[HN Gopher] Training my smartwatch to track intelligence
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Training my smartwatch to track intelligence
Author : dmvaldman
Score : 125 points
Date : 2026-01-14 22:19 UTC (2 days ago)
(HTM) web link (dmvaldman.github.io)
(TXT) w3m dump (dmvaldman.github.io)
| runjake wrote:
| I've tracked sleep using a number of devices and algorithms and I
| haven't found a single one that regularly aligns with what and
| how I feel.
|
| I know it's tracking real data, but the conclusions feel
| completely made up.
|
| What are other people's experience -- especially from those who
| are more bullish about sleep tracking?
| guzik wrote:
| by tracking sleep, what exactly do you mean by that? sleep
| phases, sleep score, sleep duration?
| runjake wrote:
| Yes to all.
| dmvaldman wrote:
| it's a lot of work, but something you could do is track how you
| feel (manually or some other way) and do a similar statistical
| analysis. chess elo was just convenient and aligned for me.
| runjake wrote:
| Yeah, I didn't mean to discount your article. Pretty clearly,
| it's working out for you.
|
| I do have an iOS shortcut that tracks my mood with janky
| emojis. I use it at least once daily.
| esperent wrote:
| I track sleep and energy levels with a galaxy watch and there's
| a strong correlation with how I feel on a given day. Sometimes
| it surprises me, and day where I wake up thinking I slept well
| but after an hour or two I'll realize my energy level isn't
| great, and sure enough I'll check the app and see it's low,
| with a warning about my sleeping HRV or resting heart rate
| being away from my norm.
|
| It's not perfect - there are definitely days when it's wrong.
| But overall I have a target of keeping my sleep and energy
| scores in the 90s and it's helpful. I think the most important
| thing is to keep in mind that it's an imperfect measurements
| but it's still the best one most of us have for now.
| wongarsu wrote:
| There are a number of studies comparing these devices with
| clinical sleep tracking. Just search for sleep tracking on
| google scholar. My take is that consumer devices have gotten
| pretty good at detecting when you are sleeping, but are not
| really good at detecting your sleep phases
| 121789 wrote:
| Garmin's body battery is very close to how I physically feel
| danielbln wrote:
| Yep, can confirm. It's surprisingly accurate to the
| subjective feeling.
| angiolillo wrote:
| I find Garmin's sleep tracking "accurate" in that it typically
| matches how I feel the next day, but that also makes it not
| terribly useful because I don't really need a gadget to tell me
| when I feel tired. Mostly I wear the watch to sleep out of
| inertia and in case I need a flashlight in the middle of the
| night.
|
| But there have been three aspects of sleep tracking that have
| been mildly useful:
|
| 1. A few times my heart rate variability went haywire and the
| sleep scores didn't match how I felt, and it turned out I was
| sick and had not yet noticed any symptoms. Since then it has
| been mildly useful to have a heads up when I'm probably coming
| down with something before symptoms show up.
|
| 2. You can use their Lifestyle Logging to track how things like
| caffeine, alcohol, and various nighttime routines affect your
| sleep. I mean, I haven't discovered anything that's not already
| common knowledge, but somehow having hard data makes it more
| compelling. I suppose if I was going to trial any sleep aids
| then Garmin's correlation would be convenient and save me from
| having to maintain my own spreadsheet.
|
| 3. It alters the suggested workouts if you haven't been
| sleeping well. Trivial to do manually, but it's a convenient
| reminder not to overextend.
| sjw987 wrote:
| Wrist based sleep tracking is worse than finger.
|
| Oura for measuring sleep. Garmin for tracking physical
| exercise. Oura always reflected the timings and my feeling much
| closer than Garmin (Enduro), which basically always told me I
| had bad sleep (started late after my last woken moments and
| ended an hour early).
|
| My own thought, it's honestly best not to track sleep unless
| you feel you have an underlying issue. It causes more anxiety
| than it solves. If you're tired, go to bed earlier, adjust tech
| use and food consumption before bed.
| Izkata wrote:
| I use an Android app called "Sleep", it just works by
| accelerometer with your phone on the corner of your bed. I've
| found it's not really good with its automatic rating and
| suggestions, but the activity graph has an extremely reliable
| wave pattern on the mornings I am well rested. Like an hour and
| a half of no movement at all, then an hour of restlessness,
| which repeats through the night. Usually the hour of
| restlessness even has the same pattern each time it happens.
| But any other pattern and I generally feel tired the whole
| morning.
|
| Originally I got this app for its alarm, it tries to go off in
| the half hour before the alarm time when you're already
| partially awake. The sleep tracking was just a bonus.
