Apple Watch : Scientific Sleep Test

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Paper on the Dreem 2 Headband: pubmed.ncbi.nlm.nih.gov/32433...
Conflict of interest note: Dreem employees are co-authors.
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Timestamps:
00:00 Intro
00:52 How Apple Tracks Sleep
02:24 Test Design
03:49 Deep Sleep Test
06:21 Light Sleep Test
06:48 REM Sleep Test
09:05 Sleep Cycles Test
09:53 Awake Detection
11:53 37 Watches Tested
13:25 Sleep Timing Test
14:34 Limitations
15:29 Missing Features
16:06 Am I Biased?
16:52 Conclusions
Intro: When Apple first announced their new sleep tracking functionality, they did not provide much detail as to how it actually works, but let’s briefly summarize what they did tell us, and what this means.The best way to measuring sleep stages, what scientists call the gold standard, is called polysomnography. This basically means measuring the electrical signals coming from the brain while you are sleeping, and in addition also measuring the movements of the eyes and of some muscles. This way scientists can get an accurate picture of what sleep stages you went through. So, to make sleep tracking more comfortable and readily available, Apple trained a computer algorithm that takes in the heart rate and movement data from the Apple Watch, and uses that to predict your sleep stages. To create this algorithm, they collected both polysomnography data and heart rate and movement data with the Apple Watch, on what they say is “the largest and most diverse study population for a wearable”. That algorithm then uses the sleep stages measured with polysomnography, and tries to predict the same sleep stages with just heart rate and movement data from the Apple Watch. If Apple has enough data and good machine learning tools, they could have potentially created a very good sleep tracking algorithm, making sleep tracking available to the general public.
So, how did I test this? Well, I evaluated the sleep stage tracking of the Apple Watch for 18 nights by comparing it to the Dreem 2 EEG headband, a device that can actually measure my brainwaves, and was specifically designed for sleep stage tracking. The EEG device should therefore give us an impression if the Apple Watch is good enough for sleep stage tracking. In this case I used the Apple Watch 7 as the test device, but I think both older and newer Apple Watches will give more or less the same result, since the heart rate and movement measurements are roughly equally reliable between generations, as we saw in previous videos. Measuring heart rate and movement is especially easy during the night, when you are generally relatively still with a low heart rate. I should mention that I am using the beta version of WatchOS 9, but I suspect nothing will change with regards to sleep tracking in the official release, since the algorithm was already changed.

[@TheQuantifiedScientist]

🔴 General Amazon link*: geni.us/thequantifiedscientist 🔴 Apple Watch link*: geni.us/AppleWatch7 🟢 Instagram: instagram.com/quantified_scientist/ 🟠 Shorts: studio.kzbin.info/door/cpARGzXNaC62UQWns2dh2Q 🔵 Newsletter: www.robterhorst.com 🟡 Twitter: @QuantifiedRob * Affiliate (paid) links support the channel by earning me a commission on any sale, and it doesn't cost you any more! My opinions are completely my own, and this content is not sponsored. Paper on the Dreem 2 Headband: pubmed.ncbi.nlm.nih.gov/32433768/ Conflict of interest note: Dreem employees are co-authors. ▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬ 👇 $30 off any new WHOOP membership, affiliate* (paid) link, supports the channel!👇 join.whoop.com/QuantifiedScientist ($30 off any new WHOOP membership) ▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬ 👇Amazon Affiliate* (paid) links. Supports the channel, doesn't cost you any more!👇 ▬▬▬▬▬▬▬▬▬▬BEST WATCHES▬▬▬▬▬▬▬▬▬▬ Whoop Strap 4.0: join.whoop.com/QuantifiedScientist ($30 off any new WHOOP membership)

[@drorthomaster]

I always tried to search apple watch on that graph since so many days.... now I finally got 😂

[@pezzmania]

You would think that something with a poor battery life would be collecting plenty of data points, and thus be more accurate with predictions.

[@hyperninja1987]

ok but there aren't info about the app you used?

[@PatrickZajac]

This watch will need to be charged very frequent, you cannot check your sleep while charging, can you?

[@_yuri]

with a battery life of one day i guess the best way to use it is to charge it when you bathe and eat idk

[@MrJeremydb91]

How can anyone accuse this guy of bias lol this has to be one of the most scientific testers I’ve ever seen. Nice work sir!

[@TheQuantifiedScientist]

Thanks so much! I think some small bias in the interpretation and presentation might be inevitable, but I try to do my very best!😊

[@mdhz786]

Same. Can't find any other scientific testers at all.

[@stephw1363]

Absolutely, the people who say that are I think a bit unused to looking at raw data and dont seem to listen to the whole video because he usually points out any weaknesses in his own testing methods and qualifies the results as preliminary when more data needs to be gathered.

[@jzpat]

I just told my girlfriend this! Truly scientific and loved that he acknowledged the limitations

[@goldennamedcooper]

@@TheQuantifiedScientist hey! Can you test the new amazfit t-rex 2 since it is a Garmin competitor and at that price point it would be awesome if it was accurate

[@Tony_YT]

We need more folks like you in the tech review community. Thank you for the videos!

[@TheQuantifiedScientist]

I appreciate that! Thanks Tony!!

[@xander0901]

Apple has a proven history of putting their health tracking programs through rigorous scientific vetting before release. In fact, they often have the hardware and software in the watch without enabling it until they’ve gotten all approvals. This feature will be great once it launches. Apple has been at the forefront for health features for a long time and this is another chapter in their history.

