Garmin HRV to guide training?

I’m a big Doubting Thomas when it comes to HRV, but I’m giving it another whirl as my focus this winter is on health.

My doubts are because historically I get the opposite to expected results - when I have a really hard day my variability goes up, not down. When I have a really relaxing day, my Hrv goes down, not up.

Something has changed with Garmin on my Fenix 6 a few months ago and now they seem to be less insane:

So do people really turn down intensity of the Hrv is bad, or skip working out altogether?

How do you action HRV data?

The “new” hrv of the fenix 6 is really a new feature, that is tracking hrv during the whole night and calculating a baseline over the first 3 weeks before it even shows a status.

For me, it shows a bad night sleep (in my case sub 30 on a ~40 ms baseline. Last week I got home after work, not feeling OK, threw up a few times at night. That scored also a 28 ms. The next night and the night before were ok (41/40). I was indeed only sick 1 day. (But I did take a few days off to be sure…)

So yes, it seems to be a correct indicator of your how you are rested… sometimes it’s also lower after a hard workout, but not consistent… it seems to be more consistent low after a bad sleep.

Regarding your remark “something has changed” yes indeed, this is completely new. For the older/previous hr stress calculation, you had to wear a strap and start the measurement manually. So you can’t compare those two.

I don’t really use the daily hr values for training, but if the trend is going down, I do take action (more sleep, less intensity).


Haven’t been sick, so no experience with sickness-related HRV dip.

But from training perspective, it has been interesting:

  • doing POL with balanced hard/easy days mix, HRV graph is quite steady, but
  • after VO2max days, it shows drop over night, from usual ~55ms → ~45ms, and recovers over next day
  • with VO2max block periodisation (a la week mostly of Z5 and after that 3weeks of Z2 recovery with single Z5 per week), it plunges into low 40s for many days
  • Z2-Z4 does not seem to affect it

Basically, it tells what I did but not what I should do :slight_smile:


On Twitter I’ve seen one coach that appears to promote the idea of doing workouts when HRV is good, and not when bad. Or something. He uses AI/ML in his coaching. However it is social media, I may have misunderstood him. I have a hard time wrapping my head around an overly simplistic approach.

Frank Overton developed an app that takes sleep and HRV and training load data, and gives actionable advice on what to do. There was some collaboration with Dr Phil Skiba on it. This recent blog post What do the Optimize numbers mean? – FasCat Coaching is worth a read for some ideas on how you might use Garmin data along with training load, what’s coming up on your calendar, and possibly other subjective measures.

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It sounds a damn sight better than the recovery feature on my 830. If I listened to that I’d have to take 3 days off after every ride.

My Garmin watch has Body Battery which apparently is a culmination of HR, stress and HRV. I never had much faith in it except a few weeks ago I got a covid/flu vaccine. For exactly 14 days after the shot my score never went above 80-85. Some days as low as 70. During that time I also wasn’t riding as I strained my back. For the 9 months prior to that I avg 650-1000 TSS and not once did I wake up with a score of under 95. And almost all mornings I woke up with 100.

I’ve spent the past three months or so tracking my HRV with my Forerunner 955 and separately, every morning, with the HRV4Training app with a Polar H10 HRM, and not only did I see little correlation between the readings and my perceived fatigue level, they often didn’t match each other, either the readings themselves or the recommendations. I just wasn’t getting anything actionable out of measuring my HRV so I gave up on it :man_shrugging:


I follow the plan, but definitely take note if my RHR is high and HRV low. If I get multiple days in a row where it won’t rebound to normal I’d definitely look deeper. Usually it aligns with fatigue/illness too so it seems pretty intuitive in that respect.


Having used HRV4Training with a Polar H10 strap, Garmin Fenix 7x HRV, and also various AW apps + the hack to increase HRV samples, I find them interesting curiosities. And keep in mind the feedback you’ll get when you ask are samples of one. Ultimately, it’s how you feel from illness, workout, sleep/rest, etc. If you find one of these various and sundry tools align well with how you feel, great! But I don’t think how it works for one person necessarily implies it will work well for another person. At least that’s what I’ve found.

Why does it feel like it’s either use hrv as the full basis of everything or don’t use it at all? Should be more used as one point of many with this data point more useful to tell when you aren’t fully recovered but not the only data point.

I realize keeping track of lots of different days points and how they all correlate to mean different things is hard but this is what machine learning is good for. Also why I wish trainer road started to include data from outside workouts like this to feed into their machine learning

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Interesting - what would you correlate it with?

Some people have greater self awareness than others, so objective measures can be much more truthful than subjective. Theoretically anyway.

As I’ve got older the more I realised how ignorant I am of how I feel, and it’s not something that can be learned at least by me.

Unfortunately HRV doesn’t pick up emotional stress for me. I’m not sure about sickness yet, as I haven’t been properly ill in the last few months. It may pick up on minor illness that I otherwise don’t notice.

It does seem to align to training stress though and maybe lack of sleep….or is it just alcohol consumption?

Team OxygenAddict promotes this in one of his latest podcasts too, over the winter.

The problem I have is that Garmin rolled the feature out in a period where I was taking a full break from training.

I started winter training (LV + z2, also lifting/yoga), have been guided by ai FTP (which is currently quite a lot below where I was last season) - haven’t struggled on a single workout yet and am feeling fitter and stronger every day. I’ve only had 3-4 days if illness in that graph, and those are 7 day averages. If anything I think my FTP is too low ATM but I haven’t been forcing it. I’m eating well, sleeping better and lower stress than any time in last 2 years.

My watch constantly tells me I’m ‘strained’. I notice the day to day tracking - dips the day after a very hard over/under and lift in the same day, recovers after.

Is there some way of forcing a reset and making it do baselines again?

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Just noticed that graph I posted is a 7 day average, the overnight Hrv can be much lower/higher.

I guess Garmin has that as well with Training Status which combines load, HRV and vo2max.

This is absolutely unscientific, but I’ve found that if HRV is low and RHR is high for more than a few days, I’m almost always overdoing it and need more rest. Also, when HRV is low and RHR is high, I feel stressed out and I have difficulty sleeping, which can be a vicious circle.

Unfortunately, I tend to realize all of this retroactively rather than notice the trend before I go too far and have to dig myself out of a hole.


Only 1 Tip, in Garmin Connect Web you have an better view of your HRV under Reports → Training Status:

This is my Prep Phase, now the long Base Phase is starting


the only way is to reset the watch and then wait another 3 weeks for it to reestablish a baseline. But Garmin says your baseline range will continue to adjust so it may not be necessary to reset the watch.


After all, it’s a trailing average-it’s constantly being recalculated. Therefore, it makes no sense to reset the clock.


It’s not a very trailing average as I’ve been below despite good training for months.

There is a difference between (for example, not sure which watches have exactly what), the fenix 6 and 7. The 6 tracks the same, but the 7 has the readiness widget, (which takes the info from HRV, RHR, Recovery time and maybe more). On the F6, the Training status widget is indeed updated with HRV and combines more info then before, but lacks the specific actionable readiness… (the different statuses like productive, overreaching etc did not take HRV into account before and after the update, maybe… I couldn’t find it.)