Changes

Because E2 has substantially more sleep than the minimum threshold for most people, it allows a range of scheduling options. Over the years, there have been several successful adaptations to the variants below.

Because E2 has substantially more sleep than the minimum threshold for most people, it allows a range of scheduling options. Over the years, there have been several successful adaptations to the variants below.

=== 5h core ===

=== 5-hour core ===

[[File:5h core.png|right|thumb|E2 with 5h core]]

[[File:5h core.png|right|thumb|E2 with 5h core]]

This variant is still called E2 (not extended), as it is a minor extension. The reasoning behind this is that, as most of the SWS should have been accounted for by the 4.5h mark, adding sleep after it should allow more REM and light sleep to be gained, potentially easing the adaptation. However, during the adaptation, it may be somewhat difficult to wake up from a 5h core, before one gets used to the length.  

This variant is still called E2 (not extended), as it is a minor extension. The reasoning behind this is that, as most of the SWS should have been accounted for by the 4.5h mark, adding sleep after it should allow more REM and light sleep to be gained, potentially easing the adaptation. However, during the adaptation, it may be somewhat difficult to wake up from a 5h core, before one gets used to the length.  

=== Early core ===

=== Early core ===

[[File:Early E2 Core.png|center|thumb|E2 with a core in SWS peak]]

[[File:Early E2 Core.png|right|thumb|E2 with a core in SWS peak]]

A much less popular E2 variant, an early core variant places the core in the whole [[SWS peak]], or parts of it (e.g, starting core at 10 PM). At the exchange of evening social life, those who pick this variant may benefit from their early bedtime on monophasic sleep, or a very early riser. Both naps are also rotated backward on the clock to start earlier. The second nap, now close to noon, can fit better into the noon break.  

An early core variant places the core in the whole [[SWS peak]], or parts of it (e.g, starting core at 20-21). Those who pick this variant are often early sleepers. Both naps are moved back to to start earlier. The second nap, now close to noon, can fit better into the noon break.  

This variant gives a lot of nighttime hours for night owls, which may be a similar advantage to Segmented sleep. However, it is generally tougher to adapt to this variant, because there is only one nap around sunrise hours after staying awake for many hours during graveyard hours. Those who usually have a later bedtime (e.g, 11 PM or later) should only attempt this variant if there is no other scheduling choice to make E2 work.  

This variant provides many nighttime hours awake, similar to Segmented or other [[Dual core]] schedules. However, this variant may be more difficult to adapt to, because there is only one morning nap after staying awake for long hours at night. Those who usually have a later bedtime should avoid this, unless it is the only viable option.  

=== Late core ===

=== Late core ===

[[File:Late E2 Core.png|center|thumb|E2 with a core out of SWS peak]]

[[File:Late E2 Core.png|right|thumb|E2 with a core out of SWS peak]]

Contrary to the previous variant, this E2 variant allows the core to be scheduled out of SWS peak, or at even as late as 2 AM, with strong management of dark period (e.g, 3 hours of dark period before the core), food and exercise. The reason is that the core, 4.5h is long enough to sustain SWS and some amount of REM sleep as it is pushed closer to REM peak. Those with lower SWS requirements will greatly enjoy this variant, as it also allows them to have '''social time in the evening'''. However, some criteria need to be considered carefully before one decides to follow and adapt to this variant.

This variant allows the core to be scheduled out of SWS peak up to about 2 AM, with circadian management (daylight lamps before dark period, later food and exercise). Those with lower SWS requirements will have an easier time adapting to this variant.  

First, REM pressure is still relatively '''low until after 2 or 3AM''', so SWS should have no problem entering the early sleep cycles of a late core. What’s more concerning is the '''nap timing'''; don’t rotate naps equally late unless you are using good circadian management. Otherwise, <u>shorten the gaps before both naps 30-60 minutes</u>. On '''sunlight-based''' circadian, you want to keep the first nap in or close to REM peak ending by 9AM (latest 10AM), and keep the second nap before 5PM to retain some chance of an afternoon REM nap, and to avoid getting SWS in your evening naps. Either way, neither the wake period between the naps nor the second nap and core should be longer than 8 hours, as that has often caused failures to adapt. Some people did manage to adapt to a gap larger than 8 hours, but this is very rare and is therefore not recommended.

