Circadian management

Circadian management includes various ways to optimise one's circadian rhythm with respect to one's sleep schedule. The stability as well as the alignment of your circadian rhythm is critical to maintaining the quality of your sleep. However, depending on the timings of your sleeps and your scheduling restraints, you may or may not be able to sleep at optimal hours. To this end, it is possible to mitigate the effects of suboptimal sleep timings through shifting the circadian rhythm itself.

Circadian structure

Typical circadian timings of physiological processes

The circadian rhythm regulates a range of physiological processes that controls sleep-wake cycles. These rhythms are synchronized to local solar time (rather than clock time) when they are stabilised. In some regions, local clock time can differ substantially from the solar time, and additional consideration is required to correctly plan circadian management measures.

Those living in red regions should subtract hours from their clock time to get the solar time, and those living in green regions should add hours. The number of hours is to add can be seen according to the colour legend below.

Typical circadian markers

Local Solar Time	Marker	Note
21:00-00:00	SWS peak
01:00-03:00	Lowest alertness	Sleep is most favoured in this time
04:00-06:00	Min. body tempeturature	This may or may not be the time with the strongest subjective feeling of coldness
06:00-09:00	REM peak
09:00-11:00	Highest alertness
11:00-17:00	Daytime nap zone	This corresponds to the circadian dip in the early afternoon.
17:00-19:00	Max. body temperature