| asdff wrote:
| I'm surprised people need this data. Are they not aware if they
| had a good night sleep? Always had been obvious to me.
| cyberpunk wrote:
| I think it's more a way to explore the effects certain other
| behaviours can have on your sleep quality; for instance does
| a magnesium supplement help you get more deep sleep, what
| about workout timing does it effect how long it takes to fall
| asleep or interruptions and so on.
|
| I don't trust the raw numbers at all, really, but since i'm
| wearing the same sensor i can use it to spot trends at least.
|
| Or that's what i tell myself anyway...
| pedalpete wrote:
| Your devices are tracking sleep time, which makes about as much
| sense as measuring your diet based on how much time you spend
| chewing.
|
| Time in deep sleep is not a direct marker of slow-wave delta
| power, which is just one of the measures of repair and
| glymphatic flush which occurs during deep sleep.
|
| If slow-wave activity is slightly impaired, your brain can try
| to make up for that reduction by increasing time in deep sleep.
|
| However, larger impairments mean your brain will struggle to
| stay in deep sleep.
|
| This is why our work at https://affectablesleep.com focuses
| directly on enhancing the Neural Function of Sleep (and
| specifically deep sleep) rather than focusing on time.
| sinoue wrote:
| I hope Garmin sees your passion project and greenlights it for
| inclusion. You have the right approach to ensuring folks are at
| their optimal health to grow intellectually as a person.
| dmvaldman wrote:
| thank you! i think it's ridiculous how little they invest in
| their developer ecosystem. i have been thinking about jumping
| ship to oura or whoop simply because of this.
| gavmor wrote:
| Yes, likewise! I've bounced off their developer portal
| several times, and I've colleagues who note they're
| extraordinarily difficult to integrate with.
|
| I will gladly invest in a more accessible developer
| ecosystem.
| echoangle wrote:
| > Often, it would also contradict how I was internally feeling.
| I'd wake up feeling rested, see my stats are low, and play a game
| of chess out of algorithmic rebellion, only to feel my mind up
| against a barrier and handedly lose.
|
| It would be better to only look at the stats after playing if you
| want to verify it, this could easily be a self-fulfilling
| prophecy.
| Ethee wrote:
| The biggest thing for me is I don't understand how people can
| sleep with these watches on, it's so uncomfortable to me
| personally which is why the different ring technologies appeal to
| me more. I just wish either Garmin made one or that there was one
| I didn't have to buy a subscription to use.
| fifilura wrote:
| People used to sleep with watches 50 years ago too. You just
| get used to it.
| mhitza wrote:
| True. Though the difference with smart watches is that they
| tend to be significantly bigger in size than what common
| watches used to be like.
|
| Smart "bands" tend to be less perceptible.
| formerly_proven wrote:
| They're not that much bigger than an automatic, though they
| are heavier than most.
| fifilura wrote:
| Yeah, they get bigger if you spend more money on them.
|
| I have a Garmin Forerunner 165, it is not very big, and
| not heavy compared to an old style watch made from metal.
| sva_ wrote:
| I think it depends what kind of smartwatch you choose. It
| should fit your wrist. The amount of people I've seen with
| e.g. a Galaxy Ultra watch that stands over their wrist on
| both sides is staggering to me.
|
| For me, the Galaxy Watch 7 in 44mm fits perfectly
| sobjornstad wrote:
| Surprisingly, I find the Apple Watch significantly more
| comfortable and less perceptible than any other watch I've
| worn in the past. My theory is it's the contoured back for
| the heart rate monitor, etc. But maybe I'm just weird.
| pixl97 wrote:
| How didn't they sweat their watch to corrosion? Or is that
| just a me problem when wearing something on my wrist?
| jagermo wrote:
| I'm the opposite; I do not like wearing rings. I have no issue
| with my watch, however.
| xhevahir wrote:
| I don't wear one anymore, but I used to put in on an ankle
| overnight. I would wear a sock on that foot so that I didn't
| tear it off with my other foot during sleep.
| darkwater wrote:
| I thought the same, I just got used to it after a few days
| (even if I wear a slimmer watch from Suunto)
| andreareina wrote:
| The Garmin sleep tracker is reportedly pretty comfortable.
| jeroenhd wrote:
| When I started wearing a watch, it constantly distracted me and
| cause minor annoyance all day while I got used to it. At some
| point it just started blending into the background. Now, when I
| wear my watch on my other hand, I still have the same problem,
| but I don't notice my watch normally anymore.
|
| I've slept with my watch for a while (stopped because the
| battery is crap and I need to charge it every day or it won't
| last past noon the next day) and I've had the same adjustment
| period.
