Visão geral do cronograma
Um cronograma de sono é um assunto que envolve vários aspectos e deve ser feito de acordo com necessidades individuais. Com um cronograma polifásico ruim, você vai sofrer de privação do sono e provavelmente nunca vai se adaptar, desperdiçando semanas ou meses da sua vida. Essa página detalha o consenso atual sobre como construir cronogramas.
Estágios do sono
O [[1]] é um fenômeno complexo que causa mudanças fisiológicas sobre todo o corpo. No entanto, ele afeta principalmente o cérebro. De acordo com as atividades elétricas no cérebro, o sono é dividido entre os estágios [[2]] e [[3]]. O sono NREM é novamente dividido em 3 estágios de acordo com a frequência e amplitude das ondas cerebrais.
NREM Estágio 1, correspondendo a 5-10% do sono total em adultos monofásicos, é o mais leve de todos os estágios NREM. Durante esse estágio, a sensibilidade ao ambiente externo e consciência é reduzida. Algumas pessoas sentem espasmos hipnóticos ou alucinações hipnagógicas. Estão presentes uma mistura de ondas alfa e ondas teta.
NREM estágio 2, correspondendo a 45-55% do sono total, é mais profundo que o primeiro. É mais difícil acordar dele do que no NREM 1. Esse estágio é caracterizado por complexos K e fusos do sono
NREM estágio 2, correspondendo a 15-25% do sono total, é o mais profundo de todos os estágios do sono. Esse estágio contém principalmente ondas delta, que são de alta amplitude e baixa frequência. Logo, também é conhecido como "slow-wave sleep" (SWS). É muito difícil acordar desse estágio; tentativas de fazer isso tendem a resultar em [Special:MyLanguage/sleep inertia|inércia do sono]] -- um período de intenso torpor e funções cognitivas reduzidas. Esse estágio do sono tem um papel crítico para manutenção do cérebro pelo sistema glifático. Esse processo leva de 30 a 60 minutos de NREM3 contínuo para se completar, e pode ser atrapalhado por cronogramas que contenham apenas sonecas curtas.
REM, correspondendo a 20=25% do sono total, é caracterizado pela atividade de frequência alta e amplitude baixa que se assemelha ao estágio acordado e com movimentos rápidos nos olhos. Nesse estágio, músculos também estão paralisados e temperaturas corporais se tornam desreguladas. Sonhos vividos costumam acorrer nesse estágio, e a atonia muscular (paralisia) te impede de se mover durante a experiência.
Redução do sono via sono polifásico
SWS e REM (coletivamente chamados de "estágios de sono vitais") são os mais necessários para o corpo, e em geral não podem ser removidos. Quando alguém não recebe as quantidades necessárias de sono SWS ou REM, a pressão respectiva começa acumular, o corpo começa a priorizar esse tipo de sono. Eventualmente, isso pode levar ao sono inicial REM("sleep-onset REM" ou SOREM) e sono inicial SWS("sleep-onset REM" ou SOSWS), o que permite que que alguém recupere a quantidade de SWS e REM em um período mais curto de tempo. Além disso, quando o sono é restringido, estágios vitais do sono removem o sono leve (NREM 1 e 2), o que reduz ainda mais a quantidade total de sono pra sustentar um corpo.
No entanto, conforme o NREM 2 é reduzido, a habilidade de ficar acordado por longos períodos de tempo diminui. É por isso que cronogramas com redução no tempo total de sono("total sleep time" ou TST) precisam de mais períodos de sono espalhados durante o dia para serem viáveis. Fazer uma soneca de ~20 minutos ou um ciclo único de ~90 minutos ajuda um praticante de sono polifásico permanecer acordado. O tempo máximo acordado depende do cronograma, hora do dia, assim como as necessidades individuais de cada pessoa. Com intervalos muito longos, haverá cansaço e não será possível se adaptar ao cronograma.
Circadian rhythm
The circadian rhythm is the body clock aligned to local solar time by light exposure and food intake, among other factors. It generates hormonal changes throughout the day consistently to produce effects on the body. One of the main effects is the secretion of melatonin, the presence of which is essential for entering SWS, and also affects the timing of REM sleep.
After sunset when light levels reduce, the body starts to secrete melatonin to promote sleep. The rising levels of melatonin early in the night allows the body to gain SWS in the first few sleep cycles. In contrast, as melatonin levels drops in the morning, REM becomes the preferred sleep phase to be gained.
