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The Only Sleep Score Worth Your Attention Is Sleep Debt

Are app or smartwatch sleep scores stressing you out and making it harder to sleep? Use a scientific metric that helps you take actionable steps instead.
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So you've finally bought that new sleep tracking app from the App Store on your iPhone. For the first few days you're awed by the app's detailed sleep analysis, showing you everything from how much time you were wide awake in bed to your exact deep sleep duration. It even comes with a smart alarm to help you wake up in the morning!

As consumer wearables in the sleep industry get more advanced (cue the sonar smartphone technology that can detect disorders like sleep apnea), we now have more sleep data than we ever have before.

Yet the sleep score in your app may not be helping you reach your ultimate sleep goal of better energy during the day. Think about it: What exactly makes up a good sleep score? Also, does your app show you how you can improve your daily score?

If these questions have been puzzling you, you've come to the right place. Here, we bring to light why commonly used sleep-tracking metrics, like so-called sleep quality and sleep staging, aren't accurate determinants of your individual sleep “score” (if there is such a thing). Instead, sleep debt is the only metric you ever need to care about. Read on to find out more.

Sleep Debt Is the Sleep Score That Matters 

At RISE, it's no secret we do things differently from other sleep apps. For one thing, we aren't interested in how much rapid-eye-movement (REM) sleep you've gotten. Nor do we devise a "sleep quality" definition when there’s no consensus on the term’s definition in the field of sleep science.

Instead, we zero in on the only measurement that matters — sleep debt. It's one-half of the Two Laws of Sleep (the other half is your circadian rhythm, also known as your internal body clock). Before you mistake these two laws as some fancy algorithm we came up with, they are actually derived from the two-process model of sleep regulation, a scientific theory first proposed by sleep scientist Alexander Borbély in the 1980s.

This is what sets our RISE app apart from the countless other sleep apps and gadgets you've heard about. RISE is based on decades of well-established, publicly available scientific evidence. Contrast that with a company's proprietary algorithm. No one knows how it's created, much less how to use its data to improve your sleep at night.

So if your tracker or app is giving you a sleep score focused on movement, depth, or anything else, chances are its data metrics or algorithm is based on something other than the science of how to feel alert and at your best the next day.

Sleep Debt Offers a Long-Term View

Sleep score: RiseApp My sleep
The RISE app shows the one sleep score that matters most: sleep debt.

Sleep debt is the amount of sleep you've missed out on in the past 14 days relative to your sleep need (the genetically determined amount of sleep your body needs). It’s the number that best predicts how you feel and function on any given day (along with how well you’re aligned with your circadian rhythm, of course).

The 14-day timespan matters as it helps you take a longer term view of sleep health. Consistently meeting your sleep need should be something you prioritize for the long haul, given that it directly impacts your energy levels as well as your overall health, wellness, and performance in both the short and long run.

That's why the RISE app uses sleep debt as its sleep metric. Instead of looking too closely at last night's sleep to make up your sleep score today, RISE uses a near-term analysis of your sleep patterns based on the past 14 nights to measure your current sleep debt.

Where Most Sleep Scores Fall Short — and How RISE Closes the Gap

We pitted the RISE app against other sleep-tracking apps to show you why the latter fall short of helping you reach your ultimate sleep goal: feeling and functioning at your best every day.

Other Scores Don’t Reveal Your Sleep Need

For all their bells and whistles, most sleep scores fail to account for the most important metric: your individual sleep need (recall that this is the genetically determined amount of sleep your body needs).

Instead, the average sleep score is based on generalized recommendations for how much sleep you need. For instance, the SleepScore app says it “compares your nightly sleep to an ideal night for people your age and gender.”

But here's the thing — your sleep need is as genetically unique as your eye color and height. You may think you can do well on 8 hours of sleep, but your body may actually need more. In fact, the average sleep need stands at 8 hours and 10 minutes per night (plus or minus 44 minutes or so). A not insignificant percentage of the population  (13.5%) may even need a longer sleep schedule of 9 hours or more.

If an app doesn’t know your personal sleep need, how can it decide if you've gotten enough sleep, much less display an accurate sleep score?

How RISE Helps

Once you download the RISE app, it uses the past 365 days of sleep data stored in your phone to calculate your unique sleep need. This extensive data establishes the foundation for an accurate sleep score.

On a daily basis, RISE employs phone motion-based sleep detection to determine your bedtime and wake time. Measuring your nighttime sleep duration against your unique sleep need means that the app accurately calculates your sleep debt to arrive at a precise sleep metric.

Other Scores Aren’t Actionable

Sleep score: man under his blanket while using his phone

A full breakdown of your total sleep time, sleep efficiency, sleep latency, and so on may make it seem like your app is providing a valuable sleep analysis. But do any of these metrics actually allow you to affect your sleep score for better energy during the day?

That's the frustration many users face. They want their sleep apps to tell them something they don't already know, like how they can “optimize” their sleep cycle (spoiler alert: you can't — but more on that later). Or which sleep habits they can adopt for better sleep at night (including how to get more efficient sleep and less latency).