[@TheQuantifiedScientist]

Yeah, Apple tends to do things well when they do them :-)

[@marojaso843]

Think so too. I am not really an apple user, but i am considering buying my parents apple watches (and making them switch to iphones i guess) just for the health tracking alone. A watch that can literally save your life by pre-detecting a heart attack, how ridiculous is that?

[@savagedriver1967]

@@marojaso843 that's not quite true. To detect a heart attack you'd need to use the ECG function, which is neither automatic nor running continuously. It's clever, but it requires intervention on the part of the user...

[@overPowerPenguin]

@@savagedriver1967 well, still might be useful in case of an alarming pain in the chest.

[@synerg1st]

@@TheQuantifiedScientist so you are an apple fanboy? 😂

[@syreetanolan5302]

This is the first time watching one of your videos and I love the way that you present and verbally describe data on graphs to be fully accessible in this video. I love how it is basically organized as a clear and concise scientific paper, do you ever publish papers after all the work you put forth?

[@T2Studios]

Wow, this is just a super high quality video! I sometimes find it difficult to interpret graphs, but your explanations made it super clear! There was so much info but you presented it in a very concise engaging, and friendly way. Not to mention how thorough and credible your research is. Absolutely top tier, and I’ll definitely be watching more!

[@yandan8]

This video is amazing! The amount of work you did. The thoroughness of the analysis. The comparison to medical devices. Really helpful. Thank you.

[@joel_pnk]

It blows my mind on how detailed this is and how i managed to pull through all of this scientific analysis... Well done man! Another great video, visually and content/data wise!

[@TheQuantifiedScientist]

Wow, thanks!😊

[@FelipeBaezFilms]

First time watching your videos, absolutely loved everything about it and the methodology! Thanks for sharing and going through all the work to collect all the info and research!

[@TheQuantifiedScientist]

Thanks for the nice words Felipe!😊

[@yildiraykomurcu]

Great effort by Apple ! Now they almost solved sleep tracking. I wasn't expecting such an achievement. This came out of nowhere. Awesome ! I hope the rest follows. Thanks Rob for bringing it up. So if Apple is able to extract brain status from heart rate and movement data, then it should be easier to extract blood pressure from the same data. Hope they will do it as well.

[@TheQuantifiedScientist]

Hi! I guess blood pressure is a tricky one, but maybe they can pull it off. When you are asleep you are in a relatively "controlled" state (not moving to much, low HR). I could imagine that it is more tricky to predict BP from things like HR and HRV and whatever other data comes from the optical sensor. However, maybe they can find a good proxy that predicts BP okay

[@yildiraykomurcu]

@@TheQuantifiedScientist Agreed, but we know that Samsung already added blood pressure measurement with Watch 4, not even 5. Aktiia band continuously measures blood pressure using PPG signal and they claim it to be medically accurate. It is all about data analysis.

[@strout2944]

@@TheQuantifiedScientist I hope you can test Samsung again in a few months after updates.

[@dimitrioskyranas6455]

Not sure apple's "breakthrough" came out if nowhere. Years ago they bought a finnish startup, beddit which was one of the pioneers in consumer sleep tracker. I think that expertise might have helped them quite a bit.

[@leblancexplores]

Now if they can just make batteries that can keep up.

[@stephenamos4965]

Thank you Rob! I've been waiting for this exact video since the beta release of WatchOS 9! An excellent video once again and thank you for all the amazingly helpful reviews and work that you do!

[@TheQuantifiedScientist]

You are more than welcome Stephen!

[@SaschaBurkhardt]

This is the best KZbin Channel i know for real reviews, based on scientific standards and obviously very honest. Also, no waste of time, straight to the core of the questions. Thank you so much!!!

[@craigward26]

Really amazed and happy with Apple, just shows how serious they are with developing existing hardware and software features

[@TheQuantifiedScientist]

Hi! Indeed, I think Apple generally does not release things until they work well.😊

[@unotoli]

@@TheQuantifiedScientist not always true. And sometimes 3rd party do it for them (multi-device chargers). But back to topic - this amazing results means it's all about software! Almost any trackers can achieve similar results, they just can't or won't do it. 😭

[@arandomhumanbeing2464]

@@unotoli they can’t because they don’t have the massive amounts of resources Apple has.

[@unotoli]

@@arandomhumanbeing2464 Samsung? ) They are really good at twitting, though.. PS Good heart sensor is not so software I guess

[@hirnfaser7245]

@@unotoli samsung does have the money but its unlikely that they will invest much on getting as good health measurement. Software refinement to such details is more of an apple or maybe google thing

[@greenfoodcrush2602]

Awesome review as always! My husband and I wear Fitbit because in our opinion it had the best sleep tracking. This morning he showed me the new Apple Watch and I immediately said “let me see what the Quantified Scientist has to say about it!” You hold a lot of clout with me and I am always amazed at your ability to test and report, seems like so much work! It’s greatly appreciated!!

[@604stella]

Thank you so much for this video! This was EXACTLY what I was looking for (and more)!

