Choosing a correct and maintainable schedule is important but very specific to the life circumstances of the individual. There are several factors to consider, such as exams coming up, work schedules, one’s age or the ability to sleep during the day. It is highly recommended for you to carefully read through this whole article and consider every aspect of your lifestyle to determine which schedules are sustainable and whether you have the time and the flexibility to be able to adapt and maintain a given schedule. This article covers many common lifestyle considerations, but not every possible situation. If you have questions or special circumstances not covered in this article, consider joining the Discord chat server or Reddit where you are likely to come across someone with more experience or circumstances similar to yours.
People who are younger generally require a greater amount of sleep. This particularly affects those who are underage (under 18 years old) and have not fully matured yet, because they are still growing both mentally and physically1. Extra SWS time is necessary to support bodily growth, learning, and memory retention. For people who are underage, the total amount of light sleep is much lower and there is a higher percentage of REM and SWS in daily sleep totals2. Because light sleep could play a part in development3,4 getting as much sleep as possible is also likely to be beneficial. Consequently the total amount of daily sleep reduction that is possible for an underaged is very small. Polyphasic sleep schedules which aim to significantly cut sleep totals should probably be avoided.
As general guidelines, the polyphasic sleep community uses the following values as a baseline:
- <16 years – Sleeping the recommended amounts is highly encouraged. Both the brain and body are in full development and highly sensitive. The possible side effects of Polyphasic sleep are by large unknown, therefore there is a good reason to take precautions similar to nicotine or alcohol which are equally discouraged during development. With the advancement of circadian rhythm caused by artificial lighting and an early start of the school day, some may find using a polyphasic schedule to segment their sleep helpful in achieving refreshing sleep duration which would otherwise not be possible.
- 16 to 18 years – At least 6h of sleep, with more recommended when possible. The body and brain are both still developing, but at a lesser extent than previously. However, this period is one of the most important ones during life, as, in modern society, high school performance has great impact on future outlooks. It may be worth taking this into account as improper experimentation with your sleep can affect the day-to-day performance.
- 18 to 21 years – At least 5h of sleep. The body has developed to some extent, however the brain is still developing and development of some may conclude later than of others.
- 21 to 25 years – over 4h; the brain can still be in the final stages of development. Dropping below 4h is generally advised against, even after 25. Furthermore, younger adults have generally less structured lifestyles which should be taken into consideration if this applies to You (discussed in greater detail later)
In addition to the general guidelines above, it is important to consider that some people, especially males, can have growth spurts as late as at 19 years5, during which the SWS need is increased. It is debated whether people who are 17 can actually drop down to 5h of sleep, but it’s probably best to stay above it when assessing the risks. The rational part of the brain develops until the age of about 25 years old6 (possibly longer7,8). This means the safest course of action is to avoid reducing the total amount of sleep at least until that age. This also means that experimenting with extreme schedules like Uberman and Dymaxion is best avoided until later.
These recommendations are supported by growing body of scientific research suggesting that adolescents require >9 h of sleep at night, with some adolescents also requiring additional sleep during the day. In controlled conditions with 10 hours allocated for sleep, adolescents of ages 10 to 17 needed 9.25 h of sleep per night regardless of age; and that at mid-puberty there was an increased tendency to sleep during the day even in the presence of sufficient night-time sleep9. It has been shown that delayed sleep-wake behaviour present in greatest extent in Asian cultures, causes decrease in total sleep during adolescence (for review, see10), despite the amount of sleep needed to achieve optimal day-to-day performance. Many studies have demonstrated that on average they obtain between 7.5 and 8.5 h/night, with about a quarter of of adolescents obtaining <6.5 h/night and only 15% obtaining 8.5 h or more9,11.
In general, activities which involve only light-to-moderate exercise (e.g. light cardio or light sports) should not have any significant impact on sleep architecture except when attempting extreme polyphasic schedules. However, activities that are very physically strenuous or involve high-intensity exercise (e.g. heavy sports, weight lifting, HIIT, etc.) should be taken with more consideration. When engaging with these activities, additional sleep time is required due to muscle and tissue repair needing to take place which reflects an increased daily SWS requirement12. The increase in SWS usually causes a reduction in the total time spent in the NREM2 sleep stage12. Consequently, the total amount of daily sleep reduction that is possible for people who are engaging in these sorts of activities is reduced, because they require more sleep overall.