Unfortunately, a lot of obscurity surrounds the sleep-scoring algorithms used by sleep-tracking apps and gadgets. Because that information isn’t public, end users like you and me simply don't have the knowledge or tools to improve their sleep scores for better daytime functioning.

How RISE Helps

The RISE app avoids all of these frustrations by using sleep debt, a fully transparent sleep score that's immediately actionable upon waking. The Sleep screen shows your running sleep debt to let you know whether you're sleep-deprived or not (the goal is to keep your sleep debt below five hours).

If your sleep debt is more than five hours, work on paying it down by out-sleeping your sleep need for the next one to several nights. This way, you can use RISE to achieve your real sleep goal: being at your best during the day.

Other Scores Focus On Controversial “Sleep Quality”

Most sleep trackers typically use some form of "sleep quality" metric in their sleep score. Ironically enough, the term "sleep quality" is fairly meaningless because sleep scientists have yet to agree on an objective measurement for it. Any definition of sleep quality is largely subjective, as evident from the gold standard Pittsburgh Sleep Quality Index that comprises seven self-rated components.

So where does the sleep quality definition used in most sleep apps come from? Turns out a majority of apps base their own sleep-quality metric on sleep staging. However, sleep stages aren't clearly defined either. They are merely terms that sleep scientists thought up in the 1940s and 1950s.

Digging deep into the scientific literature, we even found that sleep staging is subject to change with every new discovery. Case in point: When sleep experts recognized REM sleep as an individual sleep stage in 1953, the entire sleep-stage system underwent a face-lift in 1957.

As you can see, a sleep score based on nonexistent "sleep quality" is a non sequitur. Still, many people believe "quality sleep" is somehow achieved by spending an "appropriate" amount of time in different stages of sleep. This belief is fueled by most sleep trackers, which rely on sleep-stage data in their own interpretation of "sleep quality." (Bear in mind that this misconception doesn't have sleep scientists' stamp of approval.)

Research even shows that if you're told you had better "sleep quality" even when you didn't, you're more likely to perform well. The opposite holds true too. You're more apt to perform badly if you're told you slept poorly — even when you had actually slept well.

The sleep and machine-learning experts at Stanford University agree, too — extracting all the best data on "sleep quality" from lab-based sleep studies still leaves them no clue about how you'll actually feel the next morning.

Clearly, the stage-based definitions of sleep quality don’t have biological underpinnings to your next-day performance.

How RISE Helps

Instead of telling you something as subjective as “sleep quality,” the RISE app lets you be the judge of that.

To break the conditioning that we should feel refreshed, or even amazing, the moment we wake up, the RISE "Sleep Quality" habit only prompts you to rate your sleep after your Grogginess Zone has passed (about 90 minutes after waking). This is the period during which you experience sleep inertia, a completely natural part of your sleep-wake cycle.

Take note that RISE doesn’t include how you feel in your sleep score. As we’ve mentioned before, adding “sleep quality” to the mix will only dilute an otherwise impartial — and wholly precise — measurement that’s based entirely on sleep debt.

Other Scores Aren’t Very Accurate

Sleep score: man wearing a brain wave headset

Most sleep apps monitor how much time you spend in each stage of the sleep cycle to draw up your sleep score. However, contrary to popular belief, any sleep-stage tracking done outside a sleep lab is likely inaccurate. Even the best sleep trackers on the market aren’t as precise as the polysomnography (PSG), which is the benchmark for tracking sleep stages.

For those new to the term, PSG is a lab-based sleep study conducted by professional sleep technologists. The PSG measures several metrics, like your brain activity and heart rate, to gauge your sleep patterns each night.

Before you assume a sleep study is an exact science, you should know that automated sleep scoring is still not possible. Currently, sleep-stage scoring in a professional sleep lab is done manually, and sleep experts agree with each other on the final score only about 80% of the time!

A recent study even stated, “It is unusual for 2 human scorers to achieve 100% agreement on any sleep record.” It went on to acknowledge that PSG “is an indirect and imperfect measure of sleep.”

So if a sleep app proclaims it can somehow deliver lab-quality results for your sleep score, particularly relating to your "sleep quality," you may want to take it with a grain of salt. That's because, in lab-based PSG, the tools used to track your sleep patterns have to be in physical contact with your face and neck to get an accurate reading. Needless to say, this is entirely impossible with your Fitbit device or Apple Watch.

More recent scientific evidence indicates "there is a remarkably high degree of variability in the accuracy of commercial sleep technologies." For example, PrimeNap (a sleep tracker) cautioned that it "will still show sleep cycles if the phone is placed on a desk" because it "assumes that the user is actually sleeping.”

And if you're a dedicated Fitbit user, this next part will probably disappoint you. According to a 2019 study, the Fitbit gadgets cannot replicate the accuracy of PSG. The study's findings showed that the brand’s sleep-tracking models actually underestimated how much time you take to fall asleep. This could potentially affect other sleep metrics, like your total sleep time and sleep efficiency (how much time you spent asleep in bed).

