Peer-reviewed

Introduction

The aim of this section is to share scientific, peer-reviewed articles on polyphasic and biphasic sleep in adult humans. Many of the studies have a short summary in hopes to ease the search process of people looking for specific points or claims. If you find an article about polyphasic sleep that is not included in this list, do not hesitate to contact the moderators on Reddit or Discord.

Content

  1. Research on specific polyphasic schedules
    1. Siesta
    2. Segmented
    3. E1
    4. E2-shortened
    5. Standard E3
    6. Non-reducing E5
    7. SEVAMAYL
    8. DC1
    9. Triphasic
    10. TC1
    11. QC0
    12. Uberman
    13. Dymaxion
    14. SPAMAYL
    15. Tesla
  2. General peer-reviewed research on polyphasic sleep
    1. Sleep drive and regulation
    2. Napping behavior
    3. Tendency for polyphasic sleep
    4. Short-term polyphasic sleep strategies
  3. Master’s theses
  4. Bachelor’s theses

Peer-reviewed research discussions playlist on YouTube

Schedule-specific peer-reviewed research

In this part, peer-reviewed research about specific polyphasic sleep schedule will be presented.

SIESTA

Cognitive Effects of Split and Continuous Sleep Schedules in Adolescents Differ According to Total Sleep Opportunity.

  • Reducing Siesta benefits adolescents short-term (~2 weeks). The scheduling variant of focus was 5h sleep at night and 1.5h daytime sleep respectively. This study also compared this Siesta version with an extended version (6.5h night core).
  • The study concluded that “as long as the total sleep opportunity across 24h is within the recommended range (7-9h), students may fulfill sleep requirements by adopting a split sleep schedule consisting of a shorter period of nocturnal sleep combined with a mid-afternoon nap, without significant impact on basic cognitive functions”.
  • Multiple enhancements in cognitive functions were also present in these adolescents during the course of the study.¬†

Daytime naps can be used to supplement night-time sleep in athletes.

  • This study examined the daytime napping behavior in athletes. The daytime nap lasted for 1h and 2h for different tests. This overall non-reducing Siesta seems to benefit athletes very well. Researchers concluded that the siesta is an effective strategy for athletes’ performance in conjunction with nocturnal sleep.¬†

Sleep pattern, duration and quality in relation with glycemic control in people with type 2 diabetes mellitus.

The Effect of Prior Endurance Training on Nap Sleep Patterns.

  • The recovery mechanic behind a daytime siesta helps athletes tremendously. This paper found out that after an endurance training session, SWS pressure rises. The occurrence of SWS in the long siesta releases the growth hormone (GH). GH regulates glucose levels and glycogen storage as these storages often deplete under a long and intense exercise session.

Is the Siesta an Adaptation to Disease?‚ÄĮ: A Cross-Cultural Examination.

SEGMENTED

Ring the Bell for Matins: Circadian Adaptation to Split Sleep by Cloistered Monks and Nuns.

  • This research cements the natural tendency for Segmented sleep in some monks and nuns4; these subjects can even anticipate when they would wake up at night.
  • All subjects are healthy and live an ascetic lifestyle.
  • There are very negligible, if any, consequences with a segmented circadian in the long run.
  • The researchers also suggest a possibility of using Segmented sleep to resolve certain nocturnal insomnia in some individuals.¬†

Sleep pattern, duration and quality in relation with glycemic control in people with type 2 diabetes mellitus.

  • In the elderly, a segmented sleep pattern is also prevalent; the ability to sleep in one chunk wanes.
  • In one study about sleep pattern’s relationship with glycemic control and diabetes, the participants are 58 years old on average5.
  • Researchers concluded that those with a split sleep pattern (sleeping in more than one chunk at night) have a lower HbA1c (hemoglobin A1c).
  • There is also a negative correlation between the number of night time sleep blocks and HbA1c level.¬†¬†

E1

Association of estimated sleep duration and naps with mortality and cardiovascular events: a study of 116,632 people from 21 countries

While there has not been any official research on specific Everyman 1 variants (mostly the standard one), there are certain implications. Multiple studies have noted the correlation between night sleep duration, napping behavior and mortality rate. However, more studies would be necessary to fully determine the relationship between these variables. 

ck1bn.png (600√ó600)
A seemingly “ideal” E1

The focus of the discussion is on one specific study. This study with over 100,000 participants from more than 21 countries supported the E1-alike lifestyle1. Most notably, it is also one of the few long-term studies on the most basic form of polyphasic sleep, a reducing biphasic schedule with a daytime nap. Despite the flaw of a self-reported study, there are noteworthy points.

