So do a bunch of citizen-scientists who donated their Fitbit and health data for a massive study of heart efficiency. A total of 6,947 individuals (mean [±SD] age, 54.6 [±15.1] years) were included in analysis, including 5.8 million person-days and 50 billion total steps of individual-level Fitbit device data. I love big data!
Fewer heartbeats for more steps → more efficient heart.
Calculate heart efficiency: Divide your average daily heart rate by your daily average number of steps. The resulting ratio — the daily heart rate per step, or DHRPS — provides insight into how efficiently the heart is working. People whose hearts work less efficiently, by this metric, were more prone to various diseases, including Type II diabetes, hypertension, heart failure, stroke, coronary atherosclerosis and myocardial infarction.
Average daily heart rate was calculated by averaging the heart rate across all minutes in a day (midnight-to-midnight). Steps per day were also counted. A derived metric, DHRPS (daily heart rate per step), was calculated by dividing daily heart rate by steps per day for each available day, then averaging across all days with data.
DHRPS quartiles: low quartile (<25 percentile or raw DHRPS value <0.0081), medium group (>25 percentile and <75 percentile), high quartile (>75 percentile or raw DHRPS value >0.0147). Lower is better.
That’s true. The study also didn’t take exercise into account.
I’m not good at programming so it’s hard for me to extract the data from my Fitbit in a meaningful way. But I just did the best I could.
Here is a chart of my steps per minute from 12/22/24 through 3/30/25. The Fitbit has a motion sensor so it only records steps when I’m moving and then it records a data point every minute. I do Zumba dancing and the steps are very fast. I wasn’t able to figure out how to download the pulse rate but typically when I’m dancing that fast my pulse rate is 125 - 135 bpm. I also do a daily walk when my pulse rate is lower – 110 bpm because the trail is partly uphill. You can see the walks in the chart since they would be about 20 - 30 steps per minute. That’s why the chart has a 2-tier appearance.
I couldn’t figure out how to extract the data to get average daily heart rate divided by daily average number of steps.
People who participated in the study were self-selected. It’s fair to say that they are more interested than the average population in physical fitness. Many people with circulatory system problems (such as peripheral vascular atherosclerosis) probably wouldn’t be exercising much, if at all. So the strong signal that the study found would probably be even stronger if the non-participators were included.
Wendy
It looks to me like this is a metric that mimics the estimated VO2MAX that a good many wearables have embedded these days. The manufacturers tend to be a bit cagey about what measurements power the algorithm but basically correspond to the idea that greater cardio respiratory fitness (as measured by VO2MAX) is demonstrated by a lower heart rate response for a given submax workload (or the ability to work harder at the same HR/ Rating of Perceived Exertion) The foundation of Z2/MAF/my ASCVD mitigation training, that I’ve mentioned many times.
I purchased a new Garmin a month or so back and, coincident with my strength training getting stronger and a return to pain free running and walking, my VO2MAX has slowly but steadily risen to almost the level I was at before my lapiplasty and my fitness age has dropped to 62.5 years…allegedly.
Glad you are working it hard and staying in better shape.
I agree with the allegedly statement.
Personally I get very uncomfortable with these gadgets. They demotivate me if that is a word. I find them intrusive. Just me. Everyone is different.
Both my parents were in the Irish medical schooling systems in the late 1950s. There was a common sense around death that is missing from many cultures. Mainly because Ireland could not afford to hook everyone up to the machines that were coming in by the late 1960s.
I am very choosy about what I measure and let go of.
Interesting data.
But this doesn’t take into account what you are doing. Climbing stairs would show you as being less efficient, for example, since your heart beats more per step.
This average over your whole day (or week) would be a good metric comparing to yourself but maybe not as well to others.
Here’s what I use (and others like it) to keep me motivated on those Z2/MAF/ASCVD mitigation sessions on the treadmill …
I think it’s in this podcast where I read that a similar study had been conducted a while back. In Denmark and involved regular folk who classified themselves as non exercisers. The higher quintiles VO2MAX corresponded with low morbidity and greater lifespan
Thanks, Wendy. I was really beginning to think that I’d lost my MOJO for good. Given that it’s so hard to regain fast twitch fibers with increasing chronological enrichment.
Interestingly, I started wearing a heart rate monitor for gauging exercise intensity back in the early aughts. First week of January 2002, to be precise. I’d been out of action for close to 2 years with plantar fasciitis and then, just like that it disappeared. This was just before Christmas and, although pain free, was very out of shape and felt very schlumpy. My daughter was having none of that and bought me a Polar basic HRM, a Runner’s World Training Log and a month’s membership to a local gym. The rest is history. She did the same again last September when I was so down with my foot. She added me to her gym subscription, introduced me to one of the trainers…and the rest is history. Sometimes you need a bit of help.
Since then I’ve used a lot of models …every upgrade usually has a few features that I don’t need or want. Heart rate variability is another metric that’s gaining quite a bit of attention…basically a measure of the autonomic nervous system’s effect on the heart.