In other words, your sleep score on the Fitbit app may not accurately reflect each night's sleep performance.

How RISE Helps

To avoid contributing to the ever-expanding mountains of sleep misinformation out there, the RISE app purposely doesn't track sleep stages. Instead, we zero in on sleep debt, the much more credible measurement.

Other Scores Focus On Superfluous Sleep-Stage Tracking

Sleep Cycles chart

Years from now, consumer wearable technology for sleep may become so advanced that a sleep app could track your sleep cycle as precisely as PSG does. But even if that day arrives, there's still not much you can do with all that information.

The reason is that you don't need sleep-staging data to optimize your sleep. Your brain is already doing it for you because it knows exactly how much time to spend in every stage of the sleep cycle throughout the night.

Your job, then, is to have faith in your brain's built-in mechanisms and do your best not to interfere with the natural sleep process. One of the best ways to do this is by making it a point to consistently meet your sleep need.

While you can't optimize sleep beyond the healthy, naturalistic version that your body is already primed for, you can avoid sleep-corroding activities. Common examples include late-night light exposure (especially blue light from electronic devices), caffeine and alcohol consumption too close to your bedtime, and large evening meals.

How RISE Helps

RISE is a sleep-tracking app that helps you meet your sleep need so you can keep your sleep debt low. It uses 16 science-based habits pegged to your unique chronobiology that you can add to your Energy Schedule. Doing so helps you structure your day with sleep-promoting activities aligned to your circadian rhythm (your daily energy peaks and dips) to promote good sleep hygiene.

For example, you can add the "Block All Blue Light" habit to remind yourself to block out blue light exposure at night so that it doesn't interfere with your body's melatonin production (a sleep-promoting hormone). Or try the "Limit Caffeine" habit so you know when to stop consuming caffeine at the cut-off time that is unique to you, as this stimulant can stay in your system for up to 10 hours.

When you reliably practice sleep-promoting habits at the right times throughout the day, your brain has the best chance of achieving naturalistic, healthy sleep at night.

Other Scores May Turn You Into a “Sleep Perfectionist”

As sleep-tracking apps have multiplied in recent years, there’s been a growing trend of orthosomnia. If you haven't heard, it’s a sleep disorder that causes you to develop an unhealthy, almost obsessive relationship with your sleep score in the quest for "perfect sleep."

Based on a 2017 study in the “Journal of Clinical Sleep Medicine,” more and more people "are seeking treatment for self-diagnosed sleep disturbances such as insufficient sleep duration and insomnia due to periods of light or restless sleep observed on their sleep tracker data."

In other words, the sleep score on your app may stress you out more than it helps you. Perhaps your recent sleep report shows you spent too much time in light sleep than the average user. Or maybe your sleep score hasn’t improved despite incorporating the advice you’ve read about online. Whichever the case, you're letting your sleep metric get to you.

To worsen the issue, not many people realize their sleep score isn't as accurate as it's made out to be, as we mentioned earlier. You may be self-diagnosing a sleep problem where there is none. In fact, the same 2017 study described a woman who thought she had sleep problems (even though she had been successfully treated for restless legs syndrome) because her Fitbit device reported her sleeping badly. When she underwent PSG, the sleep experts found that she actually slept pretty well.

How RISE Helps

Instead of encouraging you to fixate on an impossible or ill-defined goal like "perfect sleep," RISE focuses on the one measurement that matters — meeting your unique sleep need to bring down sleep debt. This sleep score is imminently actionable and has nothing to do with manipulating your sleep stages (which, if you’ll remember, is totally out of your control).

Plus, we know how unrealistic it is for your sleep debt to hit zero, which is why we never make that a hard and fast rule. Because life can sometimes throw you curveballs, try your best to keep your sleep debt below five hours, which will have you at or near your best.

RISE Is the Sleep Score That Can Give You Better Days

RiseApp My energy schedule
RISE uses "feel-good" ratings to motivate you to keep your sleep debt low. Still, the best encouragement comes from how you feel as your sleep debt drops and your energy levels rise on the daily.

A good sleep score should provide information you can work with to improve how you feel and function on a day-to-day basis. It certainly shouldn’t leave you obsessing over some dubious measure of "sleep quality" or inaccurate (and somewhat unhelpful) sleep-staging data. The only metric your sleep score should be based on is your unique sleep debt.

In which case, RISE is the only sleep tool you need for better days ahead. Need more proof? Eighty percent of our users feel real benefits (in terms of productivity, performance, and well-being) in as little as five days.

Ready to experience better days? Get the RISE app today.

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About Rise
Rise is the only app that unlocks the real-world benefits of better sleep.

Instead of just promising a better night, we use 100 years of sleep science to help you pay down sleep debt and take advantage of your circadian rhythm to be your best.

Over the past decade, we've helped professional athletes, startups, and Fortune 500s improve their sleep to measurably win more in the real-world scenarios that matter most.

Rise Science is backed by True Ventures, Freestyle Capital, and High Alpha; investors behind category winners Fitbit, Peloton, and Salesforce Marketing Cloud.

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