[@cluckyweb]

This analysis and test is the best I have seen. Awesome work and thank you for all the effort that went in to this

[@anneskeen3195]

Thank you Rob! I was very curious about the accuracy as I recently started wearing the watch and amazed by the data but was curious how accurate it is. I am 51 years old and have had sleep issues all my life, did home studies and PSGs but finally got a doctor who ordered a MSLT (which stupid insurance took almost a year to approve because of all the other things they insisted be done first to rule out). I finally was diagnosed with Narcolepsy w/cataplexy in the last 1 1/2 years. I spent almost my entire adulthood being diagnosed and treated for depression, anxiety, ADD and being told it was all in my head and nothing was wrong. Most people don't understand the impact it has on every day life. May sound silly but it is gratifying to finally have a diagnosis that makes sense, that I can see test results that support the diagnosis. So now having the ability to track without full sleep studies is invaluable!! I have only been using the Apple watch for a short time but already finding the information extremely insightful. Using the data, making a few changes and already seeing some results (albeit just a little) that I am hoping can lead to significant improvements. Thank you for the detailed analysis and helping me determine how much assurance I can have in in the data!

[@matteodayde5377]

Hi, great video as usual, always a very clear explanation! And I think that making a video where you explain us how to interpret the sleep stages would be really great. Thanks for these great videos!

[@TheQuantifiedScientist]

Great suggestion! Thanks Matteo!

[@BradgerKing]

I love how well you tested and explained between the two devices. Thank you for being so informative 👍🏻👍🏻

[@spillledcarryout]

Great methodical work and background insghts here. I encourage you to continue! Thanks Rob.

[@benjaminfox7105]

G'day Rob, I was sooooo excited when your name came up on my feed! :-) Thank you so much for doing the hard yards for us! Going to sleep with the Dreem 2 Headband doesn't look comfortable. Even worse with the sonography equipment. You've gone through 37 watches? OMG, what an effort! Legend! As a health professional (Advanced Practice Remote Area Nurse), the utilisation of evidenced-based research practice is ever so important to me. Testing-wise, it's great to hear/see the results of the Apple Watch. People may have a crack at Apple, but what they've done for health with this product is mind-blowing. Keep being brilliant, Rob and thanks again, mate! B. ps. good luck with your 'mingling!' - I'm sure the right person is out there for you! :-)

[@TheQuantifiedScientist]

Thanks for the very nice response Benjamin! I'll do my best mingling (but maybe I'll leave out that I sleep with an EEG headband on the first dates ;-) )

[@weekendwarrior8179]

I like how you had to make the graph bigger just for the Apple Watch…it’s nearly half the reason I switched to the apple eco system. I’ve been using the “auto sleep” app and it has been showing the things you mentioned

[@TheQuantifiedScientist]

Hi! Thanks for being such a loyal follower Weekend Warrior!

[@NostalgicMem0ries]

what about batery life? how do you use your watch full day and then use it while sleeping ? cause batery life is just 1 day isnt it?

[@Kilrathal]

@@NostalgicMem0ries I use my series 7 around the clock. 1 charge including 90minute exercies the battery lasts me about 24 hrs without exercies 30 hrs. With the fast charger it has it does 10% charge ever 5 minutes. or if it's lower from 10 to max in 45m. but i generally pop it on and off charge throughout the day. for like washing up/showering stuff where you don't want the watch getting soapy and basically never run out of charge

[@NostalgicMem0ries]

@@Kilrathal that sounds complex, i would rather see apple do some research on battery , week of battery life should be standard for that small device. garmin and even huawei are reaching and surpassing those limits, sadly samsung and apple so far behind, even new samsung pro 5 barely last 3 days

[@Kilrathal]

@@NostalgicMem0ries the issue you've got there is you're comparing 2 complex devices against effectively two basic smart watches. you can make apple watches last ages. but you have to turn everything that makes the actually good and smart off.

[@ThePieSnatcher]

Your videos are the best scientific testing videos on KZbin, thankyou for taking the time to make this!

[@isds6310]

Great video and great work. First time to this channel and I’m pretty skeptical of the information that I take in, but this seems very scientific and certainly delivered in a very friendly and inviting manner. I wouldn’t be surprised if this channel grows much bigger in coming years because of the quality of content and how you explain it. Also, don’t listen to all the critics; they don’t know what they are talking about and people will find anything to complain about or be nasty about. There is absolutely no reason that a small friendly KZbinr would want to be biased in favor of Apple. Keep up the good work and I look forward to watching your channel grow as more and more devices get serious about health related tech.

[@najibyaghoobi5609]

The best review I’ve ever seen. It’s a lot of work to make such scientific research . Great job and thank you for the video

[@Milkshakman]

Just wanna say I’m really glad this brilliantly cogent and in-depth video is doing so well views-wise. It has long been difficult to find good, detailed EEG and PSG comparisons with wrist devices without digging through dozens of random (often outdated) PubMed papers.

[@ankurdeo8416]

Just an observation: Apple Watch seems to show a lot more transients (or spikes) in readings compared to the Dreem2. From a software perspective, this might be because of the sensitive transient and suppressing techniques used. If you do actually filter the short duration spikes, the accuracy of Apple Watch is remarkly high! Great video by the way.

[@TheQuantifiedScientist]

Hi Ankur! Indeed, great points! It also depends on what we define as "awake" (what guidelines in the scoring are followed), and e.g. how much smoothing is applied.