  • Higher mortality rate correlates with a longer nighttime sleep duration.
  • Nocturnal sleep duration of no more than 6h alongside a short daytime nap (no longer than 30m) have better prospects. These E1 individuals avoid the increased risks of cardiovascular diseases and eventually mortality.¬†
  • Participants with a reduced monophasic schedule suffer the same amount of high risks as those with an extended monophasic equivalent.¬†

This spurs interesting insights into potentially better sleep with shorter night sleep. However, there have been rarely any direct adaptations to this E1-modified variant; 30m naps should generally be avoided on reducing polyphasic schedules. 

E2

Napping reverses increased pain sensitivity due to sleep restriction

A short-term radical Everyman 2, 2h core and 2 30m naps, has shown the ability to reverse pain sensitivity in a study1. The study lasted for 6 days total; 3 days for the shortened monophasic protocol, and 3 days for E2-shortened.

32rfl.png (600√ó600)
E2-shortened in discussion

Results

  • This E2 scheduling also outperformed the same shortened monophasic sleep with only 2h total sleep.
  • With the reduced hyperalgesia effect, both of the naps contained mostly SWS and light sleep. There was more SWS in the afternoon nap than in the morning nap.¬†
  • The role of SWS in physical recovery from napping is noteworthy.¬†

Further notes

  • The EEG results from the schedule is in line with when adaptation first begins on an extremely restrictive sleep schedule. The short core sleep together with the naps contain SWS.¬†
  • SWS has stronger homeostatic pressure than REM; even around morning hours, the 30m nap in the study still contained some SWS.¬†
  • As the total sleep tries to account for SWS, REM debts will ensue.¬†
  • Results from the study show that E2 can also be an emergency polyphasic schedule; it would fit those who choose to only cut down less sleep with a default 4.5h core.¬†

E3

Psychological Impacts of Polyphasic Sleep (Bachelor’s Thesis)

  • The thesis, also the only study on E3 to date, clarified that performance is not reduced below monophasic baseline levels. In fact, performance even seems enhanced compared to that of monophasic sleep.
  • The single-case study was the most glaring limitation, together with an unsuccessful E3 adaptation. The subject did not conduct his E3 adaptation in laboratory environment. This has likely boosted the difficulty level of E3, which resulted in some oversleep and sickness.¬†
  • Despite numerous measurements, the study was not peer-reviewed and contained some human errors.¬†

E5

Ultrashort sleep schedules: Sleep architecture and the recuperative value of multiple 80-, 50-, and 20-min naps

Up to date, there is only one short-term polyphasic study on Everyman 5. The variant of E5 was non-reducing; it contained a 4h core and 5 50-minute naps. The goal of the study was to compare performance prenap, postnap, the levels of sleep inertia following varying nap durations with an 8h monophasic baseline. The nap durations under scrutiny were 80 minutes (which resembles a core sleep), 50 minutes and 20 minutes. Each nap duration testing phase carried on for 4 days, alternating with recovery in between. Four subjects participated in the study. 

kk4y3.png (600√ó600)
E5-extended with 50-minute naps

Results

  • Because of the non-reducing condition, the performance output was basically similar to that on monophasic sleep.¬†
  • The 50-minute naps generated the most amount of sleep inertia among the three different nap durations. This was because participants consistently woke up during SWS.¬†
  • SWS amount was basically intact on this E5-extended pattern compared to monophasic.
  • REM sleep suffered from a penalty short-term (but not long-term). This is owing to the early adaptation stage, where sleep cycle architecture remains the same as a usual sleep cycle.¬†
  • 50m naps were not long enough to contain more REM sleep, hence the initial REM penalty.
  • The recuperative powers of the naps were confirmed; once sleep inertia dissipated, subjects performed better than before they napped.¬†

Brief analysis from community standpoint

  • 50-minute naps prove once again why polyphasic sleepers should avoid scheduling them. They are mid-cycle naps that are prone to SWS wakes.¬†
  • Non-reducing E5 variant from the study is NOT a long-term polyphasic schedule. The clunky scheduling is too burdensome to keep up.¬†
  • Although there was a lack of sleep reduction from the default E5 variant, the study hinted at important polyphasic adaptation mechanics. On a multi-core schedule (e.g, QC0) with a high total sleep, SWS deprivation symptom can be absent. The adaptation would then focus on repartitioning REM sleep as time goes on.¬†
  • The results also confirm that Everyman variants with a ~4.5h core on average should cover all SWS requirements even during adaptation. This assumes dark period application and an average SWS requirement.¬†
  • The study hinted that in the long term REM sleep will behave differently. This suggests that a complete adaptation will provide more REM sleep to meet each personal REM baseline on monophasic.¬†

