HRV / stress and sleep

this year I’ve been tracking my sleep with a Garmin. I’ve got Long COVID/CFS so my ‘body battery’ never recharges brilliantly.

I’ve noticed my stress levels actually go up when I sleep (or, for non-Garmin users, I understand that’s my HRV going down). Not a huge increase, but my watch always tells me off for it: I’ll be in bed, after eating sensibly, no alcohol or caffeine for weeks, with a nice low stress level.  Then I drop off to sleep and my stress goes up. It’ll stay in the lowish orange levels for at least half the night.

Does anyone else get this? I’m wondering if I can improve my stress levels and see if that helps me recharge better. But I like to think I do most of the right things…?

Are you wearing the watch all the time?

Yes – I noticed my average stress levels went up when I started wearing it overnight (about 8 months ago) because my stress levels are often lower when awake than asleep…

Probably nothing to do with ‘stress’. The watch is measuring heart rate variability, and then Garmin chooses to tell you that is a stress indicator, but it will be massively variable by individual and hrv will be affected by so many things. How has the device determined your ‘normal’ readings? I would ignore the ‘alarms’ and if you are a worrier, actually monitor the numbers it’s giving you and note down when you feel ok or when you feel poor the next day. If you are having periods of high/low heart rate, there are so many other possible factors (as well as caffeine, alcohol, there are all the hormonal things, sleep cycles and moving around, propensity for nightmares, and breathing related things, snoring, sleep apnea).

My HRV is all over the place during the night.
It usually starts at around 40, drops to 20 then peaks at 60-ish and then varies between 20 and 50 throughout the night.
My overnight averages for the last 4 weeks are mainly 36/37 with a few dips down to 34/35. These figures put me right on the border between green and orange.
My body battery never gets anywhere near full and I start most days between 50 and 75.

(Garmin Fenix 6 Pro Sapphire)

How has the device determined your ‘normal’ readings?

I don’t think it really has.  I’m aware that this is a £200 consumer device and not a serious medical piece of kit.  But I’m still interested to hear other people’s experiences.

I do notice a correlation though: if my stress is particularly high overnight (eg from a rich meal, or being in a social environment, even without booze) then my body battery will be low in the morning and I’ll feel like crap.

I’m sort of coming from the angle that it just seems odd that my ‘stress’ levels are lower when sitting at my desk working, than while I sleep, and perhaps there’s something I could do to change that? I’m aware that this may seem like clutching at straws, but as anyone who’s suffered from CFS will be aware, there’s a strong tendency to clutch at every straw that comes within range, on the off chance it might help a bit!

My body battery never gets anywhere near full and I start most days between 50 and 75.

That’s interesting to know.  Are you broadly healthy? I rarely get into the 70s, but I’m chuffed when I do. If I wake up on 50 I’ll be barely able to spell my own name until midday…

I’ve seen occasions where my Stress level will be relatively high for a short period on going to bed, before settling down overnight.

If I’ve been on a hard day of activity and/or had a few beers it can be high all the way through until morning.

As regards Body Battery, I normally recharge quite well overnight. I’ve seen 100. This morning I was on 89.

Saturday was a long run (34km) and then a night out with drinks. Hence the 15.

I’d say that the various figures generally match what I’m expecting to see based on “feels”.

It’s a bit of a toy and I wouldn’t be hugely worried by the numbers but fwiw my garmin tracks my stress level rather well.

As you already sound like you’re doing all the right things regarding sleep quality, not a lot else you can do really! Do you think you are sleeping well enough?

I’ve been working on my breathing lately especially through my nose, seems to slow my rate right down and this is supposed to aid HRV with long slow deep breaths.

quick google on heart rate and dreaming says this…

When you dream, you enter the sleep phase known as REM (also known as dreaming sleep). “Your heart rate can vary quite a bit during REM sleep because it reflects the activity level occurring in your dream.

I also have LC and had something similar quite early on in the illness. I think it was literally my body being extremely ill and fighting it through the night. I’d wake up feeling more tired than when I went to bed. I think time was really the answer, but further into LC, when I had recovered a bit, I also found a short easy stroll each day really useful to help get better sleep quality. I also did vagus nerve breathing exercises when I was unable to walk without crashing – I think these also helped.

It could also be connected to dysautonomia – something I still suffer from post exercise – where my heart rate stays quite high for something like 10 hours post exercise. I always have terrible quality sleep because of this after any evening exercise.

