The Science Behind the OuraRing

Harpreet Rai

I’m good Sanjeev, you know probably like your readiness score I wanna say like 84 today so doing pretty good, pretty good, how about yourself?

Sanjeev Goel, MD, FCFP (PC), CAFCI

Yeah my readiness score is, I tracked this religiously for every two, the last three years or so. 81 at readiness, 87 sleep so-

Harpreet Rai

Okay.

Sanjeev Goel, MD, FCFP (PC), CAFCI

It started like at about 74 in the morning and then I went back to sleep ’cause I wasn’t happy with that reading and I got it bumped it up.

Harpreet Rai

I almost did the same cause I had like a 93 yesterday. So I was like, should I sleep in an extra hour? But I was like an 84 is pretty good, I, you know, let me get about going my day is so glad I did.

Sanjeev Goel, MD, FCFP (PC), CAFCI

So I was just telling you just to just offline that you know everyone I’ve interviewed all the biohackers and scientists and doctors all have an Oura Ring so it’s nothing like, it’s really has taken over I think the biohacker community and all the physicians that are interested in precision medicine. They understand the value of the technology. But maybe before we get into that I’d love to just, if you could just give a bit of background on how you even got involved in this field why is it, why you wanna dedicate your life to this you know area?

Harpreet Rai

Yeah, I mean, I honestly I think for me it was a little bit of probably, you know an interest in health to place for me at a young age primarily out of two reasons. One, fear, unfortunately just saw too many loved ones, grandparents at the time just have a heart attack or stroke or pass at a young age. So all four grandparents of mine have had a heart attack and stroke in their 60s. And then one of my grandmothers actually he was living in Windsor, Canada, not too far from Toronto, she passed in her late 50s. And so congestive heart failure and you know, I was only like 10 years old but I think it was like the first time sort of realizing like that shouldn’t have happened right? I think just even as a young kid hearing like oh it was so young, so young and then you know I’m like, oh wait, how long do people live? 

‘Cause you don’t really think about that stuff when you’re a 10 year old and they’re like, no, 70, 80 years old and you know she’s like, you know not even 60 and so and then you know shortly after that saw all three other grandparents that have heart attack or stroke, luckily didn’t, you know they didn’t pass as quickly, but still. And then I think from the performance side my own personal experience was I felt like playing, trying to play sports you know, I just felt like I had to work twice as hard to be half as good as everyone else. So I felt like no matter how I trained or what I seem to eat or thought I was eating or how I was eating that I just, you know couldn’t perform at the same level as my teammates. And my sport was soccer, you know 5’5, 5’6 with a turban as I like to say I had.

Sanjeev Goel, MD, FCFP (PC), CAFCI

Like the Indian Messi.

Harpreet Rai

Yeah exactly I wish. But yeah I think, so for me it was like a little frustrating and then I start to just track things religiously at a young age ’cause you know, I started learning about exercising, calories, even just out of frustration being forced to learn about that stuff. And then I think, you know, long story short I studied electrical engineering, my dad was an electrical engineer and my grandfather was an electrical engineer as well and I specifically studied sensor tech you know MEMS which is, you know movement, sensors, accelerometers, but even now lots of things like the optical sensors along with a movement sensor in an Oura Ring is coming from MEMS technology. 

And that was really my first ideas in like thinking of like, well everyone’s body is different, you know, my body reacts differently. Where am I in my health? How can I improve what’s good for me? Well I had this idea of like well eventually we should all just have these sensors and these sensors should just measure where we are. I, you know ended up not going directly into health and engineering when I graduated but into investing I worked at a year after college at an investment bank at Morgan Stanley and spent nine years of the hedge fund. And at the bank I gained 50 pounds and that was probably my first time being seriously overweight. You know I was like 190-ish pounds, right? Doing investment banking. And then in the proceeding probably two, three years that’s when I became just a whole different level of dedication and I lost about almost about 55 pounds got down to like 135 pounds and well you know had visible abs like for an Indian person I feel like that doesn’t happen much, but like I just you know, I started tracking every single meal I ate. I started, you know in a spreadsheet I used to weigh my food. I went on my first keto diet, probably 2009 and my first intermittent fasting diet 2010. 

And you know, I’m actually not one of the founders of Oura I’m the CEO, but I met one of the co-founders and eventually all of them, you know after they’d just done a Kickstarter for the generation 1 Ring. And I saw what they had and even though the ring was really big and bulky the battery life was only one night. I sort of knew the advancements that would happen on the technology in power consumption side from both my investing and engineering experiences. But even more, I think, you know what I saw was like how many people needed this? Like, ’cause once I started using the product and it was so easy to track sleep and things like HRV and recovery I could just start to make better day-to-day decisions. 