[@fridaphonebackup6599]

Thank you for this video Rob! ✨️

[@ThEBoOoM]

Such a great review quality! Keep going, hope to see more of these tests and with more data an more accuracy

[@tazahsan]

I just want to say that your videos are amazing!! The amount of time, effort and intelligence it takes to put an unbiased video together like is extreme! Thank you so much for all your hard work and cannot wait to see more! I recently bought (and then returned) the Oura Ring and now am trialing a whoop but love my Apple Watch! Can’t wait to return my whoop, not spend any more money and still have the best sleep tracker out there 😬 Keep up the amazing work! 🙏✌️

[@TheQuantifiedScientist]

Thanks a lot Taz! Happy I was able to help 😊

[@tazahsan]

@@TheQuantifiedScientist now, the question is, do we upgrade to a Series 8 or the Ultra?!

[@aaronburns7477]

When the public beta was first released I compared it to my withings sleep analyzer and was pretty impressed at it’s similar results. I’m curious if the rumored new temperature sensor in the soon to be released Watch will have any impact on the sleep algorithm. Also great job on the video I felt like this was a bit more polished than maybe some of your others in the past. Can’t pinpoint what it was but you are doing an amazing job at the production process.

[@TheQuantifiedScientist]

Thanks so much Aaron! I am curious what sensors will be in the new one too!

[@dave-vl7kl]

no

[@tomas_m]

The reviews on this channel are absolute gem, didn't hope to find such a high quality stuff

[@TheQuantifiedScientist]

Thanks so much Tomáš!

[@zapeterson90]

Great video, I have really enjoyed watching these over time! Keep up the good work!

[@TheQuantifiedScientist]

Thanks Zach!

[@julioantoniogonzalezgarcia6392]

Congratulations Rob, everyone may think different, but I don’t think you show data as a fanboy for any company, on the contrary I think you show data quite unbiased and very well analyzed. Thank you very much for your channel, I enjoy it very much.

[@TheQuantifiedScientist]

Thanks so much Julio! It is really appreciated😊!

[@silviui.]

The most awaited review of the year! Thank you so much, Rob! This is excellent news. If they implement a smart wake alarm, I can forever say goodbye to Fitbit.

[@TheQuantifiedScientist]

Thanks Silviu! And thanks for sticking around for such a long time already😊

[@stephw1363]

Oh my gosh.....what is a smart awake alarm?

[@silviui.]

@@stephw1363 Smart Wake alarm A vibrating alarm wakes you during the optimal sleep stage, so you feel refreshed.

[@lalalala-ce3fn]

Doesnt Fitbit literally have this feature tho?

[@silver1588]

@@lalalala-ce3fn yes, it has.

[@painless29]

You're doing an amazing work! Congrats

[@joeblack729]

Thanks a lot for such great tests!

[@DawidVelCatweazel]

Hi Rob. Great stuff as always. Are you aware if apple will add something like readiness score and/or sleep score? Having just raw information about sleep stages might not be that useful without some additional feedback based on that. Btw. do you plan to review Garmin forerunner 955? It seems to have so many data and metrics accessible for user, very interesting watch.

[@TheSambev]

The alternate angle at 14:39 is awesome! Can’t wait to see how this all stacks up against Oura ring’s revised algorithm later this year (hopefully)!

[@TheQuantifiedScientist]

Thanks Sam! Yeah, really excited about the new Oura algorithm too!😊

[@jamesfhIII]

I’ve been awaiting the new Oura algo for nearly a year now.

[@AATTPP1991]

Love your videos and have been a longggg time viewer, thank you for your work! Please keep going strong!

[@josephskeller]

I've been anticipating your analysis of these new features and I'm glad to see them. Great work!

[@Ronin-fr1wm]

thnak you sir keep supporting our channel

[@kana-is-sleepy]

Thank you so much for putting so much work into this comparison! I’ve had 3 sleep studies during the past several years (2 PSGs+ MSLT, 1 home study), so I’m very familiar with how complex and sensitive those tests are. After my latest PSG/MSLT, my neurologist diagnosed me with narcolepsy type 1, a rare neurological disorder that causes all sorts of sleep dysfunction, particularly with REM sleep. To put it simply, my brain goes into REM sleep far too quickly and easily, even when I’m awake. Daytime REM sleep intrusion is a frequent occurrence, and can cause sleep attacks, “micro sleeps” (staring episodes that resemble absence seizures), hallucinations (visual, auditory, and tactile), and cataplexy, a weird symptom that causes partial or full body muscle weakness as a result of strong (usually positive) emotional stimuli. This muscle weakness resembles the paralysis that keeps you from acting out your dreams while sleeping. Because of these issues, watch sleep tracking isn’t as accurate for narcoleptics, but it’s better than nothing. Luckily, some researchers are currently conducting a study to help make fitness trackers more accurate for narcoleptic patients. The study is currently limited to just Fitbit devices, but hopefully it’ll be open to Apple Watch users (like me) soon. That said, it’s cool to see just how remarkably accurate it is for the general population! Even if it’s not 100%, I’m glad I can generally rely on my Apple Watch sleep tracking data.

[@anneskeen3195]

Kana - I have almost the exact same diagnosis as yours. I am 51 years old and have had sleep issues all my life, did home studies and PSGs but finally got a doctor who ordered a MSLT (which stupid insurance took almost a year to approve because of all the other things they insisted be done first to rule out). I finally was diagnosed with Narcolepsy w/cataplexy in the last 1 1/2 years. I spent almost my entire adulthood being diagnosed and treated for depression, anxiety, ADD and being told it was all in my head and nothing was wrong. Most people don't understand the impact it has on every day life. May sound silly but it is gratifying to finally have a diagnosis that makes sense, that I can see and track and to hear others with the same struggles. I have only been using the Apple watch for a short time but already finding the information invaluable! Using the data, making a few changes and already seeing some results.

