sleep-wake cycle
Technical term in sleep science and chronobiology; refers to the daily alternation between sleep and wakefulness.
When the sleep-wake cycle is disrupted, daytime sleepiness increases.
Light is an important factor that regulates the sleep-wake cycle.
概日リズム is the broader circadian rhythm, while 覚醒周期 specifically refers to the sleep-wake component of that rhythm.
睡眠周期 refers to the sleep cycle (stages within sleep), whereas 覚醒周期 covers the full daily sleep-wake alternation.
Compound of 覚醒 (かくせい, 'awakening') and 周期 (しゅうき, 'cycle'). A modern technical term with no known historical derivation issues.