Understanding how to measure sleep quality and what can disrupt it.
You go to bed at 11:00pm and wake up at 7am, that means you got 8 hours of sleep, right? Sure—but was it good sleep? While the topic of sleep once focused solely on duration, the conversation as of late has shifted more towards the concept of sleep quality. In fact, Mattress Firm has even created a whole marketing campaign around it, tapping actor Liev Shreiber to outline the pitfalls of so-called “junk sleep” in its latest ads. But is there a way to really measure sleep quality?
According to sleep specialist and Mattress Firm partner Dr. Chris Winter, junk sleep can be defined as “sleep that is not optimized for maximal health and wellness benefits.” By which he means that said sleep experience is not “long enough, nor high-quality enough, to sufficiently nourish our brains and bodies.”
“Falling asleep in the living room with a television shining light in your face and blaring noise is a daily report from my patients in my clinic,” Winter explained. “Are those patients getting sleep in that situation? Yes. Is it healthy sleep? No.”
But how can the average person measure the quality of their sleep? Is it defined by habits and environment? Or is it something more intrinsic to the sleep experience?
Back in 2017, the National Sleep Foundation published its set of “scientifically sound recommendations regarding indicators of good sleep quality at different ages across the life-span.” Bringing together a group of experts to create the Sleep Quality Consensus Panel (SQCP), the NSF came up with a number of defining characteristics of good quality sleep, most of which centered around “sleep continuity.”
Characteristics Of Good Quality Sleep:
- After getting into bed, you fall asleep within 30 minutes or less.
- You sleep straight through the night, waking up no more than once.
- If you do wake up during the night, you fall back asleep within 20 minutes.
One interesting thing about these conclusions is that they moved away from a previous hypothesis that tied sleep quality to sleep architecture. Sleep architecture refers to the “structural organization” of sleep—its phases and stages. While some experts believe that normal sleep architecture consists of four to five alternating non-REM and REM phases of sleep, the SQCP was not able to find consensus on whether or not that structure is a defining element of good sleep quality.
These ideas were reinforced by another study that explored the subjective meaning of sleep quality, which found that “most subjective sleep measures tend to covary across conditions and that ‘good sleep’ is mainly a question of sleep continuity.” The more consistently you sleep through the night, the better quality your sleep is.
In that way, sleep quality is in fact closely linked to sleep quantity. Waking up a lot during the night and having trouble falling back asleep are some of the clearest signs of poor sleep quality—and they also shave time off your total amount of hours spent asleep over the course of the night. What makes this tricky, though, is that it’s possible to wake up repeatedly throughout the night without even really registering that it’s happening. And that means people can wake up thinking they slept eight hours, when in fact they’ve slept much less. Diagnostic technologies like sleep trackers are designed to deliver this type of data to the user, showing them how many times they woke up and how long it took them to fall back asleep. But users should be careful not to rely solely on this information; many sleep trackers on the market are not as precise as they purport to be—and faulty data can negatively impact how you feel in the morning.
Because what happens during the night is not the only metric sleep experts monitor. According to the NSF, the final characteristic of good quality sleep is that “you feel rested, restored and energized upon waking up in the morning.” That idea was echoed by another study that “aimed to complete a detailed and systematic investigation of the subjective meaning of sleep quality”—which determined that it is beneficial to look at both nighttime behavior and daytime feelings in tandem when measuring sleep quality. Exploring reported data from individuals with insomnia along with normal sleepers, the study concluded that “a preliminary definition of sleep quality should include reference to tiredness on waking and throughout the day, feeling rested and restored on waking” in addition to “the number of awakenings in the night.”
It’s normal to feel a little groggy when you first open your eyes, but if you wake up every morning feeling like you need to immediately crawl back under the covers—then the quality of your sleep may be poor. Unfortunately, for some people, “junk sleep” has simply become a way of life; they have grown so accustomed to being over-tired that they may not even now what it would feel like to be rested, restored and energized. This is why it’s important to balance both measurements—both nighttime sleep continuity and daytime tiredness—in order to get a comprehensive picture of sleep quality.
How To Measure Sleep Quality More Precisely
There are two different ways to precisely evaluate sleep quality—using technology to monitor the body, and scientifically designed questionnaires to measure daytime feelings. The most prominent methods are as follows:
Polysomnography Test: This medical procedure is comprised of a number of individual but concurrent tests that monitor different body functions during sleep. They include Electroencephalogram (EEG) to measure brainwave activity, Electrooculogram (EOG) to record eye movements, Electromyogram (EMG) to record muscle activity, Electrocardiogram (EKG) to record heart rate, Pulse oximetry to monitor oxygen saturation, and much more as needed. Depending on the specific sleep study, Polysomnography Tests can be administered at home or in a sleep laboratory—and is often used to diagnose sleep disorders such as sleep apnea, narcolepsy and unexplained chronic insomnia.
The Pittsburgh Quality Sleep Index: The Pittsburgh Quality Sleep Index (PSQI) is a self-reported series of questions about sleep-related behaviors. Used in both clinical and research settings, the questions cover seven categories—including sleep quality, sleep disturbances and daytime dysfunction.
So Your Sleep Quality Is Poor – What Can You Do About It?
Knowing that you’re not getting good quality sleep is just the first step; the next step is understanding the underlying cause. There are a number of different issues, behaviors and factors that can be disrupting the quality of your sleep:
- Hot flashes and night sweats
- Pain (including back, hip and neck)
- Sleep Apnea
- Snoring (your own)
- Acid Reflux
- Uncomfortable mattress or pillow
- Bed partners
- Snoring (your partner’s)
Figuring out what is really at the root of your sleep quality issues may require a little bit of trial and error. By addressing the different potential problems one by one, you can start to see what changes make the biggest impact on how you feel during the day.
Good sleep quality doesn’t have to be elusive. By understanding what it truly means and what factors can hinder your ability to get it, you are one step closer to a healthier, more energized life.