Study uses wearables to show that physical activity lengthens REM latency

https://news.utexas.edu/2024/04/01/move-more-sleep-better-ut-study-finds/

by gmays • 2 years ago

151 96 2 years ago

news.utexas.edu

jeffbee3• 2 years ago

I tried wearing my Garmin to bed for a while, but the information just wasn't that interesting. I can see where science gets value out of a population study but for the N=1 population consisting of yourself, I just wasn't seeing the point.

creaghpatr• 2 years ago

I enjoyed getting the metrics (not sure how accurate they were) but my garmin is so clunky it's impossible to sleep in. Great for everything else.

jeffbee3• 2 years ago

I wear the women's model of the smallest one they make for this exact reason. Most of the watches Garmin is making are just ridiculously big.

phildenhoff2• 2 years ago

On the contrary, I’ve been wearing my Apple Watch nearly 24 hours a day for a few years and find the sleep info extremely useful.

Really, the primary benefit I get is twofold:

1. I know approximately how long I slept for and remind myself of that all day via a widget. A short sleep is common for me, but I end up feeling foggy. Being reminded that it’s OK, I had a poor sleep, helps ease my mind.

2. I see approximately when I fell asleep and when I woke up. I end up having to add extra time if I sleep past my alarm, but seeing that I didn’t really fall asleep until late into the night helps me manage the pattern of late nights.

Both of those are easily covered by even semi-diligently tracking your sleep on paper, but having my watch do it for me is what I like!

ScoobleDoodle• 2 years ago

I end up having to add extra time if I sleep past my alarm

I find this one a painful design decision on the Apple team's part. The end time of the normal desired sleep schedule does not mean the literal end of sleep every day. I wish they wouldn't clip the data at the end of the sleep schedule. Maybe it's because they're using heuristics and so all the data is guesstimates?

wiredfool• 2 years ago

Mine was absolute crap at sleep detection. Typically it would report that I fell asleep before I went to bed, or I was asleep longer than I was in bed.

Heart rate detection and so on was generally fine through the night, as was Hrv. I sort of wonder if the actual sleep detection is done on the phone, and if the phone is not nearby, it just fails. (My phone doesn’t go to the bedroom. Makes it far easier to actually sleep)

(Also, Watch is dead now, and didn’t replace it, so I might be misremembering the exact bits, but the results were generally paradoxical)

wodenokoto• 2 years ago

I've been considering buying an apple watch just for the stats. I really don't like how my co-workers watches light up when the move, or when they receive a message, so I wonder if I can turn off everything except health stat collection, at which point the whole thing seems a bit absurd.

_qua• 2 years ago

I used to be someone who might have a single beer with dinner a few nights per week. When I got a Garmin and saw what it did to my stress levels and sleep, I essentially stopped drinking at all except for rare social situations.

In addition to improving the numbers, I noticed a qualitative improvement in my sleep, energy levels, and exercise recovery.

esel2k• 2 years ago

What are measurements for stress levels? Are they accurate enough?

Aromasin2• 2 years ago

I had the same experience. It puts things into circumspect when you can physically see how erratic things like heart rate and sleep stage times differ with just a single drink. The difference for my was so stark you'd think it were a bug if it weren't for the fact I could spot the pattern and test to see the truth of things.

DefineOutside2• 2 years ago

I find my Apple Watch information useful. I don't remember when I fell asleep but my apple watch does. This keeps me honest about going to be too late.

Additionally, when I first got it, I found that I was only getting 40 minutes of deep sleep which is why I was always somewhat tired. After adding magnesium to my diet I am getting around 70 minutes of deep sleep. I wouldn't have been able to pinpoint this without the data. The apple watch is the best sleep tracker [1] so your data might be too noisy to find results.

[1] https://youtu.be/LPqtfC70QTU?si=6tTayfNCkcJwDayW&t=12m30s

greymalik• 2 years ago

Does Watch accurately capture when you fell asleep, as opposed to when you lay down and stopped moving?

aaronrobinson• 2 years ago

It is interesting but I find Garmin data completely unreliable. For example, it claims I’m awake for 2-3 times each night for 30 minutes or more, it claims I’m asleep when I know I was on Tik Tok because I couldn’t sleep.

pedalpete3• 2 years ago

I had the same experience when I first started sleep tracking before beginning our start-up https://affectablesleep.com.

My oura would tell me I didn't get enough deep sleep, or REM sleep, and I was like - so what? What do I do with that information?

We're using auditory stimulation to increase the efficiency of deep sleep during the night. The data after a night of sleep is less valuable than the real-time intervention.

genewitch2• 2 years ago

what do you think of binaural beats (cool edit pro did them the best, you could even use arbitrary audio) for helping with sleep?

