Changes

=== Equal core lengths ===

=== Equal core lengths ===

This DC2 variant offers a somewhat higher total sleep than usual (not high enough to be grouped into the extended category), and both core sleeps last for 2.5h each. So far there has only been one success with this variant, however. The premise behind this variant is to '''provide some buffer total sleep to advance to DUCAMAYL''' with both cores becoming flexible. This example sets the consideration for appropriate core durations to ensure that they can receive some flexibility after adaptation. Because of the highly uncommon and ill-advised 2.5h core duration, beginners and inexperienced polyphasic sleepers should avoid this variant.  

This DC2 variant offers slightly more time in cores, with both core sleeps being 2.5 hours. Only one success has been documented with this variant so far, however. This schedule prepares one for DUCAMAYL, in which both cores are flexible. Because of the 2.5h core duration, beginners should avoid this variant.  

An easier way to schedule a similar amount of sleep duration for both cores is to have a '''3.5h core and a 1.5h core''' respectively. The 3.5h core duration has been used in E3 in a lot of successful adaptations and the idea behind it is to make use of the potential +30m from the 3h mark for more REM sleep (even though the better statistically likely REM period is oftentimes a 5h core). Once adaptation is complete, it may become more comfortable to flex both core sleeps.   

An easier way to schedule a similar amount of sleep duration for both cores is to have 3.5h and 1.5h cores, both of which being more common core lengths. Once adaptation is complete, it may also be possible flex both core sleeps.   

===Early rotation/Pronap===

===Early rotation/pronap===

[[File:DC2 Early Rotation.png|thumb|A DC2 variant with the first nap around dawn|alt=]]

[[File:DC2 Early Rotation.png|thumb|A DC2 variant with the first nap around dawn|alt=]]

This interesting DC2 variant rotates the whole schedule backward, to earlier hours. The premise behind this distribution of sleeps is to place most sleep blocks to night hours, and only have one nap in the day. As a result, the wake gap between each core is possibly smaller than on the standard version. The first nap is placed at the usual position of the second core, and as a result, it is very similar to an [[Everyman|Everyman schedule]]. The first core likely will contain most SWS needs, while the second core may be a mixed core (containing both SWS and REM, but likely more REM sleep). Both naps may contain REM sleep, which can boost the chance to recall dreams.  

This variant rotates the whole schedule backward to earlier hours. The goal of this is to place 3 sleep blocks at night, leaving only one nap in the day. As a result, the core gap is also shorter. The first nap is placed at the usual position of the second core, resembling an [[Everyman]] schedule. The first core will likely cover most of the SWS, while the second core may be mixed (containing both SWS and REM, but likely more REM sleep). Both naps are more likely to contain REM sleep, which can boost dream recall.  

Alternatively, the first nap can be extended to become a '''Pronap''' (e.g, 30m) to better sustain wakefulness and provide more REM sleep for individuals with somewhat higher REM requirements, because the first nap is located in REM peak. The reason a Pronap can be used is that both core sleeps mostly cover all SWS needs, leaving basically no room for SWS to occur in this hypothetical Pronap. The Pronap can then yield better wakefulness sustaining, and can become flexible after adaptation. However, it is important to note that this is a new proposal for an alternate DC2 variation, and has not been tested. There is also little incentive to try out this early rotation/Pronap variant, because the first core is too early in the evening, and becomes a liability for social time for a lot of people.  

In this variant the first nap can also be extended to become a [[pronap]] (30-40m) to better sustain wakefulness and provide more REM sleep. However, this variant has not been tested, with the obvious issue of the early first core conflicting with social time for most people.  