I also agree that the Garmin numbers should be taken with a pinch of salt, especially when your ill as it’s more designed as a sports watch rather than a medical one.

Have a look on the Long Covid Support for Endurance Atheletes Facebook group – some good stuff on there and lots of knowledgeable people.

My sleep generally shows as rest on the Garmin graphs with occasional exceptions. My body battery metrics will recover well with rest, and are suppressed by harder exercise without sufficient recovery over several days. I’d say it’s fairly reflective of what’s going on in my body though I don’t focus that much on the numbers. It occasionally doesn’t start sleep tracking until I’ve actually been asleep for a couple of hours, and I’ll just grumpily disregard the body battery numbers when it does.

I’ve had long covid woes too, which finally seemed to improve when I focused on calming my sympathetic nervous responses in various ways. If you lie down but don’t sleep does your stress measurement increase too, or is it definitely sleep-related and not postural?

I too get disproportionate stress responses to some social situations (and frustratingly many other everyday things), and have worked on managing that as best I can at its root: I think that for me it’s another component of those sympathetic nervous system dysregulation and my inappropriate fight-or-flight responses which seem to have surprisingly long-lasting effects and in particular degraded sleep and recovery if not calmed.

I’ve used HRV4Training for years and see very little correlation between exercise, sleep, resting HR and HRV. I keep wondering why I continue using it. It presumably relates more to athletes than to slow old men.

Simple solution, don’t track your sleep. Sleep trackers are mostly harmful IMO as a GP with an interest in sleep.

What matters most about your sleep is how you feel about it. If you feel that you’ve slept ok, then that’s all you need.

Although i have my suspicions about HRV i think the OP has a reasonable question

I’ve only been wearing a Garmin watch at night but it seems to have done idea what’s going on in my life

I’ve just been talking to a colleague. We both think that stressful dreams are picked up by our watches. He spent an hour last night being given the run around by B&Q, that’s in a dream.

So OP are you feeling stressed at night? Or having stressful dreams?

My hunch is that the stress is broad and complicated. We tend to think of is being lifes worries. It’s more than just that. I suspect long COVID is a stress

Agree with Kramer – i stopped tracking my sleep years ago and feel all the better for it. Sleep anxiety is real!

I’ll still have nights where i have inexplicably poor quality but i don’t worry about it anymore…. then it doesn’t turn into a self fulfilling prophecy

Yes, it definitely tracks on a broad sense. I can see it on the graph when I’ve had nightmares for instance. If I wake up feeling like dogshit it will usually correspond to a high night’s stress. And I definitely agree that Long COVID / CFS is a stress thing: my stress response is very easily triggered now; noisy environments like being in the car or a plane, busy places like pubs or restaurants. A big roast dinner or some alchohol will make me feel flushed and like my heart is beating out of my neck (despite not beating super fast). And when I was drinking one coffee per day, i’d regularly see my heart rate at 130bpm just from getting up to do the dishes.

I’ve had long covid woes too, which finally seemed to improve when I focused on calming my sympathetic nervous responses in various ways. If you lie down but don’t sleep does your stress measurement increase too, or is it definitely sleep-related and not postural?

It’s definitely sleep-related!  Most evenings I lie in bed with a book for 45 mins before going to sleep. My stress level will be low then, but will immediately double as soon as I drop off. It’s consistent – does this every night. But since I didn’t have a Garmin before I had Long COVID, I don’t know if this would be a normal pattern for me, or indeed if healthy people see the same thing?

I have been thinking more about the sympathetic nervous system responses too – have been meditating the last few weeks and trying to get into breathing exercises. Hopefully that’ll start to help in time.

Simple solution, don’t track your sleep. Sleep trackers are mostly harmful IMO as a GP with an interest in sleep. What matters most about your sleep is how you feel about it. If you feel that you’ve slept ok, then that’s all you need.

Not a terrible idea! I only got a Garmin watch last year, and it’s easy to get sucked into living by the numbers. But my sleep does seem to be out of all whack – sometimes I feel like I’ve slept reasonably well, and yet I wake up feeling more tired than I was before I went to sleep. It’s maddening.  Very occasionally I’ll sleep well and wake up actually rested. I live for those days!

Simple solution, don’t track your sleep. Sleep trackers are mostly harmful IMO as a GP with an interest in sleep. What matters most about your sleep is how you feel about it. If you feel that you’ve slept ok, then that’s all you need.

or indeed if healthy people see the same thing?

As above – yes