I'd take all of this with a giant pinch of salt. If the data is anything like the sleep data generated by my Garmin vivosmart HR+ it's not much better than garbage.
It frequently counts me as sleeping when I sit down to watch TV in the evening, or read a book in bed. Sometimes I stay up until 1am reading and it always tracks me as deep sleep from 10pm when I got into bed. I usually take it off for my morning shower (It is waterproof, it just annoys me when washing) and it nearly always counts the walking from bed to shower as a few minutes of restless sleep and the shower itself as deep sleep.
I'm not sure how it makes an assesment of my sleep level. I don't know if it's just based on movement or if it takes heart rate data into account but it does have a heart rate sensor. It seems to usually be wrong.
In theroy it would be possible to know about these limitations and adjust your use of it to make it more accurate, but unless the participents of the study are aware of that and have been manually correcting the data then that won't be the case.
(Not a general critisim on the device, I like it for everything else, but it's sleep data is clearly rather inaccurate)
These are all worthy considerations for these trackers... I can only speak for the Fitbits, specifically the Charge 2 (which has a HR monitor too).
Fitbits have 2 measurement modes for sleep - normal and sensitive. Normal pretty much tracks me as sleeping like the dead for 8 hours each night (however long I'm immobile in bed). Sensitive, on the other hand, tracks much more detail and can tell when I'm restless, sleeping deeply, and even when I get up in the night and move around. I highly recommend the sensitive sleep setting for Fitbit users - it gives you more data to play with!
Fitbit recently re-worked the way they track sleep in its HR-monitor-equipped devices (Charge 2, Aria HR, etc.). It introduced more details (it was just tracking restless/deep before) and this upgrade greatly improved the sleep tracking for me. Before Sleep Stages, it would track only 3-4 hours of my sleep each night. Now, it catches the full 6-9 hours.
Now, all of this is to be taken with a grain of salt in terms of accuracy, but to compare among Fitbit users and to yourself over time, this information is incredibly useful!
The strongest example of the usefulness of this for me so far has been the effect of moderate alcohol consumption on the quality of my sleep. I am far more restless and get much poorer sleep after drinking just 1-2 beers on a full stomach. This has led me to cut back almost completely on alcohol and the quality of my rest has dramatically improved!
>The strongest example of the usefulness of this for me so far has been the effect of moderate alcohol consumption on the quality of my sleep. I am far more restless and get much poorer sleep after drinking just 1-2 beers on a full stomach.
I'm curious, did you not notice this before? I have an MS Band, but the sleep tracking seems similar to the new Fitbit tracking. It did give me some concrete data on how drinking affects my sleep, but that data wasn't really valuable because I already knew that drinking too much or too late would have a negative impact on my sleep because I felt tired the next morning.
For me, it was the difference between assumptions/inferences and repeatable measurements... Being typically human, I was able to be unobservant, post-rationalize my poor sleep, believe I still had the drinking constitution of a 20-year-old, and otherwise ignore the effects.
Having months of daily Fitbit records that I could look back on well after I forgot about my "rough morning" the following day drove the point home as only hard data could.
Like I said, accuracy isn't so much the goal... The readouts I get show pretty consistent measurements over time, which gives me enough confidence to compare them to other Fitbit users among my friends/family as well as to myself over time (see the alcohol anecdote above).
Setting the sensitivity to "normal" just raises the noise floor in their filter so high that it obscures the data.On sensitive, I've never had issues with it identifying "sitting" as "sleeping", yet it still effectively tracks my sleep (including periods of wakefulness immediately pre- and post- slumber in bed as well as mid-night disruptions that wake me up). This suggests that I'm getting pretty good data (though not equivalent to a sleep study with ECG/EKG equipment). In this case, "good" is good enough for my uses.
I've done a sleep study at a hospital to see if I was an actual insomniac or had sleep apnea. It turns out I slept like absolute crap at the study mainly because the thing they put up my nose tickled my nose hairs and the thing on my head was uncomfortable, so I just was restless the entire night.
> It frequently counts me as sleeping when I sit down to watch TV in the evening, or read a book in bed.