===Extended variant===

===Extended===

[[File:DC2-ext Base.png|thumb|alt=|A DC2-extended variant]]

[[File:DC2-ext Base.png|thumb|alt=|A DC2-extended variant]]

'''DC2-extended''' simply extends the second core sleep by a full cycle, making it 3h total. This variant shares the same total sleep as E2-extended, with the exception of having 2 core sleeps. People with high sleep requirements (especially in both REM and SWS) can make use of the sleep frequency and the assistance from naps to meet the necessary vital sleep requirements. The only advantage of this version is that the first core can be delayed to the last hours of SWS peak - meaning it is possible to schedule this core at 11 PM or later. However, while looking realistic on paper, DC2-extended has never really reported any successes. It is also outclassed by '''E2-extended''', which is more convenient in scheduling, more success and an allegedly easier adaptation. While it is possible to schedule the first core to be 4.5h long and the second core to be 1.5h long (for more SWS recovery from intense exercising or high SWS requirement), DC2-extended is also shadowed by '''DC1-extended''', which has the same total sleep for both cores combined while only requiring 1 daytime nap (more comfortable to keep up long-term).   

The second core can be extended to a 3h sleep. People with high sleep requirements (especially in both REM and SWS) can make use of the sleep frequency and the assistance from naps to meet the necessary vital sleep requirements. The only advantage of this version is that the first core can be delayed to the last hours of SWS peak - meaning it is possible to schedule this core at 11 PM or later. However, while looking realistic on paper, DC2-extended has never really reported any successes. It is also outclassed by '''E2-extended''', which is more convenient in scheduling, more success and an allegedly easier adaptation. While it is possible to schedule the first core to be 4.5h long and the second core to be 1.5h long (for more SWS recovery from intense exercising or high SWS requirement), DC2-extended is also shadowed by '''DC1-extended''', which has the same total sleep for both cores combined while only requiring 1 daytime nap (more comfortable to keep up long-term).   

[[File:Dc2tc1.png|thumb|A DC2 variant with TC1 structure]]

[[File:Dc2tc1.png|thumb|A DC2 variant with TC1 structure]]

===TC1 structure===

===TC1-alike ===

This is an experimental variant, proposed by [[User:Sekvanto|Sekvanto]]. Both cores have the same length of 2 hours. Three blocks of sleep are placed during the night hours: both cores and one of the naps. The second nap is placed midday. Such schedule resembles the structure of [[TC1]], replacing one of the cores with a nap and extending the remaining cores. This variant has fewer naps during the daytime, which potentially makes it more convenient socially for some. An early core may be an issue, on the other hand. Another benefit is a dawn nap, which may increase dream recall.

This is an experimental variant, proposed by [[User:Sekvanto|Sekvanto]]. Both cores have the same length of 2 hours. Three blocks of sleep are placed during the night hours: both cores and one of the naps. The second nap is placed midday. Such schedule resembles the structure of [[TC1]], replacing one of the cores with a nap and extending the remaining cores. This variant has fewer naps during the daytime, which potentially makes it more convenient socially for some. An early core may be an issue, on the other hand. Another benefit is a dawn nap, which may increase dream recall.

It should be noted that 2h [[cores]] are usually considered a bad choice since they are a bit longer than an average sleep cycle, which makes SWS wakes more possible. This schedule overall isn't popular and had only a couple of successful adaptations. However, 2h cores work for some, supposedly either by having extended sleep cycles or by getting more light sleep at the end of the cores.

It should be noted that 2h [[cores]] are usually considered a bad choice since they are a bit longer than an average sleep cycle, which makes SWS wakes more possible. This schedule overall isn't popular and had only a couple of successful adaptations. However, 2h cores work for some, supposedly either by having extended sleep cycles or by getting more light sleep at the end of the cores.

== References ==

==References==

{{reflist|refs=

{{reflist|refs=

<ref name="polysoc">{{cite web |url=https://web.archive.org/web/20190418071441/https://www.polyphasicsociety.com/polyphasic-sleep/overviews/dual-core/ |title=Dual-Core Sleep |website=Polyphasic Society |access-date=2020-12-18}}</ref>

<ref name="polysoc">{{cite web |url=https://web.archive.org/web/20190418071441/https://www.polyphasicsociety.com/polyphasic-sleep/overviews/dual-core/ |title=Dual-Core Sleep |website=Polyphasic Society |access-date=2020-12-18}}</ref>