WHOOP Podcast - The Science of Human Performance: Your Guide To Better Sleep

Episode Date: July 8, 2026

Welcome Back to the WHOOP Podcast's Science of Human Performance Series! This week, WHOOP Global Head of Human Performance and Principal Scientist Dr. Kristen Holmes sits down with WHOOP SVP of Research, Algorithms, and Data Emily Capodilupo for a deep dive into the science behind the WHOOP Sleep Score and the habits that have the biggest impact on restorative sleep.Emily explains why sleep consistency is one of the strongest predictors of performance, recovery, and long-term health, and walks through the four metrics that make up your WHOOP Sleep Score: sleep duration, consistency, efficiency, and sleep stress. Together, Dr. Holmes and Emily unpack how nutrition, exercise, alcohol, stress, and your daily routines influence sleep quality, share practical strategies for falling asleep and staying asleep, and discuss how poor sleep can sometimes be an early signal of underlying health issues.Whether you're looking to better understand your WHOOP data or simply wake up feeling more rested, this episode offers a science-backed framework for building healthier sleep habits that last.01:11 How WHOOP Built The Sleep Algorithm02:17 The 4 Pillars of Sleep: Duration, Consistency, Efficiency, & Stress03:20 The Secret To You Best Night’s Sleep: Sleep Consistency08:06 Sleep Efficiency Explained11:38 Impact of Alcohol on Sleep Quality18:01: How Your Day Shapes Your Night19:34: Exclusive Offer For WHOOP Podcast Listeners20:07: How Sleep Stress Impacts How Rested You Feel24:08: Is Your Sleep Normal?25:48: Why Sedatives Don’t Actually Make You Sleep Better26:59: Defining and Combatting The 2 Types of Insomnia28:57: Light Timing: Benefits of Red Light Therapy on Sleep 30:57: Winding Down Before Sleep: Breathwork & Stress Reduction34:07: Understand Your Health with WHOOP Advanced Labs34:41: Impact of Exercise on Your Ability to Fall Asleep 42:40: How to Prepare for Sleep & Stay Asleep44:28: What Your Lab Results Can Tell You About Sleep 53:40: Creating Contrast Between Day and NightSupport the showFollow WHOOP:Sign up for WHOOP Advanced LabsTrial WHOOP for Freewww.whoop.comInstagramTikTokYouTubeXFacebookLinkedInFollow Will Ahmed:InstagramXLinkedInFollow Kristen Holmes:InstagramLinkedInFollow Emily Capodilupo:LinkedIn 

Sleep consistency predicts a lot of outcomes better than sleep duration does. It predicts mental health, like adverse outcomes. It predicts performance better than sleep duration. And it predicts self-rated fatigue, so how well-rested you feel. And that has a lot to do with the fact that when you sleep at a time that your body is expecting sleep, it sleeps better. And so it's not so much that the clock is magical. But when you tell your body, hey, you can rely on, you know, at 10 o'clock,

I'm going to be in bed, we start to produce these sleep promoting hormones like melatonin two hours in advance of the anticipated bedtime. And so if you get into bed when your body's anticipating it, hormonally your body's like, I am ready for sleep. And if every night's sleep is a total surprise, your body stops producing the melatonin and all these hormones because it basically gets this message of sleep is unreliable, so I'm going to wait. And so then what you notice is that people who sleep inconsistently have trouble falling asleep, have trouble staying asleep because their body's like trying to respond instead of anticipate.

And so the more you let your body anticipate what's coming and have those signals be dependable and reliable, sort of the better prepared you are. Emily Capitaluppo, welcome. Thanks for having me. This is fun. I know, it's really fun. You know, I think about sleep a lot. And I know, I know you do too.

And, you know, we really share this passion. And, you know, when I think about just the last 10 years at Woop and how much we think about, and how much I've learned from you about sleep. You know, I'm so grateful. And, you know, and I think we've been able to iterate on various aspects of sleep as it relates to the product specifically and coaching and in ways that I think, hopefully I've had a really positive impact on our members. But today, I want to just dive into sleep in a way that will help our listeners

and our members just understand the very basics of sleep. So they can be empowered to think about these data. the context of their own life, what matters, what maybe is, you know, less relevant to pay attention to. So if we just start very simply with, number one, sleep is the greatest performance and health enhancer on the planet, right? And it's relatively democratically available and free. So it's something that we should be leveraging, right? When we think about the four pillars of sleep that are inside our app, and we can kind of go back and forth on this, but let's just talk about what those are and why they are included in the app. Sure. So, you know, if you go back two years

ago on WOOP, our sleep score was a little bit simpler. We were really just focused on, let's make this really easy to understand, are you getting enough sleep? And that actually had been our sleep score for 12 years before that. While getting enough sleep is incredibly important, it's not the only thing that matters. You have to get good quality sleep. And so we updated it, little over a year ago to make sure that we were capturing all of the dimensions of not just did you get enough sleep, but are you going to feel rested? Did you get the right kind of sleep, high enough quality sleep? And we still wanted to keep it really simple and easy to understand and the data supported keeping it to just these four things, but also to sort of capture stuff

that over the last decade we've really learned are incredibly important. So the most important thing that we added to the sleep score is sleep consistency, which put simply is just, are you going to bed and waking up at the same time? So are your sleep opportunities, whether they're nighttime sleep or daytime naps, are they happening at the same time every day? You know, sleep consistency has been something that sleep researchers have been studying for a long time, but really exploded about eight years ago. Andrew Phillips put out this research, and he basically showed that sleep consistency, predicted GPAs in Harvard undergrads better than sleep duration did, and created this new metric that he called the sleep regularity index. And then we built upon for a wearable

application instead of for like a retrospective research application, created sleep consistency. Andrew was actually my thesis advisor. So somebody I've known for 17 years at this point. And so we were able to kind of get, you know, his input to this and his buy-in to adapt this for Woop. And it was something that we added to the product. And then, you know, fast forward over the years that followed adding this concept of consistency as sort of a really important metric of sleep, but not yet in our sleep score. We started doing a lot of research on this metric. And this is a place that you've been really passionate too. But basically, sleep consistency predicts a lot of outcomes better than sleep duration does. It predicts mental health, like adverse outcomes. It predicts performance better

