Changes

A [[biphasic]] [[Template:Polyphasic Sleep Schedules|schedule]]<ref>[https://www.polyphasic.net/schedules/biphasic/ polyphasic.net]. Retrieved 20-11-2020.</ref>, which consists of a longer [[Cores|core]] at night and a shorter core during the day.{{TNT|Siesta}}

{{TNT|Siesta}}Siesta [[biphasic]] schedule<ref>[https://www.polyphasic.net/schedules/biphasic/ polyphasic.net]. Retrieved 20-11-2020.</ref>, which consists of a longer [[Cores|core]] at night and a shorter core during the day.

== Origin ==

== Origin ==

Throughout the course of history, Siesta has been very common in Spain and many other countries around the world. However, it is most likely that humans naturally sleep in the non-reducing form of these schedules, meaning there is little to no sleep reduction involved.

Throughout history, Siesta has been a very common sleeping pattern in Spain and many other countries around the world. However, it is most likely that humans naturally sleep in the non-reducing form of these schedules, meaning there is little to no sleep reduction involved, and with more flexible sleep timings.

== Mechanism ==

== Mechanism ==

Siesta sleep shares a lot of similarities with E1 - when research confirmed the existence of the '''circadian nadir''' around noon and early afternoon, both Siesta and E1 become very popular. In the case of Siesta, a longer sleep in the nadir region is picked over the short nap of E1. In the context of polyphasic sleeping, Siesta contains 2 core sleeps, because the daytime sleep lasts for 1 full cycle, with much higher restorative power than a short nap. The longer daytime sleep paves the way for a shortened nocturnal sleep, which opens up for more evening time or earlier wake time in the morning. By having more than one core sleep, Siesta is capable of delivering very high sleep quality without compromising long-term health status. Like E1, a bigger portion of total sleep is dedicated to nighttime, where sleep pressure and the need to rest after a long day is often high, while the daytime sleep complements with a bit more sleep to fit into the circadian nadir. Usually, the wake gap from the end of the night core to the daytime core is anywhere '''between 6-9 hours'''.  

Similar to E1, Siesta sleep takes advantage of the circadian dip around early afternoon. Siesta is considered to have 2 core sleeps, a long one at night and a short one in the day. In contrast to E1, the day core contains 1 full cycle, which is much more restorative than a short nap. The longer daytime sleep also allows for a shortened nocturnal sleep. Usually, the wake gap from the end of the night core to the daytime core can be between 6-9 hours.  

However, unlike most standard scheduling where a core sleep would make use of a multiple of the 90m sleep cycle, the reducing Siesta version (totaling 6.5h each day) utilizes a 5h core (rather than the would-be 4.5h core). This is because the +30m from a 4.5h core can act as a '''statistically likely REM period''', where there is more chance and more room to get extra REM sleep in this 30m duration. Similar to the 6.5h core proposal of E1, it is expected that SWS has been fully covered in the first 3 full cycles of sleep (4.5h) with properly repartitioned sleep and high quality SWS from proper sleep hygiene. On monophasic sleep, the REM cycles in the morning do appear to become longer than 90m, so the 30m help sustain alertness better than a 4.5h core would. This small extension coupled with a daytime core would be equivalent to 4 full cycles from the E1 core.  

However, unlike most standard scheduling where a core sleep would make use of a multiple of the 90m sleep cycle, the standard reducing Siesta (6.5h total) utilizes a 5h core (instead of 4.5h). This is because last 30 minutes acts as a [[statistically likely REM period]], which is likely to contain extra REM sleep. Based on the typical human sleep structure, it is expected that SWS would be almost, if not fully covered in the first 3 full cycles of sleep (4.5h). On [[monophasic]] sleep, the REM cycles are often longer than 90m, so the 30m may also help with waking up after completed sleep cycles.

== Adaptation==

== Adaptation==

It is likely that when adaptation first begins, waking up from the 5h core (rather than 4.5h) could be difficult with '''SWS wakes''' (SWS repartitioning in progress) or '''REM wakes''', due to wakes falling into the statistically likely REM period. Over time, waking up from the main night core should no longer pose any serious problems, and waking up will become refreshing and invigorating. The daytime core is usually reported to be less challenging to manage, however, for those who are never were used to sleep this long in the daytime hours (or are only accustomed to napping for a short amount of time), it can still be difficult to first deal with the change in sleep habits.

It is likely that during parts of adaptation, waking up from the 5h core (rather than 4.5h) could be difficult with '''SWS wakes''' (SWS repartitioning in progress) or '''REM wakes''', due to wakes falling into the statistically likely REM period. Over time, waking up from the main night core should no longer pose any serious problems, and waking up will become refreshing and invigorating. The daytime core is usually reported to be less challenging to manage, however, for those who are never were used to sleep this long in the daytime hours (or are only accustomed to napping for a short amount of time), it can still be difficult to first deal with the change in sleep habits.

== Difficulty ==

== Difficulty ==