Consumer sleep tracking devices are all the rage, but are they accurate? We share our experiences wearing the Oura ring, plus break down the studies which have measured popular consumer sleep tracking devices against the “gold standard” in sleep tracking – polysomnography. Aaron plans to buy an Oura Ring, but despite an overall favorable impression of the product, I stopped wearing mine. For more, see this blog post: Why I Stopped Wearing an Oura Ring.
This Episode Covers:
- Lessons on sleep hygiene learned from Oura Ring [6:00];
- Oura Ring and the “Nocebo” effect [8:00];
- Consumer sleep tracking technology vs. gold standard polysomnography [16:41];
- Can Oura Ring accurately detect sleep? [21:00];
- Why Aaron is impressed with the Oura Ring [28:30];
- Is sleep tracking useful or is it too much data? [35:00];
John: I already have all these wellness trackers that are linked to apps, for me, is that I’m at my most healthy and calmest and most productive when I’m not, like geared into my phone in an addictive way and I’m having another reason to check my phone just incessantly.
Aaron: Maybe it’s one of these ones where you have to do it in a cyclical fashion as well. You know, you go use it to improve your sleep hygiene. And then once it gets to the point where it’s actually causing it to be a bit detrimental, you step away from it again and you pick up the bad habits again and then you need to come back to it in a month, two months’ time.
John: Welcome to the “Gene Food Podcast.” I’m your host, John O’Connor. Hey, guys, we have an episode today about sleep tracking. I was wearing an Oura Ring and tracking my sleep and getting my REM and deep and light sleep and all that and trying to pay attention to sleep hygiene because it’s something that’s very much on the mind of people in the health and wellness world, and we know that sleep is really important for achieving a good state of health and just reducing stress and feeling good in general. But the question we ask today is, are the popular sleep trackers that are on the market, especially the Oura Ring, which is the device I was wearing, are they accurate? When do they tend to overestimate or underestimate sleep? Do they accurately track REM, deep sleep, all that? And should you buy one?
And we also discuss when is data good and when is there too much data? In other words, is it overkill to track sleep? Does tracking sleep actually hurt the quality of sleep? So those are all the issues that we get into the podcast today. I want to say also for those of you playing along at home, we have launched our Gene Food test kits. So we have our own genetic test kits that have over 120 genetic markers linked to nutrition, we test for APOE4, we test for histamine clearance, chronotype, if you’re interested in sleep, your ideal chronotype is genetic. We have that on the report. Sleep score caffeine metabolism, those are now live and for sale on the site. And for podcast listeners, we can offer you a 15% off discount, just type in PODCAST GF, all caps, and we will give you a 15% discount on your first order of a nutrition plan kit from the site. Thanks for listening. And without further ado, here is Dr. Aaron and I discussing sleep trackers.
Okay, Aaron, so this is going to be a different kind of an episode today. We’re going to do more of a quick hitter and we’re just going to talk about sleep tracking devices. You and I have…I know you’ve been debating getting an Oura Ring. I used an Oura Ring, I bought one and used it for four to five months, and then as we’ll discuss here, I actually destroyed mine. So, yeah, it was kind of like Frodo, you know, to use the “Lord of the Rings” analogy. I feel like I kind of…it’s like you to take the ring and put it into the fiery pits of Mordor. I think it was me taking my iPhone and crashing it under my Oura Ring in a moment of just sort of like frustration.
I will do that from time to time. You know, maybe every twice a year I’ll just destroy something kind of like that. For me it’s very cathartic. I know someone listening at home or even maybe Ray or Aaron, you guys might be thinking that sounds kind of insane or something but, you know, maybe it is and it very well could be. It’s just something that I do, and so I did it and actually it’s very satisfying.
Aaron: A bit of catharsis is good for the soul.
John: You know, honestly, it is kind of good for the soul. Yeah, yeah. You know, I was like, that was kind of a bizarre thing to do. So then I found myself on like a sub-Reddit, like what was the most valuable thing you’ve ever destroyed, like people sharing on Reddit what things they’ve destroyed. But I’ll get into it in a minute here as to why I destroyed my Oura Ring. So you were considering getting one though, right, Aaron?
Aaron: Yeah. Because you have these other devices that you can use as sleep trackers and they’re never good really. Actually you first mentioned the Oura Ring and it made look into it. And you sort of read the feel about it and the thing that it does and, you know, how it’s supposed to sense the different stages of sleep as opposed to just saying you’re asleep or you’re not asleep. And that seemed to be a better way of going. If you really want to track your sleep, it’s not just about how much you have, it’s about the quality of the sleep that you have as well. And that seemed to be the way forward. And then we sort of decided to sort of look into it a bit more detail, see if people have done research on it and come across some interesting stuff, which is what we’re going to talk about in the podcast.
John: Yeah, we’re going to get into an actual study that was done where they took 41 young adults, I think, ages 14 to 22 and compareddo you pronounce it? Polysomnography?
