Should I be concerned about low HRV (heart rate variability)?

#41

HRV - the Variable aspect of this measurement is exactly that, highly variable. As it should be, sometimes low, sometimes high variability.

This is why it’s useless to measure HRV in an ongoing manner (hour by hour, minute by minute), it’s basically meaningless. Walk a bit, sit a bit, work out, sleep, the HRV will vary significantly and not tell you anything useful.

But if you measure HRV 1 time a day, at close to the same time, under the “same” conditions, you can establish a trend. Spot HRV measurement is meaningless, I feel that the trend of 1 single daily measurement on the other hand has meaning.

What got me interested in HRV was using it as an indicator of ANS status, parasympathetic vs sympathetic. As we age the ANS becomes more sympathetic, this causes a number of issues both mental and physical.

When I started measuring it I found mine to be low - 40 to 47 over the first week of testing. Then I started tVNS, my HRV increased, my system became more consistently parasympathetic, my HRV increased to 57+ and is holding at that number for over 3 years now.

The app I use is used by a lot of fitness people, I’m not that. Yet I scored above average for my age group. Certainly not because I was fit LoL! I was obese and very low on the fitness scale during that process. Today, I’m not obese and my fitness level is getting much better. And interestingly my HRV has not “improved” through that 14 month transformation.

So I’ll keep doing tVNS 3 to 4 times a week, when there is a hockey game on, Go Leafs Go!

#42

To answer your initial question @AlexKChen:

Phenotypic but not genetically predicted heart rate variability associated with all-cause mortality 2023

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We performed Kaplan–Meier analyses to compare the risk of death for quartiles of HRV traits (considering the 4th quartile with the highest HRV values as a reference) (Figs. 4 and 5 and Supplementary Data 3).
Participants in the 1st (lowest) quartile at baseline for RMSSD and SDNN had 1.31 (95% CI: 1.15–1.51; P = 9.29 × 10−5) and 1.46 (95% CI: 1.27–1.68; P = 1.16 × 10−7) times higher risk of death from any cause compared to participants in the highest quartile.

It seems that as long as you’re not in the bottom quintile for HRV, your HRV doesn’t matter much. Unfortunately, they don’t give the quartiles. But Elite HRV provides that (I assume that Elite HRV users have better HRV than the overall population but it gives an idea): Normative HRV Scores by Age and Gender [Heart Rate Variability Chart]

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See also: THE INTERPLAY OF HEART RATE VARIABILITY AND RESTING HEART RATE ON MORTALITY IN TYPE 2 DIABETES 2024

During a mean 9.9-year follow-up, 1,321 deaths were ascertained, including 443 cardiovascular deaths. Low SDNN was associated with increased all-cause mortality in the high RHR group (HR 1.60; 95% CI 1.29-1.97), but not in the normal RHR group. Compared with the reference group (normal SDNN and normal RHR), the presence of either low SDNN or high RHR alone was not associated with all-cause mortality. In contrast, the combination of low SDNN and high RHR was associated with a significantly increased risk of all-cause mortality (HR 1.68; 95% CI 1.43-1.97). Similar findings were observed in analyses using rMSSD, and in MESA.

So HRV doesn’t matter that much unless very low (bottom quartile) and/or high RHR @Steve_Combi?

#43

HRV varies quite a bit particularly depending upon whether the autonomous nervious system is in a parasympathetic state or sympathetic state.

Hence really any measurements need to take these things into account.

#44

What do you mean John?

#45

If you are in the parasympathetic state HRV will be higher. It will be lower in the sympathetic state.

Hence you cannot just measure a value and say that defines someones HRV. You need also to measure the activation of the HPA axis.

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#46

As noted by @John_Hemming HRV is quite “variable” in a depending manner. What is the depending manner? Activity and time of day will change a measured HRV. Does the study tell us how and when HRV was measured?

The Elite HRV data is probably more representative for people who are actively monitoring their HRV in the prescribed way, same time, same position, etc. But they are also more likely to be fit and active compared to a “normal” group of people.

The all cause mortality thing is very interesting and would indicate that staying out of the very low or very high ranges has some benefit.

My HRV was 57 this morning :slight_smile: but Tuesday to Thursday I was in an extreme parasympathetic state and it was 63 and 67. Measured same time, same position.

Since I’ve been taking TA-1 (thymosin alpha-1) the past week I expected something to indicate a change and the HRV seems to have performed as expected. I’m going to ride this experiment out and see what happens with the HRV as I plan on doing the TA-1 experiment until the end of the year.

tVNS is something that has increased my average HRV and put me in the mid range for the 65-75 age bracket. What does that mean? not sure but at least it’s not at the extremes.

I have noticed my SDNN is slowly increasing, even though I’ve been delinquent with the tVNS procedure. In the study the SDNN to HRV ratio at one extreme High SDNN, low HRV - not good. Then we see the Low SDNN, high RHR - not good.

Seems like these may be good health parameters to keep an eye on.

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#47

That’s actually a common misconception.

Predominance of either branches of autonomic systems parasympathetic or sympathetic can cause low HRV, albeit the predominance of parasympathetic is much less common.

Highest HRVs are achieved by a healthy balance of both branches.

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#48

I am going on the results from Elite HRV which tends to say these things. If it is wrong then fair enough.

I can tell subjectively depending upon how alert I feel as well. After drinking the afternoon/night before RHR will be higher, I will be to some extent vasodilated and HRV will be lower.

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#49

I have a HRV stimulator, I also got bay area peak performance to measure HRV (it’s higher eyes-open than eyes-closed, 40 EO and 30 EC).

It could be a symptom of rigidity in my brain waves in general (this could be related to the “developmental event”/“trauma” I have…)

I got to rent a vagus nerve stimulator