Before starting this post, just wanted to say that it’s cool that a community like this exists!
I’ve been measuring my heart rate variability (HRV) in the morning for the past year using a smartphone app, to inform me when I should try and spend more time relaxing (if possible) in a day, as would (I think) be indicated by a lower HRV level than my average. HRV theoretically measures your body’s parasympathetic activity, or how rested your are physiologically. I find that if my HRV is pretty low on consecutive days, I feel pretty burnt out and miserable, and may experience symptoms like headaches and heart palpitations. So I try to keep my HRV levels higher, by doing things like replacing demanding activities (e.g. playing video games) with less demanding ones (e.g. listening to calming music) when possible. Morning HRV seems to be affected both by things that happen in the moment, and the restedness of your body, so that’s something to watch out for. For instance, if I’m stressing out about something while taking my HRV measurement or if I sneeze, it will be pretty low. After taking the measure again though using my typical protocol (e.g. sitting in a calm state), then readings are often closer to what I would expect them to be.
Has anyone else ever measured their morning heart rate variability for an extended period? If so, have you found it useful?
I’m asking because I’ve really liked the measure, and am interested in contributing to efforts to make it useful clinically. However, I’m thinking that there’s a chance that I may be overestimating its utility, especially if I’ve fallen into the trap of confirmation bias. If no one has used it (which I guess could be implied by no responses), that would be useful to know too haha.
Below I share some data I collected because I thought it was pretty cool, though possibly impacted by confirmation bias.
Below is my morning HRV collected over a stressful week at work:
Hello. I’ve measured my morning standing HRV with ECG chest strap (Polar H10) and did regression analysis. In my case HRV was associated with sickness (read here) and train load(read here).
By utilizing camera or external measurement device? Did you verify accuracy of your measurements?
I’ve started measuring hrv with same throughts, but after reading 100+ papers and months of measurements i became less confident in this. Right now i’m using hrv as indicator of sickness and overtraining. In general, low hrv or high hrv alone isnt enough to influence my decisions.
I would recommend to blind yourself if you can and confirm that connection. So you measure hrv in morning and not looking at it. And log your symptoms somewhere. Seeing low hrv in morning may cause some negative reactions just by itself.
Yeah, that seems to be right physiological responce. But a lot of other things cause this. Even just posture change from sitting to standing will influence HRV in a huge amount. Or exposure to light, cold etc. All external (and some internal) stressors influence HR and respiratory rate which results in changes of HRV.
I wouldn’t relay on a single HRV measure, most interesting is looking at trends - some of professional sport medicine papers utilizing 7 day rolling average ln(rmssd) and coefficient of variation of 7 day hrv. Also hrv should be complemented with other biometrics and used / interpreted in context.
Confirmation bias is a huge problem in QS and it’s hard to account for it. Blinding may help, but not always possible. There are also some other biases.
No response != nobody measures A lot of people doesnt bother to write on forums. Also a lot of athletes measures it but i havent seen them here…
Thanks for the thorough reply! Some thoughts on your responses below. Overall, it's great to hear that others have been working with HRV, and lots of your comments were consistent with my experience.
The level of detail you put into your qs hrv experiments was really cool. In both, it seems like morning (standing) HRV had stronger associations with the dependent variables (i.e. sickness and training load). It would be cool to expand these studies from n=1 to n=200 one day, to see if they still hold. From the training load post, I find it fascinating that 7 day rolling HRV and physical activity had a positive association. Two thoughts came to mind for this:
Maybe HRV could be used as an objective metric in lifestyle interventions to capture the benefits of the introduction of an exercise program into a client’s routine.
For me, I’ve found that engaging in exercise more challenging than my usual routine drops my HRV the next morning. To me, this calls to mind potential differences between single day HRV rolling average HRV. Perhaps increased physical activity may result in a decreased HRV in the short term, but an increased average HRV over the long term.
I used a smartphone camera, which I know isn’t gold standard like the polar h10, but I was thinking that if patients were going to use it, smartphones cameras would be more accessible. In term of verification of measurement accuracy, I relied on articles I found where smartphone camera HRV measurement was validated against ECG readings. Smartphone HRV measurement was found to be consistent with ECG readings, but only in stationary conditions. If any type of movement was done, then the motion artifacts would make the smartphone HRV measures more wonky. So I tried taking my morning HRV measurements while seated, and limiting movement.
Yes, there’s so many different factors that can impact HRV measures, and it’s hard to account for all of them. For me personally, aside from accounting for overtraining, I think HRV for me has also been sensitive to when I overwork, but I would probably need empirical data of the quality you had posted prior to back this up, haha.
Great ideas. Will try.
I try to control for the other things that impact HRV by using a consistent measurement approach, much like you did in your posts. For instance, I make sure not to go from sitting to standing so that the change in movement doesn’t change the measurement (and because smartphone camera HRV measurement has evidence supporting its validity only in stationary contexts). Also, I empty my bladder too prior to measurement, as you said you did in your post. I found that holding back the urge to urinate in the morning to get the HRV measurement done would decrease my HRV score haha.
I know I’ve posted this link in other threads when the topic has come up, but just in case @hern939 didn’t catch it, I think Marco Altini’s work is a reliable touchstone. place to check: https://www.marcoaltini.com/. Right now I use resting heart rate measured over night to help assess changes in wellbeing, rather than HRV. I’ve been doing this for quite a long time and I feel like I have a better understanding of the background (both physiologically and in terms of technical measurement details). But I can see that more people are beginning to use HRV, so may start doing this also with a once a day measurement under controlled conditions.
A lot of people doesnt bother to write on forums. Also a lot of athletes measures it but i havent seen them here…