This is why I pushed for sleep on v1 of Microsoft Band to be manually triggered. Eventually cloud detected sleep was lit up, but we benefited from lots of gathered data at that point, but even so, it is a hard problem to solve. The best solution would be per user training, allowing users to correct auto detection and use that to improve future tracking, but AFAIK no one in industry is doing that.
> I'm not sure how it makes an assesment of my sleep level. I don't know if it's just based on movement or if it takes heart rate data into account
This is an incredibly hard problem. For sleep studies, multiple doctors look over all the vitals gathered (and for a full sleep clinic study, subjects are very wired up!) And to determine when the subject is in a given phase of sleep, they vote, and it is not always a consensus decision![0] Trying to then make a machine algorithm out of that is difficult, especially working with consumer level sensors.
That said, across most users, data tend to be mostly correct, which is what these consumer devices target. Being able to say someone got 7.5hrs of sleep is good enough, the 10 minute bathroom break doesn't impact the overall numbers too much. Being able to give a good summary of weeks and months is huge, and being able to spot large regressions and improvements is key to user satisfaction.
The ultimate goal is to gather a lot of data, noise or not, run it through machine learning, and start being able to give people actionable advice that they will see real results from.
[0] this was relayed to me by the team who doing sleep classification, other sleep studies may happen differently.
> It frequently counts me as sleeping when I sit down to watch TV in the evening, or read a book in bed. Sometimes I stay up until 1am reading and it always tracks me as deep sleep from 10pm when I got into bed. I usually take it off for my morning shower (It is waterproof, it just annoys me when washing) and it nearly always counts the walking from bed to shower as a few minutes of restless sleep and the shower itself as deep sleep.
Speaking as a Fitbit Charge 2 user, none of that happens with my device. I don't know how accurate the rest of the data is, but it does track sleep only when I'm actually sleeping.
Ditto. I had zero of those issues when my Charge HR was working. (I just threw it out yesterday as it finally gave up the ghost).
It would accurately identify when I was asleep vs just sitting still, and lest you think it was biased towards nights, it accurately counted naps on the rare occasions I took one. The only thing it was BAD at was managing the data when changing timezones. I can hardly blame it. Who really knows what "time" it was when I was half-sleeping on the plane to Australia, and the clock is wrong anyway until I sync it two days later.
This review [1] compared the results of 6 sleep trackers with sleeping laboratorium measurements. It concludes that the trackers were able to track the lenght of the sleep quite accurately. OTOH all trackers displayed large errors in measuring the type of sleep e.g. deep sleep, light sleep & REM.
They conclude that sleep trackers are good for creating awareness of your sleepquota.
I had a Fitbit and now the Garmin you have. The latter is a better device from almost any POV but sleep tracking. Fitbit sleep tracking is much more reliable and actually almost never reports non true things.
I have a Xiaomi band 2 which I bought for some 30 EUR and it also considers me asleep when playing games before I go to sleep and sometimes when watching TV as well.
Other than that it's pretty accurate, it even detects the occasional 15 steps to the toilet and back as awake time and I'm generally happy with it.
It has a heart rate sensor but AFAIK you need to put some other firmware on it to use that during the night at predefined intervals.
Regarding tracking sleep quality (it only has light, deep and no sleep as categories), I feel it tracks it well enough and I treat the duration of deep sleep as an upper bound (usually around 2h30).
So if the band shows me little deep sleep it's almost always correct (i.e. I don't feel I slept well). If it shows lots of deep sleep I can sometime confirm and sometimes not.
Of course, all this is subjective, so "sample size = 1" holds ;)
I have a Garmin 935 and had a 235 before it and for me the sleep tracking seems to be quite accurate. I can't vouch for the deep/light sleep, but the time of sleep/wake is almost always correct.
The 935 also has "Move IQ" events where it auto-detects certain patterns. It captures when I walk my dog, and even captured some laps I did in the pool the other day. The optical heart rate tracking also looks pretty good.
