We can't tell you how often we are asked:
Why don't you track REM, light, or deep sleep?
Why don't you track sleep quality?
The short Answer
Because it doesn't impact how you feel and perform on any given day, and doesn't help you make meaningful changes to your sleep.
The longer (detailed) answer:
None of those variables (restlessness, REM, deep, etc) have an impact on how you're going to feel or perform the next today. In fact, there's some amazing research performed by sleep and machine learning scientists at Stanford: they took all of the best "sleep quality" data from polysomnography* to figure out if they can predict how you feel in the morning. Turns out, they can't.
So why is everyone hot and bothered about REM sleep?
Don't get us wrong - REM is terribly important. That's why humans developed it as we evolved. However, how much time you spend in REM does't have an impact on how you feel and perform. Unless something is measuring your brainwaves, it is not accurately recording time spent in NREM, REM, light, or deep sleep. And you can't control how much time you spend in REM.
Let's dig into those ideas:
REM has become a darling because mattress and sleep tracker industries are trying to sell you their products. Full stop. They aren't concerned with actually helping you materially affect your sleep. The two questions you should be asking of anything related to sleep:
Does it affect sleep debt?
Does it affect the timing of when I perform my tasks relative to my 24h circadian rhythm.
The answer is: if it has an affect on one of those things it's going to have an affect on performance and how you feel.
Research proves that apps and wearables that claim to track and report how much time you spend in various sleep stages (NREM, REM, "light", "deep") are not accurate. In short: if you're not sleeping with electrodes connected to your head measuring brainwaves, you're not going to know how much time you spent in sleep stages.
Even if you did have accurate data on your sleep stages...
That information isn't going to be helpful. At all. Why?
Because your body naturally regulates and calibrates your sleep. In other words: on any given night, your body will spend the time it needs in various stages of sleep dependent upon what it needs. You don't have any control over that.
Our entire experience is focused around the indicator that matters most to how you feel and perform - sleep debt.
Take the next few days and let Rise help you focus on your evening routine to take advantage of your energy schedule. Nail bedtime, pay down sleep debt, and note how you're feeling and performing when sleep debt is low.
If you have any questions or would like to learn more message us through your app, or email firstname.lastname@example.org We're here to help!
*Polysomnography records your brain waves, the oxygen level in your blood, heart rate and breathing, as well as eye and leg movements during the study.