Sleep Is Structure, Not Just Hours
Why we study the stages of sleep — light, deep and REM — plus the score, respiratory rate and temperature trend that reveal how well you actually rest.
At a glance
- Sleep staging: Light, deep (N3) and REM, derived from heart rate, HRV, movement and breathing.
- Sleep score: One number that summarizes the quality of the night.
- Respiratory rate: Your overnight breathing rate as a recovery signal.
- Temperature: A skin-temperature trend for sleep, illness awareness and cycle context.
- Women's health: Cycle tracking and reminders — a wellness record, not a medical tool.
Why Stages Beat a Single Hour Count
Eight hours of restless, stage-poor sleep is not the same as seven hours of well-architected rest. The structure of the night is what the body actually uses.
The architecture of a night
Sleep runs in cycles of roughly 90 minutes, moving through light sleep (N1, N2), deep sleep (N3) and REM. Deep sleep is when physical repair dominates; REM is when the brain consolidates memory and mood. A Fitaos wearable estimates these stages from heart rate, HRV, body movement and respiration — faster, steadier heart rate with little movement points to deeper sleep, while more movement and HR variability mark lighter stages and REM.
The sleep score
Rather than leave you to read four raw signals, the device combines stage balance, duration, timing and movement into a single sleep score. It is a summary, not a verdict — a quick way to see whether last night helped you recover.
Respiratory rate and temperature as supporting signals
Your overnight breathing rate trends quietly with recovery and illness. A skin-temperature sensor adds a temperature trend that is useful context for sleep quality, early illness awareness and the menstrual cycle. Both are tracked as trends, not as clinical readings.
Women's health
Menstrual-cycle tracking, symptom logging and period reminders sit alongside sleep and temperature, so the cycle becomes part of your full health picture. It is a wellness record-keeping tool — never a contraceptive or medical device.
How People Use It
🛌 Build a wind-down
See how late caffeine, screens or stress push your deep sleep down, then protect the routine that works.
🌡️ Spot the shift
Connect a poor-sleep night to a temperature bump or a high-stress day to find the real cause.
🏋️ Recover smarter
A low sleep score is a signal to train lighter; a high one is your green light to push.
🌸 Cycle context
Track your cycle alongside temperature and mood for a clearer personal pattern.
Sleep & Daily Wellness — The Brand Playbook
Sleep tracking is now table stakes — but each brand emphasizes a different piece of the puzzle. The principle is the same one Oura and WHOOP are built on.
Oura — the ring-format pioneer of sleep staging plus a Readiness score; sleep and recovery are its entire reason to exist.
WHOOP — Sleep Performance and Recovery, built around how much sleep you owe versus how much you banked.
Apple Watch — Sleep Stages (detailed sleep architecture) plus a wrist-temperature trend for cycle and illness context.
Garmin — Sleep Coach and Body Battery, with an overnight HRV Status score to guide the day.
Huawei — TruSleep, a clinical-style sleep-staging engine, plus temperature and cycle tracking.
Fitaos — stages sleep from HR/HRV/movement/breathing, adds a temperature trend, breathing-training sessions and women's health in one wearable.
The differentiator across brands is rarely a single sensor — it is how the signals are stitched together. Fitaos pairs sleep staging with breathing training and temperature so the picture closes the loop from insight to action.
Your Day & Night, In One View
😴 Sleep Trends
GBAND charts light/deep/REM stages and your sleep score so you can see what is helping.
🌡️ Temperature Log
A daily temperature trend sits alongside sleep and cycle for fuller context.
🧘 Breathing Sessions
Start guided breathing in the app and watch stress ease in real time.
🌸 Cycle Tracking
Log symptoms and get period reminders, all synced to your health timeline.
FAQ
How does a Fitaos wearable track sleep stages?
What is a MET?
Is the body-temperature reading a medical thermometer?
How does breathing training reduce stress?
Is women's health tracking a contraceptive or medical tool?
Related Research
Trademark notice. Apple, Apple Watch, Garmin, WHOOP, Oura, Samsung, Huawei, Fitbit and other brand names are trademarks of their respective owners. References to other products are for general-information comparison only and do not imply endorsement, sponsorship, or affiliation.
Feature comparisons reflect generally available consumer capabilities for illustration only; they are not medical claims and do not imply endorsement of or by any brand. Fitaos features are wellness tools, not medical devices.