SEVAMAYL

Polyphasic sleep strategies improve prolonged sustained performance: A field study on 99 sailors

The fourth fastest competitor in the transatlantic race in 1980 slept SEVAMAYL1. This sleeper reported having a core sleep of 3-4h each night, and varying 30m naps in the day. He slept a total of roughly 5h per day. The core sleep acted as some sort of “anchor sleep” to stabilize the circadian rhythm. The naps supplemented alertness in the day on a sleep reduction regime.¬†

However, given that he spent only a couple weeks doing SEVAMAYL cold turkey, it was likely he did not fully adapt to this pattern. In fact, SEVAMAYL requires the accumulation of resilience in changes of sleep times to get used to the flexibility of sleep hours. However, SEVAMAYL proved its usefulness in tight situations where sleep cut is obligatory. Thus, SEVAMAYL’s flexibility is very helpful in hectic, short-term situations; the core sleep also helps provide some vital sleep stages, being less extreme than a pure nap-only schedule.

Learning to nap freely and then recovering on monophasic sleep can also pave the way for an actual polyphasic adaptation later on with strict sleep times and the obtained ability to effectively nap for 20m. SEVAMAYL therefore can be a less extreme alternative to Naptation. 

DC1

There has been some official report of Dual Core 1 practice.

Does the moon influence sleep in small-scale societies?

The Malagasy agriculturalists have demonstrated the ability to sleep in two separate segments at night and daytime napping1. 

Sleep pattern, duration and quality in relation with glycemic control in people with type 2 diabetes mellitus.

There is a decent possibility of DC1 in a study about sleep patterns in the elderly and glycemic/diabetic control2. Some of them slept 3 segments per day, including 2 segments in the night and a daytime nap. Researchers concluded that those with more than one sleep segment at night and a daytime nap had better HbA1c control than monophasic sleepers. However, it is important to note that the likes of DC1-extended/non-reducing would produce these results. Thus, it can be inferred that the extra daytime nap put DC1 over Segmented sleepers in this study.

Triphasic

Study 1

Hartley, L. R. (1974). A Comparison of Continuous and Distributed Reduced Sleep Schedules.

Through the stream of time, there was very limited on Triphasic sleep. However, as usual, the researchers did not name the schedule in the study. The focus of the study was to compare performance of 12 subjects on a monophasic pattern, a shortened monophasic duration and a variant of Triphasic1. Each sleep pattern lasted for only 4 days, however. The performance test was a 70m visual vigilance task; participants were exposed to it every evening. 

0ubet.png (600√ó600)
Triphasic-modified with 80m cores

This Triphasic variant was non-equidistant and had short core durations than the standard version. The wake period in the afternoon was also very long for a total sleep of mere 4h. The primary reason for this Triphasic choice was to compare between the baseline of 8h monophasic with only 4h of sleep each day. 

Results

  • The Triphasic participants performed slightly worse than the 8h monophasic group, but better than the 4h monophasic group (1-5 AM).¬†
  • No EEGs on sleep architecture were available; it was unknown how much recuperation each core sleep provided
  • Multiple short sleep chunks could help offset performance decline if necessary; this accounts for the need to perform during sleep reduction scenarios (at least short term)

Analysis from the community standpoint

  • The time each participant spent on Triphasic was far from enough to conclude the adaptation stage. In fact, the adaptation phase had only begun.
  • Triphasic, along many other reducing polyphasic schedules, can be supportive during emergency situations.¬†
  • The longer sleep duration from each sleep potentially sustains wakefulness better than short naps. This may also make Triphasic a superior choice to schedules with a lot of short naps when adaptation first starts. With the correct timing, it is usually easier to fall asleep in a longer sleep block and get actual rest.¬†
  • With the 90m cycle design, waking up from Triphasic cores at the beginning of adaptation can be very manageable. For short-term situations that only last a couple days, Triphasic can fuel energy to complete a lot of cognitive tasks without total sacrifice of performance.¬†

Study 2

Sleep pattern, duration and quality in relation with glycemic control in people with type 2 diabetes mellitus.

