Sleep Physiology
To win, you must understand the metabolic and neurological processes you are optimizing. Sleep is not a passive state; it is an active biological reconstruction.
The Two-Process Model
Sleep regulation is dictated by the Borbély Two-Process Model: Process C (Circadian Rhythm) and Process S (Sleep Homeostasis).
Process S (Adenosine)
Sleep pressure. As you remain awake, adenosine accumulates in the basal forebrain, binding to receptors and inducing sleepiness. The only way to clear it is through deep sleep.
Process C (Circadian)
Your biological clock, driven by the suprachiasmatic nucleus (SCN). It dictates alertness independently of sleep pressure, heavily influenced by light exposure and core body temperature.
Sleep Architecture
A normal night consists of 4-6 cycles, each lasting approximately 90-110 minutes. Scoring heavily penalizes fragmented architecture.
| Stage | Primary Function | Target % |
|---|---|---|
| N1 (Light) | Transition phase. Easily awoken. | < 5% |
| N2 (Light) | Memory consolidation, sleep spindles. | 45-55% |
| N3 (Slow-Wave / Deep) | Physical restoration, GH release, glymphatic clearance. | 15-25% |
| REM | Emotional regulation, cognitive processing, dreaming. | 20-25% |