In modern times with the advent of artificial light, many people's circadian rhythms have been pushed forward (i.e. later). However, this exposure to artificial light sources also compromises people's ability to gain SWS efficiently. The extent to which light influences the circadian rhythm is given by the melanopic light sensitivity function, which peaks at ~480nm (blue) and drops off on both sides. To reduce this effect, a dark period must be employed, during which blue and green lights must not enter the eye. This can be done in many ways, such as with red goggles or screen filters.
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
Since vital sleep stages are generally not possible to reduce, the extent of compression required to sustain a schedule increases dramatically as total sleep time reduces. Compressing sleep, however, requires adaptation, and greater levels of compression necessitates harsher and/or longer adaptations. As such, schedules can be classified by their difficulty level, which is mostly a function of the amount of sleep cut.
It is worth noting that younger individuals whose brains and bodies are still developing will need more SWS and REM than adults, which increases their minimum sleep thresholds and makes reducing sleep more difficult. In addition, it has been suggested that NREM2 might have other functions in the development of the brain, and thus cutting it could be potentially problematic.
| Age | Recommended minimum sleep |
|---|---|
| <16 | 7.5 hours |
| 16-18 | 6 hours |
| 18-21 | 5 hours |
| >21 | 4 hours |
It is recommended that one stay above these limits at all times to prevent adverse effects on health. The necessity of vital sleep stages also implies that certain schedules, such as Uberman or Dymaxion, will be unachieveable for most people as its total sleep is below the total vital sleep required for most people.
Here is a basic classifcation of schedules by their difficulty level, assuming a typical sleeper with 8h monophasic sleep and normal levels of SWS and REM:
| Difficulty | Example schedules | TST range | Sleep time cut | Note |
|---|---|---|---|---|
| Easy | BiphasicX, E1-ext,
Siesta-ext, Segmented-ext |
7-8 | <1 hour | Recommended for beginners or those needing significant flexibility. |
| Moderate | E1, E2, E3-ext, Siesta, DC1, Triphasic-ext,
Segmented, DC1-ext |
5-6 | 1-2 hours | Require a significant adaptation process, but can be quite flexible after adapting. |
| Hard | E3, DC2 | 4-5 | 2-3 hours | Require harsh adaptations and are not particularly flexible for most people. |
| Very hard | DC3, Bimaxion, Triphasic | 4-5 | 2-3 hours | Considered harder than the "Hard" ones because they do not contain a longer core during SWS peak hours. |
| Extremely hard | E4, E3-shortened, Uberman, Dymaxion | <4 | >4 hours | Not considered possible for most people. |
Sleep block lengths
Cores are long blocks of sleep that contain at least one full sleep cycle. They are typically scheduled to be a multiple of a 90 minutes, which is a common sleep cycle length. However, alternative core lengths can be done to either to plan for alternative cycle lengths or in an effort to gain extra time in SWS or REM. Cores are generally considered to be essential, because they provide the necessary amount of SWS to sustain life. As such, schedules without cores (i.e. nap only schedules) have extremely low success rates.
Naps are short blocks of sleep, typically about 20 minutes on default schedules. Naps allow for a small amount of REM to be gained. Moreover, naps help sleepers sustain wakefulness through gaps. Longer naps (up to ~45 minutes, known as pronaps) can be used in during the REM peak around dawn to gain even more time in REM. Longer naps in other times of the day can lead to SWS wakes, which can be exceptionally difficult to wake from for some people, especially during periods of high SWS deficit.
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
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
Two main schedule types have been practiced by humans since time immemorial: Segmented -- with two long sleep in the night separated by a wake gap, and Siesta -- one long sleep in the night and a shorter sleep in the afternoon. Of course, the schedule timings of the ancient people are more flexible and thus likely contains more total sleep than the current standard ones. Most current polyphasic sleep schedules evolve from monophasic sleep as well as the above two historically common schedules.
The Biphasic line of schedules consists of the two historical polyphasic schedules, as well as E1, which is also considered a variant of siesta in an Everyman style.
The Everyman line of schedules are formed by removing sleep cycles in the end of monophasic sleep, and adding naps to compensate for the lost time in REM and sustain wakefulness.
The Dual core line of schedules does the same thing, except to Segmented instead of monophasic sleep.
Over the decades, the polyphasic sleep community has developed several lines of schedules that have been known to work.
| Schedule line | Description | Notes |
|---|---|---|
| Biphasic | Two sleeps | Usually deemed the easiest and recommended to beginners. |
| Everyman | One core sleep and two or more naps | |
| Dual core | Two core sleeps and one or more naps | |
| Tri core | Three core sleeps | |
| Nap only | No cores and any number of naps | Not deemed to be achievable for most people. |
| Experimental | Those that do not fit into the above categories | Not usually recommended for beginners due to insufficient evidence of them working |