FWIW I have been using a flex 2 for two weeks now and I couldn 't believe how I messed up my sleep. I was a trainwreck and going for no more than 5 hours per night while misevaluating my sleep time to 7-8h. I decided to break the cycle and I have been sleeping much more for one week and already can see the difference. I think I should have bought an alta or a charge to get the benefits of the HR monitor. Still, I am glad I bought one. It was a reality check. And I bought it because I really wanted an vibrating wrist alarm.
I'm with you though. I thought I was doing a good job on sleep and then picked up a Charge 2 and was super surprised at just how little I was getting. It's helped me get better at going to bed at a reasonable hour.
I don't sleep much, I never have. However, I can pretty much shut my body down and meditate, which probably has similar outward physiological expressions as sleep.
I call it my time in my rejuvenation center. It isn't sleep. I'll do that for hours and then get three to five hours of sleep - estimating, of course.
When I did my sleep study, they asked me to not do that. So, I sat there awake and it was not a very fruitful study. I am sure I am not unique but I am only finding generic information when I search.
I could but I think I will trust the doctor. We had this conversation. I can just lay there and do something, but I prefer to meditate as it seems to offer some level of rejuvenation.
By slowing myself down to a restful position, it affords some of the same benefits of sleep. I am very much awake for those few hours, and then I fall asleep. There's no pseudoinsomnia involved.
I stay nearly perfectly still, inasmuch as a human can, and meditate. Once I am asleep, I guess I toss and turn, as well as snore. I highly doubt that I am unique, in these regards.
The proscribed medical solution is a rotation of pharmacutical sleep aids. I don't usually bother with them, as I dislike the groggy feeling that I have the following day.
But yeah, I am very much awake. My pulse rate slows, as does my respiration. At some point, I'll change position and that's when I have actually fallen asleep. The duration varies, and I sometimes just give up and go do something else.
I have the Fitbit Blaze and I really like the vibrating alarm. I have it set a few minutes before my phone alarm. It always wakes me up so I have time to pick up my phone and kill the alarm before it wakes my wife. I also find I'm less "startled" by the vibration than the alarm sound (though using alarm sounds which increase in volume over time help that too).
This has been my experience as well... Coming out of deep sleep to a blaring alarm clock is about the worst case scenario. If I can get natural light or a vibrating alarm to "warn" me, I'm much more receptive to the strong alarm and able to become alert much more quickly.
Right now, I don't have much control over ambient light, but I'd like to find a solution. I think that probably means automatically opening window shades in the summer (anyone tried this?) and, since I live in Seattle, a 10 KW spotlight rigged to a timer in the winter...
Similar story here. I always thought I slept like the dead and nothing short of a force of nature could wake me.
Fitbit rolled out their new sleep types tracking and I find out I'm actually a super light sleeper. Most nights I don't get anywhere near the low-end benchmark for Deep Sleep and I overshoot the high-end benchmark for Light Sleep by many points.
It's weird because my subjective experience and the data that Fitbit shows are so out of whack. I could swear that I sleep well, but nope.
I hate to be so pessimistic but since Fitbit doesn't measure brain waves (among many other things) any "sleep" data generated by the Fitbit is somewhere between those novelty love tester machines and random bits in accuracy. Don't trust it over your subjective experience.
Crazy thought, but perhaps the device is actually pretty terrible at measuring when the user is asleep? Wrist-band heart-rate monitors are known to be fairly less accurate than chest-band HRMs.
Who's really right here then? I'm curious, if you have some nights where the Fitbit says you sleep better or worse than average, does that correlate with your subjective experience?
Or possibly not all 7 billion people need the same amount of each sleep stage? Maybe you and your Fitbit are both right, but the benchmark is wrong for you.
Just curious, could you elaborate on how you were so far off on your sleep estimation? Microsoft's Band has had this feature since its inception, and while the graphs are pretty, I found it utterly useless. My personal experience was that it told me exactly what I already knew.
I know that fitbit thinks this is really cool, but this is really creepy.
Everyone who owns a fitbit has doubtless signed off on being part of these kinds of studies if you dig all the way into fitbits EULA, but I bet none of them actually got an email saying "click here to opt in/out". For a lot of fitbit users, they will never see this study and it will never cross their mind that they're being studied.