There is a very interesting finding on the versatility of sleep patterns in the elderly. Certain people slept with 3 nocturnal segments. Some very few example even take a daytime nap. The study’s focus is on sleep patterns and glycemic/diabetic control. Below are the rough sketches of their Tri Core sleep habits.

hh4s6.png (600√ó600)
Triphasic without a daytime core
w3na3.png (600√ó600)
Triphasic-extended/Non-reducing

 

 

 

 

 

 

 

 

Reasons for the napchart setup

Since there is no direct specifics of the exact sleep times of the subjects, the charts are only estimates. Based on the study:

  • Participants slept for 6.6¬Ī1.5 hours at night and 1.3¬Ī0.6 hours during daytime. The shortest nap duration, thus, is around ~40 minutes. The longest daytime sleep is up to ~2 hours.¬†
  • Researchers also categorized sleep patterns into 1, 2, 3 and 4 sleep segments at night.
  • Since there was no mention of more than 1 daytime nap, all participants are assumed to only take 1 daytime nap. This includes the possibility for a “longer nap”, or a daytime core.¬†
  • It is possible to have a longer daytime sleep if there are only 2 nocturnal segments. Thus, a Triphasic-extended variant with a daytime core is possible in some elderly people.¬†
  • The Tri Core distribution of sleep at night resembles Segmented sleep, or interrupted monophasic sleep. The elderly often struggle to have a continuous chunk of sleep, so each “core sleep” may be close to each other. They are, however, distinct enough to be classified as “3¬†segments“.¬†

Conclusions

Researchers came to the following conclusions:

  • More sleep segments at night results in a better control of HbA1c (Hemoglobin A1c).
  • Those with a daytime nap fare even better than without naps.
  • The sleep quality of people with longer duration of each segment and fewer segments is better than more segments and less duration. This means that the segmentation of Tri Core at night is unnecessary, as each sleep block becomes quite short. Thus, compared with Segmented sleep, Tri Core has less beneficial effects; its polyphasic behavior is still better than those with monophasic sleep, though.¬†

It is worth noting that these Tri Core variants are only natural for the elderly in the study. There were also no records of “adaptation”; this implies that their sleep has natural fragmentation. The Triphasic-extended version with 2 night segments is, however, more optimistic.¬†

Study 3

Actual Conditions of Work, Fatigue and Sleep in Non-Employed, Home-Based Female Information Technology Workers with Preschool Children. 

This study focused on the actual work conditions of non-employed and home-based females3. Researchers examined on the cumulative fatigue throughout the day following the amount of workload and sleep patterns. The study lasted for approximately 2 months. 

m1ayc.png (600√ó600)
Non-reducing Triphasic

Results

  • The Triphasic-extended group had the lowest level of accumulated fatigue. Researchers agreed on the benefit of having extra sleep fragments as naps for more recuperation.¬†
  • Working around late night hours (1 AM) caused the most amount of tiredness.¬†
  • The nocturnal core sleep is poorer in the Triphasic-extended group. This is because of the evening “core sleep”.¬†
  • The Triphasic-extended group got the most amount of sleep out of the non-napping group and the Siesta group.¬†

Further notes

  • This is not an optimal way to schedule Triphasic-extended; this takes into account the total sleep amount and the distribution of sleep throughout the day.
  • The variant in the study is definitely suboptimal; even so, it has demonstrated enough versatility to help the female workers complete their required workload.¬†
  • It is generally difficult to schedule non-reducing Triphasic variants. The amount of sleep from either of the two cores can hinder the quality of the longest core at night.¬†
  • Non-reducing Triphasic may help determine the total amount of sleep an individual requires each day. However, a non-reducing Biphasic equivalent would be easier to schedule.¬†

TC1

Sleep pattern, duration and quality in relation with glycemic control in people with type 2 diabetes mellitus.

There is a very interesting finding on the versatility of sleep patterns in the elderly. Certain people slept with 3 nocturnal segments. Some very few example even take a daytime nap. The study’s focus is on sleep patterns and glycemic/diabetic control. Below are the rough sketches of their Tri Core sleep habits.

iowfo.png (600√ó600)
TC1-extended         

Reasons for the napchart setup

Since there is no direct specifics of the exact sleep times of the subjects, the charts are only estimates. Based on the study:

  • Participants slept for 6.6¬Ī1.5 hours at night and 1.3¬Ī0.6 hours during daytime. The shortest nap duration, thus, is around ~40 minutes.¬†
  • Researchers also categorized sleep patterns into 1, 2, 3 and 4 sleep segments at night.
  • Since there was no mention of more than 1 daytime nap, all participants are assumed to only take 1 daytime nap.¬†
  • It is possible that having 3 night sleep segments reduces the duration of the daytime nap. Therefore, the daytime nap duration should be short.¬†
  • The Tri Core distribution of sleep at night resembles Segmented sleep, or interrupted monophasic sleep. The elderly often struggle to have a continuous chunk of sleep, so each “core sleep” is close to each other. They are, however, distinct enough to be classified as “3¬†segments“.¬†