Aaron: Yeah, that’s right. Yeah. It’s not an easy one to pronounce.
John: Yeah, which is the gold standard for tracking sleep where they take actual little nodules and attach them to your brain and then read your brainwaves while you’re sleeping, I believe, correct?
Aaron: Yeah. So when you see those pitches [SP] of the people, basically they look like big hair nets of electrodes all over their head, that’s what are those.
John: Yeah. And it blows my mind that anybody could sleep under those conditions, which just being in a lab and having that attached to your head, it seems like that might not be the best way to sleep.
Aaron: Yeah, I think that’s the problem with a lot of these sleep studies is, you know, you’re, A, you’re sleeping somewhere that’s not your normal place where you might want to sleep, and, B, you’re in a very uncomfortable position. I think in all of these studies they acknowledge that this is an issue and I guess that’s where the makers of the Oura Ring think that they could come in. It’s a lot less invasive. And if it was performed as well that would be a really great development.
John: Right. And I actually have overall, if you did a favorable, unfavorable, I had to click one on Oura Ring, I’d say favorable. I think the Oura Ring is really well done. I think the branding is excellent and the ring itself is kind of stylish and kind of cool to wear. I found that the benefits were front loaded for me. So I wore the ring for four to five months-ish. And at the beginning, the insights are, I think, pretty valuable. You get an idea of, okay, for me, for example, if I have more than a couple of drinks, if I have one drink, my resting heart rate will go up a little bit and it disrupts my sleep, the quality of sleep I see in the ring goes down. But if I have two or three drinks, it was amazing to me what would happen to my heart rate and my sleep quality. It just went through the floor.
And I noticed… A lot of it is common sense. The more caffeine I had, the less I would sleep. If I was up looking at screens or doing a lot of computer work late at night, my sleep would suffer. You know, if I was really stressed out or worrying about something, I might not have a good night’s sleep. If I had just traveled or if I was jet lagged, I wouldn’t get a good night’s sleep. Conversely, for whatever reason, if I got in really cold water early in the morning, I noticed that those were my best nights of sleep at night. And the supplements that helped me the most with sleep were probably magnesium, Epsom salt baths before bed.
Taking CBD is calming. I found that taking CBD, actually, like if I got up in the middle of the night and I felt like I was going to have trouble getting back to sleep, taking some CBD was actually a really effective tool for getting back to sleep more so than getting to sleep. Because what I learned is that my sleep latency, the time when…how long it would take me to fall asleep was actually always very low. I tend to be more of a restless sleeper and have wake ups during the night. And so you learn all this stuff. And what it makes you do is it makes you really prioritize your sleep hygiene. You think, “Okay, sleep is important. I’ve noticed I feel a lot happier and better when I get a good night’s sleep. And so I’m going to make this a priority in my life.” And that’s what the Oura Ring does for you.
And then I found that as I continued to wear it, it became a source of stress. It just became too much data. So if you wake up in the morning and you haven’t had a good night’s sleep, I don’t see the benefit for a device telling you that. In other words, there’s this no-cebo effect of, “Okay, I had a bad night sleep.” And then this ring assigns what’s called a readiness score, which is basically a combination of your heart rate variability, resting heart rate, sleep stages, total sleep, all that. It gives you a readiness score. So if your readiness score is really low, to me, that was just almost like an insult to injury and just it was almost like a suggestion like rather…I already knew I needed to prioritize sleep. This was almost like a suggestive thing like your day is going to be worse kind of a thing.
Aaron: You almost needed it to knock you in the evening and say, “Because you didn’t get a good night’s sleep last night, you should probably stop looking at your phone on your computer now and consider…” Whereas, what’s the point of it reminding you in the morning that you didn’t get a good night sleep and telling you to take it easy because, you know, you might not be able to take it easy during the day because you’ve got a busy day ahead of you?
John: I found that that wasn’t that valuable. And to its credit, it will remind you. It will tell you like, yeah, a couple hours before bed it will say, “This is your ideal bedtime.” The ideal bedtime for me was like 8:30 to like 9:45, which is funny because we just found out on the whole chronotype thing of the Gene Food testing that my chronotype is actually an owl, but it was suggesting early bedtimes and it does do that. It’s just overall it just seemed like data overload for me. And I don’t think, just for me, I don’t think it’s consistent with a good night’s sleep or feeling restful and feeling tired with this obsession of like, “Oh, I hope I get over two hours of REM sleep tonight,” or, “I hope I get extra deep sleep tonight.”
When you start really thinking about your sleep on that granular of a level like before you’re going to bed and then you’re waking up and the first thing you’re doing is checking your Oura Ring to see how you slept, for me I found it stressful. And I actually in the last week or so not wearing the ring, I think I sleep better, not wearing the Oura Ring. I’m just not as worried about sleep. I’m not thinking about it. I have a general sense that I’m getting a pretty good night’s sleep. When I was wearing it, I was getting an average of about 6 hours and 45 minutes of sleep at night when I was wearing the Oura Ring. My readiness score was usually somewhere in the 80s, low 80s typically. And I would get about an hour and a half of REM and maybe an hour and change of deep sleep. That was a pretty average night for me.