And I felt like that ease of knowledge and access to the human body on a day-to-day basis without having to use spreadsheets, without having to use things like, you know, even the Omega wave which a lot of athletes used to use or just doing, you know a chest strap measurement and HRV for the morning, I just found something, this was so easy, it was so easy to stick to and it was just such an easy reminder I could just look at my data and be like oh, no yesterday I slept like crap. Oh that’s right ’cause I ate late don’t do that again today and I wouldn’t do it again today. 

And so I think, I, you know the founders need some help growing the business, generating revenue, you know I think just understanding how to get to profitability basic business things but I understood all that technology too. And so I think we just hit it off, I ended up investing in the company and joined the board of directors, I think three months after that I was spending probably 30, 40 hours a week with them, first my regular job and you know they asked me to join full-time which I did and then, you know after a year, both the board and founders thought it made sense for me to be CEO. So, yeah it’s been three years now as CEO, four years with the company and five years as an investor. So, but it definitely been a journey, but it’s been a ton of fun.

Sanjeev Goel, MD, FCFP (PC), CAFCI

Well I think you’re right at the exact right time. I mean this technology, you know, the Oura Ring came right I think the time of technology made it possible and all the interest came in also at sleep at the same time I think would also see an understanding of the impact of sleep on our health and you know so it’s a whole perfect storm. So maybe I just loved if you could just maybe chat about what are the cool features that you think make, you know the Oura Ring special.

Harpreet Rai

Yeah.

Sanjeev Goel, MD, FCFP (PC), CAFCI

And I think that would be really cool.

Harpreet Rai

Yeah, I think, look I think sleep and tracking sleep, frankly if you look at wearables today even still the Apple Watch doesn’t do it. You know they’ll track time in bed but that doesn’t really tell you much. So I think understanding sleep, deep sleep, REM sleep, the different stages of sleep. Even just frankly like consistency of sleep timing and how much that makes an impact on circadian rhythm. But I’d say the other one is really HRV. I think so many of our users probably look at HRV as, you know I think the science indicates that an overall measure of stress whether it’s physical stress and recovery, or frankly mental stress. And so I just think it’s such an easy, accurate way to do it. 

We’re the only commercial wearable still shock, well it doesn’t shock me, no why, but we’re the only wearable that’s shown that our data, our sleep data, you know our heart rate and our heart rate, heart rate and heart rate variability data during sleep is 99% and 98% correlated to an EKG. And no wrist-based wearable has shown that and so I think for us it’s just such an accurate measure and such an easy thing to do. You know you, a ring weighs four grams or five, you know less than five pennies and you know just sort of put it on and forget it’s there in the last a week. So I think it’s that accuracy and the data it looks at and then also the convenience. Those two things together the accuracy and convenience I just think are so easy, make it so easy for the customer to use.

Sanjeev Goel, MD, FCFP (PC), CAFCI

So maybe let’s just, let’s do a little bit of deep dive on each one of those. You mentioned the accuracy of the sleep parameters like as a sleep study I guess. What exactly, how does that compare to, I know Fitbit has sleep you know monitoring and I think I went to the World Sleep Congress they did say that yeah it was one, the Oura Ring was the most accurate, but I’d love to just hear from you like how you’ve proven that.

Harpreet Rai

And no so I, I’ll and there’s some good stuff coming on the way soon publicly probably in the next call it six to eight weeks that’ll be out there as well. So I think, yeah so the way you form these algorithms is essentially and test them, you know same way you create them is the sort of the same way you test them. You take a lot of people and you have them sort of do what’s known as the gold standard or reference. In the case of sleep it’s polysomnography. A hard word to say, but it’s, abbreviation is easier PSG polysomnography. And all that is is if you were to go in a sleep lab at University of Toronto, at NYU wherever, what they do is they strap your head, you know and even your nose and your mouth to probably 16 different wires. 

So you have all these wires like pasted to your head, it’s really hard to sleep in a sleep lab. And what they’re looking at is you know breathing rate, heart rate but mainly actually they’re looking at your frequency of your brain that your brain waves, the frequency of your brain waves and the speed of those waves while you’re sleeping. And they then score these, you know sleep science is relatively new science but they’ll basically look at those different frequencies to figure out if you’re in REM light and deep sleep or if you’re awake. And so what you do to create these algorithms as you look at all the data that’s coming off of your sensor like in the case of an Oura Ring the LEDs, the movement, the respiratory rate, the heart rate, heart rate variability even the temperature that we track and you compare it against these brainwaves and you create an algorithm. 

And so, I think what, you know wearables in general well, I should take a step back. Sleep staging as a whole if I took that test and showed it to a sleep score at University of Toronto, where I showed it to a sleep score at NYU, they’d agree on about 80% of the data. So sleep’s a pretty noisy science. They’re still like, hey where are you really in REM sleep or deep sleep? Because it looks like you switched between the two you know three times within, you know sort of that 30 seconds or 5-minute epic. And you know that 5-minute period in the sleep study exam. And so there’s a lot of variability in how these are scored. 