I know it's probably a big ask to wear headphones prior to sleep but when i was younger i used binaural beats for a few years to try hacking my brain a bit. When it "clicks" the sensation is pretty noticeable and intense. I described the default "noise" binaural beats "activating" like the sound of a helicopter circling around you, but quietly and quickly.

dsalzman2• 2 years ago

This is one of the great “no shit” type studies. Good to validate basic and ancient wisdom I guess.

phildenhoff2• 2 years ago

First you validate the no shit, and then you can ask why!

hattmall• 2 years ago

lol, the why is also no shit too though in this case.... because you are tired.

abdullahkhalids• 2 years ago

Some sequence of studies are not meant to validate that an effect exists, but to quantify the size of the effect. And the size of the effect under varying circumstances.

shawnz• 2 years ago

What? Exercise decreasing the proportion of sleep spent in the REM phase is "basic and ancient wisdom"?

Exercise improving sleep quality, sure, but this study is saying something much more specific than that

0xcde4c3db• 2 years ago

From this study I don't think it's even clear why or under what conditions higher REM latency is better, or that increasing it in an individual can necessarily be considered an improvement.

(I also don't think that's what the study was for; I think they were mostly trying to validate the methods against established results.)

dsalzman2• 2 years ago

“65 participants (Mage = 21.40, SD = 3.21, N = 42 females) with an average of 35.20 (SD = 27.01) days of observation per participant.”

kingrazor2• 2 years ago

This doesn't surprise me. A personal anecdote: a couple of years ago I traveled to Japan for the first time. During my time there, I walked much, much more than I usually do. As a result, I was physically exhausted at the end of each day, and had some of the best sleep I've had in years.

fkkffdddd• 2 years ago

If you’re missing that now - perhaps a great opportunity.

adversaryIdiot• 2 years ago

yes lets leave our 9-5 to walk instead

Fire-Dragon-DoL• 2 years ago

The body gets used to it though

ReptileMan• 2 years ago

You can always try and walk faster

evantbyrne• 2 years ago

I've noticed the same phenomenon myself. On days when I don't go to the gym or engage in some otherwise exhausting activity in the evening, I get much lighter sleep. It also fits my personal wacko hypothesis as to why so many retired old people have so much trouble sleeping, which I continue to recklessly propagate despite a complete lack of solid evidence: they just don't work hard enough.

Modified3019• 2 years ago

That’s definitely an intriguing idea, and imo would be worth studying. (Then we could ignore the results and instead demand pills that don’t help or have pyrrhic side effects if they do.)

zeroCalories• 2 years ago

My own anecdote is the opposite: I can't sleep well if I don't regularly exercise. I think we all kinda know this, but it's good to see more data to refine our intuitions.

astrange2• 2 years ago

Hey, that's the contrapositive, not the opposite.

mjevans• 2 years ago

Same experience here. That's my 'Convention Attendee' / 'Theme park '''vacation'''' exercise and get the heck to sleep program.

frameset• 2 years ago

Sadly a Disneyland Paris season pass is more expensive than a home gym over the long term.

francisofascii• 2 years ago

Not disagreeing, but another contributing factor is the exposure to outdoor sunlight which helps regulate circadian rhythms. People who sit at the beach all day sleep pretty well. I think both outdoor sunlight and exercise improve sleep quality.

busymom0• 2 years ago

Personal anecdote: when strength training, I find that I have the best sleeps on the night and second night after I do a session of heavy farmer walks/carries. They are one of the most exhausting exercises for me and great sleep is a good reward.

alwayslikethis• 2 years ago

Wrist watches can't really detect sleep stages. That requires at least an EEG to do reliably. The best they can do is maybe distinguish between sleeping vs awake. The only consumer device with an EEG is the Zeo, unfortunately they went bankrupt and people are unable to distinguish the flukes from the real ones.

https://pubmed.ncbi.nlm.nih.gov/25991187/

cassianoleal• 2 years ago

There was the Dreem 2 as well but they have also ended production.

magicalhippo• 2 years ago

Heh my SO just showed me her Garmin-something tracker log the other day, and it showed her having an hour of deep sleep when she'd been lying on the couch watching TV.

It's also showing various sleep stages whens he knows she's been awake, trying to sleep.

chimeracoder• 2 years ago

It's also showing various sleep stages whens he knows she's been awake, trying to sleep.

To be fair, people actually aren't that great at detecting when they (or others) are really sleeping. Especially for one's self, it's common to believe that you spent more of the night tossing and turning than you really did, when in reality you actually got some light sleep sprinkled in those periods.

That said, consumer-grade wearable devices are demonstrably not great at this either.

drewg1232• 2 years ago

I love Garmin watches for many reasons, but their sleep tracking is horrible. Even my ancient MS Band did a better job than my Garmin Fenix 6

nottorp• 2 years ago

it showed her having an hour of deep sleep when she'd been lying on the couch watching TV

The Garmin may be right considering the quality of TV... even if she had her eyes open...

ornornor• 2 years ago

Same here. Sleep tracking is mediocre at best. Some nights I’ve spent hours wide awake but lying down, the watch thinks I was awake for 20 min. Or when I wake up in the morning and read a book or scroll the phone to not wake anyone else up, the watch will usually log it as REM.

