The Garmin watches - as well as Suunto and TomTom - use FirstBeat's proprietary analytics software to give you the "recovery status." https://www.firstbeat.com/en/consumer-products/

I've found it to be reasonably accurate relative to what I can feel. But in that sense, it's not really adding anything. And that's generally true of HRV. At its *best,* studies have shown that HRV tracks reasonably well with RPE and basic self-assessment (e.g. "How do I feel?"). That's not particularly compelling. The fact that some "sports scientists" use this as evidence as to the value of HRV is baffling to me. Especially since, on average, HRV fails to even measure up to something as simple as a basic self-assessment.

If you think you're tired, then HRV might (in the best case) "confirm" that, but I don't see the real utility in something that tells you what you already know.

And, as with sleep trackers - where anxiety about reported sleep "scores" actually lessened the quality of sleep, HRV seems to me to be adding stress to your life as opposed to taking it away.

You clearly have very good built in calibration. Like most people. Just rely on that.

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"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

I'll feel recovered. Then I'll head out for a workout and I'll find the my HR is 5bpm higher than it should be and the targeted pace or watts is a helova lot harder than it should be. But then my ass gets kicked by my own tenacious optimism as I tell myself "lets just give it a bit more and maybe it will be ok". So instead of immediately stopping the workout, I give it another 5-10min before I've given up.

And that means that not only have I accomplished nothing, but the effort required is probably going to cause even more delay in recovery. So I'd have been much better to ID before the workout...."take another day off. Don't even put on the running shoes, just take the day off. Which his how I got all the way from Saturday to Thursday before I could do a hard run.

Saturday. Hard ride.
Sunday. Tried to swim but was pretty wiped out so I only did half a workout and that at an easy pace.
Monday Swim.
Tuesday Tried to run hard but HR was high so I cut the workout way short. But this meant I hosed my recovery.
Wed. Swim. Legs clearly don't want to run.
Today. Hope to god I can do a hard run.

Being old sucks.

Articles on HRV and recovery. I'm still reading these so I present them with no editorial commentary.
https://www.scienceforsport.com/heart-rate-variability-hrv/
https://www.trainingpeaks.com/blog/using-heart-rate-variability-to-schedule-the-intensity-of-your-training/

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Books @ Amazon
"If only he had used his genius for niceness, instead of Evil." M. Smart

From what my 820 throws out, its a random number generator at best!

A bit like those HRV testers that use your phone camera...

I tracked my morning HRV reading for a couple months last winter. I noticed a very strong correlation between my recovery/fatigue state and the readings so I'm convinced it "works." But after a couple months. I stopped, mostly because, while I found it accurate, it was not telling me anything I did not already know and at the time I was following a specific plan that was giving me some rest right around the time the HRV was suggested I needed it anyway so I was not using it to change anything. Plus, at this point in my life, I back off when I get tired and between feel and closely tracking TSS, I know when that is happening.
But I can see though how HRV would be a great additional data point for serious athletes who are really pushing the limits. I can think of some times back in my swimming days where I would have been putting that HRV graph into a PowerPoint with whatever other data I had and briefing my coach at length on why I should be getting a morning off ;-)

Not an expert, but I think I read somewhere that chest straps can measure HRV while optical monitors can't or something along those lines.

I used the iThete app and I had to get a new strap but I think that was because the app required bluetooth.

Bigger than the strap issue was that because you are tracking variances which are quite tiny rather than just a pass/fail number, you need very accurate and consistent measurements to accurately see changes. iThlete had a very specific protocol to get usable data. The reading had to be taken first thing in the morning, preferably before you got out of bed and the app even ran you through a very specific breathing rhythm for the 1 minute the app was getting data since apparently even how you breath affects your HRV reading. Finally, because you are measuring for changes, not simply a universal hard target, you had to have a week or more of consistently gathered data to get anything usable.

So, at least based on what I read at the time, even if you have a device that can get a good single reading, numbers spit out at random times during the day under various conditions are essentially useless.

And, all of that "fun" is why eventually i just decided to sleep in an extra few minutes instead ;-)

I just found iThlete and other HRV measuring Android based apps. It's a lot more appealing to experiment with those instead of buying a $500 dedicated recovery gizmo.

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Books @ Amazon
"If only he had used his genius for niceness, instead of Evil." M. Smart

I tracked my HRV, and RHR for most of the last year during my return to Tri (along with TSS, TSB, etc). What I found was that HRV/RHR tracked my TSB and fatigue very well during the first 6 months or so. Eg,

Hard / high-TSS workout today ==> low HRV / high RHR tomorrow.

The pattern was pretty predictable. The few times it didn't follow this pattern there were other reasons (alcohol, illness, travel, etc). However, as I became more fit in the last few months...and started adding more intensity (average IF > 0.8)...HRV, in particular, started to look more like a random number. In fact, quite often I might see:

Hard / high-TSS workout today ==> high HRV / high RHR tomorrow.

I thought that maybe that intensive days were elevating HRV, and extensive days depressing it, but that didn't seem to fit the data. So, it just sorta seems to be a random occurrence that HRV elevates or depresses from baseline now following a high-TSS workout or day.

I've seen a general positive trend between average HRV and "fitness/performance", and a general negative trend with average RHR. Otherwise, I see no real value in HRV/RHR tracking any longer...and have stopped bothering to spend the 5-minutes in the morning to collect it. I'd rather get the extra sleep or workout time (its funny how valuable 5 minutes seems at 5am).