|
| I also think some people are just more sensitive to these
| things. Some sleep with full-on CPAP machines hooked up to
| their faces like it's nothing, but others can barely stand
| wearing clothes when they're sleeping. Plus, some watches are
| more comfortable than others.
| johnmaguire wrote:
| > I've slept with my watch for a while (stopped because the
| battery is crap and I need to charge it every day or it won't
| last past noon the next day) and I've had the same adjustment
| period.
|
| I'm guessing this is an Apple Watch? Garmins typically last a
| week or more.
| jeroenhd wrote:
| Samsung Galaxy Watch from years ago, still running Tizen.
| Got it as a company Christmas present, so I'm not too
| fussed about the mediocre battery life. From what I can
| tell the Garmin models in the same price range don't last
| much longer either.
| lawgimenez wrote:
| I wear Huawei WatchFit during sleep, battery also lasts
| over a week. I didn't know Apple Watch batteries are that
| bad.
| thebruce87m wrote:
| Nylon straps are pretty comfortable. The default strap with the
| metal buckle would dig in to my wrist, and also it was
| difficult to have a perfect fit since you had to pick a hole.
| The nylon strap allows for analogue refinement.
| sjw987 wrote:
| Not sure why Garmin or any of the exercise tracking watches are
| being used for sleep tracking. They're infamously bad at it
| from my experience.
|
| The rings (notably Oura) are much better. I used to wear both
| and they gave completely different results, with the Oura being
| far more accurate to how I feel and the timings of going to
| sleep and waking up. Garmin almost always reckoned I woke up an
| hour earlier than I did and ended the tracking there.
|
| It's honestly best not to get too involved in tracking sleep.
| The analysis does more to ruin your mood and give you nocebo
| effect than it really gives useful information.
|
| I will confess, I do still wear my Garmin to bed because I like
| the vibration alarm over anything audible.
| asdff wrote:
| Golf watch is another beffudler to me. I don't want anything on
| my wrist when I swing. I don't even want anything in my
| pockets.
| J_Shelby_J wrote:
| The Apple elastic bands are comfortable.
| PaulHoule wrote:
| I didn't believe the stress numbers on my Garmin watch were very
| meaningful until I started taking Nebivolol (an atypical beta
| blocker) because there were so many gaps (even when I was
| sitting) that I didn't feel I could eyeball them or trust
| averages over time.
|
| Taking that drug, however, it sees far fewer gaps and I show up
| in the blue "rest" zone most of the time.
|
| I've been watching my heart rate a lot in the last month part
| because of health concerns and part because of a new stance I am
| practicing that has a physical component (e.g. adjusted gaits
| that are energy efficient) and a mental component, being an
| oceanic reservoir of calm with close mind-body-environment
| coupling 95% of the time but disconnecting that connection under
| peak stress -- like I am standing between two people who are
| screaming at each other and holding a barrier at my chest that I
| don't let my breathing cross and glance at my watch and my HR is
| 52 and it is not just the nebivolol talking because when I lose
| my shit it would be more like 70.
|
| People taught me conventional Pranayama (diaphragmatic breathing)
| as a kid and it never helped me in "lose my shit" situations
| involving unstable environments and moral injury, with the
| intense practice I was doing recently it was clear to me that I
| was never going to do it better and I started researching
| emergency techniques for managing sympathetic overload and that
| one worked for me and now I feel like one of the people in [1]
| particularly when I show people my HRV web app [2] and
| demonstrate that I can turn my Mayer oscillation off
|
| [1] https://en.wikipedia.org/wiki/Scanners_Live_in_Vain in the
| sense of ironclad autonomic control but with full sensory
| perception
|
| [2] ... soon to be on Github
| benbarbersmith wrote:
| Which techniques did you try, and which worked for you?
| FL33TW00D wrote:
| I love this, the interday variability in my intelligence is
| extremely annoying.
| dmvaldman wrote:
| may the REM sleep gods light your path
| jollyllama wrote:
| In Soviet Russia, intelligence tracks your smartwatch.
| immibis wrote:
| In the USA, too. That's one of many methods they use to decide
| where to send ICE.
| FredrikMeyer wrote:
| I really wish Garmin had an official API that can be used by
| their users instead of the reverse-engineered solutions (although
| they're very good), but they're at the mercy of Garmin.
| dmvaldman wrote:
| 1000%
| maxverse wrote:
| Absolutely love this kind of project, combining different data
| sources to predict/model how you're doing. I also use chess as a
| proxy for my brain is working!
| what_was_it wrote:
| > exercise-induced fatigue impairs complex cognitive tasks
|
| Apparently your study is strictly about cardio.
|
| Heavier compound lifts can surely knock me out for 30 minutes to
| 2 hours. I don't know how in the heck people train in the
| mornings. But a lot of this is because they _are_ complex
| cognitive tasks.