Researchers came to the following conclusions:

  • More sleep segments at night results in a better control of HbA1c (Hemoglobin A1c).
  • Those with a daytime nap fare even better than without naps.
  • The sleep quality of people with longer duration of each segment and fewer segments is better than more segments and less duration. This means that the segmentation of Tri Core is unnecessary, as each sleep block becomes quite short. Thus, compared with Segmented sleep, Tri Core has less beneficial effects; its polyphasic behavior is still better than those with monophasic sleep, though.¬†

It is worth noting that these Tri Core variants are only natural for the elderly in the study. There were also no records of “adaptation”; this implies that their sleep has natural fragmentation. Younger polyphasic sleepers or beginners should attempt other schedules.

QC0

Sleep pattern, duration and quality in relation with glycemic control in people with type 2 diabetes mellitus.

Certain elderly people slept with 4 nocturnal segments. Some very few example even take a daytime nap. Below are the rough sketches of their Quad Core sleep habits.

q9i6n.png (600√ó600)
Quad Core in a segmented style
rxxb7.png (600√ó600)
Quad Core with a nap (QC1)

 

 

 

 

 

 

 

 

Reasons for the napchart setup

Since there is no direct specifics of the exact sleep times of the subjects, the charts are only estimates. Based on the study:

  • participants slept for 6.6¬Ī1.5 hours at night and 1.3¬Ī0.6 hours during daytime. The shortest nap duration, thus, is around ~40 minutes.¬†
  • Researchers also categorized sleep patterns into 1, 2, 3 and 4 sleep segments at night.
  • Since there was no mention of more than 1 daytime nap, all participants are assumed to only take 1 daytime nap.¬†
  • It is possible that having 4 night sleep segments reduces the duration of the daytime nap. Therefore, the daytime nap duration should be short.¬†
  • The Quad Core distribution of sleep at night resembles Segmented sleep, or interrupted monophasic sleep. The elderly often struggle to have a continuous chunk of sleep, so each “core sleep” is close to each other. They are, however, distinct enough to be classified as “4 segments“.¬†

Conclusions

Researchers came to the following conclusions:

  • More sleep segments at night results in a better control of HbA1c (Hemoglobin A1c).
  • Those with a daytime nap fare even better than without naps.
  • The sleep quality of people with longer duration of each segment and fewer segments is better than more segments and less duration. This means that the segmentation of Quad Core is unnecessary, as each sleep block becomes quite short. Thus, compared with Segmented sleep, Quad Core has less beneficial effects; its polyphasic behavior is still better than those with monophasic sleep, though.¬†

It is worth noting that these Quad Core variants are only natural for the elderly in the study. There were also no records of “adaptation”; this implies that their sleep has natural fragmentation. Younger polyphasic sleepers or beginners should not attempt them.¬†

UBERMAN

Endocrine and cognitive effects of a radically polyphasic sleep schedule

Up to date, there has only been one official study on Uberman sleep, which is motivated by its existence and creation from Puredoxyk and its widespread practice over the decades. In 2013, the research focused on the endocrine and cognitive effects of Uberman sleep. This study lasted for 5 weeks. Unfortunately, after we emailed the researchers in charge, only the Abstract section remains available.

Nonetheless, the study sheds some light on the vision of a long-term Uberman lifestyle and its implications on overall well-being of polyphasic sleepers. Remarkably, the subjects quit the experiment because of social life constraints rather than the grueling adaptation by week 3; in addition, one remaining subject lasted until the end of 5 weeks without showing any cognitive impairments. Under laboratory conditions, it is guaranteed that these participants were woken up timely during this adaptation, hence possibly no oversleeping.

None of these sleep subjects were habitual nappers or sleep mutants. However, the remaining subject might have adapted to Uberman after 5 weeks. The following two assessed variables deliver surprising results:

  1. Cognitive performance
  2. Cortisol secretion pattern

Both these variables stabilized and matched his monophasic condition. However, 5 weeks may not be enough for a successful Uberman adaptation. Even if it was a success, it took laboratory-controlled environment to get this far; a regular adaptation with multiple alarms, no human assistance as mentioned before, will most definitely lead to failure.