Does anyone have any feedback on the "HRV Stress" test option that the Garmin 935 and Fenix 5 have?

How accurate is that to determine how recovered you are?

I know it doesn't provide an actual HRV number but HRV score based on First Beat scale.

The other downside is it takes 3mins.

I cant speak to how "recovery" is measured by a garmin, but I can tell you that if I rested as much as my garmin tells me to id train 3x a week at the most. I always chuckle when a 40 hour recovery time pops up after my workout.

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2x Deca-Ironman World Cup (10 Ironmans in 10 days), 2x Quintuple Ironman World Cup (5 Ironmans in 5 days), Ultraman, Ultra Marathoner, and I once did an Ironman.

True. But, to be fair, that metric is supposed to be to the next "intense" workout. When I look at it from that point of view (and only intra-sport) I find it a little more reasonable. Even if my 920 tells me to rest for 48 hours after my 2x20 bike, the next morning it will give me a "good" recovery status on my easy run. But, I might only get a "fair" on my bike that evening. These seem to match up pretty well with how I "feel". The easy run feels "fine", but on the bike I definitely feel the effects from the 2x20 the day before.

But, as Rapp said...I don't really find much value in the watch telling me something I already know. Even worse, it gives me the thumbs-up, "good", but I KNOW that my legs have nothing left---and, I'm crawling along at 9:00 / mile. That's when *I* chuckle---good, my ass.

My impression based on the recovery statuses reported by 920xt and Edge 520. I am 44 btw.

920xt - every now and then it throws fair/poor recovery status at me. It usually happens when I double up on the run that day or try to run after a hard race. The recovery windows it reports are completely fucking stupid - as in telling me that it will take 60 hours to recover, and then I'd go for a run 9 hours later and it tells me that my recovery is fair, but yet after I am done with the run it'd tell me that it will be another 50 hour recovery.

520 - totally fucking useless. I ride 4x a week - 2 hard trainer rides, 1 long ride, 1 random (usually a commute). It never gave me anything but the green light on my recovery.

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Next races on the schedule: none at the moment

HRV if measured properly is very precise and shows recovery state quite well, also will show sickness symptoms 1-2 days before you will feel it or get seezy nose.

https://en.wikipedia.org/wiki/Heart_rate_variability


I measure it every day for last 2 years, each Wednesday morning my HRV droops indicating Tuesday Crit or Cross session. More than few times showed symptoms of getting sick, 1-2 days easy recovery and never got sick in last 2 years. There are few good apps, and handful HR straps that can measure it properly Polar H7 being one of them, there is a lot is bad apps, and a lot of bad devices that are not measuring TRUE HRV but trying to determine R-R based on some magic formals and magic.

more reading for you,

http://alancouzens.blogspot.com/...-help-you-avoid.html

agree with Rappstar and STP - it's difficult to get decent (consistent, repeatable, accurate) measurements of HRV, then add in the proprietary algorithms of the vendors and it's most likely to be a pseudo-random number generator..

What I've been doing since getting old and losing my ability to tolerate much intensity (or volume, or.. ;-) is a simple calculation of time x RPE for each workout, and summing this over a week. That gives me a point score which is intended to roughly simulate the more accurate TSS from power monitors etc, see cyclingpeaks for details. Then the idea is to track this score and make sure the addition of speedwork/intensity doesn't spike the score.
I tried this on previous years training log data, and it was predictive..

Have a hardware/app recommendation?

I can imagine that it would be interesting to have a means to test recovery rates more. I have a couple beers every night like clockwork. What would the impact be on having only 1, or god forbid, making the sacrifice to switch to alcohol free beer? What would the impact be by somehow getting 8hrs sleep a night? To what extent does swimming extend the recovery time needed for running/riding? How hard of an effort causes how much recovery time? To what extent does multivitamins and protein pills help? Having rigorous #'s that could be trusted would definately be a step forward.

Back to my recovery woes. I just returned from a failed attempt to do a hard run. Made it mostly thru the 1mi warm up before I gave up and walked home. Sure is easy to recall being an invulnerable youngster that could train 2x/day with only an occasional break to chase loose women. At this rate it's going to take a year to accomplish an honest month's worth of workouts.

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Books @ Amazon
"If only he had used his genius for niceness, instead of Evil." M. Smart

the only time i recall seeing anything other than "good" status on my garmin FR90 over several years (i got it as soon as they came out) was when i won a 10km so had to wait around for prize giving before my planned run home. even brick runs after a ride where i'm dead on my feet say i'm "good"

more recently i got an edge 820 and its scoring is much better - negative when i'm tired, positive when i'm fresh. i think this is the same as on the FR935. it still doesn't probably add much beyond what i can feel but can be good as a confirmation.

i also track RHR through a fitbit charge2. i don't find i get any meaningful change in RHR (as fitbit define it) through training stress - it will go up a beat or 2 sometimes if i'm tired but other times not. it seems to be more another measure of sleep quality to me. i have found my RHR goes up significantly when i get sick, however it is a delayed effect so i'm all too well aware that i'm sick by the time this happens rather than getting an early warning. it is perhaps useful to track when i'm fully recovered afterwards.

i've considered trying HRV but really not seen any evidence it will add enough to be worth the cost and/or inconvenience of measuring.

as with most metrics, the question has to be is it giving you information that will change what you would otherwise do?