This is why I searched high and low for a fitness tracker that doesn't have an online component. I eventually settled on a garman fitness watch plugged into turtle sport: http://turtlesport.sourceforge.net/EN/home.html
I don't really worry about this kind of data being in The Cloud(tm). All the GPS integration is disabled, and I've explicitly forbidden the app any access to location services, so it's not tattling to the world about where I am, and the level of exertion I'm hitting at the present moment, or the extent of time during which I'm asleep, isn't something in which I see any significant potential for exploitation.
These types of articles often have a correlation vs causation problem. For example, the article says that if you want better deep sleep, then move your bed time to between 9 and 10 PM. Ok, sure the data shows that people who go to bed at this time have more deep sleep, but why? Maybe it is a longer window to sleep in without light/noise? Maybe people with fewer sleep problems go to bed earlier? Is it because going to bed at 9:30 is magic?
I guess, the inner clock is adjusted to that time because that's when the sun goes down in summer, and when melanin increases, because of changing light levels, we become sleepy.
It's interesting insight into how much sleep people actually get, but the article mixes up actual statistics with some random data pulled from elsewhere. What's missing is, for example, the data on how the amount of deep sleep impacts the individual's short-term memory, activity and "feeling refreshed" (sic).
We don't actually know where those stats come from, so this conclusion is a bit far-fetched: "these findings further support the general recommendation that most adults need to consistently sleep 7 to 9 hours per night".
Mine didn't have HR monitoring, but I found the movement (aka actigraphy) to be pretty much useless. Fitbit was counting all the time I was laying still trying to fall asleep as "deep sleep", and looking at the chart I couldn't differentiate movement at 12:00 when I knew I was awake from movement at 6:00 when a noise woke me up but I fell right back asleep.
The movement data is probably enough to tell when I've slept better or worse, but I wouldn't trust the absolute "number of hours of sleep" they report.
Fitbit does not attempt to track sleep stages w/o HR monitoring; it's just Awake, Restless or Asleep. Yes with nothing but accelerometer data stillness can be mistaken for Asleep, but I think you're misremembering when you say "deep sleep".
It depends on the device. I used to use the Microsoft Band 2, and it seemed pretty good to me - at least it helped to validate what I believed to be my sleep patterns. In contrast, I now use a Garmin Fenix 3, and it's completely and utterly worthless for sleep tracking - it routinely decides I'm sleeping when I'm in bed even if I'm on my phone or change the display on the watch, and it rarely picks up the times I wake up during the night. --It's too bad, because for activity tracking throughout the day it's actually really good.
But doctors don't seem to trust the consumer devices (probably with good reason). When I had an actigraphy, they used a special device made by Phillips, and used the results to verify that the sleep study results weren't a one-off night.
My own research has shown that a single EEG channel with traditional techniques gets you into the ballpark of 60% accuracy (another human rater on all sorts of data gets you to ~80% accuracy and state of the art methods around 75% accuracy on a single EEG channel). Movement + heart-rate has much less information, so I'd expect about 40% accuracy overall.
My work has been traditionally done with AASM sleep labels which may be a bit more complex that what fitbit uses, so that may bring up their overall accuracy. Additionally I assume that fitbit would use a hidden markov model to predict the sleep stages (which can produce very deceptive results in the context of sleep IMO). I'd say that this would bring their overall accuracy up to around 55% based upon my best guess.
Zeo made a very good one called something like Zeo Sleep Manager. They stopped making them a few years ago, but you can still find them online and there's a fairly active community around them still.
Yes, and the Zeo is a REAL sleep tracker in the sense that it uses EEG -- not accelerometers -- as sensors (where the latter actually don't measure anything that has to do with sleep, just a proxy that is somewhat correlated but also easily fooled). Remember, when you get a real lab sleep study done, the primary measurement of sleep is via the spectral powers of your brain waves via EEG -- these measurements represent your sleep stages, by definition.
