HRV Nerds

Are you using an iPhone? If so, I just downloaded and tested Elite HRV, enabled sync (of the morning report) to the Apple Health app, then using HealthFit app to sync the RHR & HRV data to intervals.icu. Seems to work and have setup the graph to use HRV SDNN data (which is what Apple Health uses instead of rMSSD):

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Thanks, but no, I have an android phone. cheers

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Wondered why I have been struggling with workouts this week! Check out my “tapers” result from yesterday compared to 3 months ago!! HRV has plummeted.
!
Hope I am ok for next weeks tour? Primers tomorrow then we are full steam ahead…

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Wow! I’ve had sessions like this and I’m off tge bike and on foot!

I don’t use anything except the data from my Garmin FENIX 6S Sapphire watch, but the HRV while sleeping mode was added to this watch about the end of August '22. It happened to coincide with my getting pleurisy a couple days later, 9/2, and pneumonia on top of that, diagnosed on 9/12. I was certainly sick but the pain of pleurisy was the worst of it, experientially at least, and the pneumonia seemed pretty tame by comparison and having had it before decades ago, I felt I wasn’t nearly as sick as the previous times. Fever was never much at all, didn’t feel completely wiped out at all, but definitely did NOT have the stamina I had right up to the start of the pleurisy.
Pleural effusion pain was REALLY bad for about 10 days, but after that, no more attacks, just a nagging pain I could deal with. Was off the bike quite a lot, but not entirely for more than about 6 days, I think. I could ride and manage my effort and still get up a long, moderate climb but MUCH slower than before, and could be gasping for air at barely zone 2 and have to control my cadence and effort accordingly.

That went on awhile, but I was making gains as weeks went by and became months. But I was NOT getting my strength back, even though my mileage was back up, and I felt I was doing just about normal distances again and about as many days a week as before. Power numbers were down, average speed down… I was feeling my age! (turned 65 this February.)

So what I find very interesting is that the HRV night time sleeping numbers from the watch are pretty much spot on to what has been going on. I was fretting at not getting power back up, FTP findings from my EDGE 830 were clearly about 10-13% lower than I was most of 2022 until getting sick. And not coming back up.

That changed in about the last month or so. Started feeling stronger, started seeing segment times get a little better, average speed was coming up a little more.

I do a daily HRV 3 minute measurement with the watch as well, (but haven’t always done it consistently) and those numbers are at least a little bit useful and sort of accurate, but I do not base my daily ride decisions on them unless I also feel they agree with what I intuitively sense is true. Sometimes I’ve done HARD rides when that morning check would suggest I do very little, and my performance was strong anyway. That’s only a sometimes thing…

But what I DO SEE clearly in all the historical data gathered the last 7 months is that the HRV nightly measures DO show how down I was from the pleurisy and pneumonia, AND that the recovery was VERY slow and extended, far slower than I expected, even though I felt capable and able to do whatever rides I wanted to do, but I just COULD NOT approach the power or speed I used to take for granted. I really started feeling that age was taking an unfair advantage over me; much too fast a decline for me to accept that it was age causing this…
And I had ongoing CT scans to follow up, 4 of them in all, the last being in mid-February. There STILL was a very small pleural effusion remaining even then, but the pneumonia was long gone.
I had Covid in early December, did Paxlovid as treatment, and it felt like a minor nuisance for the most part. Fever wasn’t ever more than a degree above norm for me. No biggie. But I’m not sure if it affected me more than it seemed at the time. Probably won’t know.

After the last CT-scan, things have FINALLY turned upwards! I’ve regained speed and power almost back to previous levels, and I’ve been seeing PRODUCTIVE on my Garmin training status for a solid 4 weeks plus, which I rarely ever saw during the last 6 months except a few short days in November. The rest were varying degrees of bad.

So below are images of my HRV sleep score values over that period. I’ll try to order from oldest to newest, ending with the long-hoped for recovery and improvement.
The graphs show a Balanced Band range that represents a Balanced HRV.
They also show a dotted line that represents the actual Nightly Average HRV score.
And they show a small icon, be it orange or green for IN or OUT of the Range Band, which represents my Ongoing Average HRV Score.
(It took a couple weeks to get a Balanced Band range developed, and it took about 3 more weeks before I got up into the Balanced Band range, all of which was shortly after getting sick. And the Band was high to begin with because my HRV scores were decent until the sickness really showed up, especially the pneumonia.)