than sleep duration, and it predicts self-rated fatigue, so how well-rested you feel. And that has a lot to do with the fact that when you sleep at a time that your body is expecting sleep, it sleeps better. And so it's not so much that the clock is magical, but when you tell your body, hey, you can rely on, you know, at 10 o'clock, I'm going to be in bed, we start to produce these sleep-promoting hormones like melatonin, two hours in advance of anticipated bedtime. And so if you get into bed when your body's anticipating it, hormonally, your body's like, I am ready for sleep. And if every night's sleep is a total surprise, your body stops producing the melatonin

and all these hormones because it basically gets this message of sleep is unreliable, so I'm going to wait. And so then what you notice is that people who sleep inconsistently have trouble falling asleep, have trouble staying asleep, because their body's like trying to respond instead of anticipate. And so the more you let your body anticipate what's coming and have those signals be dependable and reliable, sort of the better prepared you are. And this is true in so many ways. When we eat at predictable times, our stomachs are more ready. So we tend to like get less bloated or like sort of uncomfortable GI symptoms. Systemic inflammation. Yeah, inflammation, all these things,

right? And it's the same thing. It's, you know, our all is our stomach and, you know, our whole digestive system ready to receive food. It's actually really interesting research too that like people who cook their own food, because all the like smells and the stimulus and stuff, like sort of tell your body food is coming and so tend to handle it better. And that actually positively contributes to your gut biome. Yeah, yeah. Which I literally just year yesterday. Yeah.

But sort of the point is with sleep consistency, it's not this like magical thing. It's just the more you can let your body anticipate it, then like when it then gets this opportunity to sleep, it's ready and so makes the most out. And so you get this kind of like more efficient. you get into the deeper stages of sleep better, you stay asleep. And so minute per minute, it's more valuable, restorative, great sleep. So sleep consistency, really, really important. And I might just add just a couple things to that, because just to pile on, there is lots of

literature at this point. And Daniel Windred and his colleagues published a paper in January of 2024, where by they found sleep consistency was a greater predictor of all-cause mortality than sleep duration. So just to pile on that. And I think you make such a great point. I want them to make sure that they hear you on this, that bypassing that anticipated sleep comes at a cost. Yep. Right?

So that extra couple shows of Netflix or, you know, whatever it might be. When you push past that pressure for sleep, it does come at a cost. And it's a reduction in melatonin, which we know is not just the sleepy, you know, drugs. No, it's a super powerful antioxidant. So powerful, right? It just goes away. It's cancer protective, right? It actually reduces the cancer tumor genesis, you know, like, and so it has the,

these incredibly valuable properties beyond just making you feel sleepy. So sleep consistency. I, you know, there's just can't say enough about how important that is. Yeah. And to that point, you know, we put sleep consistency in our health span metric because of all this powerful research, tying it to all cause mortality, which is the sort of underlying metric that health span is optimized for. And so, you know, we felt that once we were doing all this research, putting it into health span, to not have it reflected in the sleep score just didn't make sense. And so we're glad that we were able to make those updates and they came out relatively like right around the same time. The third thing that we added to the new sleep score was sleep efficiency.

So that's the percentage of the time that you, like of your sleep opportunity. So from when you first get into bed until you get out, that you're actually asleep. So physiological sleep. Yes. So actual sleep as a fraction or as a percentage of the total time in bed. And maybe if it's okay, if this isn't giving too much away, I don't think it is. but I love looking at just how we model sleep, like how we know you're in physiological sleep. Because I think that will give a lot of confidence to our members that like we're looking at

respiratory rate and HRV and heart rate. And, you know, we're looking at all these components to determine are you actually in physiological sleep. Yeah. So we're looking at, you know, your heart rate data, your heart rate variability, respiratory rate. And then from those things and from the sort of raw PPG signals that we're getting your heart rate, We've created all these other features that aren't necessarily themselves human readable. It's a sort of machine learning problem in order to predict the stage of sleep that you're in.

We're very good at doing this. And we've been working since 2017 with our sleep lab in Australia. To refine this and just make it as good as being. Yeah. And, you know, they have a sleep lab. And every single night we have people who are wearing usually five whoop straps because of the whoop body product. So on all different parts of their work. body undergoing polysymognography, which is the gold standard clinical sleep test. Those tests get scored by humans. And then we take those results and the whoop results. And then we train

our machine learning algorithms to predict the human scored gold standard clinically collected data. So we are going, you know, the absolutely like the most rigorous way possible. We've had this third party validated multiple times. Strong accuracy. And so our ability to tell the difference between sleep and wake is really strong. And we know that sleep efficiency tells you a lot. And what's interesting about sleep efficiency is you don't want it to be 100%, right? And so if you notice the way the sleep score works is you don't, in order to get like full credit in terms of like how that contributes to your sleep score, we're not looking for that

to be 100%. In fact, when your sleep efficiency is too high, really above like 96%, we start to get worried that that's a sign of chronic sleep deprivation because the more tired you are, the more your body's going to easily sleep, but that often means that you're not getting enough sleep. And so when you do want to kind of wake up, you know, every 20, 30 minutes is sort of different from person to person. You want to roll over. You want to have these, they call them like micro arousals where like you're technically awake. You might not even remember that they happened, but whoop captures them. Anywhere from kind of like 30 seconds to four minutes and fall right back asleep, those are times

where you roll over, adjust your pillow, pull the blankets, and that stuff's really important, both in terms of like relieving pressure off of your muscles just from, you know, staying in the same position all night's not great for you, but also just a sign that like healthy sleep does involve these periods of wake. If your sleep efficiency is too low, below 90%, that's often a sign that maybe your environment is not conducive to sleep. So you want to think about your room being cool, dark and quiet. And then you also want to think about are you having any stimulants, whether that's the sort of what we traditionally think about stimulants. so nicotine, caffeine too late at night that would get in the way of sleep or stimulants in the form of stressed or... Maybe like you haven't dealt with stress throughout the day.