Aaron: Didn’t get to the personality thing maybe, and people who are less inclined to worry about things might perform better with one, but then maybe if you’re less likely to worry about things, you may be more likely to sleep better anyway and you’re less likely to go out and buy an Oura Ring. So maybe it’s a self-fulfilling thing.
John: I think so. I definitely think so. You know, I wasn’t worried about it for the first four or five months wearing it. I mean, my girlfriend at the time when I got the ring initially said to me, she goes, “Congratulations. You just bought a ring that’s going to make you crazy. Well done.” And that’s exactly what she said to me. And I was like, “Okay, you know, touché.” I could see that that’s true. Somebody like myself who’s, you know, getting on podcast with you and talking about my month to month LDL particle, and we’re talking about our C reactive protein, sometimes this can just be overkill. I don’t know. But as I wore it is when the worries set in. At first it was kind of a cool thing to see in the mornings, but then it became something where it just became too much.
Aaron: Yeah, I mean, that’s one of my reasons why I’ve been [inaudible 00:11:36] about it. So I have like, you know, the sort of fitness trackers. And I find that they work quite well for me because they give me that nudge towards the end of the day where, you know, I’ve been a bit of sedentary and it gives me that nudge to get up and do something, hopefully you have just a short burst of exercise, whereas with sleep, like you say, there’s not really much…it’s almost giving it to you at the wrong time. There’s not much you can do other than it making you worry that you’ve not had a good night’s sleep and that becomes a vicious cycle.
John: Let me ask you this, Aaron. So we’re going to get into this study here. For those people that have not worn or aren’t familiar with an Oura Ring, obviously it’s a sleep tracker. It basically has two components. It has this piece actigraphy. Is that pronounced correctly? Actigraphy is the type of sleep tracking versus polysomnography. It has that, and essentially detects motion. And then it also is…it seems like the best, most accurate piece of the Oura Ring is this whole heart rate. It has the literal sleep and then it’s also tracking your heart rate, your resting heart rate, your resting heart rate relative to the night that preceded it, like the resting heart rate you wake up with, your heart rate variability, which is the distance and time between heartbeats, which is a rough proxy for how relaxed you are and how well recovered you are and basically what kind of cardiovascular shape you’re in.
And then it has on top of that it kind of marries that heart rate data, which is supposed to be a sign of overall health, with your sleep stages. And the study that we’re going to look at, looked at one night of sleep, polysomnography versus the Oura Ring or alongside. And the first thing, the first question I had for you is, and I don’t know if this is something that you can even speak to, but I’m just curious, I noticed that my best night of sleep that I had wearing the Oura Ring was the very first night I wore it. And I gave it to my mother. And she was saying that she hadn’t been sleeping that well and she slept like a freaking baby on the first night that she wore it, too. Very N equals one, very anecdotal. And then this study that they have is one night.
Aaron: I mean, I guess, because you bought this fancy piece of equipment that’s going to help you improve your quality of sleep maybe on that first night you do everything correctly. You know, you don’t have your caffeinated beverage, you make sure you avoid your screen time, and you’re basically very compliant with good sleep hygiene on that first night because you really want to enjoy this new purchase that you’ve made. And then just your compliance goes downhill from there, and that’s when you start worrying about it. That’s probably the only reason I could think why.
John: Yeah. Okay. So there’s nothing to that basically. So…
Aaron: Well, no, I mean, yeah, I think it definitely is. You know, a large part of sleep is your sort of psychological state. And if it gets you in that right state on that first night, then that’s obviously it’s having a beneficial effect to get how you keep in that state over, you know, how you extend it beyond just the first night of excitement with this new thing you’ve bought and make it so that you keep that level of compliance throughout just for the rest of time.
John: Yeah, I mean, one of the big ones for me was I think that morning, actually, I was in Miami and I like to go to the Standard Hotel in Miami, which is this kind of like off the beaten path. It’s not on the tourists’ chain of Collins Avenue. It’s kind of in the…for people that know Miami it’s called the Venetian Islands. It’s these like manmade islands that basically sit between Miami Beach and mainland Miami, and I was down there. I forgot why I was down there. I think I was down there probably for no reason, just to kind of like try to get out in New York. They have a cold plunge pool there.
So I woke up that morning, hadn’t slept well the night before, may or may not have heard some, you know, stuff going on the room next to me for quite an extended period of that night. Woke up the next morning, got on the cold plunge, and was just out like my body in the sunshine like a sunny South Florida morning and then traveled that day but then I ended up sleeping really well. So maybe that was just like a cold exposure thing because I did notice that that helped my sleep a ton.
