Non-reducing

A non-reducing schedule is simply a schedule, which doesn't reduce total sleep time compared to a personal monophasic baseline. Having no sleep reduction, these schedules usually offer other benefits, such as being more alert and refreshed during the day compared to mono, flexibility from the very beginning and a very mild adaptation.

Biphasic schedules

The standard biphasic schedules reduce little sleep, albeit they are not non-reducing for a person with an average monophasic baseline of 8 hours of sleep per night.

Biphasic sleep has been widely represented historically. It includes segmented or bifurcated sleep and schedules with a long core at night, which is supplied with a short nap / core midday. The versions, which were traditionally practiced, supposedly do not reduce total sleep time.

E1

A sample non-reducing E1 setup

As a non-reducing biphasic schedule, this E1 provides much flexibility. The nap can be anywhere between ~10 and ~40 minutes. The nap duration can change from day to day, and can start at different hours each day if desired. Similarly, the core duration is not fixed and sleepers should rely on natural wakes for it. This scheduling variant can be strict, or have slightly different sleep times each day from day 1 of adaptation (it is recommended that the core should not be more flexible than an 2-hour window when first adapting, to keep the circadian rhythm consistent).

Thanks to the flexible nature of the nap, it is necessary for sleepers to recognize the time they are naturally tired or drowsy in the day to place the nap accordingly; if the one's work schedule does not allow for a large range of nap time, then a smaller nap window can be chosen. Most importantly in this variant, late naps (past ~5-6 PM) should be avoided because it may interfere with the core at night, which is more likely as the total sleep time is higher.

Recently, there has been some success of this variant with very young teenagers who pursue a safe and easiest way to partake in polyphasic sleeping with the option for a daytime nap to train for napping. This usually serves as a groundwork for them to move to a more difficult schedule when time allows. A great advantage non-reducing E1 has over its counterpart Siesta is that the short daytime nap is very easy to schedule around meal times and social events, and usually short enough to avoid being interrupted by daytime activities.

A non-reducing Siesta variant

Siesta

Under a non-reducing schedule, it can be natural to wake up after 60m on Siesta. Without repartitioning, all sleep cycles follow the regular order of NREM1, NREM2, SWS, NREM2 and finally REM sleep. Since little vital sleep has been removed, the body naturally wakes up before reaching REM. However, for reducing variants, 60m sleep blocks should not be scheduled from the start.

Segmented

Non-reducing Segmented variants

The difference between Segmented-extended and non-reducing Segmented is that the former can reduce some sleep for long sleepers, whereas the latter aims not to reduce any sleep (e.g, 4.5-4.5 core combo for 9h sleeper). The non-reducing variant is believed to resemble the historical sleep pattern in pre-industrial Europe. Both variants occupy hours in both evening and morning, which can clash with social commitments.

Compared to the default or other reducing variants, these two allow for some flexibility of either core, even during adaptation, and naturally segmented sleepers can adapt to the schedule by simply follow their natural patterns of tiredness. One success from the non-reducing variant (~6.5h total sleep on average) has the first core being ~4.5h long consistently while the second core hovers around 2h. This suggests that non-reducing variants can still be utilized by short sleepers to achieve a flexible Segmented schedule. For non-natural Segmented sleepers, it is still advisable to try to sleep at the same time everyday for each core sleep.

However, without reducing total sleep, it is expected that it will be significantly harder to fall asleep, which may contribute to the difficulty of the adaptation.

BiphasicX

BiphasicX is a flexible non-reducing schedule, which can be a combination of all the biphasic schedules.

Further information: BiphasicX

Polyphasic schedules

This section described the schedules with 3 blocks of sleep or more, starting with the standard ones and further showing a few more experimental variants.

DC1

A Non-reducing DC1

Because DC1 is heavily built on the Segmented sleep habits, naturally Segmented (non-reducing) individuals can learn to add a daytime nap around the hours they are drowsy enough. This would effectively create a non-reducing DC1 variant. Despite this, non-reducing DC1's true adaptation success is very rare, and mostly rely on the naturally Segmented tendency coupled with the circadian nadir around noon-afternoon to take the nap accordingly. It may also be redundant to a lot of people, because non-reducing Segmented already provides all the necessary sleep in the cores, and does not require taking any daytime naps. However, a slight benefit from doing this variant is to start to learn to have effective daytime naps to further transition to other reducing schedules/variants, because Segmented sleep does not teach napping skills. Even so, with the overall much lower sleep pressure on a non-reducing schedule, it may still be a tough task to fall asleep in the nap.

Non-reducing Triphasic

Triphasic

Non-reducing Triphasic often may fit people with a natural tendency to Segmented, who are unable to get enough sleep at night, often because of frequent WASO or being unable to go to sleep early and wake up late, thus having a need to cut the second core, which would make Segmented sleep reducing. Adding a core during the day would have a similar mechanism to Siesta.

For sleepers without an affinity for Segmented sleep, a method to achieve non-reducing Triphasic is to use alarms both for the first and the second core, making total sleep time at night reduced compared to their monophasic baseline. The core midday can have a natural wake without using alarms.

A PC0 variant

Multicore schedules

This section describes schedules, which consist of several cores, other than Triphasic. These are pretty experimental and are rarely used. They are a result of splitting a long monophasic core into a few short cores, often 1-cycle ones. Possible variants are QC0 (4 cores) and PC0 (5 cores).

Both schedules have very few known successful attempts, such as Cristiano Ronaldo, a famous footballer, or GeneralNguyen, an active member of the polyphasic sleep community.

Dividing monophasic core into several cores can be beneficial for intense exercising schedule, since the refreshment from sleep can be met more often. Also, there is a benefit for those, who need to be socially available throughout different hours during the day, or simply to make a sleep structure more exotic.

Lifestyle benefits

Non-reducing schedules generally are recommended to teenagers, people who prefer to have a very flexible sleep schedule, or those who prefer to avoid sleep reduction for a period of time. They are also a viable variant of recovery on instead of the usual monophasic recovery.

Non-reducing schedules keep the amount of NREM2 the same as on monophasic sleep, which makes it safer for the young individuals, since this sleep stage has been suggested to play role in development. Non-reducing schedules provide a possibility of staying on a safer side in this case.

People with a hectic lifestyle might also find non-reducing schedules beneficial, if they don't have enough time or consistency in life for the adaptation to a strict reducing schedule.