So, most people don’t realize that. So the best you can sort of get even gold standard, gold standard is about 80% accurate or 20% standard error. I think wearables as a whole, you know I think have shown sort of, you know high 60s and I think even us that’s what we’ve shown historically. And we were the first wearable to actually have an independent sleep study analysis on gen 1 you know which is a ring that came out in 2015, 2016. Our gen 2 just recently is starting to get some validation stuff done and we’ll have something updated there. But I think, you know we sort of feel like we’re in the mid-70s now early to mid-70s and so I think we’ll have that validated pretty shortly here. 

And so I think that’s gonna be pretty exciting. But most other companies haven’t really attempted to do much validation. I think that’s a little bit of a disappointing thing. And I would point out here that what matters more here than accuracy is precision. So I think the benefit of a wearable is well it may not be as accurate and I’ll give a real-life example, it can be more repeatable day to day. You don’t wanna go to that sleep lab with 16 wires, but you can sit in the comfort of your own home or anywhere I would tell every minute where you are and see the changes in the data. 

So whether it let’s say you’re 40 minutes of deep sleep or 50 or 55 or even 60 minutes of deep sleep, what matters is, hey those nights you have a lot of stress, you drink alcohol and you you know eat really late, like you’re up late you know binge watching Netflix right? Or whatever it may be your stressed out because of work or if you’ve got in an argument with a loved one, I think it’s the change night tonight that’s super important. And so we’ve actually focused our algorithms on that change, on that precision, because that’s sort of how the customer uses it and understands which lifestyle choices are good for them and which lifestyle choices are bad for them.

Sanjeev Goel, MD, FCFP (PC), CAFCI

So it’s not, yeah so, give you an example like my wife regularly has a deep sleep over two hours and if I have one my one hour and 20 minutes I feel that’s amazing. So you’re saying it’s not so important to compare to somebody else but rather against yourself. I can tell when I make an hour and a half I’m very happy if I’m at 45 minutes, it’s a different type of sleep. So I’m not gonna ever hit two hours, it’s very unusual for me to hit that type of level.

Harpreet Rai

Correct and even for, I think it’s the, you know, just like yoga it’s like don’t look at anyone else focus on yourself, right? Like you know, that’s exactly right. We’ve actually made our algorithms the way we calculate our scores all based on the relative changes to you. And we’ll actually rebaseline you so we have a rolling baseline average but, you know that way as you improve or if you get worse it doesn’t keep penalizing as much and encourages you just to do a little bit better. So yeah I think the relative change, it’s trendlines not headlines and that’s something that Walker says often and you know really famous sleep scientist and author wrote “Why We Sleep.” And so I think he’s absolutely right with that statement. It’s sort of trend lines not headlines that you wanna look out for.

Sanjeev Goel, MD, FCFP (PC), CAFCI

That’s really interesting. What’s your, I know, I do notice that if you have a couple of good days and you’re gonna have it kind of helps to have another good day I guess the algorithm is kind of, like you build up to a good day. It’s hard to jump from 60 to 90 over overnight.

Harpreet Rai

Yes, I think partly because you know, if you have one night of bad sleep you can sort of like tough through it, but it’s like that repetitive sort of like six hours five and a half hours, five hours in a row that sort of really wanes on you, so the way we create the readiness score, it specifically it actually looks at both last night of sleep and last day of activity, but then also looks at a two-week average of your sleep and activity balance and then a bunch of physiological changes from the night before your heart rate, heart rate variability versus their norm, your respiratory rate and temperature. And so we sort of get that longterm view. And to your point it’s like, you know you wanna build a little bit of resiliency, you’re not just gonna go from a 60 to 90, just by one good night. And frankly your body physiologically is not covered just with one night of recovery after a couple of bad nights either.

Sanjeev Goel, MD, FCFP (PC), CAFCI

Right, do you think that, so for example the activity part like I know there’s some people perhaps are wearing it during the daytime, only for the nighttime, like are you seeing people get value from the daytime as much now?

Harpreet Rai

Yeah, no I think 90% of our users wear it all day long I think 10% just wear it all at night. So yeah, we actually have now started doing a lot more activity things. So we added something called Automatic Activity Detection recently, so that’s a really new cool feature. Yeah you were asking about key features so, AAD as we call it Automatic Activity Detection, you know if you go skiing or snowboarding you’ll open the app and I’ll even say, hey where you just skiing and you know you can confirm it. And by the way it’s an adaptive algorithm to you. 