Aaron: There is stuff out there about, you know, like cold showers and hydrotherapy, getting used to sort of increased metabolic function in the early in the morning, and then that basically gets you awake, it gets you firing on all cylinders, and then that corresponds to a better night’s sleep at the end of the day. It’s always quite…it’s difficult research to get into because how would you ever really investigate something that broad, but there is evidence out there that cold showers in the morning can be beneficial for health and sleep.
John: Yeah, I mean, if I was going to do one thing and I had to go into an Oura Ring competition, it was like the Oura Olympics and I need to get my score as high as possible, what I would do is I would get in a cold plunge pool that morning or Epsom salt bath close second at night. That seems to help take, it’s like the magnesium and all that. But kind of the point of this episode is really just getting to say, okay, so let’s talk about the accuracy of the Oura Ring and some of these other sleep trackers.
There’s actually studies that have been done. We’ve got you here, PhD in research. Even on Reddit, there’s a lot of confusion about what these statistics mean. You know, I was confused by these studies as I read them trying to get a feel for what they actually meant. So we’re going to basically use your expertise here. And we have the study we alluded to, top level, before we get into the details, how accurate are sleep trackers and specifically the Oura Ring in your view?
Aaron: So the gold standard, which you come across that you just mentioned is the PSG.
John: Polysomnography. Got it.
Aaron: So that’s the gold standard. That’s what you want to be measuring yourself against. And there are several studies out there, not just looking at the Aura but other trackers as well. And basically these movement-based trackers where it’s just based on, you know, it may be something you’re wearing on your wrist or an ankle, and it’s just tracking movement throughout the night. And from that it’s inferring whether you’re awake or asleep. And some of them maybe also include a little bit of heart rate and measurement as well but not in any real depth.
And they’re basically useless. Because you can have a huge variety in how some people sleep and they’re moving around all the time and then they’re going to be registering as not having any sleep. Other people can lie stone still but they’re wide awake and then their sleep tracker, in those cases, will be recording them as being asleep. So a movement-based sleep tracker is useless.
John: By actigraphy? Is that the pronunciation for this type of technology, actigraphy? Well, if it’s not, then it’s not. But A-C-T-I-G-R-A-P-H-Y, actigraphy, whatever. They use movement, too, though.
Aaron: Anything that uses movement alone is going to be useless. It has to be in conjunction with something else.
John: Okay. So the Oura Ring is layering actigraphy on top of heart rate variability and body temperature and that’s how it’s getting accurate sleep data or relatively?
Aaron: We don’t know exactly how they’re doing it because it’s a custom algorithm that they’ve got this interpreting all this, but those that are bringing in those other bits of information, especially the distance between the heartbeats, to try and give them better metric of when you’re asleep or not asleep, but also important to give you the different stages of sleep as well to say which…if you’re getting enough REM sleep and a deep sleep or how much light sleep you’re getting. And they’re layering it all together. So it’s based on movement as well but with other stuff on top of it as well.
John: Yeah, I mean, for the simplified version for the audience, it’s basically heart rate variability and heart rate data and body temperature, plus actigraphy. And that is the first point. It was the point that I’m finishing up a blog that I wrote on this. I think that subjectively what I found in terms of how I actually felt when I’d wake up is that the Oura Ring would do a phenomenal job. If I knew I got a terrible night’s sleep, then the Oura Ring was right there with me.
If I knew I got a really good night’s sleep generally there with me. But the thing that I thought was most reliable from the Oura Ring was the readiness score. And the readiness score is not your total sleep. It’s not your heart rate variability. It’s basically a measure of those two variables put together. And so your readiness kind of gives you an overall kind of just top level of how are you feeling. And generally speaking, if you have a readiness of like 80 and above, you’re feeling pretty good. If you’re in the 70s, high 70s, maybe you’re a little off, that’s like if you’d had a drink. And then if you’re in the 60s, it’s because you either got drunk the night before or you’re traveling, you’re in a hotel room, you’re jet lagged, you’re sick, something like that.
And I found that the readiness score for me was usually pretty spot on. But I found that the actual sleep duration seemed counterintuitive because some nights I’d feel like I got a really good night sleep and I’d wake up feeling great. And then I turned on my Oura Ring and it would be like, “Oh, you only got 6 hours and 30 minutes of sleep.” And when they looked at these 41 individuals in this study, they used two different types of analyses of their sleep data because they’re comparing it to the gold standard. They measured them for one night. There’s the Bland-Altman plots and the epoch by epoch analysis. I’m going to read you some quotes and then let you riff on this. And we can talk about those distribution charts we saw to speak to the total sleep time.
One of the things I have that I pulled out of the study is, compared to polysomnography, actigraphy has high sensitivity, parents ability to detect sleep, although specificity parents ability to detect wakefulness is lower, with a wide range of accuracy, depending on the amount of nighttime wakefulness and the population studied. So there’s issues in the specificity in detecting wake. And what I read that to essentially mean is it was pretty much what you just said a minute ago, which is that these devices have a difficult time detecting, in some cases, whether you’re awake or whether you’re asleep. It seems that the difficulty increases after the first time you’ve woken up.