Yeah, and so you're like waking up and thinking about something. Alcohol can be a sort of interesting one because alcohol often will help you fall asleep faster, but alcohol is broken down into sugar as we sort of digest it and that sugar can then, you know, cause us to wake up in that like horribly groggy gross like I don't feel good I don't know why I'm awake but you have this almost like sugar high and even if you're kind of passed out and you don't realize that's happening your heart rate is because of the sugar is operating at a higher level than so when we when basically the machine learning with the algorithm is kind of assessing all these different components even though you're passed out and you think you're sleeping your heart rate is actually

elevated to the green bear yeah I mean what we see with alcohol is you can actually see the half-life of alcohol. So we process about like one standard drink per hour. And you can just see that breakdown in the heart rate as they would often be wildly high for sleep and then return to baseline as you process. Let me ask you a fun question. Would you recommend? So I did this experiment a few years ago, but basically looked at stress score and I drank a perseco and I could see like my heart rate, you know, changing. My stress score was essentially higher. So I basically, you know, kind of went to bed at my normal time. And sure enough, my stress court during sleep was high. And so, but the next time I did the experiment, I basically waited until my stress court, you know,

came down, you know, to below one. And then I went to bed. So I kind of sacrificed my sleep consistency, but ended up having a much better sleep experience. What do you think about that? I think you have to be careful with that. So if you're going to say, hey, at 9 p.m., no matter what, I'm going to drink this glass of Persecco. And my normal bedtime is 10, but should I stay up until 11 in order to like sober up before I go to bed or go to bed at 10 per normal, knowing that I will be, you know, still drunk or have alcohol in me at that time? You're still getting non-zero amounts of sleep while the alcohol is in you.

So if you're still going to wake up at the same time and all those things, like that hour between 10 and say 11 when the alcohol wears off will not be great quality sleep, but it isn't on zero. And so if the choice is like have nothing or, you know, have say 30% efficient sleep, I would still say go to bed. I'd also say that because by the way, like when we drink, we tend to like bad habits, beget more bad habits. So now you're more likely to have a junkie snack. You're more likely to like do other things. A slice of pizza. All these things. And so you're also just, you know, if going to bed at 10 is an option, that's still at that point the best option. That said, if you're saying, hey, you know, I would love to have a drink tonight and your choice is,

I'm going to go to bed at 10, should I have the Prosecco at 8 or 9, that would totally say 8, because if you're, the further you separate the alcohol from the sleep, if you're sober when you go to bed, you're not processing the alcohol during sleep, and so you will sleep better. One of the things that happens that's really challenging with alcohol because it breaks down into sugar, you almost have this slow release sugar. And our bodies do not expect to receive carbs during sleep. Right. So like that whole system is in sleep mode. And then all of a sudden these carbs are like slow releasing into our bloodstream as if we're eating kind of, you know, throughout the night.

Which is like very counterintuitive to our body. Right. is like hormonally, it doesn't make sense. And so we tend to let our blood sugar get higher because, like, the system is not like, okay, like we're eating carbs now, right? The normal physiological experience of sugar entering the bloodstream is, you know, it's coming in through your mouth. And so all those like receptors in your mouth are saying, like, we're getting sugar,

which says to insulin, like, get ready. And the whole system activates from that. But when it's like sneaking in hours later, that system doesn't activate. And so much of what's happening that's like very disruptive to sleep. sleep is that like, you know, these sort of like carbs that aren't supposed to be there or there. Right. And so you get like the inflammatory response to the sugar. Like the alcohol itself isn't great.

But the sugar in sleep is also this like totally separate disruptive thing that's very different than like if I have ice cream right before bed where I still might have like relatively high sugar that I need to deal with. But I got all the stimulus of, you know, tasting something sweet or my body's like, okay, sugar's coming and I could like mount their response in terms of, you know, the sort of like caskies. it removing that. Amazing. Is there anything else sleep score-wise that you want to point out around efficiency? No, just that the thing to watch for with efficiency is if it's too low, it's worth looking at your environment. It's worth thinking about like, you know, stimulants, nicotine and caffeine in

particular. And making sure caffeine has a half-life about seven hours. And so you really want to make sure that you've got a good seven, eight hours between your last cup of coffee and bedtime I'm out of minimum. And it's worth if you have trouble with sleep to try and make that window even longer and see if that helps. And then the other thing, because I think so many people just love to max things and get 100%, like do not get tricked into thinking that if you're winning at sleep efficiency, you're winning in some way.

Like this is one of those rare metrics where if it's kind of 96 to 100%, especially consistently, that could be a sign that you're not getting enough sleep. and that if that comes down a little bit, you're sleep deprived, right? You see this in shift workers. Yes, so much sleep pressure. There'll be, you know, five hours of, you know, of like deep, deep sleep, you know, of like deep sleep, you know, of like the military and stuff too. Like they can go to sleep like that and they think it's a superpower. And in some ways it's a sort of necessary survival thing for the environment that they're in.

But I think also sometimes they freak out a little bit when like, you know, they start getting more sleep and their stats get worse. Right. Their sleep efficiency comes down a little. that's actually a sign that your body is like getting into a healthier sleep state. So if it happens, you know, every so often we all have those like, whatever situation makes us exhausted and we just totally pass out. And we know what it's like to have so much sleep pressure that you just like sleep like a baby or whatever.

But that's a sign of sleep deprivation. And so that's something to watch out for. I'd love to just hit on a couple things there. So with, because I do think people are really, not everyone gets high sleep efficiency consistently. And I think the one of the other. components that could potentially be disrupting your sleep efficiency is generally a lot of things that are happening during the day. So you mentioned cold, dark, quiet, your environment really matters.

