Heart Rate Range & Target Heart Rate

[SumBigGuyRowing]

Why does a lower Resting Heart Rate (i.e. more fit) lead to lower Target Heart Rates (i.e. less fit).

My Max Heart Rate Range stays the same, so with a lower Resting Heart Rate I have a greater Heart Rate Range,

Previously I did a two-fingers-on-corotid-artery and found my resting heart rate to be 74. (That didn't seem right.)
Then today, I used a Polar OH1+ heart rate monitor to get my resting heart rate (64).
I entered that into my spreadsheet.
Strangely, I found that the lower Resting Heart Rate (more fit) led to lower Target Heart Rates (less fit). Why is that?

My spreadsheet uses:
Tanaka Max HR Formula
206.9 - (0.67 x your age)

And
Karvonen Target HR, (Heart Rate Reserve Method)
Target Heart Rate = [(max HR − resting HR) × %Intensity] + resting HR example
Age 55
Tanaka Max HR 170.05
Resting HR 64 OR 74?
Hrt Rate Range 106 OR 96

* Resting Heart Rate 64 *
Tanaka Max HR 170.05
Hrt Rate Range 106
% Target HR
70% 138
75% 144
80% 149

* Resting Heart Rate 74 *
Karvonen Target HR, (Heart Rate Reserve Method)
Target Heart Rate = [(max HR − resting HR) × %Intensity] + resting HR example
Age 55
Tanaka Max HR 170.05
Hrt Rate Range 96
% Target HR
70% 141
75% 146
80% 151

[Allan Olesen]

lead to lower Target Heart Rates (i.e. less fit).

Could you elaborate on your assumption that a lower target heart rate indicates lower fitness?

[iain]

If you are fitter you can go faster at the same HR, so a lower HR cap may well still be faster. The reason it goes down is that the heart is working harder at the same HR relative to its resting state (as more elevated from rest).

[sjors]

Why does a lower Resting Heart Rate (i.e. more fit) lead to lower Target Heart Rates (i.e. less fit).

That is a wrong assumption.
A lower target heart rate means more fit.
As you get fitter your heart get also stronger/bigger.
And therefore is able to pump the same volume of blood in a lesser rate.
Your resting hart rate will therefore decrease, as does your heart rate decreases at the same level of performance.
The only thing I noticed is that my max heart rate is also decreasing the fitter I get.
I assume that’s is because of is stronger/bigger character it’s harder to go quicker, or maybe it is because my vains cant handle more blood?

[SumBigGuyRowing]

Good point!

I know that a very out-of-shape person will have a higher Resting Heart Rate. For example an obese person's heart has to work hard even when that person's inactive.

But for a relatively fit person
They can row 2k at Heart Rate X
Then they become more fit and can row
2K at a lower heart rate

Thanks for the explanation

[Gammmmo]

Nah it's more to do with the HRmax...that indeed may come down if you get alot fitter if you gain muscle mass and/or your heart can't compensate for the upregulation in the rest of your cardio/pulmonary system.

Another thing, taking HRresting with a HRM IME can give you a slightly slower reading that the true value if you eagerly see it dip from time to time and decide to adopt that "because it looks better"
The above was a male bravado thing my peers and I did in our 20s which is of course total nonsense. Yes, in general HRresting will correlate with fitness but you could equally have two endurance profressional sportsmen of equal standing having a difference in HRresting by 5-10 beats...there are multiple factors that go into performance.

[sjors]

Nah it's more to do with the HRmax...that indeed may come down if you get alot fitter if you gain muscle mass and/or your heart can't compensate for the upregulation in the rest of your cardio/pulmonary system.

Or is it maybe the other way around: your heart does not need to go any faster since it's not the limiting factor? Other parts of your energy-system are the bottleneck?

[Nomath]

I do not think that there is a strong relation between the heart rate at rest and fitness. If there is such a relation, it must be very weak. For example in https://en.wikipedia.org/wiki/Heart_rat ... heart_rate the resting HR for well-trained athletes is listed as between 39 and 60. This is quite a wide range and many unfit persons have a HR below 60. Of course, we are all impressed reading that the 5-times Tour de France winner Michael Indurain had a resting HR of 28, but this is anecdotal evidence als long as we don't know the resting HR's of his competitors, who were also very fit athletes.

On the other hand, there is a strong relation between fitness and Heart Rate Variability (HRV). Given a certain HR at rest, the time intervals between successive beats are not exactly constant, like for a mechanical metronome, but vary continuously by tiny amounts. Rather counter-intuitively, the larger the interval variations, the higher the fitness. The fitness test instrumented on many Polar devices measures HRV in rest during about 5 mins to predict VO2max quite accurately. HRV is also used as a clinical diagnostic and as a predictor of mortality.