So the first WASO, wake after sleep onset, once that kicks in, each subsequent time they have it more difficult time telling whether you’re awake or asleep. And when you look at these distributions, you see as they’re measuring total sleep time versus polysomnography, for a lot of people, it’s spot dead on, right? So out of the 41 people, I think you probably had 30 of them that were right in line with what the polysomnography measurements said. But in about 10 cases, you had people who, it either underestimated sleep by 20 minutes or it overestimated sleep by 20 or 30 minutes. Or in some cases I think was 3 or 4 of the people in the study, just total sleep time, 4 people out of the 41 people, they had total sleep time either under or over wrong by 50 minutes.
So if you’re somebody who gets this ring and you’re looking up on the internet, and you’re like, “Okay, this is an accurate sleep tracker at 98% accuracy,” whatever the case, keep in mind that out of 41 people, a lot of them, it matched directly up with polysomnography. But a bunch of them, the distribution is such that it had their sleep off by, you know, just under an hour, one direction or the other.
Aaron: Yeah, I mean, that’s the sort of the headline take, isn’t it, that you can have an hour’s difference either way.
John: That was what I took away as like a layperson. But when you looked at this, you were like, “Well, I actually think it’s pretty damn good.”
Aaron: So the Bland-Altman plots that they show, that type of plot is a way of comparing two different techniques and showing how compliant they are. And you’re going to put these graphs below the podcast in the show notes. That thick black line running across the middle layer is showing that you have a really tight compliance. And like you say, you can see the majority of people sit really close to those. And then it’s once you go outside those red dotted lines, looking at the total sleep time, and these are the people who…where they didn’t really tie in with what they were seeing with the PSG.
So I think we counted them up as about nine individuals who are out by, you know, between half an hour and an hour, total sleep time. And it’s just trying to figure out, well, which individuals with the… You know, is there any way that you can tell which of the…if you’re going to be someone who ties in really tightly with the measurement or you’re going to be someone who’s going to get under or overestimated with the sleep tracking?
John: Yeah. Because if you get an Oura Ring and then you’re like, “You know what? I think that I slept…my sleep was either better or worse or my intuition tells me that I got 7 hours and 20 minutes of sleep. And my Oura Ring is telling me I got 6 hours and 30 minutes of sleep.” You’re not crazy to think that because in this test that they did, out of 41 people, there were a number of them where the sleep was really off, you know, 30 minutes, 40 minutes off. Most people it was not off. So you could get the ring, and this was only based on one night’s sleep. What’s not clear to me is whether…
It’s not clear from this study whether it’s going to maintain its inaccuracy relative to your sleep over a period of time or whether one night you’re going to get a really accurate reading and the next night you’re not because you woke up or you drank caffeine or whatever the case, right? I mean, I kind of told myself, “Well, you know what? Even if it is an accurate, then it’s relatively speaking, it’s going to be tracking me in the same way each night.” I’m not sure that that’s true based on this study. And I think that somebody could buy it. You could take two things away from this. I think one you could say, “Okay, about this ring, I think it’s great. It’s really accurate.” And you know what? For you it very well maybe, but then for somebody else, it may not be because 9 people out of 41 and these are kids, right? These are like 14-year-olds, like 22-year-olds, 17-year-olds. Presumably they picked that age group because they are people that sleep like logs, I would assume.
Aaron: Yeah. Probably also because it’s easier to get young people to take part in trials, but the quality of sleep will also be better as well. And I guess the other aspect is they’re less likely to, especially in an American study, to have been out drinking and things like that the night before.
John: No, actually, I think they’re in America, I think they’re probably more likely to have been out drinking the night before, I bet you at least. But okay.
Aaron: That’s the idea behind it.
John: Theoretically, yeah. I thought to myself, well, they want to get younger kids in because of the fact that it seems like their issue here is wake after sleep onset. So once you get that first awakening, it’s harder for them to detect what’s happening with sleep. So they want a young group of people because the younger people will be the lowest in that problem. And so therefore, they’ll have greater accuracy.
Aaron: Yeah, the week after sleep is quite an interesting idea. If you think about how you feel when you go to sleep for the first time, how you feel, and then if you wake up in the middle of night, you do feel different. You know, you can feel that you may be…because you’ve had a bit of sleep, your heart rate is going to be lower, your temperature of your body has changed. It’s going to be mimicking, you know, because you basically have just woken up from sleep so it’s going to be mimicking what, your sleep types should be like. And that’s why these things are struggling to actually pick up on that differences whether you’re awake or whether you’re sleeping, those periods in the middle.
John: They can tell that you fell asleep and they can tell the total amount of time that you’re in bed. And for a lot of people, they’ll accurately measure during that time how much of that time you were asleep, but for a number of people, that won’t be the case. What does this mean, Aaron? This is the epoch analysis. EBE analysis show that Oura accurately detected light sleep and deep sleep, and 65% and 51% of the epochs respectively. It’s a quote from the study.
