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Scheduling sleep is a complex topic that involves many aspects and must be done in accordance to one's individual needs. With a poorly designed polyphasic schedule, you will experience crippling [[wikipedia:Sleep_deprivation|sleep deprivation]] and most likely never adapt, wasting weeks or months of your life. This page details the current consensus on scheduling.  

Scheduling sleep is a complex topic that involves many aspects and must be done in accordance to one's individual needs. With a poorly designed polyphasic schedule, you will experience crippling [[wikipedia:Sleep_deprivation|sleep deprivation]] and most likely never adapt, wasting weeks or months of your life. This page details the current consensus on scheduling.  

== Sleep stages == <!--T:2-->

== Sleep stages == <!--T:2-->

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REM, accounting for 20-25% of total sleep, is characterized by high frequency, low amplitude activity that resembles that during wakefulness and rapid eye movements. In this stage, muscles are also paralyzed and body temperature becomes unregulated. Vivid dreams are also often experienced during this stage, and the muscle atonia (paralysis) prevents the sleeper from acting them out.

REM, accounting for 20-25% of total sleep, is characterized by high frequency, low amplitude activity that resembles that during wakefulness and rapid eye movements. In this stage, muscles are also paralyzed and body temperature becomes unregulated. Vivid dreams are also often experienced during this stage, and the muscle atonia (paralysis) prevents the sleeper from acting them out.

== Sleep reduction through polyphasic sleep == <!--T:8-->

== Sleep reduction through polyphasic sleep == <!--T:8-->

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However, as NREM 2 gets reduced, the ability to stay awake for long periods diminishes. This is why schedules with less total sleep time (TST) need more sleeps spread throughout the day to be sustainable. Taking a ~20-minute nap or a ~90-minute single-cycle core helps a polyphasic sleeper sustain wakefulness. Maximum wake gaps are dependent on the schedule, time of day, as well as the sleeper's individual needs. With gaps too large, one will always experiences bouts of tiredness during it and be unable to fully adapt to the schedule.

However, as NREM 2 gets reduced, the ability to stay awake for long periods diminishes. This is why schedules with less total sleep time (TST) need more sleeps spread throughout the day to be sustainable. Taking a ~20-minute nap or a ~90-minute single-cycle core helps a polyphasic sleeper sustain wakefulness. Maximum wake gaps are dependent on the schedule, time of day, as well as the sleeper's individual needs. With gaps too large, one will always experiences bouts of tiredness during it and be unable to fully adapt to the schedule.

==Circadian rhythm== <!--T:11-->

==Circadian rhythm== <!--T:11-->

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To maintain the stability of the circadian rhythm, all polyphasic sleep schedules must stay relatively consistent day-to-day, without large changes in core or dark period timings. As such, schedules that are not aligned with the 24-hour day are unsustainable and unhealthy. Examples of which includes cycles longer than 24 hours (delaying sleep phases continually) or employing drastically different sleep schedules on a day-to-day basis.

To maintain the stability of the circadian rhythm, all polyphasic sleep schedules must stay relatively consistent day-to-day, without large changes in core or dark period timings. As such, schedules that are not aligned with the 24-hour day are unsustainable and unhealthy. Examples of which includes cycles longer than 24 hours (delaying sleep phases continually) or employing drastically different sleep schedules on a day-to-day basis.

==Minimum sleep threshold== <!--T:14-->

==Minimum sleep threshold== <!--T:14-->

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Core sleeps are favoured during night time, as they allow sufficient time to complete SWS-filled sleep cycles. They are also easier to schedule at night for most people due to social obligations. Naps are favoured in the day, since deeper sleep stages are less likely to appear then. After adaptation, naps can be relatively flexible, whereas cores are much harder to move.

Core sleeps are favoured during night time, as they allow sufficient time to complete SWS-filled sleep cycles. They are also easier to schedule at night for most people due to social obligations. Naps are favoured in the day, since deeper sleep stages are less likely to appear then. After adaptation, naps can be relatively flexible, whereas cores are much harder to move.

==Consistency== <!--T:22-->

==Consistency== <!--T:22-->

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During adaptation, most polyphasic schedules (other than non-reducing ones) are strict, that is, they must be done very consistently, without missed sleeps, moved sleeps, oversleeps, or undersleeps. If your life schedule cannot accomodate the sleep schedule you are planning for almost all days, it is unlikely that you will ever be able to adapt to it. One or two minor mishaps should not cause too much damage to your adaptation. However, as the mistakes accumulate, your chance of successful adaptation decreases. It is therefore necessary to plan ahead and avoid these mistakes, by carefully scheduling your life around the sleeps as well as setting proper alarms to avoid oversleeps.

During adaptation, most polyphasic schedules (other than non-reducing ones) are strict, that is, they must be done very consistently, without missed sleeps, moved sleeps, oversleeps, or undersleeps. If your life schedule cannot accomodate the sleep schedule you are planning for almost all days, it is unlikely that you will ever be able to adapt to it. One or two minor mishaps should not cause too much damage to your adaptation. However, as the mistakes accumulate, your chance of successful adaptation decreases. It is therefore necessary to plan ahead and avoid these mistakes, by carefully scheduling your life around the sleeps as well as setting proper alarms to avoid oversleeps.

==Schedule lines== <!--T:24-->

==Schedule lines== <!--T:24-->