[Mortie31]

I do not think that there is a strong relation between the heart rate at rest and fitness. If there is such a relation, it must be very weak. For example in https://en.wikipedia.org/wiki/Heart_rat ... heart_rate the resting HR for well-trained athletes is listed as between 39 and 60. This is quite a wide range and many unfit persons have a HR below 60. Of course, we are all impressed reading that the 5-times Tour de France winner Michael Indurain had a resting HR of 28, but this is anecdotal evidence als long as we don't know the resting HR's of his competitors, who were also very fit athletes.

On the other hand, there is a strong relation between fitness and Heart Rate Variability (HRV). Given a certain HR at rest, the time intervals between successive beats are not exactly constant, like for a mechanical metronome, but vary continuously by tiny amounts. Rather counter-intuitively, the larger the interval variations, the higher the fitness. The fitness test instrumented on many Polar devices measures HRV in rest during about 5 mins to predict VO2max quite accurately. HRV is also used as a clinical diagnostic and as a predictor of mortality.

I track HRV as well, but not sure about the strong link with fitness, how much is good? Mine varies widely over a 24 hour period, even a restless nights sleep dramatically reduces the daily average, could you link any papers you have read, as their are multiple factors that affect HRV, stress being one of them, HRV is a good measure of the balance of the autonomic response. There appears to be a strong link with HR recovery and CV mortality, ( https://www.nejm.org/doi/full/10.1056/n ... 0283411804 )
significantly if reduced faster and further during the first 10 seconds seeing to offer greatest benefit, most sports watches and allied devised measure 1-2 min recovery, but again the evidence is emerging and is difficult to quantify given the small number of events and co factors, as is the link with endurance athletes and CAC

[sjors]

I do not think that there is a strong relation between the heart rate at rest and fitness. If there is such a relation, it must be very weak. For example in https://en.wikipedia.org/wiki/Heart_rat ... heart_rate the resting HR for well-trained athletes is listed as between 39 and 60. This is quite a wide range and many unfit persons have a HR below 60. Of course, we are all impressed reading that the 5-times Tour de France winner Michael Indurain had a resting HR of 28, but this is anecdotal evidence als long as we don't know the resting HR's of his competitors, who were also very fit athletes.

this study : https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4024745/ states that it certainly does, but that you should not overdo it .
One quote from the study
“In the present study, the heart rate of the trained rats and mice was ~26% and ~20%, respectively, lower than the heart rate of sedentary animals. This decrease is less than in elite human athletes. However, severe bradycardia in human athletes is uncommon. The heart rate of exercise-trained human subjects in various studies reviewed by Boyett et al.15 varied between 52 and 58 beats min−1, ~17–26% lower than the heart rate of sedentary individuals, a reduction similar to that observed in the animal models in the present study.”

[Nomath]

I do not think that there is a strong relation between the heart rate at rest and fitness.....

this study : https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4024745/ states that it certainly does, but that you should not overdo it .
...

The cited study does not show a strong relation. It only shows an effect of exercise in a peculiar part of the animal world, held in captivity. But even if we accept that exercise reduces the rest-HR by a certain amount, what does that mean?

Suppose, as a thought experiment, that all active rowers would add 4 cm to the circumference of their biceps. Would this enable us to distinguish rowers in a general population?

Tools for measuring the heart rate at rest have become very common for at least 3 decades. If there would have been a strong relation between the rest-HR and fitness, we would have known it by now from glossy magazines and fitness gurus. It would probably be as much-debated as the well-known formula: HFmax=220-age. The observation that such a formula can nowhere be found is evidence that the relation is weak and fuzzy.

[sjors]

If there would have been a strong relation between the rest-HR and fitness, we would have known it by now from glossy magazines and fitness gurus.

Do a google search on the subject. Plenty to find if you are willing.

[Nomath]

I track HRV as well, but not sure about the strong link with fitness, how much is good? Mine varies widely over a 24 hour period, even a restless nights sleep dramatically reduces the daily average, could you link any papers you have read, as their are multiple factors that affect HRV, stress being one of them, HRV is a good measure of the balance of the autonomic response.

On the internet you can find many scientific papers on Heart Rate Variability in relation to athlete performance. Some of them are very technical about how to measure HRV. Here is one that concentrates on monitoring physical performance : https://www.researchgate.net/publicatio ... Activities . I could download it free of charge.

Fitness is a common word used in many ways. It can be used to characterize a person's physical performance level with respect to the general population. It can also be used to describe one's day-to-day fluctuations in performance. The aim of the Polar fitness test is clearly to rank a person's physical ability compared to a general group of the same age: https://support.polar.com/en/support/ho ... tness_test . Over the last two months I did this test 10 times. The average was 41.7 and the standard deviation 0.5. In my age group (>70 yrs), a result >40 is excellent ; the age group's average is 29-32. So the test is clearly able to discriminate within a large group of people. I don't think the test can track day-to-day fluctuations.