Aaron: So it’s just whether it can classify you into the correct stage of sleep because, you know, we have the three stages of sleep, well, four if you want to break up the light sleep. So you have your light sleep, deep sleep, and your REM sleep. And basically bit by you’re getting the most benefit is in your deep sleep. That’s where you’re recuperating the most. And so that’s where you want to be getting most sleep and that’s where you ideally want your sleep tracker to be the most accurate. And it’s basically saying that it has a reasonable ability to place you into those categories. Sixty percent is reasonable. Obviously, it’s not as good as the PSG but it’s still a good way of predicting, you know, basically timing how much sleep that you’re actually getting.
John: Okay. And then there’s another famous quote that’s been circulating on Reddit. Ninety six percent sleep accuracy, 48% wake, 65% light sleep, 51% deep sleep, and 61% REM sleep. A lot of people on Reddit, there’s a lot of conjecture about what that actually means. Does it mean that it’s only detecting light sleep 65% of the time and deep sleep 51% of the time and REM sleep 61% of the time or does it mean that…like how do we interpret those statistics?
Aaron: I mean, the way you described is kind of the right way. That is how 64% of the time is putting you into the light sleep category correctly and 50% of the time into the deep sleep category correctly. So, yeah, that is probably the lay best layperson way of describing it. It’s based on the correlation with the PSG so that there still could be more variation on that because, although PSG is the gold standard, it’s not a perfect technique in itself. So just because it is descriptive with that, it still could be classifying you correctly. It could just be that the PSG was wrong as well.
But those overall, those figures are actually pretty good. Deep sleep is one of the hardest ones to categorize without using an EEG because basically, that’s when it’s measuring the slow waves in your brain. So being able to get a 50% accuracy in conjunction with all of the other different types of sleep is actually quite impressive.
John: Right. It’s a good device. The question is, I think people would assume, “Okay, it’s not accurately tracking my deep sleep, but I’m in some other state of sleep while it’s tracking my sleep.” And that could be the case or it might not be the case based on what we’ve seen in total sleep time.
Aaron: It knows you’re sleep and it can be fairly accurate in classifying what type of sleep you’re getting. So as long as you know that you’re getting a long enough period of sleep, you should be getting the benefits of the deep sleep, even if it’s not as accurate as the total sleep recording is.
John: Yeah, it’s underestimating deep sleep and it’s overestimating REM sleep. When you look at these distribution charts, which, again, we’ll just take a screenshot of this and put this in the show notes. But this is the Bland-Altman distribution, right?
John: These charts, the ones that have the dots on the…I mean, the deep sleep numbers on 41 people are all over the place. Some of them are up in the difference in minutes at the…I mean, there’s 1, 2, 3, 4, 5, 6 that are between 80 and 120 minutes overestimating deep sleep. And then there’s a number that are under estimating deep sleep. But there’s almost none that are at that baseline with the polysomnography in terms of deep sleep.
Aaron: No. And there is a bias towards overestimating it overall, isn’t it as well?
John: Yeah, I thought for deep sleep, they said in the paper that they actually underestimated and then they overestimated REM. But I could be wrong. I think the whole takeaway here is if you’re wearing the Oura Ring, you might be getting really, really accurate readings that are on par with polysomnography. And it’s more likely than not, would you say, Aaron, that you are?
Aaron: It’s more likely than not that you are. So a thing for me that I took from this is that it’s only done one night. So we’re talking about maybe like 80% of people have an accurate recording of their total sleep time over one night. But the really interesting question to me is if you took it over night two with those same 80% of people be the ones who are also reporting well.
John: That would be really interesting.
Aaron: Because it’s not the thing…is it just the people that have got overestimation or underestimations, is it because the ring didn’t fit them that well? They weren’t wearing it properly or there was some other issue with their sleep and then maybe the next night they’d be improved? So is it saying that, you know, if you buy this ring and you’re one of the lucky 80% of people, you’re going to be tracked perfectly over time? Or is it saying that 80% of the time the ring is going to be accurate, but there will be one day a week, two days a week where it doesn’t work for you? That’s a really interesting question, and they don’t really answer that in that study yet.
John: Yeah. And so at the end of the day, the thing that’s really interesting about this is, if you buy the Oura Ring and you have a night sleep that’s completely crap and it shows that you got 10 minutes of deep sleep, it’s much more likely that you did have a really bad night of sleep. You know, I’ve heard some people talk about the Oura Ring on podcast. I won’t mention the podcast but it’s a vegan podcast, and one of the guys talks about how he went night after night after night of getting like two or three minutes or five minutes of deep sleep. In those situations, it’s probably pretty likely that you’re not getting very good deep sleep.
But if you’re on the fence, and you got, say, like an hour of deep sleep or 45 minutes of deep sleep or an hour and 10 minutes of deep sleep and then the ring is telling you that you got 6 hours and 40 minutes of sleep, somewhere right in that middle fence because, you know, the sleep scientists like Matthew Walker say you really want to be getting between seven and nine hours of sleep. It’s really important. If you’re on that fence, it could have either overestimated your sleep or your decent night’s sleep is actually a pretty poor night of sleep, or you could have had… And one of the ways to judge this, I think, is probably by looking at readiness score.