It has been reported that people engaging in high levels of exercising are able to do a polyphasic sleeping schedule with 3 cycles in the SWS core without any problems, but additional naps compared to the standard schedules may be needed to allow for more SWS to be present over REM in the core. During adaptation it is best to not raise the SWS need unnecessarily, as this could lead to an elevated risk of entering an SWS rebound. Typically, you can continue the level of physical exertion that you were used to after you have fully adapted to your new sleep schedule. While significant muscle and tissue repair generally increases sleep duration13, exercise and an active lifestyle can reduce feeling of constant tiredness which some inactive people experience even on regular sleep schedules longer than general recommendation. Many people also find physical activity helpful during adaptation when it can be used to combat the urge to sleep, especially during the second and third stage, where oversleeps are mostly present.
After adaptation, sporadically increasing the length of the core by one cycle in order to support more exercise is possible, but should not be done too often. Some decompression or adaptation setback is to be expected as a result that can take a few days to heal. Doing this once a week at most will greatly help with stability of your sleep schedule and avoid significant fluctuations in energy or chance of oversleeping.
Many people’s sleep quality is also impacted by exercising too close to a sleep, thus it is best to leave a gap of at least 2h between exercise and before sleep14, unless you know a shorter gap doesn’t hinder your sleep. If you are still able to fall asleep fast and dream in the naps close to exercising, at least during the later part of adaptation, then this may not apply to you or potentially not to the full extent..
Due to a significant SWS deprivation during adaptation on schedules with extreme levels of sleep reduction, especially nap-only schedules with severe SWS rebounds during adaptation, care should be taken not to engage in overexertion. It may take extra time to recover even after light or moderate levels of exercise, especially with a physically active job. After the adaptation period, this effect should be less noticeable but will likely persevere especially on extreme schedules.
Exercising can contribute mildly to establishing the circadian rhythm, by setting the new circadian morning15. This means that exercising should be avoided during the dark period, although the circadian effect is minor compared to light exposure. Night shift workers may opt to use exercise as a way to favorably shift their circadian rhythm to better accommodate for their sleep and work schedule.
Melatonin is important for correct SWS initiation and healthy sleep architecture16. An inherent feature of circadian rhythm and melatonin secretion is the suppression and delay of onset following exposure to blue and green light (wavelengths 400-530 nm), by 65-81%17, or roughly 2h18. While this feature of the rhythmic processes has been very effective in aiding the entrainment of circadian rhythms with the day-night cycle as blue light was only available during day, in recent years it became increasingly apparent that this can have adverse side effects of circadian misalignment when combined with exposure to artificial lighting during night time. Some studies suggest that as little as 100 lux of room lights for 6.5 hours19, or 250 lux (office lighting) is enough to completely disrupt the melatonin levels20. These findings warrant reduction of all non-red light types to absolute minimum during the dark period. This should not, however, be done at the expense of increase in brightness of red light sources, as red light may have the same effect as light in the blue/green frequencies, but to a lesser extent. Some studies have linked the misalignement of circadian processes with elevated risks of developing cardiovascular diseases21, diabetes22 and cancer23, hence, it is unlikely the impact on sleep is the only possible negative outcome.
The dark period should start 2-3h prior to the core (first core on DC schedules, night core on TC schedules) and continue for 6-12h (preferably 8-10h) after its start. Sleep times are included in the dark period. The reason it should continue even after your wake time, if you have a short core, is to ensure the stability of the circadian rhythm. Light24 and food25 can be used to alter the start of the circadian day, which results in a shift of the SWS and REM peaks accordingly. Darkness is still preferred over red light. The light blocking can be done by wearing blue-green light blocking glasses like red colored laser safety goggles. Make sure the glasses block the right wavelengths, as many glasses (like yellow-tinted ones) actually allow green light to leak through. Having side protection is also preferred. Using programs such as F.lux and sunsetscreen on a low kelvin setting (around 1000K) is also possible if you’re only exposing yourself to light from screens. Using red light bulbs is also an option.
Schedule line specifics
Dual core: if your cores are within 5h from each other, then the dark period should cover the whole core gap.
Everyman: if the first nap is relatively close to the core you should have the dark period extended until the end of it. As a rule try to have the dark period be between 8 and 12 hours long.
Tri core: with triphasic the gap between the night and dawn cores should be covered in the dark period, and with TC1 and TC2 at least two of the cores should be covered in the dark period, according to how they are placed relative to the local time.
For other schedules, a good rule is to follow the day-night cycle of your country, unless you live in location near the poles in which case you may want to create an artificial light and dark period to establish a stable cycle over the course of the year and to avoid any seasonal affective disorders related to the greatly fluctuating light levels.
Fasting (consuming only water) should coincide with the dark period, as nighttime eating has also been correlated with an increased risk of some diseases, like night eating syndrome and sleep-related eating disorder, and both of those diseases are often connected with an increase of the body mass, obesity, psychiatric disturbances26 and diabetes27, a delayed sleep onset, a worse quality sleep28 and the setting of the circadian morning. Aim to have the fast last for at least 8-12 hours29. If handling the hunger is too hard, try to minimize the consumption of carbohydrates in the evening and only consume low caloric foods with low glycemic index (GI), as this has anecdotally helped people, likely due to the slow blood sugar and energy release.