So the more you actually confirm things or even if it’s incorrect you correct it or if nothing comes up, just go in and add a tag, hit the plus button on the bottom of the right of the app, that algorithm actually gets personalized to you. So that’s a really cool feature ’cause most other wearables don’t personalize to the individual and there’s slight variations in how we do these things and just how we all move. I think another really cool feature we’re seeing get a lot more usage out of is something we call the Moment or meditation. So you can listen to an audio track or do an unguided meditation and actually after five minutes or a longer session you can see your HRV and even your skin temperature change during your meditation session. 

And as you continue to meditate most people will notice trends where their heart rate variability improves more and more during the session as a you know measure to sort of look at how relaxed you’re getting during that session. So I think that’s really cool. And we even added something new called sleep sounds. So there’s even a couple libraries where you can actually if you have a hard time falling asleep or if you just like, you know blocking up those sounds and listening to something, you can actually listen to a couple of stories or soundscapes and we found users getting a ton of usage out of that. So I think as, yeah, as we kept growing, you know start from sleep, but have started to do a lot more during the day to keep engaging user and frankly to keep them practicing healthier and healthier habits.

Sanjeev Goel, MD, FCFP (PC), CAFCI

Right, let’s move on just before we move on from sleep, I know a lot of, I think it may have even asked you this a couple of years ago about sleep apnea. And have you been able to look at the data and maybe give some help to people who might be suffering from this?

Harpreet Rai

Yeah so.

Sanjeev Goel, MD, FCFP (PC), CAFCI

Or is that much a silent kind of condition sometimes.

Harpreet Rai

Yeah I think we’re gonna do more there. Right now what we’ve seen with a lot of people that do have sleep apnea is they’ll have a lot of interruptions in their data during the night, or they’ll have really low stages of sleep you know deep or REM and that’ll be reflected in their data. And so people start asking themselves, like I feel like I’m doing all the right things to go to bed but I’m still not getting appropriate scores and so we found a lot of people just noticing that and hence going and getting a sleep study done and then realizing they have apnea.But I do think over time we’ll start to actually see what we can do as a company to do more in the app about like giving the user a little bit of a check engine light if something looks off. 

The FDA is pretty particular about sleep apnea and so as a result like we gotta be careful and make sure we have enough specific data on that. And probably, you know like we’ve done and we did of COVID, do a large-scale study, publish results, then when we make a feature refer back to, hey this looked like data in XYZ study or similar to that study, you may wanna go see someone about it, versus trying to, you know what the FDA hates is if you try to diagnose or treat, so I think let the user sort of, giving them enough data and enough context to make their own judgment call and let a doctor make the diagnosis. But I think there’s more we can do in the future and I’m pretty excited for it.

Sanjeev Goel, MD, FCFP (PC), CAFCI

So it looks like there is some type of signature perhaps like from the data you’re collecting. I would think that there should be like from heart rate or something if they’re going to hypoxic they should.

Harpreet Rai

Totally, I think, yeah. Hypoxic you can definitely see changes, rapid changes in respiratory rate, heart rate and heart rate variability and frankly more fragmented sleep. Right? A lot more wake ups, a lot more tossing and turning and a lot more you know or more light sleep, less REM and deep.

Sanjeev Goel, MD, FCFP (PC), CAFCI

Have you seen any, are you collecting any way to find out the impact your app is having on people’s health?

Harpreet Rai

Yeah, so we did I know something, there was a professor at UCLA who recently did a study on behavior change and wearables and he recently just submitted that to a medical journal. So we’re eagerly awaiting. I think what we have been told is that it’s a cut ahead, just because I think a little bit is focusing on sleep and recovery instead of focusing on steps. I think most of the wearables you know really just don’t focus like Fitbit did early days of just hitting this certain activity score. And frankly like we know the stats on activity, like most people unfortunately aren’t as active as they should but even if they are and you eat really poorly or if you’re doing work super late at night or if you’re you know drinking alcohol really close to bedtime like you’re never gonna feel great, you know the next day. 

And so I think just leading with sleep is something that is frankly more beneficial, lets people sort of understand those decisions outside of movement a lot better, like you know timing of food, quality of food, right? Even just how stressful activities you wanna engage in before you go to bed. So I think it just builds healthier lifestyle habits as a whole by focusing on sleep. And then as we know from the science of sleep right? If you sleep better, you’re gonna have more energy, you’re gonna feel more productive, your hormones are gonna be in the right place, your hunger, you know grueling or have fully fuel left in, right? All your key hormones, your, you know your general and you know insulin response they’re gonna be so much better if you’re sleeping properly. So I think that’s part of the other reason too, just, you know when you start with sleep sort of everything else becomes easier.