You could have had what looked like, you know, okay, night of sleep, 6 hours and 40 minutes of sleep, where you might have actually gotten 7 hours and 35 minutes of sleep, or it’s more likely they would be in that plus-minus 30 minutes. So you could have gotten 6 hours and 45 minutes of sleep that was actually 7 hours and 12 minutes of sleep and your deep might have been more in your REM, might have been a little bit less.
Aaron: Yeah, it’s as long as you’re in that order part where it’s giving you that buffer to go either way on it. And as long as you’re not getting just a tiny amount of deep sleep you should be all right, really.
John: Yeah. And so at the end of the day, like we keep saying it’s usually accurate, but in many cases, it’s not unusual for it to be off by close to an hour one way or the other. And what I found is that when I would be sleeping, I found that there was a lot of nights for me where it said that I had a lengthy periods of being awake when I just…like it said I’d be awake for an hour and 44 minutes and I just wasn’t. Like, I wasn’t awake. I certainly wasn’t conscious. I mean, I felt like I had slept the whole night.
Aaron: But do you have issues because things like restless leg syndrome or anything like that?
John: No, I don’t.
Aaron: No, because that’s one of the major issues with these like the actigraphy thing they’re trying to track you. It’s very difficult.
John: I don’t. Yeah, no, I mean, I sleep generally on my stomach. But I’ve never had anything with restless leg syndrome or anything like that. And so, you know, for me, I just think the whole focus from the health and wellness world on sleep is a little bit ironic. I don’t know how you guys are in the UK. But here, it’s become very trendy to talk about sleep, and it’s just almost this like sleeper die kind of a thing. And it’s just it’s the last thing you want to hear if you’re actually trying to sleep.
Aaron: Yeah. Well, I actually did an interesting little bit of work about one of these headbands that was designed to basically increase your slow waves and basically improve the quality of your deep sleep. And it was this huge…I think there’s been quite a few startups have been trying to do it and they basically…there’s loads of research out there that you can get into this deep sleep, you can improve it, but I’ve not seen anything that’s actually managed to ever come out where they can actually get you into that deep sleep and then also keep you there and improve the quality whilst you’re in there. That’s going to be the money spinner, if someone could have a crack on it.
John: To actually create a device that would optimize for deep sleep?
Aaron: Yeah, so basically, you wear it on your head or whatever or however it’s going to come around, something that you basically gets you into that deep sleep. And that keeps you in there for long as possible or not as long as possible but for a reasonable length of time. That’s going to be the one that makes someone the next billionaire.
John: That will be amazing. I found for me that taking magnesium was probably the single best thing I could do to increase my deep sleep. I thought it was kind of funny in the study they found that deep sleep was lower in older participants, which is consistent with data, which I thought was such a ridiculous way of framing that considering that I think the oldest participant in the study was like 22 years old.
Aaron: They’ve got more stress and more to worry about.
John: I mean, got it. That just to me seems like such a throwaway cynical line, like, you know, “Yeah, we’re accurate and we’re even showing that sleep goes down as you age.” I mean, if you just read the abstract of the study, you’d be like, “Oh, wow, I’ll just…” It’s like, “Dude, no. This is 14-year-olds, 17-year-olds.” So like, yeah, there’s 22-year-olds, they’re really screwed. Their deep sleep quality is really in the toilet compared to their 14-year-old self. It’s like come on.
Aaron: Yeah. I mean, the big take for me is that compliance because they have that interesting little thing at the end talking about how they noticed a discrepancy based on which finger you wore the ring on. And that’s the kind of thing that screams out to me. It might not be an individual difference, it might just be about how you wear the ring because, you know, if you ever go in front of these PSGs and they stick all the electrodes on the head, you know, it’s done by someone with a lot of training, they spend a lot of time positioning and accurately, whereas the Oura it’s just a ring that you slip onto your finger and it’s not as if they come in, you know, vast numbers of different sizes. I think there’s just three sizes. So if it’s not fitting perfectly, then you’re going to possibly open yourself up to getting a much, much…a lot of variation in your response.
John: Well, they’ll send you a sizing chart to figure out your ring size and then you…
Aaron: Oh, they only give you three sizes, don’t they? I think…or at least one in the UK versions when I’ve looked at it, they’re only three sizes.
John: I don’t know. I think there’s more than that. I think it’s like wherever the ring sizes are, I think, it corresponds to. I could be wrong.
Aaron: It might be different in the U.S. compared to the UK?
John: Wasn’t the least accurate finger the ring finger?
Aaron: Yeah, which is bizarre.
John: Yeah, that is strange. I always wore it like on kind of in my index finger. And then I guess just in closing, did you see anything else in in in the other studies you read? Were there other tracking devices that stood out over and above the accuracy of the Oura Ring? I know there were some stuff on Fitbit and some of these other ones.