I’ve learned that my nightly score will definitely be impacted by how hard my efforts have been that day and the days shortly before. It will be lower and have more restricted range when I’m beat down, and it will be higher and have a greater range when I’m rested and ready for harder work. It has been absolutely spot on in this regard. No exceptions at all, that I’ve ever seen. This relates to both healthy times and sick times. VERY accurate, in my opinion. (The greater range I refer to doesn’t show in the charts, but I watch it carefully. It shows the HIGHEST value for HRV during every night, and the PEAK values are always higher when I’m rested and fit, and lower when I’m not. There are graphs of the values for EACH night that I can look at, but obviously not posting those all here.)
What’s critical to know, though, is MY HISTORY. A specific number would be pretty useless to me UNLESS I have a good baseline of data to compare. That’s what I love about the sleep readings. They’ve proven to me that they are accurate, giving me a good measure of my rest and recovery state as well as my strength and readiness for bigger work.
If I’m missing too much sleep, it will show up with lower readings and more restricted range. If I’m sick, it shows up. If I’m extra rested, it shows up.

Here are the graphs:

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Ive addded this as well. Going to see if it correlates to EliteHRV numbers.

@jmckenzieKOS I’m interested in what you find, over time.

With the Fenix sleep HRV method of taking readings, my experience suggests it is likely at least relevant and can be useful. As to how PREDICTIVE it’s value is, I think that comes down to how well one pays attention to trends over time, not only trends of the HRV values provided by the device, but also the trends of one’s own training and results, as well as lifestyle trends, like sleeping habits, eating habits, job or home stressors, etc.

I’ve been more than surprised at how much the lower end scores for extended periods AND the higher end scores for extended periods AND the gradual trend that occurred between those opposite ends of the spectrum correlate to what was going on in my experience.

I’m not sure how easy it would be to clearly tie the changes in HRV scores to smaller life events, sicknesses of less serious nature, etc. I do think if one gets very familiar with his or her own data and stays aware of the fluctuations, the picture provided by the HRV readings can be very helpful in guiding training decisions and suggesting changes in other areas of life, like possibly giving a warning that continuing to neglect healthy sleep times or continuing with unhealthy eating patterns will result in greater health decline or fitness losses.

I’ve already realized the impact of my own HRV scores making me more conscious of these very issues, and the result is that I’m more willing to make changes than I used to be. It’s one thing to be told in generalities that you need more sleep or better sleep than you’re getting, or you need to reduce the quantity or frequency of the very late night ice cream indulgence, or you oughtn’t drink coffee so late into the evening, or whatever one’s own “vice” may be. It’s another thing altogether, and much harder to ignore, to see your very own scores improve or degrade based on exactly what choices you’ve made in those areas.

Anyone looking for instant feedback loops is probably going to be frustrated by HRV scores, partly because there are many factors that are at play in affecting it, but looking at trends over time can be really instructive and very persuasive, at least for me!

That’s what is so valuable to me about the Fenix sleep HRV score method; if you can handle wearing the watch on your wrist while you sleep, you’ll have a continually growing data record that takes no other discipline to develop, and it will be a reasonably consistent scenario for when the readings are taken. My bedtime varies more than most, by several hours difference, but the Fenix is pretty well able to tell when I’m sleeping and it cover that timeframe as it should.

(It was super-easy for me to adapt to the watch on my wrist while sleeping; my wife couldn’t stand it and abandoned in probably the first night, tried maybe one or two more times, but didn’t last the night before taking it off.)

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Been using it for years. One thing you have to be aware of is ‘one-offs’. For example, my normal HRV is in the 50 range. I received, after two attempts, a reading around 70 and the graph was all over the place. I ignored it as an anomaly that the product couldn’t handle. I was correct in doing so. I went back and received a post-exercise value which was correct. Otherwise, the values proved spot on.

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Similar to @DameLisa and @DouthatBiker I find my HRV values to be very predictive of performance and over the past few years feel like I have gotten better at “reading the tea leaves” before things go off the rails.

I started with Whoop and then ditched it with the most recent Whoop 4.0 (which has a terribly inaccurate HR sensor compared to both a Polar chest strap and my Garmin Fenix 7). What I have commonly observed is that HRV trends are very important (so the HRV over 4 weeks graph that DouthatBiker shared above), as well as overall max/min values within that.

Garmin’s baseline band is somewhat helpful, but also seems to get confused by sustained hard efforts (i.e. average HRV is near the bottom of the band) and can also be a bit slow to respond once you are trending more positive (i.e. a bad HRV Sunday, but a streak of great HRV Monday to Friday still may have you showing as unbalanced).

The key component for me to interpret HRV data is how does it compare with my overnight resting heart rate. For me at least I have found that a low body battery/low overnight HRV can be tolerated and not a detriment to training when RHR is in its normal range, but that I need to be very careful and opt for a rest day when RHR is high and HRV is low. Right now I just got back from a trip with poor sleep, and a sick niece, and HRV is low/RHR is high - so I’m taking it easy rather than getting out on my bike on what is a glorious day for riding. I’m hoping by doing that I can avoid getting sick and get back on the bike properly tomorrow.