But I think it's worth maybe talking about stress too during the day. We published a beautiful paper in emotion last year that looked at threatened challenge appraisals. So we know if you're feeling threatened during the day chronically, we saw an association with sleep quality, sleep efficiency. So, you know, just understanding that how you're living throughout the day actually impacts the quality of your sleep at night. Obviously, one of the big drivers is sleep consistency, so just that regularity will help improve your sleep quality. But knowing that in order to back into a consistent night's sleep and get that quality efficient sleep experience, it really does start the moment you wake up. So just a reminder to folks, you know, getting that sunlight,

right, that will tell your body it's time to wake up. And then 60 hours later, you know, you'll feel sleepy, right? So that cortisol and melatonin kind of bookend to start the day and end the day is really important, and you do that by viewing lots of light, getting as much light during the day as possible. And then dimming lights after the sun goes down to the best of your ability, certainly in the hour, half hour in the lead up to bed, making sure that you're dimming your environment so you can get that melatonin release. But those are just a few of the things to consider during the day that will help facilitate, create conditions that will allow you to fall asleep at a regular time and create this more efficient sleep experience. Exactly. Yeah. Okay. So the fourth component that we added to

our sleep score is sleep stress. And this is a uniquely whoop metric, but we've had a stress score, continuous measurement based on heart rate, heart rate variability. It's actually trained on blood pressure data that tells you how stressed you are. And stressed is not just sort of the colloquial thing we say, we're like, I'm so stressed right now. It's like how activated your body is. And that can be appropriate. Like you should be stressed when you're exercising, right? You want to be activated or even when you're giving a presentation, right, you want to be focused and dialed, and that's a certain level of appropriate activation. What's interesting is during sleep, it should be pretty close to zero.

And what we were noticing, because this metric just runs 24-7 as long as you have your whoop on, was that when people were sick, it was skyrocketing. We measure stress on an arbitrary scale of zero to three. And, you know, what we were seeing for most people most of the time is as soon as they fall asleep, their sleep stress goes to zero and more or less stays there the entire night. But then you'd get sick and it would be like two out of three all your sleep, right? Or certainly if you're drunk, but even like if you were dehydrated or emotional stress or sort of struggling with any kind of like anxiety or mental health, it was showing up in the

sleep stress metric. And what was so interesting was unlike stress during the day where it's difficult to get the context of, you know, is stress elevated appropriately or not during sleep, like, you like you know that any elevated stress is not appropriate. And so we started looking at how much elevated stress people were having at night and what it correlated with. And it correlated very strongly with illness. It correlated very strongly with perceiving the night of sleep being really crappy,

even if there was a lot of sleep. And so it let us start to tease apart. Like we all have had that experience where like you have the flu and you can easily sleep for 14 hours, right? And it's like your body just needs so much sleep. And what we were trying to really respond to is when you have the flu and you just sleep all day, you're still exhausted, right? And so like, and we might look at them and be like, wow, you got so much sleep.

And it's like, yeah, because your need for sleep has skyrocketed here. And so what sleep stress allows us to do is to tease apart, like, did you get an enormous amount of deep, deep sleep because your body's needs are, you know, 10x, what they are? There's so much that your body is processing. Or did you get a lot of sleep and you're just like really rough? And so it teased apart the like, what was funny was that like perfect sleep scores in the old metric when it was just about duration were like correlated with sort of challenging days the day before, whether it was like really intense physical days or not feeling well or all these things because, you know, we all do that thing. We're like when we feel awful at some point you are like forced to get more sleep. And so the ability to tease that apart and say, yes, there was a lot of sleep here, but it doesn't count. but you're not going to feel rested.

This wasn't a great night to better reflect how you feel. And now, like, sleep-wise, how you are showing up the next day, which is exhausted despite 16 hours of sleep, that was what allowed us to capture that. And so it almost serves as this like foil to the other three metrics of, you know, you were consistent. You've got an enormous amount of sleep. You know, being sick or drunk or all these things can be correlated with really high sleep efficiency, right?

Because, again, the sleep pressure is atypical high, but then we can say, oh, but this wasn't good. So that was why we put that. and there. And so we were able to ultimately create something that better reflected. Did you do the things that ultimately land you in a place where like you're going to feel good and be well rested and have all the benefits of sleep that you can get? So we're trying to capture like did you get what your body needed or to what extent were sort of opportunity left on the table? That more holistic view of these four metrics instead of just basically the one better reflected that.

Emily, I know you get a lot of questions about sleep, and I know I get a lot of questions. And I think what people want to know is, is my sleep normal? How do you think about that? How do you answer that for folks? You know, with those questions, there's always two important things to tease apart. One is like, are you giving yourself enough of an opportunity for sleep? Because so much of what people are like, oh, I don't sleep enough. And then you sort of dig into why. And they're sleeping. is totally fine. It's not a sleep issue. It's like they've got a toddler or maybe an infant who's not sleeping through the night yet or they have to get up really early for work or any, you know, whatever those obligations are. And so they're only allowing themselves maybe six, seven hours for sleep each night. And so fundamentally that's not a sleep issue. Yes, they're not getting enough sleep, but sort of me telling you about cold, dark, quiet and, you know, morning sunlight and all those things. Like, you can't start with the, like, optimizations until you've gotten the basics. And in some ways, that's why getting enough sleep was our just North Star core focus for,

you know, the first decade of last of a loop. Like, you have to have, yeah, like the number one thing you got to fix is there has to be enough time in bed. Like, that sleep opportunity, that window has to be there. And the good news is is that naps totally count. So if it's just impossible with your lifestyle to get enough in, you know, overnight and you can get it in mid-morning or something like that. That's totally great. But you do need to figure out how to make that opportunity. And so there's not a lot I can do for you if you're like not willing to make that happen. Unfortunately, there are no drugs that are going to make you like sleep twice as fast. And in fact, I'd say like so many of the things that look like they do that wildly do the

opposite for you. So I know a lot of people who feel like, of there's not enough time per sleep or whatever might use like the sedative hypnotics, so like Ambien or any of these kind of like drugs that help you sleep. Anything that's sedating you is not getting you into like the active parts of sleep. Like our experience of sleep is like, oh, right? Like nothing's going on. Sleep is incredibly active. There are so many things that are happening.