I try to run or bike several times per week. Will be adding tennis soon if I can. What seems to affect my sleep is occasional restless leg. I have to get up and do stretches or use something like the TigerTail to be able to stop the nerves from firing off. I'll toss and turn if I don't address it.
I was doubting the effectiveness of my CPAP machine and decided to take the night off. I usually sleep close to eight hours with 3 to 4 hours of deep sleep; without the machine I sleep about the same time but log only 30 minutes to an hour of deep sleep.
> I usually sleep close to eight hours with 3 to 4 hours of deep sleep
Sounds like you are getting better sleep than most healthy people. I always wondered if one could benefit from a CPAP machine even without suffering from sleep apnea.
My partner sleeps poorly and I have wondered the same.
You are right, I should be grateful for the machine. But the mask is a hassle and I find myself getting cranky about it. Still, I wear it every night. It was definitely reassuring to see what a difference it makes.
I should try and talk my partner into trying it. ;-)
I will check this out. It stores data on the card, but I had forgotten about this. It might be interesting to see if any correlates with the sleep data.
Data from Fitbit can help you see patterns which otherwise you won't notice.
I used to stay near a Railway Station, and my sleep used to get disturbed every 30 mins. I did not realize this until I saw the data from Sleep tracking. I was getting less than 50 mins of deep sleep and I could easily see that the deep sleep was disturbed at exactly the train timings daily.
With this knowledge, I moved to a new place with less disturbance during night. Now my Deep Sleep is increased by 50% after this move.
I am almost exactly typical in hours of sleep and mix of sleep type to the aggregate. What's hidden is all the volatility in my sleep... In my last week, there is a range from 5.5 to 8.3 hours of sleep in a given night. The longest sleep nights don't necessarily follow the short sleep nights either, so it doesn't appear to be catch-up sleep. Weird body is weird.
Other interesting notes:
1. Women need an extra half hour?
2. People sleep less as they age?
3. "Generation Z" is what we're calling kids these days?
> In my experience a lot of older people seem to say this. Note sure why it's true.
Because after age 30 your body, more or less, starts to die. There is a lot of discomfort and pain that is usually associated with this and as a result affects the quality and duration of sleep.
In the case of my own family members, this seems to stem from physical maladies that are correlated with age - back injuries, for example, or weight increases aggravating sleep apnea. I'm not sure how things look for old people who are extremely healthy, though.
"The mean sleep duration (from PAM) equaled 7.29±0.8 (S.D.) hr compared to 7.84±0.62 hr as estimated from the daily diaries. Neither parameter was correlated significantly with age (p>0.05)"
According to my Fitbit _(which I wear constantly)_, I get on average ~3h45m of "sleep". It apparently doesn't count restless as valid sleep, so it heavily eats into my sleep. Most of the ~8h chunk I'm asleep it marks as restless.. probably not a good sign lol.
Though, I don't think I'm using their new sleep phase metrics, as my Fitbit app doesn't seem to have it.
I had this issue as well but I realized my Sleep Sensitivity setting was on "Sensitive" rather than "Normal". Once I changed it, my average nights rest went up to 6h+
Can you have sleep apnea without it being loud and disruptive? My partner knows of sleep apnea (her father has it), but she doesn't think I have it. (also, I don't snore or gasp while breathing)
The only thing I know I have is some form of restless leg syndrome. Often I go to sleep without symptoms that I can feel (thank god, it's terrible), but apparently I kick a lot in my sleep like a dog.
> People who sleep 5 hours or less a night deprive their body of the opportunity to get enough deep sleep, which occurs near the beginning of the night.
I'd like that explained to me. If it's something that happens near the beginning of the night how does duration affect it?
The sleep tracking from my FitBit is my favorite feature. Even the cheapest FitBit Flex provides good analysis of my sleep (restless, awake, duration, etc). I use it more to make sure I get 7-8 hours to sleep than to count steps.
It'll be really interesting to see the sleep data compared against other countries or continents. Sex and age is interesting but you can't tell much from this data. Could comparing it with other countries correlate with a country's economy, culture, general state of affairs? Also, if there is a year to year trend cross reference with country.