My next door neighbour, Marcel, lived to be 105. When they celebrated his 100th birthday he danced with the ladies. Every time I met Marcel I would greet him, “How are you Marcel?” Invariably he would reply, “If we are alive we are well.”
The Captain
needs 19 years to catch up with Marcel
As a simple dinner napkin calculation, not bad. But study full of potential holes. Main one is self selection/reporting and not just from donating data. I would wager people wearing FitBits are more healthy/active than those that don’t. The other 2 big holes: doesn’t take into account medications, i.e., beta blockers (slows the heart rate) nor activity like being on a rower (increase heart rate but no steps).
This is exactly what I was thinking! When I swim, my HR goes up and stays up for 30-45 minutes, but no steps at all. So on days that I swim it would be a “negative” effect on this data, and on days that I walk or do elliptical, it would be a “positive” effect on the data.
True enough up to a point, but it may not be that relevant. One of the things about heart rate response to work effort is that it isn’t static and there are a whole slew of challenges that don’t increase step count per se but do improve fitness quite dramatically. Stair climbing/stair stepper, swim, rower…or, in my case SPIn bike for the high intensity stuff. So, although the time I spend on the SPIN bike doesn’t add to my daily average steps, it certainly adds to a superior training effect over and above my Z2/MAF/ASCVD mitigation sessions on the treadmill alone al9ng with general organic movement. The 80/20 rule in action.
Improved aerobic fitness results in a lower heart rate response to sub max work efforts, so that temporary higher heart rate for a far lower step count is more than likely to result in the average daily heart rate to trend downwards with the passage of time. Physiology in action.
My pulmonologist professor in residency training “chided” me about working out and using up my heartbeats. I told him I came out way ahead because my resting heart rate at the time was in the 30s and in the 50s just walking around. While his was in the 80s all the time. Doing the math, I used way less heartbeats per day than he did.
Yep…a conversation similar to one I would have with my husband back in my fitness instructor days. He’d complain I was using up too many heartbeats with all this exercise…and my response was similar to yours.
Of course, if I knew then what I know now, my praise of exercise would be even more enthusiastic. Even he’s had to eat crow with regard to what must be a staggering collateral circulation.
Another reminiscensce about resting/ambient heart rate…
Back when I was younger, dad kept his first aid skills current and was a member of St John’s Ambulance Brigade. Had regular meetings and tests and whatnot. One of the lecturers/examiners was our local GP…a Dr R Bannister. Actually we knew he wasn’t THE R Bannister as he was a Glasgow not a London man.
Anyways, dad was having one of his periodic re-exams and was called upon to record Dr B’s radial pulse. Dad kept fumbling about thinking he was doing something wrong, as he was counting down in the low 40s. Both dad and he were about the same age and dad knew that his, mum’s, most of his cronies’ sit-down pulses were in the 60 and low 70s or so. Mine was always low (I’d be late teens and a stalwart member of the track team at school) and he kept nagging me to go to the doctor’s as the must be something wrong with me.
Dad finally confessed that he could only count 43 bpm…and was gobsmacked to hear he was correct! Dr B then told him that he was a regular runner still…had been something of a champion at university and beyond…and gave him a brief outline on long term exercise and heart rate. Dad asked if he was any relation to the other R Bannister. Yes, they were cousins.
@JLC please explain to me how someone can “use up” their heartbeats. The heart is a muscle, right? Nobody chides bicyclists that they can “use up” their rectus femoris. Muscles become stronger when they are exercised.
My cardiologist told me to stop exercising until after cardiac rehab. He must have been talking about “those people” – the sedentary heart failure patients. Since I have exercised continuously since age 15 (generally 5 days a week before surgery) I knew that I would completely lose my conditioning if I stopped exercising.
I was dreadfully weak after my open-heart surgery. Even after 9 days in the hospital it was hard for me to stand up from a chair. I honestly don’t know how old, unfit people can survive this surgery.
Using common sense (and my Fitbit watch) I gradually added exercise until I was back to doing 40 minutes of Zumba. After I passed my cardiac stress test I added in my usual HIIT class (5 pound weights). Plus a daily walk on woodland trails. I’m beginning to feel like myself again. It has been over 4 months since my surgery.
The cardiac rehab service still hasn’t returned my call. It’s only 1 hour a week on a treadmill anyway so it’s useless to me.
My paradigm is: the more the heart works the more stamina it will have. Like other muscles.
Wendy
Some people believe you only have so many heartbeats in a lifetime since the heart muscle never rests nor has recovery times (compared to skeletal muscle). Never made much sense to me other than having an excuse to be a couch potato.
On a tangent, upper limit of life span has stayed around 85-90 despite all the medical advances. We just get more people now to the upper limit than 50 or 100 years ago. So the heartbeat limit people are probably doing the math of X beats per minute multiplied out over 85 years.