| byproxy wrote:
| Mornings (~6am), I often walk ~40min to my gym, do heavy
| compound lifts (~1hr total with ~2-3min rest between sets),
| walk ~40min back, and I tend to feel fine by the time I get
| back home. It's usually at the end of the day where the fatigue
| seems to catch up to me.
| asdff wrote:
| You've built up endurance already. The hard part of working
| out is getting to the point you got of not being completely
| sore for days after a single workout. I think that puts a lot
| of people off from consistent routines. I remember the first
| two weeks of track season no one could walk up stairs we were
| getting worked so hard, puking after ladder workouts 5 days a
| week. Eventually that petered out over the season but that
| initial hump from insufficient activity to being active is
| massive, and I don't think a lot of us on the team would have
| surmounted it without essentially peer pressure and mutual
| support in suffering.
| byproxy wrote:
| Oh, yea, for sure. One thing that keeps me consistent is
| that I know what happens when I take > 1 week off (which is
| sometimes unavoidable) and attempt to get back into it.
| DOMS0 for days.
|
| ---
|
| 0:
| https://en.wikipedia.org/wiki/Delayed_onset_muscle_soreness
| icefish wrote:
| A petty correction to this excellent post: you say "Even a single
| serving of alcohol disproportionately impares REM sleep", but
| your source says "Reductions in REM sleep were observed starting
| at approximately 2 standard drinks".
| dmvaldman wrote:
| thanks for catching this!
| andai wrote:
| I hear that the performance on Dual n-back is exceptionally
| sensitive to sleep quality. You might feel totally fine but
| notice that your cognition has actually tanked in measurable
| ways.
| lackoftactics wrote:
| Isn't it a well-known fact that Garmin has terrible sleep
| tracking? The wearables can't handle deep sleep at all; even Muse
| with EEG can't reliably predict it, so I wouldn't be drawing
| conclusions here.
|
| A small curiosity: I recently learned that sleep trackers in
| commercial wearables are terrible for people with sleep disorders
| like apneas, UARS, etc. It makes sense, as this isn't a typical
| dataset, but it's worth knowing.
|
| https://www.youtube.com/watch?v=6FAz7QGmlBM
| dmaa wrote:
| Lot of hate on Garmin sleep tracking in this thread, but I love
| it.
|
| Maybe it is not super accurate, but it was eye-opening for me to
| see how the score changes for the worse even with a little bit of
| alcohol. I am way more careful with when and how much I drink
| since I've started wearing a Fenix 6 few years back
| johschmitz wrote:
| Since this talks about sleep quality I want to add something that
| was almost unknown to me for over 30 years. Smartwatches AFAIK
| don't have CO2 sensors. It seems to me though, that that would be
| extremely useful for sleep quality tracking. I have just a couple
| of years ago found out that CO2 levels are having the highest
| impact on my sleep quality besides temperature. I can highly
| recommend getting a CO2 sensor to get a good feeling for that
| effect. Also understand how much air is available in your room
| and how much CO2 your body produces per hour. I totally
| underestimated this until I was able to measure it. In a small
| sleeping room with closed doors the amount of CO2 will reach
| unhealthy levels at the end of the night.
| pedalpete wrote:
| I work in neurotech/sleeptech and though I commend @dmvaldman on
| the project, it falls for some of the common flaws of current
| sleep medicine/research and some strange decisions in the program
| itself.
|
| Measuring sleep by time is an antiquated idea, and the industry
| is just barely starting to move away from this metric. You
| wouldn't measure your diet based on how much time you spend
| chewing.
|
| Decreased slow-wave activity, the hallmark of deep sleep, can
| increase time spent in deep sleep as your brain tries to
| compensate for the lack. This only works to a certain point, and
| with significant decrease, such as after drinking alcohol, your
| brain is unable to make up for the deficit and is actually unable
| to stay in deep sleep. The deep sleep length doesn't map directly
| to function.
|
| Chess is an interesting metric because there is an opponent being
| played against, so what does that really say about the players
| mental clarity? There are too many factors.
|
| I wonder if sleep regularity (consistent wake in particular) was
| a metric which was fed into the algorithm, and if it did not
| correlate?
|
| Though many people say "garmin (smartwatch X) isn't good at
| tracking" that misses the point that tracking time isn't a
| valuable metric, and why so many people say "my sleep score
| doesn't match what my watch tells me".
|
| Beyond just tracking, we have the ability to directly enhance the
| Neural Function of Sleep, and this is what we're working on at
| https://affectablesleep.com
|
| However breaking people away from the "sleep time metric" is a
| challenging one.
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