Tracking my HRV values over time has also led me to planning to switch to a 3 on, 1 off, training cycle, as with 4 on, 1 off I tend to see my numbers really crater after that fourth week, and so I’m hoping I can see less of a dip by pulling my rest week up by one week.

The other thing I’ve become aware of is hyper-recovery - where a string of very high HRV values over a few days is not in fact “wow I’m so healthy” but is actually “oops I have dug myself into a pit of the wrong type of suffering”. I do credit my experience with Whoop for teaching me a lot about interpretation of that, but find my Garmin way more consistent in what it says vs my subjective “feel” and performance. The new potential/stamina stuff is also really good on longer or sharper efforts, and seems to correlate well to whether I have anything left in the tank.

All in all, I find it a helpful tool for understanding my body and also enjoy the data geekery of it all.

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@Rearviewmirror Good feedback… I agree that Garmin’s baseline (or Balanced?) band is not the greatest. I take it with a grain of salt when it does exactly what you described, like showing me at the bottom or even out of the balanced bandwidth for too long. (It hasn’t done that for awhile, though, now that my overall fitness and health has returned closer to my “normal.”

As long as I maintain my own sense of where I am, I find it a useful but not determining factor in my conclusions and choices. And yes, it is pretty slow to dial itself in when things are changing.

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Would recommend HRV4Training on iOS/Android/Web - which has been created by Marco Altini who has a pedigree in HRV research; his website has countless valuable articles on the measurement, utility and interpretation of HRV and associated metrics.

I’ve been using multiple HRV apps (Elite,ithlete,Athlytic,TrainingToday as well as HRV4Training) to process my on-waking data (expert advice is to measure HRV on waking, after a wee, in the sitting position (especially if RHR is low) to provide a little sympathetic tone (Altini discusses the physiology behind this in detail).

Do I find it useful? Well it’s a trend monitor; as I’ve got fitter the deceasing RHR is paralleled by my increasing HRV. I’ve had a few aberrant readings when mildly ill; but nothing which has drastically altered training; I use it alongside RPE (how I feel… which is probably more important!)

One does need to think about how the data is collected (PPG (smart watch) vs ECG; as there can be inherent differences using PPG as a surrogate for a timing point between electrical signals, although HRV4Training has an algorithm for this which is a neat feature). Nice primer on this here: Blood flows when the heart beats - Marco Altini’s Substack

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How did you get the HRV values to show up? I tried to add chart, and there were 2 different HRV metrics available (rmssd and SDNN), but neither would show any data on the plot. I use a Garmin Fenix 6x which tracks this. Are you on Garmin or another HRV tracking device?
Thank you!

I directly import my data from an Oura ring. Not sure if that option is available from Garmin. Check with David as he would know.

I have felt pretty average for about 10 days; I think I picked up a small bug from my wife, but managed to keep training - without doing any thresh/Vo2 work of course.

If I look at my charts & the last 24 hours, I seems to be getting worse. I normally ride 6 days a week, this week it was 4, including one of the strongest 100k rides I’ve ever done (power wise) yesterday…but I was wasted today.

The thing that seems to doing the damage is lack of sleep.


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It’s been a long 6 weeks…!

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I used whoop for a hwile but eventually ditched it because the HR readings were so bad. I wasn’t really using it to track exercise intensity anyway, but i eventually kinda realized, if the active HR values are so wrong, why would i be at all confident in the resting/sleep values?

but fundamentally, even when it seemed to work, it was never superior for predicting readiness than my own subjective feelings were. THe HRV and subjective feeling either matched, or the few times they didn’t, the subjective feelings were the ones that were right.

i’m curious others’ experience in that regard.

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I’ve had a very similar experience to yours, using Elite HRV, not Whoop. The numbers rarely matched my subjective feelings. I persevered for a while, then stopped using the app. I still check my resting HR at times, but HRV was not a useful metric for me.

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I don’t want to be too negative though. If it works, great. People are experimenting and that’s great even if (for now) it doesn’t work!

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I am starting to think the same. My Elite HRV figure yesterday was “6”, saying that I need to consider having an easier day or rest. Unfortunately, I had a “century” ride in the morning to celebrate 100 years since our cycling club started. On top of that I had only ever ridden a maximum of 67 miles in one go before. The ride was 17.7 mph average over a rolling terrain and I came home pretty tired with dead legs. HRV this morning was “9” which tells me I can train harder today ??? That does not correlate to how I feel this morning!

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HRV only relates to the health of your cardiovascular system. Thus your legs can feel like they are going to fall off, but your heart can be ready to go. I go by two things: Heart health and overall feeling. BTW, a recovery ride is recommended if you went hard yesterday.

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