As REM pressure is still relatively low until after 2-3 AM, it should be possible to gain SWS in the early cycles of the core.  

However, naps should not be rotated equally late without particularly strong circadian management. The gaps before both naps can be shortened by 30 to 60 minutes compared to standard. The first nap should be kept close to REM peak ending by 9AM (latest 10AM), and keep the second nap before 5PM to avoid getting SWS in it. Still, the wake gap before core should be no longer than 7-8 hours, as that has often caused failures to adapt. A few did manage to adapt to a gap larger gap, but this is rare and is not recommended.

One of the rarest E2 scheduling option is this '''somewhat equidistantly scheduled''' sleep blocks. The wake gap between each sleep is approximately 6h30m on average. The idea behind this scheduling option is to use the core as a blanket duration to stay awake until very late morning hours (close to noon/lunch break). This variant delays the first nap a lot, with at least 6h wake gap. Once adapted to this variant, the night will feel much shorter as there is more time awake until almost noon. The core usually starts around midnight or slightly earlier, which can resemble certain reduced monophasic lifestyles with a very early morning wake time.  

However, there are '''rarely any successful adaptations''' to this variant. This is mostly attributed to the very long morning wake gap, and the nap is not placed in REM peak. Staying awake during these early morning hours can become overwhelming in [[4-Stages Adaptation Model#Stage 3|stage 3]], and the second nap is reported to be very heavy (which may suggest some possible [[SWS wake]]). This variant can still work if it is possible to nap in the middle of the work gap, and right after work.  

The [[pronap]] has been applied in a lot of E2 variants and has reported some success. The pronap is a longer nap around REM peak, usually between 30 to 45 minutes, which allows more REM sleep. This may help people with higher REM requirements to adapt. The longer nap may also allow a longer wake gap after it (possibly up to 8h) if there is no chance to nap around noon or early afternoon. However, so far the success rate with the long wake gap is still not high, even with the pronap. Thus, it is recommended to still limit the gap to about 7 hours.

[[File:5h core and pronap.png|right|thumb|E2 with a 5h core and a Pronap]]

Combining the pronap with the 5-hour core yields this variant. This variant has seen few attempts, and has not seen any success so far. People with higher sleep requirements may find this variant easier to adapt to.

40- and 45-minute pronaps so far have reported adaptation success.  

As soon as the concept of a '''[[Pronap]]''' was introduced, it has been applied in a lot of E2 variants and has reported some success. The idea is to lengthen the first nap to ~30-45m as a way to get in more REM sleep. The benefits of this variant are paramount for people with higher REM requirements and often struggle around morning hours and the ability to '''schedule a longer wake gap''' between each nap (e.g, 8h as demonstrated in the chart) if there is no chance to nap around noon or early afternoon. The Pronap is expected to yield more alertness sustaining than a regular 20m nap would, so this is a tactical advantage to consider. However, so far success rate remains '''modest''' with this long wake gap. Thus, it is recommended to limit this wake gap down to ~7h at most.

Alternatively, slightly extending the core to 5h while using a Pronap is also a viable approach. Even though there allegedly is no successful adaptation to this variant, the idea behind it is to further increase the flexibility of scheduling and a longer daytime wake gap (between 2 naps mostly). People with '''overall higher sleep requirements''' may find this variant fitting. Despite the similar amount of sleep to E1, the advantage is that there are 2 naps per day, which accelerates the process of learning to fall asleep in the short naps compared to only 1 daytime nap. The Pronaps of '''40m''' and '''45m''' so far have reported adaptation success.  

It is also important to keep in mind that both variants with the Pronap pose a danger of '''oversleeping in the Pronap during adaptation'''. This in return lengthens the Pronap to a 90m core or so (DC1-extended). This is because the intensified REM wake when adapting, or only some traces of SWS can lead to an oversleep. It is therefore necessary to <u>stay on guard with extra alarms</u> when picking the Pronap. Although there have been reported incidents of the Pronap's failure, certain experienced sleepers have been able to take advantage of these oversleeps to adapt to DC1-extended (4.5-1.5h core combination) instead. This can ultimately salvage a failing polyphasic adaptation, instead of reaching for a full [[recovery]] on monophasic.  

Note that during adaptation, pronaps may be more difficult to wake up from, due to intense REM wakes or SWS wakes. It is therefore necessary to use extra alarms for it.

=== Shortened ===

=== Shortened ===