And when you are sedated, you are not sleeping. You're like not awake, but it's like this other thing. And so you will not wake up as rested. There's numerous studies not done by whoop where, you know, in sort of cognitive performance and athletic performance and just self-rated scores of sleepiness, like the sort of sedated sleep does not equate to real sleep. And at a basic level, it's because we're not getting into REM and slowly sleep. So you don't get into those deeper stages.

And you see it in the polysymography testing, right? Like that does not happen. Where it can be really helpful is many people have trouble falling asleep. sleep, but not trouble staying asleep. So there's two different kinds of insomnia, right? There's sleep onset insomnia and sleep maintenance insomnia. So falling asleep versus staying asleep. And if you have trouble falling asleep, which is often anxiety or something else like that, not actually a sleep issue, but like you can't turn your brain off, then it can help. But you actually tend to get the sleep after those drugs wear off, not while you're on them. And sort of nightcaps are in that same category.

Like if you sort of feel like you need a glass of alcohol to fall asleep, until that alcohol is processed, you're not really sleeping. You're not getting these benefits. And the chances of you waking up at 3 a.m. are very, very high. Yeah. Again, it's better than zero, which is why these drugs are still very popular. And if you can't get anything without them, they are better than zero. And the psychology of not being able to fall asleep is maddening. Yes, people getting to taste like, yeah, exists.

bad states where you get anxiety about that you're going to not be able to sleep and that can be a vicious cycle for sure. But let's assume that we're not talking about somebody whose primary issue is that they're not creating a sleep opportunity. We're talking about somebody who, despite having eight hours in bed, does have trouble sleeping. We touched on a little bit of this as we were going through the four inputs to our sleep score, but I think it's kind of worth talking about, like, what order I would sort of give somebody I loved advice. So we touched about on the difference between sort of trouble falling asleep versus trouble staying asleep. With trouble falling asleep, you really want to think about stimulants, right? So is there a reason that you're up?

Right. If it's not things you're putting into your body. The timing of your caffeine. Yeah. So are there stimulants actively in your system right now? You want to think about your sleep environment, cold or quiet. You want to think about sleep consistency, right? Is your body anticipating sleep?

Did you give it a chance to do that? And when we talk about that like cool, dark, quiet stuff, you know, it's not just that I go from jamming, whatever, like lights on, working all the stuff to, okay, I turned off my lights now. Like, I'm ready, right? Like, some of this is in the hour, two hours before bed. And it doesn't mean that you actually need to be in pure darkness that actually it's blue light that's the most problematic.

So you can either wear glasses that are blue light blocking or you can, if you have, you of like smart light bulbs. You can set them to be warmer instead of like cooler at night. And there's actually some really fascinating research that red light promotes melatonin better than pure darkness does. And so you don't need to like fumble around in the darkness. But if you have no blue light, but yes, red light, that's actually better for promoting melatonin than than pure darkness. And I can say I do my red light panel before I go to bed. It makes me lethargic. You know, like I feel. I fall asleep in it every night. It's so good. It's the greatest. And this is actually a really great hack because just with my lifestyle, like the easiest

time that I can be consistent about working out is at night, which is like sort of otherwise not great. But for where I am in life right now, it's like then or never. And so I tend to like put my daughter to bed and then work out. And the red light therapy post workout is both like good for muscle recovery after the workout. And you're probably taking a hot shower too before your red light. So you're getting this really nice double whammy of just your body is like, okay, it's time to line down. Emily's going to go to sleep. Red light bed, so it's like

full 360. It's amazing. Oh, love that. Yeah, it like goes over under and then I just like fall asleep in there, put a podcast on. It's highly recommend. But, whoa, okay. I'm definitely, I'm standing up and there's a panel.

Yeah, I'm like, shoot, I need to upgrade. No, I am like lying down and I pass out every time. And I know because it's like on a timer. So you just do 10 minutes? I do 20 and I never like, I am asleep before 20 minutes. Wow. Oh, so then you just kind of, you know, kind of scuttled to bed. Okay.

Amazing. But the point sort of is that, you know, anything like actively to wind down, especially if you've been working or working out, you know, eating, like, you do want to make sure that, like, if you are doing things that are counterproductive for sleep, there are often things, maybe you can't fully mitigate them, but there can be, like, sort of harm reduction or sort of compensatory thing. So for me, the way I compensate for working out late at night. is red light therapy.

If you are doing something stressful, which could, by the way, be stressful TV that, like, sometimes people think they're relaxing by, like, watching, like, crime shows and stuff. And, like, you realize how stimulating this is. I know, I know. You know, even five minutes or fewer of, like, breathwork or meditation or journaling. Like, you just want your body to not be in, like, the drama of, like, the high-speed chase and the murder mystery and, like, create a little bit of distance and actively bring that down can help a lot and doing it with intention as opposed to just sort of saying like, well, the TV's off

all settle. Like, it does speed that up quite a lot. And then the other thing is, and this is like going to sound funny, but ritual really helps. Yeah. Because it's all these things that tell your body, oh, this is what Kristen does to get ready for bed. Okay, let me like activate bed mode. And so like there's a, it like sounds silly, but like having pajamas that are only for sleep

as opposed to like passing out in like the same sweatshirt that you might otherwise work out in, right? Because your body then has the association of gym clothes. Okay, let's go. Right. Totally. And, you know, it might just be like a cozy sweatshirt and you don't think anything of it, but like pajamas are a thing for a reason. It's like sounds silly, but it's not. Also, almost like the opposite of like not doing stimulating things in your bedroom so that your bedroom and physically being in there is a sign of sleep. Really try to remove your TV, you know, anything that could, that is even remotely unassociated with sleep. Yeah. And then as far as ritual, too, it might even be things that you don't necessarily think about as for sleep, but that can help.