Despite the seemingly positive news on this hostile schedule, the growth hormone was completely suppressed and now it was secreted after 6 naps. This suggests that the subjects likely woke up during SWS, interrupting it in the process. Because of GH’s suppression, it would be impossible to do a lot of physical activities or training on Uberman.

DYMAXION

Introduction

So far, there has only been one single-case study on Dymaxion sleep. The sleep researcher Claudio Stampi himself conducted the study. Francesco Jost was the volunteer for the study. He participated in another study prior to this one, which also inspired the idea of an attempt to adapt to Dymaxion-6. The scheduling variant in the study is identical to the proposed Dymaxion-6. Jost is a normal monophasic sleeper (8h baseline), in good health conditions and did not have any polyphasic sleeping experience before the series of these 2 studies. 

Since he experimented with Uberman in the first 19-day study, it was not quite relevant to this second study. It also won’t be included in the Uberman page because of some minor oversleeping during adaptation, and the adaptation duration was clearly far from enough. This time the study lasted for 48 days, however, he only spent¬†34 days (~5 weeks) adapting to the structure of Dymaxion-6. There were some transition days with gradual sleep reduction. Thus, this study duration was also similar to the one in the Uberman page. The title of the study is, The Second Study: Forty-Eight Days with 3 Hours Polyphasic Sleep per Day¬†(Chapter 12, Why We Nap).

Since the idea of the study built on the first one, no EEG recordings were available in the second study. Instead, the goal was to use multiple cognitive and performance tests before (monophasic baseline), during and after adaptation (following a day where he was allowed to sleep as much as possible). These tests are as follows:

  1. DST (Descending Subtraction Test)
  2. MAST (Memory & Search Test)

It is possible to postulate the sleep stages that went into the naps based on the first study; however, overall this is not a reliable way to make absolute deductions.

Results

  • MAST performance¬†showed a¬†slight decrement¬†relative to baseline throughout days 3-21, followed by an¬†improvement above baseline Ievels¬†thereafter.
  • DST performance¬†showed a modest but more prolonged decrement throughout days 3-33, followed by a sharp increase in performance above baseline Ievels immediately after the¬†ad lib sleep day.
  • During the ad lib sleep day, he slept for a total of¬†10 hours.
  • None of these values were significantly different from the baseline Ievels. The only significant difference was the DST toward the end of the experiment. It improved from the previous weeks, but mostly because of the 10h “recovery” duration.

Analysis based on the polyphasic community standpoint

  • An equivalent of 5 weeks sticking to the schedule may be sufficient to fully adapt to a polyphasic schedule.
  • The total sleep of Dymaxion-6 (3h) is¬†below the minimum threshold for an average sleeper. The 10h baseline after the duration on the schedule suggested that he was still possibly missing some vital sleep. Objectively speaking, one would expect the “recovery” sleep duration to be much longer.
  • While the MAST results were satisfactory, the DST performance was still decreasing by day 33. The statistically significant stat is the DST performance, which worsened and only improved after the 10h sleep duration.
  • Stampi noted that “it is difficult to interpret the improvement in MAST performance after day 21 and prior to improvements observed in DST performance; this may also further confirm that the DST is a test particularly sensitive to sleep-deprivation and sleep-inertia effects“. Adapted sleepers in the community should go through a DST test for intensive performance check.
  • For an average sleeper, Jost held out quite well. Nevertheless, he was likely in Stage 4 of the adaptation, rather than a truly successful one. It is unknown if Jost would continue to improve on DST should the study continue for a couple extra weeks. One thing for certain is that he can still be stuck in Stage 3/4 if DST resumed the downward trend.
  • A sleep mutant may be able to adapt to Dymaxion-6.
  • The results further support the notion that a nap-only schedule is not sustainable for normal sleepers long-term.¬†
  • Dymaxion, regardless of variants (4 or 6 naps) remains a remarkably hostile polyphasic schedule from the nap-based lifestyles. It is beyond the realm of adaptability for most humans. Inexperienced sleepers without laboratory-based conditions or extensive adaptation and lifestyle preparations should not attempt to adapt to the Dymaxion naps.

SPAMAYL

Polyphasic sleep strategies improve prolonged sustained performance: A field study on 99 sailors

Polyphasic sleeping can improve performance during sustained operations of 99 sailors, in a field study (Why We Nap, Claudio Stampi). The focus is on the Observer Single-handed Transatlantic Race (OSTAR) since it lasted for the longest amount of time (31 days). Of the 54 yachtsmen in the OSTAR in 1980, many demonstrated that the spontaneous napping behavior that resembles SPAMAYL.