[@kana-is-sleepy]

@@anneskeen3195 Sounds like we were diagnosed at around the same time! I was diagnosed in February 2021, but I initially developed it back in late 2012. It took 8 years to get my diagnosis, and I struggled with a lot of the same misdiagnoses (depression, anxiety) plus some other ones (severe insomnia, CFS, “bad sleep hygiene”). I also had a lot of doctors who would tell me “I’ve found the answer! Treating this anemia/hypothyroidism/vitamin D deficiency will make you feel so much better!” I really did have those issues, but they weren’t the magical answer that those doctors hoped for. (I also had undiagnosed ADHD, but unfortunately, that didn’t get diagnosed until early 2022.) It took over a year for me to finally get my 2nd PSG/MSLT (the one that actually got me diagnosed) too, but that was because I did my negative home study in late 2019, and got referred for my PSG/MSLT in early 2020… right when the sleep labs closed due to COVID-19. The delay ended up being a blessing in disguise though: the sleep clinic that did my at home study took forever to restart in lab studies, so my ENT doc (who had referred me to sleep medicine due to a deviated septum) sent me to the other sleep clinic because they were already doing in lab studies again. I ended up meeting my current doctor there, a sleep medicine neurologist who’s now my all-time favorite doctor (which is an accomplishment, because I’ve been blessed with a lot of amazing doctors). My MSLT actually came back negative, but this doctor took a closer look at the results and realized it was a false negative result. I don’t think many non-neurologist sleep docs would have figured that out, so I was very lucky to end up with him. Living with narcolepsy is really hard, but luckily, I’ve found some amazing online support groups that make this narcoleptic existence a lot less lonely! I’ve also met some other people with it who live in my area. Please feel free to message me if you ever want to talk to another person who gets it! 😊

[@CrizzX]

Thanks. I was waiting for Apple to update their sleep tracking and it looks like they have. I appreciate how data intensive your research was and how you addressed its limitations.

[@TheQuantifiedScientist]

Thanks so much Crizz!

[@susieroberts8175]

Thank you SO MUCH for taking the time to produce an evidence based, objective review based on scientific methods and critical thinking! There is so much nonsense, hatred, and bias on social media. Your video is a breath of fresh air and an inspiration. You have a new subscriber!

[@EduardoHenrique-nd1ro]

Amazing video, Rob! Thanks for sharing with us! Cheers from Brazil!

[@kp66udv]

Finally! Now, the Apple Watch 8 had announced. Guess we all hope you can put that review on the new watch as priority. We are really desperate to see the results on its exercises and sleep tracking accuracy. Once again, thank you for your effort and passion! Still the best reviewer I'd ever seen.

[@TheQuantifiedScientist]

Thanks Steve! I'll start with the new apple watch as soon as I get it!

[@JohnDoe-om8im]

Thank you for your test - it was very exciting. In my opinion, the best thing so far has been a customized AutoSleep configuration in combination with an Apple Watch. I know you have already tested AutoSleep, but not with a customized configuration. Could you compare the Apple Sleep Tracking which you tested as a beta with AutoSleep with a customized configuration? AutoSleep also has years of experience and it would be super exciting to know if they are finally better, or if you should still rely on AutoSleep with an Apple Watch. I also think I'm not the only one that would be in the answer of this question of questions. By the way, there are also options in AutoSleep (together with AutoWake) where recommendations are given and a sleep account which is taken into account for it (which you are interested in, as you said at the end). In any case, thanks for your work - I've shared it multiple times with a larger audience :)

[@Felix-tj4hx]

Deine Videos sind super hilfreich! Haben mir extrem dabei geholfen die richtige Kaufentscheidung zu treffen. Du bist die einzige vertrauenswürdige Quelle, wenn es um die Genauigkeit der verschiedenen Geräte geht. Sehr wertvoller content! Danke ;)

[@TheQuantifiedScientist]

Danke! That is super nice to hear, and happy I could help!😊

[@jk.g]

Great video, thanks for the excellent analysis. I really liked your approach! Especially the graph showing the comparisons with other products.

[@TheQuantifiedScientist]

Thanks a lot JK, really appreciated!

[@BadNeighbor762]

Appreciate all the hard work you put into every video. Thanks.

[@TheQuantifiedScientist]

Thanks so much!

[@os2171]

I’m a neuroethologist (sensory biology auditory system of frogs; multimodal integration in bees and bumble bees -learning and memory). Your analysis is very deep great discussion. Your results are the only thing preventing me switching from Apple Watch into Garmin Fenix 7… I am sick of the battery…. Great work!

[@Jesus_friggin_christ]

apple just announced apple watch ultra which is in competition with the fenix 7 so might be worth looking in to

[@espressomatic]

I'm using an Ultra right now. If I don't do any GPS-based workouts and use this thing only for heart monitoring, sleep tracking and as a typical watch (with notifications) the battery will easily last 3-6 days. Here's a tip for this watch: charge it when you go for a shower. Don't rush to put it back on, give it 20-30 minutes of charging while you get ready for whatever. At that point I stop noticing this thing is even battery powered.