Yes, metal stress is known to affect the result of the fitness test, but as far as I was able to find out not in a big way. This morning I measured my fitness lying down on a bed face-up before breakfast and morning exercise : result 41. After a 5K row (final 1K at 92% of HRmax) and a shower, I repeated the fitness test sitting upright facing an empty computer screen : result 42. The next measurement was done a few minutes later while participating in a sudoku competition on the internet. This is usually my most stressfull activity of the day because the score is based on the time needed to solve the puzzle: result 40. Take this as anecdotal evidence that stress is a minor effect.

[Gammmmo]

I do not think that there is a strong relation between the heart rate at rest and fitness. If there is such a relation, it must be very weak. For example in https://en.wikipedia.org/wiki/Heart_rat ... heart_rate the resting HR for well-trained athletes is listed as between 39 and 60. This is quite a wide range and many unfit persons have a HR below 60. Of course, we are all impressed reading that the 5-times Tour de France winner Michael Indurain had a resting HR of 28, but this is anecdotal evidence als long as we don't know the resting HR's of his competitors, who were also very fit athletes.

There is and it's because the heart gets bigger and stronger so at rest it takes longer to re-fill and stroke volume goes up, so at rest it simply doesn't have to work as hard. You are somewhat right that there is variance among elite athletes but I strongly suspect if say you compared like-for-like with a sport (let's say pro cyclists) then most would be 30s and very early 40s, outside of the that would be outliers. "Well trained" is not a very accurate term -suspect that's a bit of catch-all.

On the other hand, there is a strong relation between fitness and Heart Rate Variability (HRV). Given a certain HR at rest, the time intervals between successive beats are not exactly constant, like for a mechanical metronome, but vary continuously by tiny amounts. Rather counter-intuitively, the larger the interval variations, the higher the fitness. The fitness test instrumented on many Polar devices measures HRV in rest during about 5 mins to predict VO2max quite accurately. HRV is also used as a clinical diagnostic and as a predictor of mortality.

Quite possibly, haven't really studied much or used it at all. Certainly, HRV is closely correlated I believe with optimal activity within the parasympathetic and sympathetic nervous systems so that might suggest high "wellness", low cortisol etc and you could see that someone who is "well trained" i.e. fit+healthy AND crucially well rested might score well on HRV. But what about someone who isn't THAT cardio fit but has low cortisol and eats healthily and a low-stress lifestyle....you might conclcude their HRV would be low despite not being THAT fit. So....I dunno about that one.

Yes, metal stress is known to affect the result of the fitness test, but as far as I was able to find out not in a big way. This morning I measured my fitness lying down on a bed face-up before breakfast and morning exercise : result 41. After a 5K row (final 1K at 92% of HRmax) and a shower, I repeated the fitness test sitting upright facing an empty computer screen : result 42. The next measurement was done a few minutes later while participating in a sudoku competition on the internet. This is usually my most stressfull activity of the day because the score is based on the time needed to solve the puzzle: result 40. Take this as anecdotal evidence that stress is a minor effect.

Maybe it wasn't THAT stressful...surely you've had acutely stressful situations where you FEEL you HR going up? An extreme verison of this (and admittedly this may be down to adrenaline) would be easy to envisage e.g. that sudden noise in the night where you wake up instantly and are super alert because you perceive possible danger....result: HR nearly beating out of your chest while u lie in bed!!

[Nomath]

Maybe it wasn't THAT stressful...surely you've had acutely stressful situations where you FEEL you HR going up? An extreme verison of this (and admittedly this may be down to adrenaline) would be easy to envisage e.g. that sudden noise in the night where you wake up instantly and are super alert because you perceive possible danger....result: HR nearly beating out of your chest while u lie in bed!!

You shouldn't mix up HR and HRV. The case you describe strongly affects HR. What is does to HRV is anybody's guess. The Polar fitness test measures HRV in rest. See https://en.wikipedia.org/wiki/Heart_rate_variability .

Regarding the question whether the relation between fitness and resting-HR is weak or strong, it may help to explain these terms. If a (cor)relation is strong, knowing one quantity almost fixes the other. In a large group of healthy people you can find several with a resting-HR of 55 bpm. However, they are most likely not equally fit. So for groups the relation is bound to be weak. Also taking myself: this morning my resting-HR was about 50. In the early afternoon it may easily drop to 45, occasionally 43. I assume that my fitness does not change over the day. So also for individuals the relation between fitness and resting-HR is weak.
Polar claims that their fitness test based on HRV produces a stable score and I have found little experimental evidence that this is not true.