So, like, if you have your, like, seven-step Korean skin care, like, it's just if that's what you do before bed, your body starts to go like, oh, like, this is what I do before bed. And so it doesn't have to necessarily be a sleep thing. It could be, you know, like that last walk of your dog or watering your plant. Like, I don't even know what it is or, like, tidying the living. Or like, if you have a thing that's like, I do this kind of calm thing every night before bed, You know, I think this is one of the reasons why, like, prayer before bed is such a thing. It is so cathartic to, like, put it out there and, like, have a ritual and, like, you know, have a sort of quiet, personal thing.

Right. And I think you sleep a lot better. I think what you're hitting on, too, is really important that it's highly individual. Like, it's whatever is relaxing to you. Yeah. Those are the things that you need to incorporate pre-bed. So you get your body into a state that it is, that you've created the conditions that will allow for the best chance to get the restorative beautiful night's sleep.

Yeah, the ritual is less important than having a ritual. And so, you know, what works for me might not work for you. It needs to be something like you're going to be consistent about and find, like, calming and relaxing and all those things. You hit out another really interesting point. I wanted to bring up some research that is done at, that was done at Florida State's lab with Dr. Michael Ormsby, because you mentioned exercise before bed because this is just a time frame that you can do it in. And obviously you've put into place a really beautiful ritual that allows

you to kind of bring your body down to a point where you can fall asleep. Because we know from Josh Leota's research that exercise before bed, especially high intensity, can actually impact the quality of your sleep. So you've kind of managed to, you know, insert some really beautiful rituals prior to bed to preserve your beautiful night's sleep. After exercise, you can obviously, you know, feel a little hungry. And maybe you don't immediately feel hungry, but maybe at three o'clock you'll feel hungry. So we holler at folks about their late night meals and how it really does have a negative impact on resting physiology and sleep. One of the things that we found in, and so Michael Ormsby did this experiment where where folks had 30 minutes before bed, just a high quality protein,

high-in-kason protein. And we saw no deleterious effects on sleep onset, sleep quality, HRV, rest in car rate, everything was totally fine. So I think if you do exercise at night, and this is the only opportunity that you can exercise, exercise, but take note of this kind of suite of behaviors that will preserve the quality and, you know, a really good point because one of the most common things I hear from Woot members is that if they journal, or if they keep track in the journal, late night eating, they will notice that it is one of the worst things you can do for sleep and recovery, and it skyrockets that sleep stress metric. And so so much whoop data will strongly show that late night eating is awful for sleep,

it is awful for recovery. And yet there's this counterintuitive exception where if you work out late at night, late night eating not only doesn't have that negative effect on sleep and recovery, but not eating does. Right. And this actually makes an enormous amount of sense if you think about what's going on because immediately post-workout, your glycogen stores are depleted

and your body is looking to pull sugar out into your muscles. And when it doesn't have that, right, it needs to allow like break down fat and all this stuff. And what will often happen is you will run out of glycogen overnight and the way that we activate, you know, fat to release so that we can break it down into sugar is mediated by cortisol. And so we will spike our cortisol in order to release sugar from, you know, fats from our body. And that cortisol, your stress hormone, will wake you up. And other catacolomans get released too. Yeah,

there's a lot more happening, oversimplifying a little bit. But basically it's the cortisol that wakes you up. And so if you don't replace the sugar that your body is now actively looking to pull into the muscle, you know, we're going to find it from somewhere else and that's going to create this cortisol response. And so you do want to replace a little bit of carbs, especially for, you know, an intense workout. And definitely having some protein can be helpful too. Excess protein that we don't need to use as protein. We actually break down into fats and sugars. And so protein, without you realizing it contains fat and sugar or fat and carbs. So we will sort of get that one way or another. And so you want to make sure that you replace, but not.

exceed what your muscles are going to be looking to pull in post workout. And this is actually one of the things that's really beautiful about wearable data because when I was starting like working out more intensely at night, I was very familiar with the whoop data because my team had like just, you know, seen this, that like the worst thing I could possibly do was eat. So I was like working on the not eating and I was so hungry at night. And I was like, this isn't great, but like I know it's so bad for me to sleep. You know, one of my friends was just like, you got it. Like, what are you doing? Right. And so I was just like, well, let me try the protein shake, right? Let me see what happened. And all of a sudden it was like I felt so much better. I was recovering better because I was having like a proper post workout like replacing giving my body the nutrients it needed. And it had not only no negative effect on sleep and recovery, but massively improve them. And so I was able to see in my own Woop data that like the overall trend is true. Eating before bed is sort of bad for these things. But it's because what you don't want to have is excess sugar that your body's now trying to figure. out how to convert into fat. But you also don't want to have too little. And so with most people,

and so the dominant trend that we see in our data is that when you're eating all these carbs late at night, like your body has nowhere to put them because you're not burning carbs at a high enough rate. And so you now need to convert them to fat. And so that's like what's going to become activating and disruptive to sleep and recovery. But if you do work out and you can kind of titrate what's appropriate for you with wearable data like whoop. So you can look at, you know, it was very comforting for me to see that like, you know, not only did this scary thing that I was trying to avoid not happen, but my metrics improved. And so then that became part of, you know, the habit as well. Amazing. Yeah. I mean, I think, you know, for listeners who are kind of hearing this conversation,

like ideally you're distributing your macronutrients evenly and appropriately throughout the day based on your activity requirements, right? Like, that's like the high level principle. But that always, you might not, oh, that, you know, that's an ideal world, right? But just life gets in the way. And so I think for me, you know, I've been experimenting now ever since I came across these data, you know, for a few years. And, you know, there's no question that, you know, when I'm in a situation where I can, like, time-restricted eating during the day, distributing my macronutrients, you know, eating appropriately based on activity requirements, that is the optimal. That's the North Star. But on days that I can't, I have the protein,

you know, 30 minutes before bed, no problems, right? Like it's, so I think for a lot of folks who are really busy, not able to get all of the food in that they need during the day, this is a great alternative that is not going to have any impact on their sleep and recovery and might just actually help recovery in some ways. Yeah. And before we move on, I just want to generalize what we were saying a little bit because it's not just exercise and not exercise. Like going to bed really hungry is not great for your sleep and recovery. So while the thing that we really want to avoid is like having a proper dinner at seven versus at nine is way better for you. But if you get to bedtime and you're like, I'm starving, but like I don't want to eat because that's bad for me.