Sanjeev Goel, MD, FCFP (PC), CAFCI

Right, let’s move on to the heart rate part. Particularly I always look at the lowest heart rate from my sleep, I find that as a very useful marker. I’m just wondering why did you pick that? I mean that’s usually always it’s highlighted as one of the heart rate metrics, like an average heart rate I know you have that as well but, the lowest point seems for me to be a very good indicator of how well I slept and stress my body’s under.

Harpreet Rai

Yeah, there’s pretty good research out there that sort of shares, there’s this concept of midnight, you know or there used to be this concept of midnight. And midnight used to be the middle of your night right? Classic plan of words it’s not that hard. And you know, I think as the human body relaxes throughout the night, typically your lowest resting heart rate is supposed to hit midway throughout that point. And then your hormones start to actually, you know get ready to help you wake, which means right? Your cortisol level should increase, your heart rate should rise as you get ready to be, you know awoken and attack the day. 

But I think what looking at the resting heart rate does the lowest resting heart rate and sort of when it happened, what the value was, it sort of lets you understand is like how close are you to fully recovered? If your heart rate actually, you know lowered very late in the night, chances are you were doing something stimulated and had caffeine too late and had too much alcohol, had ate really late, were stressed ’cause of work or ’cause of, you know some other, you know, personal reasons. And so it’s looking at the timing sort of shows us and we have some really good, you know, literature based on hundreds of thousands of nights of data, millions of nights of data, hundreds of thousands of users on our blog about this. 

And then also comparing just the sort of lowest resting point, versus previous days like that allows you to see like, oh am I really well recovered today? Or no am I not? Is my resting heart rate higher today? And I think it’s hard to get a resting heart rate during the day ’cause you’re always sort of doing something and so looking at it during sleep as a repeatable time, a repeatable pattern, it’s sort of like performing the same science experiment every single night when you go to bed. And so we look at it for sort of those two reasons, the timing and then also the absolute value. It’s just a really good thing to look at physiologically and stress-wise day to day.

Sanjeev Goel, MD, FCFP (PC), CAFCI

You know I don’t wanna forget asking this question yet. You know we talked a little bit about COVID I’d love to understand, see if you’re seeing any data on people’s health during COVID like not acute infections more about, you know their inactivity and what impact did that have on sleep? The fact that they didn’t really go outside as much, things like that, people gained weight perhaps. I’m just wondering, is there any signs the sleep disturbance that happened during COVID time?

Harpreet Rai

So ironically in the beginning of COVID, and so in the beginning of the COVID for sure I think people were getting used to a new norm, but perhaps three, four months into it we published this actually in our blog that people are becoming actually and you know frankly much more creatures of habit and similar patterns. And so overall sleep quality of our user base actually improved and sort of call it the first half of COVID right? ‘Cause think about it you’re not going out, you’re not staying at work late right? Like you’re sort of already at home and you’re, you know not going, seeing friends, there’s not a lot of distractions, so people actually became remarkably more consistent and so that resulted in our whole database for most users seeing an improvement through data. 

Now there definitely was some 10% or so of folks whose data got a lot worse probably just personal situations maybe that our jobs were affected, maybe they knew someone that was affected, maybe they personally got sick, all right? Or their data was at was getting worse. We haven’t published our update follow-up to that but I do think as COVID has continued on, you know it is probably gotten a little bit worse right? Where that consistency pattern is sort of like to dull for most people and you know hence leading to sort of unhealthier things that, okay now that we’re starting to binge watch TV more, right? They’re really just like sort of have nothing to do and they’re eating worse and they’re not exercising as much, not getting outside but at least in the beginning of COVID we saw some positive results.

Sanjeev Goel, MD, FCFP (PC), CAFCI

Yeah, no, I for sure I’ve seen from my patients, might even took up more drinking as they were at home by themselves or with their bored and no job. Then like all the gyms are closed in Toronto and we’ve been like in fact last year and for this you know gaining weight. The heartbeats had gone up a bit so, I think there’s definitely something very interesting there. From personal I’ve used now it’s been over two summers I’ve noticed that generally my numbers improved in the summer and became worse in the winter. So do see some type of seasonal change like that?

Harpreet Rai

Yeah we do, I think we’ve published data on this that basically shows like summers are healthy for us or more healthier and to your point you’re probably getting outside more you’re exercising more, right? It’s nicer outside and you know, frankly, as a result probably of doing those things also eating better. And then I think the sunlight exposure, you know I think for, you know, circadian rhythms getting enough sunlight during the day, you know definitely triggers all the right hormonal cascade to then even sleep better and feel more tired at night. And so I think, you know, seasonal effective disorder right? You know is a thing and hence I think you know, in the summers for sure we see better data. We definitely even see that more pronounced in the Nordics. You know our company started in Finland and so their you know the summers are really, really short but the days are long and you know, vice versa and then winters are long and the days are really short, not much sunlight. So I think we even see that even more pronounced in some of those areas of the world where there’s not as much sunlight all year round.

