Research

Hormonal

Slow-wave activity (SWA, 0.75-4.5 Hz) in non-REM sleep is modulated by both the circadian pacemaker and the homeostatic sleep process, with the circadian modulation peaking around the minimum of the core body temperature rhythm.

Deep sleep (SWA) is highest when you sleep during your biological night (temperature minimum). Additionally, SWA increases with the duration of prior wakefulness. To maximize deep sleep, ensure you are sleep-deprived enough (homeostatic pressure) and sleeping during your circadian night.

StrongSupportsHIGH confidence
Slow-wave activity... exhibited a circadian modulation... The crest of the circadian rhythm of SWA coincident with the minimum of the core body temperature rhythm... Slow-wave activity increased in the course of the homeostatic process... The interaction between circadian and sleep dependent components... was analyzed.
Derk‐Jan Dijk et al. · Journal of Neuroscience · 1995

Why this rating

Robust experimental design.

Source

Contribution of the circadian pacemaker and the sleep homeostat to sleep propensity, sleep structure, electroencephalographic slow waves, and sleep spindle activity in humans

Derk‐Jan Dijk et al. · Journal of Neuroscience · 1995

DOI 10.1523/jneurosci.15-05-03526.1995

rct · n=8Cited 1,346×
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DOI resolved against Crossref · corpus check 2026-06-10

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