like you shouldn't go to bed starving. Right. That's, again, you're going to create that cortisol response to release. This is something that I hear a lot, especially from women who don't know what they're doing when they're trying to lose weight, is like, oh, I'll go to bed hungry because then I'm like hungry while I sleep, right? And it's like, it's not like as people. And like that's their trick that like I'll just be really hungry, but I'll be asleep

and it won't matter. And like your body will not, like you just go into this low power mode. You don't sleep well. Your body doesn't feel safe. You crave food more. Like you just end up in this like awful. almost like you become like resistant to weight loss. And so like you do not want to be like so uncomfortable in the hungry that like you're waking

up. And this is a great thing to watch for when you're dieting. That if all of a sudden when you're cutting calories, you have a lot of trouble staying asleep, you're cutting too far and you're going to self-sabotage. And like it's a great like easy to keep track of thing that like if you can still maintain your quality of sleep, then you're not cutting too fast. And so keep an eye on, especially while you're cutting, that like you don't lose that like two to five a.m. sleep quality because that's when you tend to like run out of glycogen, spike your cortisol to release more, and then like totally set

yourself up for, well, now you're exhausted the next day, so you're less likely to exercise. You move less in general. You crave food, the comfort food instead of stuff that's good for you. And it's like, harder and harder to keep up. Such a great point. Yeah, you do want to kind of watch out for that. Falling asleep is one thing. Staying asleep is another. A lot of folks struggle with the 1 a.m. 3 a.m. wake up. How do we minimize the chances of just a really fragmented sleep experience? Yeah. So what's interesting is a lot of people don't realize that the falling asleep and staying asleep often have wildly different root causes. And so super important if you're like, I don't sleep great, to pay attention to which one you are.

And if you're both, you might actually have two underlying processes happening. And so worth paying attention to those things separately. But the big one that we talked about already is the sort of low blood sugar, low glycogen leading to this cortisol spike. And so especially if you are trying to lose weight or anything, it's worth paying attention to that. If you're not trying to lose weight, it also can be an early warning sign for something like pre-diabetes where you're getting low blood sugar sort of despite having eaten

enough during the day at night. And so, you know, especially if that's something that you might otherwise be predisposed to, that's something that's worth looking into. Whoop Advanced Labs is a great way to look into something like that. I was just going to say, get your labs done, people. Yeah. And this is one of those symptoms that, you know, can show up before you'd be clinically diagnosed as diabetic or pre-diabetic. There's almost this like pre-pre-diabetic. The sort of diagnostic criteria for these things is this HBA1C value going above 5.7.

that's like your pre-diabetic threshold. But, you know, there's 5.6 isn't all that better than 5.7, 5.5.5. Right. And you could be trending. And so the point in which symptoms will onset are going to be a little bit different for everybody, 5.7 is not actually this magical point. And so that can be one of those early, early signs that your blood sugar is getting low at night and especially if you're under-fueling.

it's worth calling out that of the members who have done advanced labs, I think it's somewhere in the tune of 26 percent were in pre-diabetic ranges. So I think like I just, I was shocked because we have, you know, generally kind of like a healthy user bias right in our population, which is, which is awesome. So when these data came out, I was like, wow, that is like shocking. And so I think, you know, for folks who haven't got their labs done, You just need to get it done. Yeah, I think what a lot of people don't realize is how often issues with sleep are, like, early warning signs of other things.

Metabolic. Yeah. Like, that's a huge one. Vitamin D. Vitamin D, right? Like, so if you are getting good sleep but still fatigued, vitamin D, your index of suspicion should be high. 80% of Americans are vitamin D deficient.

You know, it's such a... And most female athletes are iron. deficient. Yeah. And again, that's one that like a lot of these micronutrient deficiencies are incredibly easy to treat. You know, you're talking about a couple dollars a month. These things are all generic. There's lots of options. Just get them at your supermarket. Yeah. Very like, you know, always recommend talking to your primary care physician before starting or stopping any kind of supplement. But many of your primary care physicians do not routinely check for these things, even if, you know, you have some of the symptoms, like being tired.

It's so easy to be dismissed as, you know, oh, you're just tired because you have a high-stress job and you travel a lot. Like, stop doing that. And what's normal for a PCP is not the standard, I think, that you are actually probably aspiring to. Like, they accept a lower level of functioning. They really do because sort of the, when you just get normal blood work, what they're looking for is like, is this evidence of a disease process?

yes or no and sort of would you be diagnosed with something. But the reality is is that there's a huge range for many of these things between where I will function less well, but still like do my job and show up and like, you know, be safe in the world. And then like where sort of you're diagnosable as something. And if you supplement into the like thriving range, this is this optimal range where you're getting all the benefit of this thing, you will feel a lot better. And a lot this is very, very tricky for like clinical trials or different things to capture because, you know, people with low vitamin D like still do a good job at work, right? And they can like still kind of show up and function and do all these things. But like, could they be 10% better in

every aspect of their life? Like, yeah. Right? And I think like we hear these stories. And that's not trivial. It's not trivial at all. And, you know, we hear these stories all the time where it's like, you know, I did advance labs and then the whoop told me this. And so I started taking vitamin D and like, holy shit, I feel 10 years younger. And I, like, totally had that experience, which is why I'm so, like, passionate about talking about it, where it was, like, $5 later. I was like, oh.

Yeah, wild. You know, and it's so easy to gaslight yourself into, like, this is just, you know, menopause and it's inevitable. Or, you know, this is just postpartum and it's inevitable. Or, you know, I travel a lot for work, so there's no way I'm not going to be tired. And those, all those things are real, and they create a challenge.