Because of the competitiveness of the race, it is understandable many of them sought ultrashort sleep. Unfortunately, because of the hassles with EEG recordings, no sailors were willing to wear EEG headbands to track their sleep. However, it was remarkable that polyphasic sailors, including nap-only ones, outperformed monophasic sailors in the race. 

The 6th best OSTAR competitor’s SPAMAYL variant is below.¬†

SPAMAYL-modified with no longer naps than 20m

This sailor reported taking no longer than 20m naps, and the shortest nap duration was 5m. His SPAMAYL has an astoundingly high total sleep, 4.5h each day. He also dedicated one month prior to the race to this napping behavior. Most notably, during the adaptation period, he would use “an extremely loud and disturbing bell” to ring; the only way to shut it down was to perform complex tasks and skilled operations in more than 5 minutes.

Analysis from community standpoint

  • Because he was among the fastest to complete the race, it is reasonable to assume that he only stayed on SPAMAYL for less than 2 months total. This includes the adaptation period, which may have completed around the time the race began.
  • He might have adapted to SPAMAYL fully by the time the race was over, but there was no specific mention.
  • It was also unknown how long he could sustain the schedule, because the adrenaline wore off after the race.
  • Regardless of what the future may hold, the nap-only experience was definitely worth it for him.¬†

TESLA

Sleep Inertia: Best Time Not to Wake Up?

This study¬†evaluated experimenters’ cognitive performance upon waking up from the naps on the Tesla schedule. The effect of sleep inertia alongside these results were compared to sleepers who stayed awake during the entire study (64 hours). A number of naps on Tesla did contain both SWS and REM sleep; the conclusion supports the idea both vital sleep stages can cram in just 20m naps. Initially, when adaptation first began, sleep onset of the naps averaged to be ~3.8 minutes. The seemingly long sleep onset value suggested a period of adjustment from monophasic sleep to a multiple-nap regime.¬†

However, because the study did not last long enough, it is uncertain if this sleep onset values across the napping subjects would decrease drastically; even though this prediction is likely. Compared with other nap-only schedules’ experiences, an adapted sleeper would fall asleep within mere minutes or less on Tesla. If the adaptation is eventually possible, there would be an equilibrium of REM-SWS ratio in each nap; each vital sleep stage can take over any nap (e.g, REM nap in the nap around midnight) similar to Uberman.

    • The core body temperature, while at its lowest, made the morning nap nightmarish to wake from. This matches the recommendation that napping at nighttime is not as favorable as having core sleep(s) because of longer SWS durations at night.
    • The napping subjects quickly developed sleep aversion, the fear of sleeping.
    • The level of sleep inertia skyrocketed and became unbearable for them; they found waking up from the naps “objectionable” after a short time on the schedule.
    • Two of the subjects felt ill and four of them quit because of the ghastly sleep inertia. Finally, all the remaining subjects quit the study before it ended.

General peer-reviewed research about polyphasic sleep

Sleep drive and regulation

Concepts and models of sleep regulation: an overview

Homeostatic Regulation of REM Sleep in Humans During Extended Sleep
Subjects who were under an artificially shortened photoperiod of 10 hours (very long night) showed a tendency to switch to polyphasic sleep schedules.

Is sleep fundamentally different between mammalian species?
Proposes that humans might be naturally polyphasic sleepers, but that either societal pressure or issues with sustaining wakefulness for long periods of time caused humans to acquire a monophasic sleep pattern.

Mammalian Sleep Dynamics: How Diverse Features Arise from a Common Physiological Framework

By varying the homeostatic time constant which determines the rate of somnogen accumulation and clearance, or by varying the mean drive to the sleep-active ventrolateral preoptic area of the hypothalamus, provided by for example the SCN, human sleep became polyphasic.

Sleep and Circadian Rhythms in Space

Timing of human sleep: recovery process gated by a circadian pacemaker.
In the two‚Äźprocess model of sleep regulation (which puts forwards that a homeostatic process interacts with a process controlled by the circadian pacemaker) the frequency of sleep‚Äďwake changes are dependent upon the distance between the circadian thresholds which define sleep and wake. In simulations, reducing this interval induced polyphasic sleep.

Napping behavior 

An ultra short episode of sleep is sufficient to promote declarative memory performance 
This paper shows that even short naps consisting only of light sleep are able to improve the declarative memory of people.