Sanjeev Goel, MD, FCFP (PC), CAFCI

Are you having a lot of user base now in let’s say you know warmer countries let’s say India, I don’t know, Southern Italy like are you seeing places where much warmer? I know you, I was wondering if the same data would hold up if you’re all 24, throughout all year in a warm place but it even still be like that.

Harpreet Rai

Yeah I actually don’t know, I haven’t looked at that. I do feel like we went and actually showed some, I feel like recently or there is about to there was a study release showing different geographical patterns. But it still looked like it had seasons if I recall correctly. So I’m sure relatively there’s still some changing weather patterns so, enough for people to still be more active during one part of the year and less active. And then a lot of it may be cultural right? So.

Sanjeev Goel, MD, FCFP (PC), CAFCI

So let’s move on to HRV, I know that is definitely one of the aspects of the Ring that you really don’t find anywhere else. And I use it myself as well. So can you tell me about the algorithm? What makes this HRV I think more accurate than let’s say, you know people can wear band as well, I mean a chest band and stuff like that. So how does HRV calculated maybe in a, I know it might be difficult to explain scientifically but if you can kind of give a little.

Harpreet Rai

Well sure, I mean just maybe I can explain like why, what HRV is and how we measure it and calculate it and maybe why it’s easier to do for us than a wrist-based device. So HRV is heart rate variability. All it is is the variability or variation of each heartbeat. And so I think as you and I sit here, let’s say our, you know our heart rate often quoted in beats per minute BPM, let’s say it’s 60 beats per minute. And so what that means is across the minute we’re gonna average 60 beats. 

Now one beat might be one second apart, the next beat might be 1.2 seconds apart, the next beat might be 0.8 seconds apart, there’s some variation between each beat. It’s a little counterintuitive. You actually want high variation, you want high heart rate variability versus, you know each beat only being one second apart or very low variation. The way I like to think about it is, you know the human body is sort of, if you think about it has to adapt constantly. So if a tiger comes in this room, right? You have to jump up, you know, do the right thing, push a chair down, close the door, slam it in it’s face and get out of the way right? You have to think very fluidly and so it was sort of like this race car idling and you need to go, boom go, right? Versus if you’re this race car and your RPM is all the way up, right? And you’re probably gonna spin out right? And so you want that high variation. 

It keeps you sort of in that flow state. And so, you know, one metric that’s important to notice is that actual space between each beat, is called interbeat interval or IBI. And so what we do at Oura, this is really, you know a combination of the engineering side more so than even an algorithm, measuring those algorithms is actually, measuring that data is actually pretty easy. You just gotta be able to measure every single heartbeat. Now the problem with wearables is the signals on our wrist here are really weak. As we know these signals are strong from our arteries. These arteries carry a lot of blood you can feel the pulse that go to the palm of your hand and your skin is really thin, you can even sort of see your hands are red. 

And so as a result, the pulse signal from that, you know from your fingers got a hundred times stronger than it is from these are veins here, you can’t feel the signal right? When you touch them. It’s buried below a lot of muscle tissue, you know in my case dark scare and even, you know in dark skin and even hair. And so that pulse although being so strong allows us to use very little power but get sampled really, really fast. So we’re able to sample our signals at 250 times a second, 250 Hertz at night. And a wrist-based wearable if they tried doing that the battery would probably die in an hour. And so as a result we can just see that pulse signal so much more clearly, most wrist-based wearables because you know the power usage is so high since that signal is weak, they actually turn off their heart rate sensors for a lot of the time and then turn them back on and it’s sort of extrapolate. 

So if you have a Fitbit or Apple Watch, sort of hard to do this on your Fitbit while you’re sleeping to like try to sleep with one eye open and you’ll see that the heart rate sensor turns off and then turns on again. And so they, you know really these wrist-based devices don’t have the ability to measure every single space between each beat. And so that’s why we can do it all throughout the night, that’s why we share that data with researchers or even doctors. You can download that data on our Oura team’s portal and actually get every single interbeat interval sent to you. 

So it’s more like an engineering thing. The nomenclature that you can use for measuring this is, you know, HRV, we use the standard which is RMSSD or the root mean squared of success of differences in between each data. It’s just sort of a little bit of a formula probably not worth getting into but you know I think that that’s how we calculate. It’s more just that the other devices don’t have the battery life or the engineering accuracy to expand for a long time to capture all that data throughout the night. And I think that’s why so many people love our device ’cause it’s such an easy thing to look at and get really accurate information on.

Sanjeev Goel, MD, FCFP (PC), CAFCI

So for and if let’s say you were to get up or there’s a change in your HRV or sleep, like how many minutes or you know, is the Ring accurate for? Like I know sampling every, you’re saying is sampling so often, it’s doing it all the time so if you get up and go to the bathroom for I don’t know 30 seconds is it gonna catch that?