But, like, offset them with the right levels of micronutrients. And maybe not 100%, but a lot. Totally. Or some, you know, meaningful amount. And different people sort of obviously like depending on how bad these things are, the more opportunity to feel better when we fix them. But specifically as it relates to sleep, we think a lot about vitamin D, magnesium, iron.

You know, you also want to think about like thyroid issues, right? I mean, progesterone is huge. Hormones for sure. I mean, hormones, which we also measure. Yeah. All the, like, you know, reproductive. of hormones. Right.

And then, you know, all the metabolic health stuff. So, like, insulin, blood sugar and all of those things because those are going to relate to your ability to fall asleep well and stay asleep. And then it's also amazing how many of these micronutrients, like low iron causes anxiety. And like, it is not the first thing people check when you're, but like anxiety makes it hard to fall asleep. Right. And same with low progesterone.

Yeah, same thing. Yeah. Because the gaber receptors. Yeah. And so, you know, if you're like, oh, I'm getting in bed. doing the right things, my room is cold, dark quiet. Like, if you haven't cleaned up those basic things, I wouldn't say, like, let's go rush to, you know, these micro-optimizations.

But if you're like, I'm giving myself the eight hours in bed or seven-half hours in bed, and, you know, I'm not having a cup of coffee at dinner. I'm not, like, sabotaging myself. There's nothing obvious wrong. Like, this blood work can give you either the sort of comfort or the heads up, that like there's some other clinical process going on, almost all of which is like relatively easy to treat and the stuff that's not as very worth knowing about. And, you know, then you can go and fix these things. And whoop will put this puzzle together for you. Oh yeah. Which is

amazing, right? Like we're going to look at all of your hoop data and all of how you sleep and all the components that you've talked about, Emily, right, are going to be basically looked at up against your labs. Right. Yeah. And we can put this story together for you. And it's so beautiful. And we should I sort of link some of these screenshots in the show notes. But like, you know, my iron was low. And like in health span under sleep, it's like iron, you know, orange exclamation point. Like, fix this. Right.

And it's like, then I go to my doctor. I'm like, dude, like, fix this. And then he's like, okay, you're what you have to do. And then it's like, you know, you see it get better. And then it's, you know, it's fun to see like, not only do I like fix the lab, which in some ways can feel a little abstract. But then it's like I see it showing up in my whoop data that like, you know, waking up before my alarm clock or like all these.

saying and you're like, oh. It's just a wisdom accelerator that allows you to have a better conversation with your PCP, right? Gosh. Yeah. So, you know, I think like anybody's having trouble staying asleep and it's not like because a toddler is waking you up or something like very obviously external to your body. And the rooms cool, dark, quiet, you know, all those kinds of things.

You've ruled out the obvious. That would be like my next go to. And again, like not everybody loves blood work and I get like the fear of needles and and it is a hassle and all that kind of stuff. If you're not ready to make that step, I would really critically think about what you're eating and sort of your lifestyle to maybe give you a little bit more confidence

about whether or not this might be something for you. So like female athletes, especially who are menstruating, is more than a third are anemic, right? And there's a phenomenon. Yeah, have low iron. And there's a phenomenon. It's called like, I'm going to mess this up. but like basically like heel strike anemia where it's like you bleed a little bit when you like run really hard.

Yeah. Yeah. And so you like you basically see that like the sort of the impact of certain sports just causes more red blood cell turnover, which is what leads to the anemia. It's not in itself a bad thing. But you just have a higher iron need, especially if you're menstruating than other people might. You know, make sure you're getting enough magnesium. Make sure you're getting enough vitamin D if not from the sun, you know, supplementing for it or thinking about like fortified food. foods. You know, I think a lot about, like, if you are vegan or, you know, strict vegetarian,

you want to make sure that, like, you're getting those things that you've cut out of your diet, especially like iron and vitamin D if you're not having dairy, that you're sort of getting those from somewhere else and talking to your primary care physician about, you know, the extent to which are registered nutritionist even better, you know, to the extent to which you might be getting enough or not enough given your lifestyle. Because I think one of the things that's really unfortunate is so many of, like, the recommended. daily values are like based on your average size man in like a sort of semi-sedentary average size man and it's not based on all the demands of your high-stress job and all the athletic

stuff you're doing and you know if you were breastfeeding or pregnant in the last two years right the chances are really high that you're like still carrying some like lingering deficiency right just like all these different things and so you know I think like auditing your own diet I think even if I would highly, highly recommend that those who have access to it, access the advanced labs functionality and rule it out directly or rule it in and learn about it. But for sort of anybody else who's not ready to make that step, it's very worth being aware that nutrition and sort of these different things, metabolic health, will show up in disrupted sleep. And so if it's not, you know, the garbage truck beeps or, you know, my neighbors,

and so annoying and wakes me up or like something where it's just like that is unfortunate and there's things you can do that you know aren't worth us spending a lot of time talking about like you know eye masks for darkness earplugs for quiet like you know all those kinds of things to modify your environment that stuff's great it does work but for most of us that's actually not the problem it's these other things and so if you've ruled out the basic environmental stuff that's where I go next amazing the one thing that I would add is just creating like at the highest level just creating as much contrast between the day and the night. You want your day to be as bright as possible, your night to be as dark as possible. You want your day to be as active as possible,

your night to be as inactive as possible. You want to consolidate all of your food, all of your calories generally when it's light out and when you're active, right? And then during the night, during the inactive phase of your echidine rhythm, you want to try to minimize your food. We caveat all of that. And I think everyone has a really good sense of the nuances. Yes. exactly. But this contrast is really important. And so I think if you think, you know, if you just kind of zoom out and you think about, all right, what are the principles that will help me have a beautiful, consistent, restorative night's sleep? A lot of is it just creating this contrast between the day and the night? And if you can pay a little attention to that, sleep stuff starts to fall

into place, I would say. Yeah. Yeah. Emily, thank you so much. As always, so incredibly insightful and beautifully articulate and I know our listeners are going to benefit a ton from your wisdom and insight and just from this conversation in general. So thank you. Thank you.