Napping behavior during “spontaneous internal desynchronization^: sleep remains in synchrony with body temperature
This paper shows evidence for human sleep being polyphasic, or especially biphasic, under enforced bedrest.

When the Human Circadian System is Caught Napping: Evidence for Endogenous Rhythms Close to 24 Hours

SLEEP AND PERFORMANCE – RECENT TRENDS
This article makes the claim that short naps result in feelings of lethargy and lassitude, which leads to worse mental performance. However, motivation is enough to counter these negative effects.

Tendency for polyphasic sleep

Circasemidian sleep propensity and the phase‚Äźamplitude maintenance model of human sleep/wake regulation
Human sleep in nature is biphasic and polyphasic.

In short photoperiods, human sleep is biphasic
 Segmented sleep is popular with short photoperiods.

Natural sleep and its seasonal variations in three pre-industrial societies
This paper discusses how napping patterns change throughout the world depending on the season.

Segmented sleep in a nonelectric, small‚Äźscale agricultural society in Madagascar
This article talks about an agricultural society in Madagascar, where they wake in the middle of the night for long enough to consider it a segmented pattern about 50% of the days with noticeable variation from gender. They also have a nap ~90% of the days about an hour in length.

Sleep disorders and depression: brief review of the literature, case report, and nonpharmacologic interventions for depression
Elderly people usually have polyphasic sleep patterns.

SLEEP PATTERNS OF MEDICAL STUDENTS; THEIR RELATIONSHIP WITH ACADEMIC PERFORMANCE: A CROSS SECTIONAL SURVEY
Biphasic sleepers had the best academic performance, while monophasic and polyphasic sleepers had around the same success rate for passing their midterm exams.

Truck Drivers Sleep-Wake Time Arrangements
The article concludes that a strong social pressure from work schedule, can force a polyphasic sleep pattern. 

Sleep in Healthy Elderly Subjects: A 24-Hour Ambulatory Polysomnographic Study
Elderly people often become polyphasic sleepers with fragmented sleep, and that undesired daytime naps were correlated with being unhealthy.

Sleep we have lost: pre-industrial slumber in the British Isles.
This article talks about the natural polyphasic sleep pattern in pre-industrial societies.

The nature of spontaneous sleep across adulthood
This study showed that when people do not have to overcome the physiological sleep tendency (by doing only mundane tasks), they sleep polyphasically.

The evolution of the sleep-wake cycle through the history of humanity. Influence of artificial light

Short-term polyphasic sleep strategies

Field study of sleep and functional impairments in solo sailing races
During sailor races the participants slept polyphasically, but experienced functional impairments due to sleep loss. These people slept a much shorter total duration each day on their polyphasic schedules than they did when monophasic.

Polyphasic sleep strategies improve prolonged sustained performance: A field study on 99 sailors

POLYPHASIC SLEEP / WAKE PATTERNS AND THEIR SIGNIFICANCE TO VIGILANCE

Segmented Sleep in Preindustrial Societies
The author of this letter criticizes the conclusions made in the article ‚ÄúNatural sleep and its seasonal variations in three pre-industrial societies‚ÄĚ. He is arguing against the idea of latitudinal variation in sleep patterns, and provides evidence to support his position.

Sleep and Alertness During Alternating Monophasic and Polyphasic Rest-Activity Cycles
Forced splitting of sleep allowed people to sleep for shorter durations than when monophasic. This article provides information that it is possible to adapt to non-monophasic sleep patterns, but did not make claims regarding the cognitive performance or alertness of adapted polyphasic sleepers compared to monophasic ones.

Temporal sleep patterns in adults using actigraphy
90% of the sampled adult subjects from S√£o Paulo city slept monophasically, 7% biphasically, and 1% polyphasically. The study claims that polyphasic and biphasic patterns may be associated with the ability for humans to fall asleep several times a day, etc. with a lack of social pressure.

Master’s theses

OPTIMIZING DAYTIME SHORT SLEEP EPISODES TO MAXIMIZE PERFORMANCE IN A STRESSFUL ENVIRONMENT

Segmented Sleep in First-Century Roman Society

Bachelor’s theses

Losing Sleep: A Preliminary Investigation of the Cognitive Effects that Arise from Polyphasic Sleep Cycles

Sleep in the 21st Century: Impacts of Sleep Dysregulation on Health and Well-Being

SLEEPING, NAPPING AND STAYING UP: THE MEANINGS OF SLEEP AMONG COLLEGE STUDENTS

Main author: Crimson & GeneralNguyen

Page last updated: 8 April 2021