24 to 48 hours before other symptoms appear. If your resting heart rate is 8 to 10 beats above your normal and you feel fine, pay attention over the next day or two.
Overtraining or under-recovery — when training stimulus consistently exceeds your recovery capacity, resting heart rate climbs. It is one of the most reliable early indicators that the balance has tipped the wrong way.
Dehydration — the heart compensates for reduced blood volume by beating faster. An elevated morning RHR after a hot day or a long training session is often a sign of dehydration.
Poor sleep — inadequate or disrupted sleep elevates sympathetic nervous system activity, which raises RHR. If your sleep was broken and your RHR reflects it the next morning, that’s the system working as designed.
Chronic psychological stress — sustained stress keeps the sympathetic nervous system activated, which over time elevates baseline heart rate. This is not trivial — chronic stress-driven RHR elevation has real cardiovascular implications.
The pattern to watch: two or more consecutive mornings with RHR meaningfully above your personal baseline, without a clear training explanation, is a signal worth taking seriously.
What a Good Number Looks Like
General reference ranges for resting heart rate in adults over 50:
Excellent: Below 55 bpm
Good: 55–65 bpm
Average: 66–75 bpm
Below average: 76–85 bpm
Poor: Above 85 bpm
These are population-based references. As with HRV, your personal baseline and its trend matter more than where you fall relative to a population average. An athlete with a lifelong resting heart rate of 48 who climbs to 58 over three months deserves attention — even though 58 falls in the “excellent” category by population standards.
Know your number. Track the trend.
How to Measure It Accurately
The manual method: Before getting out of bed tomorrow morning, place two fingers on the inside of your wrist below your thumb, or on the side of your neck below your jaw. Count your beats for 60 seconds. That is your resting heart rate. Do this every morning for two weeks, then average the results. That average is your baseline.
Wearable devices: Garmin, Apple Watch, Fitbit, Polar, Whoop, and Oura Ring all automatically measure resting heart rate overnight. Overnight measurements are more consistent than a manual morning reading because they eliminate variables such as waking up suddenly or anticipating the day ahead. Check your app for a 7-day or 30-day average — that is more useful than any single reading.
The critical instruction: Always measure under the same conditions. Resting heart rate is sensitive to caffeine, alcohol, room temperature, and emotional state. The standardized window is in the morning, before rising and before coffee.
What Moves the Number
Aerobic training is the primary driver of long-term reductions in resting heart rate. Consistent cardiorespiratory training — particularly Zone 2 — strengthens the heart muscle, increases stroke volume (the amount of blood pumped per beat), and reduces the number of beats needed to maintain resting cardiac output. This is the same Zone 2 training that improves VO2 max and supports HRV. Three metrics, one training modality.
Resistance training contributes to general cardiovascular adaptation and to reducing body fat — both of which reduce the heart’s workload at rest.
Sleep quality has a direct and measurable impact. Consistently improving sleep duration and quality leads to reductions in resting heart rate within weeks.
Stress management — anything that reduces chronic sympathetic nervous system activation will trend RHR downward over time.
Alcohol reduction — similar to its effect on HRV, regular alcohol consumption elevates resting heart rate. This effect is dose-dependent and accumulates over time.
Hydration — consistently adequate fluid intake supports blood volume and reduces the compensatory increase in heart rate that accompanies chronic mild dehydration.
My Number
My resting heart rate has averaged 52 beats per minute over the past 30 days — firmly in the good-to-excellent range for my age group. I track it nightly on my Apple Watch. The number that interests me most is not today’s reading — it’s whether the 30-day trend is moving. Since starting the current training program, it has dropped by six beats from where it was at the start of the cycle.
Six beats does not sound like much. Over the course of a day, that’s about 8,640 fewer heartbeats. Over a year, it is more than three million. The heart is doing less work to maintain the same output. That is efficiency. That is what training is building.
Your Next Step:
Tomorrow morning, before you get out of bed, take your resting heart rate manually. Count for a full 60 seconds. Write it down with the date.
Do it every morning for two weeks. Find your average. That is your baseline.
Then start watching the trend. Because the trend is the story.
Sources
Jensen, M.T., et al. Elevated resting heart rate, physical fitness and all-cause mortality: a 16-year follow-up in the Copenhagen Male Study. Heart, 2013. https://heart.bmj.com/content/99/12/882
Cooney, M.T., et al. Elevated resting heart rate is an independent risk factor for cardiovascular disease in healthy men and women. American Heart Journal, 2010.
Palatini, P., & Julius, S. Elevated heart rate: a major risk factor for cardiovascular disease. Clinical and Experimental Hypertension, 2004.
Reimers, A.K., et al. Effects of Exercise on the Resting Heart Rate: A Systematic Meta-Analysis. Journal of Cardiovascular Development and Disease, 2018. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6306777/
Fox, K., et al. Resting heart rate in cardiovascular disease. Journal of the American College of Cardiology, 2007.
Zhang, D., Shen, X., & Qi, X. Resting heart rate and all-cause and cardiovascular mortality in the general population: a meta-analysis. CMAJ, 2016.