[@dan110024]

@@Jesus_friggin_christ I feel like the Ultra is just an over priced apple watch. It does a lot but nothing great. A Garmin blows it out of the water in terms of data for people interested in proper training.

[@dolbycore890]

Your test videos impress me every time, keep up the good work :)

[@petrahrabakova752]

Wow you really killed this review! You must be one of the best tech reviewers I have seen on the internet. Well done! And thank you for all the valuable information 😊

[@prgv648]

I really like the channel and it has become one of my favourites when it comes to fitness trackers. I have to admit that Rob does not seem to be the elite athlete idolizing Garmin or some of the other top sport focused brands. But hey there's a target group for all of them... in any case Apple is known to have a top notch heart rate sensor and that combined with a lot of R&D can lead to very accurate metrics.

[@TheQuantifiedScientist]

Thanks a lot Petar for the nice compliments!😊

[@fitgearhunter]

Rob - (BIG question below, praise first) this was probably one of your best videos today. Your pacing was fantastic, the explanation of different metrics was excellent, and your disclosure of biases and different testing approaches was superb. These are incredibly excellent results for sleep tracking as well, and I completely agree - I strongly wish Apple would provide recommendations or at least a simple score. Big question - some have said that on the new AW OS they are receiving significantly more HRV data points. Are you finding that at all? Like 40 versus 4 kind of difference.

[@TheQuantifiedScientist]

Hi! Thanks for the praise! It is difficult for me to balance speed of the video vs mentioning biases/disclosures, especially in the videos where I address everything from heart rate, GPS, steps, ..., to sleep. However, happy to hear it worked out in this video! Good question, and honestly, I have to say, I did not look at that. I should though!😊

[@andybuchan]

What a great review, thank you so much for the huge effort you have put in to this research. Really helpful and informative.

[@SilentG20]

Your wonderful work exceeds expectations once again! Thank you so much!

[@cyrille3169]

Great work as always. Yes, would be very interested in a video on how to interpret the data. Is n (50) minutes of X (deep) sleep enough, what should be the percentage of each sleep stage, how to compute a quality sleep metric …

[@JanZamani]

Apple is doing great on making sure the data they track is actually accurate. They're really showing up the competing brands in terms of scientific accuracy, which is really what you want when you're tracking your health data. The main problem with apple is reparability but I guess that's a problem with all health tracking devices these days.

[@RakeshBattulag]

that and their pricing is the only thing stopping me from switching over but I don't think It makes much sense to hold off any longer. I will atleast get the watch se once it is proven to work just as well and works with android.

[@LordAlacorn]

I would say durability of Apple devices is the main concern, especially wearables - way to easy to damage. Just enough to loosen hermetic sealing and failure process has begun.

[@benshulman6068]

This is great, thank you! Appreciate the thorough testing and analysis

[@TheQuantifiedScientist]

Glad you enjoyed it Ben! Have a great day!😊

[@wagnerfsj]

This was a very insightful experiment! I am so glad to see the results. It makes me appreciate my  WATCH even more. Thanks for taking the time to do this and for sharing with us. Yo got a new sub!

[@davidallred991]

Thanks so much for this video. Having sleep issues I bought the Apple Watch 7 as soon as the Watch OS 9 beta came out and have been using it every night. My sleep cycles were showing pretty poor sleep with frequent wake ups. I wasn't sure if it was the Apple Watch not working well or if I just sleep that poorly. I had a couple of family members that sleep soundly use it a couple of nights and the sleep data was completely different for them and looked like healthy sleep patterns. I figured the watch must be somewhat accurate since It showed poor sleep for me with sleep issues, and showed good sleep for family members with good sleep patterns. But this video gives me even more confidence in the Apple Watch's sleep data.

[@TheQuantifiedScientist]

Happy to hear I could confirm what you suggested 😊

[@cowswirl]

Hi David Allred, I have poor sleep too and have done overnight sleep tests (polysomnography) at hospitals. I'm now considering getting a smart device ... and leaning towards the Apple Watch, as it seems to be the best.

[@TheBigKing0]

Wow! Never seen an 80% in the confusion matrix, impressive. Great vid

[@TheQuantifiedScientist]

Thanks so much!

[@coragion5509]

Excellent video! Rob you are amazing and thank you for all your great videos!

[@TheQuantifiedScientist]

Thanks so much Coragio!

[@Tvj_films8452]

Great review. Thanks for your hard work.

[@cedric_vdbd4836]

They only need to increase their battery life to at least a couple days and I’ll buy one. Unfortunately, it doesn’t seem like to be for this year

[@theophiled]

*for this decade, probably. It won't change until some technological breakthrough is achieved

[@TheQuantifiedScientist]

Hi! Yes, that would be great. There are rumours of a more "sports oriented" Apple watch that might have a bigger battery. There is an Apple event in 2 days, so maybe there it will be revealed :-)

[@aboumawiyah]

what is the point if you need to charge it every night?!

[@Chris-gq8ev]

@@TheQuantifiedScientist rumoured to be 2x the cost. But, all their metrics are making it tempting...I would need to get an iPhone too 😡

[@bubbaj5007]

Apple Watch can do almost a full charge in 30 minutes now. So as I’m getting ready for bed I’ll charge my watch. Put it on for bed then top up when I wake up.

