Protocol Glossary
Science-backed definitions for every term in your health data: plain English and the mechanism behind it.
Chronotype
Your biological preference for when to sleep and be alert
→ Read definitionCircadian Phase
Where you are in your 24-hour biological clock right now
→ Read definitionCircadian Rhythm
Your body's internal 24-hour clock: the master scheduler of nearly every biological function
→ Read definitionN1 and N2 Sleep
The lighter NREM stages where most of sleep actually happens
→ Read definitionREM Sleep
The sleep stage where your brain consolidates memory and regulates emotion
→ Read definitionSleep Architecture
The internal structure of your sleep, not just how long, but how deep
→ Read definitionSleep Debt
The accumulated deficit between the sleep you need and the sleep you get
→ Read definitionSleep Efficiency
The percentage of your time in bed actually spent asleep
→ Read definitionSleep Fragmentation
Repeated brief awakenings that break sleep continuity without always waking you fully
→ Read definitionSleep Inertia
The grogginess and cognitive impairment that follows waking from deep sleep
→ Read definitionSleep Latency
How long it takes to fall asleep after getting into bed
→ Read definitionSleep Pressure (Homeostatic Sleep Drive)
The biological urge to sleep that builds every hour you are awake
→ Read definitionSleep Regularity Index (SRI)
How consistent your sleep timing is: the dimension duration misses
→ Read definitionSleep Spindles
The brain's memory consolidation signal during N2 sleep.
→ Read definitionSlow-Wave Sleep (Deep Sleep)
The deepest sleep stage, where your body actually rebuilds
→ Read definitionSocial Jetlag
The circadian disruption of sleeping on a different schedule every week
→ Read definitionSuprachiasmatic Nucleus (SCN)
The master clock that synchronizes every biological rhythm
→ Read definitionWASO (Wake After Sleep Onset)
Total minutes spent awake after first falling asleep
→ Read definitionMore terms added regularly. Check back for new entries across all categories.