Harpreet Rai

Yeah, we still catch it but what we do is, HRV is typically calculate in a five-minute interval. So each RMSSD is calculated sort of over a five-minute period and we’ve been in each period all throughout the night in five-minute increments. So if you get up and you move, you know you might even see a hole in your data when you look at that and that’s what that is. So we’ll catch it, we’ll still see it like meaning you got up but then because of that we don’t think the data is as accurate so we’ll exclude it from that dataset.

Sanjeev Goel, MD, FCFP (PC), CAFCI

Got it okay, perfect, I got that. Where, what about other, are you guys looking at, you know partnering with other people, you know I know there’s some companies that are working on, you know a chilly mat like working on you know cooling technology for the bed and seeing how that impacts sleep or is there any, where do you think things are going, you know with the Ring in the future?

Harpreet Rai

Yeah, I think the pandemic really gave us the blueprint for sort of how this kinda technology can be used. So you know during COVID we were actually the first wearable to partner with an academic institution. So we worked with UCSF, we were the first wearable to start a study on COVID and you know I think what we showed is basically UCSF actually had a paper published in December and what they were able to show in that paper is that you could actually see data changing on an Oura Ring up to three days in advance before users felt symptoms. And I think, you know it sort of shows the power of high quality data and then machine learning and data science that, you know you can train these algorithms amongst many different things. 

In this case it was positive COVID test. And UCSF was actually verifying that, luckily they got great funding and we’re able to actually send, you know both slides on blood tests and things like that to users who did get positive COVID tests and many users were actually tracking their symptoms every single day, which was pretty cool. And so if you think about that for the future just like a going to train this wearable sensor data on sleep, or activity, or even things like COVID there’s so many new health applications. So, think women’s health that’s a pretty interesting area. We had a study published there on Berkeley being able to look at, you know the temperature data we see plus HR, HRV and correlate that to LH surge luteinizing hormone surge. I think you could do it for sleep apnea as you were talking about. 

I think there’s lots of things you can do in the heart space, whether it’s hypertension, congestive heart failure or arrhythmias. I think there’s gonna be so many new use cases where you can keep developing all these algorithms. So that’s one area, just more health sensing features. I think the other area is you mentioned is like, okay how do I, now that I have this data how do I improve it? Should I be doing things like using a chilly pad? How much does alcohol actually affect my usage? Or working late? What if I start meditating? What if I start exercising? How much gonna improve this data? So I think, you know, I always say that people want two things, like one is this data accurate? Like what’s the use case and is it accurate? And then two, you know sort of what do I do with the data? Meaning how do I improve it? How do I change, you know, change it? And so I think both those things are what we’re focused on.

Sanjeev Goel, MD, FCFP (PC), CAFCI

Yeah I think that predictive analytics or if there’s recommendations ’cause I know generally we know that yes alcohol we have to kinda stop, put this through our own brain computer to figure out okay what impact does that one drink gonna have at 10 o’clock at night?

Harpreet Rai

Yeah.

Sanjeev Goel, MD, FCFP (PC), CAFCI

But if you can tell me, hey, it looks like if you do this you’re gonna have like a, you know 20% reduction in your sleep, that would be pretty cool ’cause you have that data. We put that through and say look this is.

Harpreet Rai

We are and I think one thing we ask our users to do is just keep tagging, like the more people use our tagging function, the more we learn. And I think you’ll see us do actually frankly more studies with volunteers right? That’s what COVID was where you’d reached out to our user base, you know, not that any of us wanted to get COVID but likely some of us were going to in the user base but what if we asked all our users to drink a glass of alcohol tonight or turn your thermostat down? I think you’ll see us engage in a lot more of that and we already are because we get, we do get you know, tens of thousands if not hundreds of thousands of tags every single night or week and so I think as we start to aggregate more of those, you know, we’ll see, well I think we’ll see us do some pretty fun stuff in the future.

Sanjeev Goel, MD, FCFP (PC), CAFCI

That’s awesome. Anything you wanna end off like with the main message to our viewers and listeners anything you wanna say?

Harpreet Rai

I mean, I sort of come back to, everyone’s gonna sleep every single night. It’s perhaps one of the most meaningful things you can do for your quality of life and improving your health. And you know, we’ve made it so easy as have other companies are making it easy for you to understand. It’s a really easy way to look at sort of cause and effect every day and start to understand what health changes you can make that are actually driving an impact. 