[@toastrecon]

It’d be interesting to compare sleep data to room temperature. I find I move around a lot more during the hot summer months compared to the cold winter.

[@HarjotShah]

Awesome video man. The effort that you've put in is commendable. Keep up the good work 👍🏻

[@TheQuantifiedScientist]

Thanks a ton Harjot!

[@louishurr393]

Excellent review. Thank you for all of your diligent effort!

[@steve_m.3403]

Hi Rob, thank you for this very informative video. I use an Oura3 ring and I’ve noticed the sleep analysis seems to overstate my deep sleep and understate my REM sleep. After watching your video, I borrowed my wife’s Apple Watch7 and confirmed this to be the case (assuming the Apple Watch is more accurate which your video appears to indicate). Within the past few days, Oura has just introduced a “New Sleep Staging Beta” for sleep analysis. I went back and reanalyzed my sleep data with this new beta algorithm and it now seems to agree much better with the Apple Watch data! Here is my question - I was wondering if you could compare the Oura3 ring sleep beta with the brain wave measurement device that you use as a control to see how accurate it is or how well it now correlates? Or do you already have plans to do so? It would be good to know if Oura finally got it right.

[@vamp07]

I have been looking forward to this review since I first got the beta months ago. I knew it was going to be good but I was not sure if it was above or below the charge 5 which I also own. I suspected it would not be as good but your review was great and unexpected. Thanks for all your hard work on this subject.

[@TheQuantifiedScientist]

Thanks for the compliment Steven! Have a great day! 😊

[@artyom_ra]

Discovering your channel today was a gift! Great video! Exactly what I needed. I love sleep, science and about to buy Apple Watch. Thank you, sir! May you and your channel prosper 🙏

[@TAMITRO]

I love your channel! I love data so much, thank you for all your efforts.

[@TheQuantifiedScientist]

Glad you enjoy it!

[@strange_man]

I was trying to track my sleep for a very looong time. Finally I came accross with this channel. Aand finally, this watch, I guess is the best I can get. Right?

[@Thron2111]

I know it’s accurate cause everytime I wake up from a dream, the health app shows, that my last sleep phase was REM sleep.

[@TheQuantifiedScientist]

Happy to hear it matches!

[@businessreform]

Excellent video, thank you for all the work you put into testing this feature and for sharing it with us!

[@TheQuantifiedScientist]

Thanks so much!😊

[@MikeSmith-rg2cw]

Great job Rob

[@Simboy93]

Bro goes all in to review these devices for us.

[@TheQuantifiedScientist]

Hi Sumit! Happy to do it 😊

[@highlanderes]

Awesome performance - seems impossible even for one person. Congrats to the team who achieved this 👍 I hope Apple will tackle recovery and recovery score for strength/cardio, as I just changed to Garmin for this (and battery life), and miss the accurate heart rate (and weather forecast) of the AW.

[@TheQuantifiedScientist]

Hi! I am sure many people at Apple (and outside of it) worked quite hard on this 😊. Have a great day!

[@StaticVapour590]

Since having first smartwatch on my wrist, i've been really interested about how such tiny thing is able to measure all that information. Your channel is awesome!

[@elias9049]

This feature alone can convince me to switch from Android to the Apple eco system... I'm gonna wait if sense 2 or the pixle watch would catch up

[@jamesfhIII]

I’ve been testing Apple’s sleep staging, since the first beta build dropped in early June. I’ve also been wearing WHOOP for over 2.5 years, and I’ve found it’s sleep staging to be very accurate. In my testing, the Apple Watch and WHOOP differ greatly in the amount of deep sleep that they capture. For example, WHOOP says I get between 1.5-2 hours a night vs. 30-40 minutes for Apple Watch. I’m curious as to how both of these feature among the best you’ve tested (upper right of your comparison graph), when they yield such different results.

[@jonathanodude6660]

maybe the WHOOP inaccuracy is due to biasing more while apple watch is due to biasing less? its also possible that the effect is unique to you.

[@PoPluto]

My results are even more skewed. I use Autosleep to track my sleep which normally indicates 1-2 hours of deep sleep per night. The Apple app has been estimating between zero and 30 minutes of deep sleep per night which is highly unlikely (although I don't have an EEG device as a benchmark). I posted a thread in the Apple support forums and some other users are having a similar experience.

[@orangelupine3761]

@@PoPluto this is happening for me too, also the sleep tracker says I have slept for about 7 hours but the sleep stages only add up to just over 2 hours and yeah almost always zero deep sleep!

[@johnadams9954]

Same for Oura. Apple watch says 36m while Oura says 1h36m.

[@orangelupine3761]

I think I have resolved my problem with it, in the health app I gave priority to my watch for sleep tracking instead of AutoSleep and now it seems ok

[@Johnny-ld3bc]

Thanks for the super professional reviews and comparisons!!

[@thomas_rellum]

Just thank you for your work. Amazing!

[@canyonblue737-8]

Apple is seldom the first, but they tend to do it best when they do. Their HR optical wrist sensor is the best. Their calorie burn estimates are the best.