But it never showed any naps as actual sleeping time. Until I saw your comment I thought that the garmin would only log sleep overnight and never during the day. Did you have to enable something for it to log naps?

KennyBlanken• 2 years ago

That study is nearly ten years old and almost certainly not relevant anymore.

The Basis Peak did a good job at tracking sleep but they got bought up and killed off by Intel for god knows what reason. The Peak also did automatic activity detection and it was quite good at it.

Basis also had hands-down the best visualization of activity and sleep trends, and was the only watch at the time to do full time HRM.

They claimed the Peak watches were a fire risk and recalled them, probably to have a reason to get rid of all the back end infrastructure.

Garmin still can't reliably autodetect biking and its sleep tracking is pretty terrible, too.

jeremiemyhren• 2 years ago

I miss the Zeo. The app would still work locally long after they shut the backend down, until there just was no more aftermarket / eBay supply of their unique silver coated contact padded headbands that actually did the brainwave monitoring. I do find the Apple Watch Ultra seems to be close to at least being in the ballpark in terms of stage and duration accuracy as its output is comparable to what I last got with Zeo, albeit 10 years ago.

verticalscaler• 2 years ago

This review channel begs to differ: https://www.youtube.com/@TheQuantifiedScientist/videos

He very throughly compares countless models with a Polar H10 strap. Some come close enough.

CharlesW• 2 years ago

Wrist watches can't really detect sleep stages.

As someone else noted, the paper you linked to is from 2015. Apple Watch couldn't do it until watchOS 9 (2022, 7 years later), but can now do this pretty reliably.

You might find the "Algorithm Development and Validation" section of this whitepaper interesting: https://www.apple.com/healthcare/docs/site/Estimating_Sleep_...

pkoird2• 2 years ago

Thanks for linking this. I always did wonder how they did it. From a cursory read, it looks like the basic approach is to collect accelerometer data and train it to predict ground truth labels generated via a consumer EEG device. Not sure if each epochs (30s) were considered iids. I'd assume that the overall sequence of activity would be much more informative than a single 30s activity considered independently.

genewitch2• 2 years ago

i have purchased 2 amazfits and they work fine for sleep records, they use the zepp app. I've had 2 other watches that had sleep tracking, but the amazfit seems better, then again, it is much newer.

pedalpete3• 2 years ago

The data quality of wearables to detect sleep stages is in the 90%+ accuracy range now. Which is near what polysomnographers score at - nobody completely agrees on what stage is what, there is always deviation. Wearables are definitely good enough at this stage.

Zeo is not the only consumer EEG either, though all the current headbands (including what we are building at https://affectablesleep.com) have some sort of sleep stimulation at it's core.

Frenzband I believe is shipping, I haven't tried one, and don't know anyone who has. We have a Somnee at the office, and it is unbearably painful to wear. I'm highly skeptical of the "science" of either of these devices as well.

tjoff• 2 years ago

90+ accuracy seems very optimistic.

Still, I'd bet that whatever accuracy wearables get only work on a population, not individuals. I'm not surprised they are decent (though they can barely detect when you are sleeping...) but I don't put any faith at all on an individual basis.

Given the data they can collect that is the best anyone can hope for anyway.

So if you want to diagnose your own sleep, which you presumably would want to do if you are suspecting an issue, I wouldn't trust them one bit.

burning_hamster2• 2 years ago

The data quality of wearables to detect sleep stages is in the 90%+ accuracy range now.

Citation needed.

1letterunixname• 2 years ago

IIRC, the qualitative (or proven quantitative) connection between exercise and improved sleep is most pronounced with morning exercise (HIIT/weight lifting).

kapp_in_life• 2 years ago

This is interesting to me, do you know any articles about this? I feel when I put off exercise until later in the evening(after 7pm) that I often get poorer quality sleep, but I'd be surprised if working out at 6am vs. lunchtime would make that much a difference.

xarope2• 2 years ago

I used to have to work out late at night (like 8-10pm), and found that 30+ mins of low intensity cardio and a long period of relaxed stretching after the workout helped.

nine_zeros• 2 years ago

Anecdotally, ever since I started wearing the whoop, I have been very cognizant of my sleep and recovery. My sleep quality has improved merely by following their recommendations. A great burden lifted tbh.

sandspar2• 2 years ago

My health watch both adds to and decreases my mental burden. I am healthier. But I often think of the person who said, "My Garmin has made me less fun." My health watch has increased the amount of time I spend feeling guilt.

twobitshifter• 2 years ago

REM latency is good because? I find I feel more rested with more REM cycles which generally means REM starts earlier.

burning_hamster2• 2 years ago

I find I feel more rested with more REM cycles which generally means REM starts earlier.

This is probably the case because your NREM / slow-wave sleep need was low to begin with. If you go to bed relatively rested, it's easy to be fully rested when you wake up. REM is typically delayed when you are exhausted.

Study uses wearables to show that physical activity lengthens REM latency

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