Aaron: All of those actually come in below. So if you’re going to buy a consumer sleep tracker, I think the Oura is the way to go just because it has that combination of the actigraphy and the heart rate monitoring. It gives it that edge. I know it’s obviously a bit more expensive than some of the other devices out there.
John: The reason I destroyed mine is because I felt like I was getting addicted to it and I just I feel like it was not good for me. I would just wake up every morning, the first thing I would do…. The irony of these wellness trackers that are linked to apps for me is that I met my most healthy and calmest and most productive when I’m not like geared into my phone in an addictive way and I’m having another reason to check my phone just incessantly. And the problem I have with the Oura Ring is it makes you get on your phone like right away in the mornings, like first things first. There is an Oura Ring cloud where you have all your data that’s backed up to the cloud.
I think probably the healthiest way to wear it at least for somebody who tends to check on these things kind of compulsively is just not even to download the app and just look at your data once a week on the cloud, I think would probably be the healthiest way to do it. But I found that the tracking of sleep, I think the irony here, just my closing messages, at least for me, I think that after the first four or five months, the tracking of sleep is actually very disruptive to sleep. I think I’m sleeping better since I actually stop wearing my Oura Ring.
Aaron: Maybe it’s one of these ones where you have to do it in a cyclical fashion as well. You go use it to improve your sleep hygiene. And then once it gets to the point where it’s actually causing…it’s being a bit detrimental, you step away from it again and you pick up the bad habits again and then you need to come back to it in a month, two months’ time.
John: Yeah, like one option would be to just like once you realize that it’s not really such a great look for you anymore, rather than physically destroying it, you could just take it and put it in a drawer for a little while and then like keep it intact and then pull it back out when you wanted to use it. That’s kind of something…that’s another option. You could destroy it. I can tell you that an iPhone 10 with a case just giving it a good whack will pretty much destroy it. I mean, it’s a pretty durable thing but that’s how I destroyed mine. But just as good. If you don’t want to destroy just want to put it in a drawer, that works just the same. That’ll be just fine as well. That way you can use it again in the future.
Aaron: Yeah, I mean the take…I don’t know how much credence it lends to anything, but based on the reading that I’ve been doing around this, I think I’m still going to go ahead and get one, just because I think it’s the best option out there for a commercial consumer-based product. And I think I need a bit of help at the moment trying to improve my quality of my sleep. And I could see something like this being beneficial. But I could also see what you’re saying in the long-term becoming addicted to it and checking first thing in the morning to see how much sleep I’ve actually managed to get. And then, you know, I can imagine it how you can get infuriated if it doesn’t match up with how you feel.
John: Yeah, look, I think the takeaway here is that this is….I once had a startup where I tried to build hardware. So I understand how difficult it is to build hardware. And I took my hat to the makers of this product, because this is a very sophisticated, very well made product, and it’s overall accurate. But my thing is that, man, I just think sometimes in this climate, we’re just overloaded with information. And I think you learn the best things from it in the first four to five months and that it teaches you those things, those hygiene things, and then after that, it’s just like it’s going to vary based on the individual.
Aaron: Yeah, and take into account your diet and genotype type as well. That’s obviously the important bit.
John: Well, I also wasn’t following my chronotype either, though, that’s the thing. I mean, I was blown away by my chronotype results on these new plans that we launched. I was an owl. That was really surprising to me.
Aaron: You are an owl, but you’re not right at the farm, you kind of…you’ve got quite a lot of owl characteristics but you’re not I like 100% owl.
John: Okay, so I wonder if we should have…
Aaron: I think you still consider yourself as an owl but you’re going to be one of these people who are like working at 3:00 in the morning style of an owl. You know, you’re talking about maybe the late afternoon, early evening is going to be your most productive time for working.
John: Okay. Well, we might want to create a fourth little category there.
Aaron: Yeah. Yeah, there will be people who are the extreme owls, who are the ones who want to be up at 2:00 in the morning doing their thing.
John: Yeah, doing their work. Okay, good stuff. Well, hopefully this is a useful interview for people that are looking buying Oura Ring. I think overall we’re pro-Oura Ring, sounds like.
Aaron: Definitely, yeah.
John: But there is the potential for pretty big inaccuracies in some people. I think that’s the take.
Aaron: Accept it as what it is, which is a consumer product. It’s not going to be giving you clinical grade measurements on your sleep quality, but it can give you the best that’s out there, basically.
John: Yeah, good stuff. All right, man. Sounds good, Aaron. We’ll be doing another episode soon. Thank you for chiming in, and we’ll be in touch.
Aaron: Cheers. Speak to you soon.
John: The “Gene Food Podcast” is our attempt to synthesize the latest developments in the fields of genetics, nutrition, and medicine, and offer you practical tips and stories you can use in your own unique health journey. If you enjoy this podcast, you can find more information online at mygenefood.com.