And so I think, you know most people don’t realize that you know, lack of deep sleep for example can be linked to early onset of Alzheimer’s, you know lack of sleep as whole can really cause, you know, weight gain mainly because your hormones start to get imbalanced, you’re grueling, your hunger hormone, you know shoots up, your leptin hormone half-full you feel after every meal, you know unfortunately it goes down and so, you know whatever you are trying to improve your health and performance for just sleep makes it so much easier. So I sort of look at it as Matt Walker said, like it’s the, perhaps the single most legal performance enhancing drug you can do right? And we all do it every night. You’re gonna do it no matter what, right? So why not get good at something that you’re gonna have to do everyday anyway that’s gonna make a huge impact on how you feel and perform for the rest of your life.

Sanjeev Goel, MD, FCFP (PC), CAFCI

Yeah, I think this is the ultimate, I think it’s the ultimate area for the biohacker and those who are trying to change their life to hack their sleep. And so I think this is amazing work that you’re doing ’cause it changes so many people’s their lives so that’s off to you and to Oura Ring.

Harpreet Rai

Appreciate it. Luckily we got awesome team and they keep growing and working really hard. I can’t do anything by myself but, you know I think we’ve had an amazing, you know experience with our community and early users who shared this with others. I think that’s a lot of it too. It’s like, you know people seeing the changes they make. We’ve had some users that are like, man I got this and I just realized I cut out my caffeine after four o’clock and I stopped eating after eight. And like I feel better, I perform better, I have more energy to hit the gym, I’ve done, as, you know, as it turned I’ve been losing weight and I’ve actually been more you know alert and productive during my workday. 

So I think all those things together right? It’s just a, all of us are a community and you know we gotta teach each other, we gotta share with each other and you know we gotta do what we can and do our part to make things for each other too. So I appreciate you putting this together ’cause this is, you know frankly, how people learn about these things and start to practice them and then, you know for your listeners right? If they do see improvement they’ve seen a positive thing, share it right? ‘Cause for every one of us that’s improved there’s still 10 other people who may still be suffering. So, just really appreciate the work that you’re doing as well Sanjeev, thanks a ton.

Sanjeev Goel, MD, FCFP (PC), CAFCI

Thanks so much, I just want to say one last thing is that the first thing I do when I get up in the morning I roll over and ask my wife what her score is. So I can tell you that I haven’t met, I mean I think there’s not too many things out there that people are that fanatic about. Like, you know you have Mac users, you know the people or whatever you know based on their type of car or whatever but I feel like they Oura Ring is in that type of situation or like so I don’t, I’m wondering, do you feel that about your user base that some of them like extremely?

Harpreet Rai

We do, I mean, no look I think, again you’re gonna do it every day so it becomes a daily habit and set a little reminder and how you can perform a little bit better. And yeah we see that behavior a lot that you know first thing people do, I think we’ve even said this that you know majority of our users, I think it’s like 75, 80% of our users check the app in the first hour when they wake up. And frankly that’s such a good reminder ’cause it’s just, you see it first thing in the morning and then it sort of shifts your focus. Okay, I’m a little behind the eight ball today, what can I do to do better tonight so I feel better, you know tomorrow or vice versa? Hey I’m feeling really good today. 

Today is probably a really good day for me to push extra hard in that workout or get it the office early and get a lot of work done ’cause I’m gonna be in the zone. So I think it’s just, it makes it a little bit more actionable. I also found that I only asked my significant other my partner how I’m doing if I know my score is bad. Because I do not like I don’t wanna get a humblebrag space. So if I’m like, you know if I’m like 70s I’ll be like, “hey how was your score last night?” And she’s like, “oh 85,” and I’m like, “oh man, I was a 70,” but otherwise I let her ask me or tell me first.

Sanjeev Goel, MD, FCFP (PC), CAFCI

What’s really interesting, I think, you know the Oura Ring is in a very unique position to actually change now people’s like how their day will go depending on like if you put the crown or not ’cause you actually getting some type of, if you’re getting some type of positive feedback you might actually change that person’s,

Harpreet Rai

Totally.

Sanjeev Goel, MD, FCFP (PC), CAFCI

By how the day’s gonna go.

Harpreet Rai

Yeah.

Sanjeev Goel, MD, FCFP (PC), CAFCI

This is you know they’re definitely more positive. But it’s kind of almost like a feedback loop.

Harpreet Rai

Yeah, I agree, yeah.

Sanjeev Goel, MD, FCFP (PC), CAFCI

Anyways thank you, I really appreciate your time today and for our viewers we’re gonna put a link for them to go to the Oura Ring so that they can get one.

Harpreet Rai

Cool, well thanks a ton for the time and thanks again for putting this together Sanjeev I appreciate it.

Sanjeev Goel, MD, FCFP (PC), CAFCI

All right, okay take care.

Harpreet Rai 

All right, see ya, bye.

Sanjeev Goel, MD, FCFP (PC), CAFCI

Bye.