[@TheQuantifiedScientist]

Hi David! Yes, Apple generally does a pretty good job once they commit

[@tracysweatt5401]

Wow! I really had believed that Apple would manage a great tracker, but to see this, I’m super impressed. I love my Apple Watch, and I am so excited to have this added sleep data to be able to talk to my doctor. I’ve done a home sleep study that was “inconclusive” so they basically said I have to go in to the sleep lab. Between homeschooling four kids, and some not so nice anxiety issues, I know that I wouldn’t sleep worth a damn at a lab. Plus they told me they could end up with the same dang “inconclusive” result even from the lab readings. At least with my Apple Watch I will have some pretty darn accurate data it would seem over time, and hopefully that will help them do something rather than nothing….

[@rileyf1242]

The information from an Apple Watch is great and helpful, but not diagnostic in any sense. In some ways the sleep staging part of polysomnography is not super important. Nine time out of ten we’re looking at sleep apnoea - unhelpful, the other times we are looking at PLMD or narcolepsy. In the former sleep stages are unhelpful, and in the latter the Apple Watch is not nearly precise enough.

[@muratturedi4696]

Fantastic analysis brother, keep up the good work

[@MrStibaer]

As always - really good review! Thanks a lot!

[@TheQuantifiedScientist]

Thanks so much, really appreciated!

[@TrueRay17]

It’s pretty clear that the scientific data you provide is an unbiased one. Some people just lack the skills to see that. Great video yet again!

[@TheQuantifiedScientist]

Thanks, that is very kind of you!

[@9sanjay]

Hi Rob, Thanks for your much awaited comparison of iWatch sleep module. Just to add, I have been using Garmin FR945 and have found its sleep algorithm excellent & very much reliable. It even recognises when I have had Coffee/Tea/Alcohol before an hour two before going to bed. Further, it shows sleep score & body battery which I have found to be very reliable. thanks

[@TheQuantifiedScientist]

Thanks Sanjay! Indeed, I mostly focus on the sleep stages and less on the sleep quality scores, so what you say might be true :-)

[@moosetruce]

Great video! I don’t ever comment on videos but this one was so detailed it deserves a like and now a subscriber to your channel!

[@marcushedges]

This was really insightful. Thank you!

[@mboiko]

Every time I see the sleep chart showing all the fitness watches, I'm always amazed that a $49 Mi Band 7...is so far to the right on the graph. While I know it's not super high up on the graph, the percentage of agreement (4 sleep stages) is better than all but a very few including the Apple watch...not to mention a 10+ day battery life...all for just $49 at Walmart!

[@TheMisterPvp]

The inspire 2 is pretty cheap too

[@TheQuantifiedScientist]

Hey! I will still do a complete review of the Band 7 too, so stay tuned for that!😊

[@mboiko]

@@TheQuantifiedScientist Sounds great Rob now all we need to know is Mi Band 7 or Mi Band 7 Pro...a question I'm already being asked by a few friends and family. Keep up the great work!

[@williamstevenson2649]

I'm not interested in sleep tracking - as an old bloke, I get up a lot at night anyway and am not bothered about it. However, I watched all of this as a data exercise and am very impressed (as usual) by Rob's determination to get it right, and by Apple's determination to do the same. I don't have any Apple products and am not about to buy any, but it's clear that if money isn't a factor then Apple is best at HR and sleep analysis!

[@TheQuantifiedScientist]

Thanks for the very kind comments William! I am happy it was of interest to you!

[@firstnamelastname3106]

Wow,great analysis! Thanks!

[@theEdwardKosmo]

For a long time I wished I could compare trackers objectively. Thank you for doing this! I hope your channel explodes 🙌

[@TheQuantifiedScientist]

Thanks Eduard! 😊 That would be awesome!!

[@shooter1536]

Im normally an android guy but apple has been making some good products lately, im considering going all apple lmao

[@TheQuantifiedScientist]

Haha, the problem is that you can only use the Apple Watch with an iPhone. So, switching means switching your whole "ecosystem"

[@_Alvaro_007]

Incredible Apple, if it had more battery it would be a perfect watch!

[@TheQuantifiedScientist]

Hi! Yes, better battery life would be amazing. Let's see if the Apple Watch Series 8 or the rumoured Sports version are any better 😊

[@arvind31459]

@@TheQuantifiedScientist Hey can you please make the test with same 18 nights of data from watch 5. And also can you please increase the #no.of people you test the watches on. The more the people the better understanding of the results.

[@_Alvaro_007]

@@TheQuantifiedScientist or if not in the future they will surely improve.

[@NostalgicMem0ries]

@@_Alvaro_007 well uif they keep adding more sensors and powerfull 5 wifi versions, idk if batery will go up fast. kinda what we wanted from smartphones but cause of bigger and more powerfull cpu/gpu and other parts bateries became bigger but drains faster too so0 kinda remains same 1 2 days from phones now

[@LordAlacorn]

Battery life and working with another phones. This is two things that are a deal breakers for me.

[@SvikDK]

What a great video. Thanks alot for the effort you made in this.

[@Arsalan_2210]

Thank you for making this video, your way of delivering information is very polite and soothing and the pace is really good, I watched the video till the end and now I have subscribed to the channel :) thank god I found your channel! I know how much hard work you put into making this one video alone, and I appreciate it a lot. Thanks again, i bet nobody has done this ever, i mean this kind of scientific comparison alone requires a lot of patience. Good luck, and i hope you reach a million subscribers soon :), I also loved the way you openly told your audience about the affiliate links down below and hopefully they work for me, i want to support and help ur channel in some way or the other. I am from India so maybe your affiliate links might not work but i will still give it a try. Thanks