If this data is accurate, it could be useful in determining a country's future economics. Ie. perhaps a general population's 5 mins of average less sleep means more stress which means more economic downturn/changes?
The only accurate sleep detection I've had from all the devices I've tried is, surprisingly, my $20 MiBand (both the original and the MiBand 2). I don't think it's a hardware issue, I'm pretty sure it's just stupid software.
The results I've gotten from the SleepCycle iPhone app - all the way back in 2009 - are more precise than any of those other fitness trackers. It used to rely on the uber-sensitive iPhone accelerometer but they "recently" switched to using the microphone for some reason.
Average is such a useless measure, what if there is a bi- or tr-modal distribution, or a huge number of outliers in one direction or the other? I wish they would include modes and medians.
I've tried sleeping with my Fitbit Charge HR 1 but often found that it hindered my sleep. The green light that monitors activity would show ever so slightly and ruin my sleepiness.
Fitbit Charge 2: if you move your arm while trying to fall asleep, the display lights up right in my face. Apple's cinema mode for the watch sounds good.
This bothered me, as well. If you disable "quick view" then the display only lights up when you tap it. That's a big improvement, IMO, though if my hands are full it's harder to check the time.
TIL Gen Z is a thing. I feel old.
Also, I'm guessing most Gen Z fitbit users are in college because there's no way high school kids can wake up at 8:12AM and go to school.
There's no way high school kids can wake up at 8:12AM and go to school because they'd be late by two hours by the time they'd arrive. I'm a millenial and I was waking up at 6:20 to catch the 6:40 bus to arrive at school for a 7:05 start.
Yup. When I was in high school I was waking up before 6 to make it to jazz band. College and the subsequent "real world" were just so, so much better in every way.
This info would look really nice as stacked bar charts. And the average sleep / wake times would look great as parallel timelines to show start / end times of sleep.
Well.... any device not connected to the internet will plainly not send your data to the cloud. Then it's the matter of parsing the data on your own, which at least for Garmin devices should be possible once you figure out the format. (If someone hasn't already, was a while since I explored that.)
I don't think any Fitbit has that functionality yet. SleepCycle for iOS has "snore detection" if you use the microphone mode (I suspect other apps have similar options by now.)
It really comes down to how much accuracy you really need. I use a Fitbit Charge HR and while I'm sure it's not perfect, it gives me a general idea of how much time I spend in bed/sleeping.
I'm sure it's not accurate down to the minute, but I do think it gives me a general idea of how much sleep I get. For me, that's fine, and really all I need.
My Fitbit Charge HR was more accurate than my pillow-sensor-based Hello Sense. By a huge margin. For one, the Sense thought I was sleeping when my wife was on the other side of the bed and I was out of the country.
You're honestly comparing the accuracy of a product out in the market, with one in the patent stages back in 2013?
I understand being skeptical of the accelerometer + hr monitor solution, there are certainly more involved ways of analyzing patterns that are available to sleep specialists. But how does it help the discussion to dismiss it in favor of a non-existent product?
Well, those of us with the top of the line model, the Surge, can't really contribute to this discussion. Why can't we contribute? Because Fitbit has, for whatever reason, chosen not to include its highest paying customers with the same features they've given to their lesser models.
It frequently counts me as sleeping when I sit down to watch TV in the evening, or read a book in bed. Sometimes I stay up until 1am reading and it always tracks me as deep sleep from 10pm when I got into bed. I usually take it off for my morning shower (It is waterproof, it just annoys me when washing) and it nearly always counts the walking from bed to shower as a few minutes of restless sleep and the shower itself as deep sleep.
I'm not sure how it makes an assesment of my sleep level. I don't know if it's just based on movement or if it takes heart rate data into account but it does have a heart rate sensor. It seems to usually be wrong.
In theroy it would be possible to know about these limitations and adjust your use of it to make it more accurate, but unless the participents of the study are aware of that and have been manually correcting the data then that won't be the case.
(Not a general critisim on the device, I like it for everything else, but it's sleep data is clearly rather inaccurate)