A shift in Circadian Rhythm
A circadian rhythm shifted in relation to the natural day-night cycle may be desirable to better accommodate for a particular sleep schedule in terms of alignment of sleep blocks with the sleep stage peaks. While this is generally not advisable when working a day job or participating in daytime activities as it requires extra care and planning, many people are forced to do this in order to be able to handle a 3rd shift job or voluntarily to be able to participate in social events happening on late evenings etc. There is only one main way to shifting the circadian rhythm and it is going to take some time. Detailed below is how to pull it off.
Have the dark period stop at the desired new circadian morning, and use light and food to start it. This method is also useful for people who are adapted to a polyphasic sleeping schedule and want to rotate their schedule, as confusing the circadian rhythm is not something you want to do while on a schedule that heavily relies on a fixed circadian rhythm.This is the best and prefered way to adapt to a new circadian time. There is an app created by academic researchers called Entrain30 which is meant to reduce jet lag by designing optimal schedules for shifting the circadian rhythm. It is suggested to be used for the slow circadian shift, as it is designed to adjust the circadian rhythm optimally. It is however advised that polyphasic sleepers do not submit any of their results through the app as the researchers are interested in results related to jet lag and using it for different purposes could skew the results.
As for maintaining this rhythm, using light and food to wake up and having a set dark period should be satisfactory, however if the circadian rhythm is shifted a lot compared to the local day/night cycle, temperature cycle is going to be useful. Exercising during the circadian morning could also be beneficial.
If the circadian is unintentionally shifted, by for example a dark period that is too short, it can lead to a reduced amount of SWS or REM in the core since the peaks have moved. This can lead to people having issues adapting, feelings of tiredness and sleep deprivation or getting SWS rebounds, which increase the chance of oversleeping drastically.
While adapting to a polyphasic schedule one’s period might be affected because of the hormonal imbalance. It might happen earlier, later or be skipped completely. The SWS need is raised to some extent by periods, which means it is best to try to aim to start adaptation right after one’s period, or alternatively have the period occur during stage 1. Extending one’s core by a cycle during this time might be necessary after adaptation (at least some days of the menstruation cycle), however it is unclear and probably highly individual if this is needed with schedules that have over 2 cycles in the SWS core.
When designing a polyphasic sleeping schedule it is important to take possible prayer times and fasts into consideration. Since the prayer times could move on a daily basis, you should aim to have a one or preferably two month timespan during which no prayer times will interfere with sleep times during adaptation. When the time comes that some interference does happen it is recommended to reschedule around these times, possibly with a DST shift or with flexing or simply shifting nap times if you’ve been adapted for a while. Switching over to a less extreme schedule could be wise during fasts like ramadan, depending on what country you live in and when it occurs. Note that eating will likely set a new circadian morning if done during the night, which leads to the SWS and REM peaks moving. Adapting during ramadan could pose problems, as eating is one way to combat sleep deprivation and food requirements are increased by the energy expenditure during the prolonged wake time. Lowered amounts of energy will also likely increase the risk of oversleeping or giving up.
Room temperature when sleeping
It has been suggested that room temperature has a notable impact on sleep quality. Some people have reported having difficulty sleeping in a room that is too cold or too hot.
Further research is required in this area to determine how much impact there is and the most optimal temperature range to sleep in while sleeping polyphasically. Monophasic sleepers seem to thrive in temperatures between 15 and 20 degrees celsius31.
At least one study demonstrates improved sleep quality in a slightly cool environment32, and another suggests improved sleep quality from keeping hands and feet slightly warmer33 (as with gloves and socks).
Meditation versus sleep
Some people have claimed that meditation can be used instead of sleep to serve the same purpose. Meditation can aid with restfulness, but can in no way replace sleep. There is also a risk of falling asleep during meditation. Further research will be valuable in this area to determine the effect of meditation restfulness.
Masturbation, porn and sex
Masturbation, porn and sex are likely to make you subsequently feel tired and want to sleep, so if you want to engage in these activities, it may be better to do them shortly before sleeping. Some people in the polyphasic sleeping community do not masturbate at all; whether this is helpful or not is debatable and with current evidence, it is purely matter of preference.
Long-term metabolic effects
It appears that even after successful adaptation there are likely to be long-term metabolic effects of polyphasic sleeping, especially on extreme schedules. There is plenty of evidence to support this and the consensus from veterans on extreme schedules seems to be that you get more hungry. A case of this is Aeia, who lived on Uberman between June 2009 and March 2010 and her experience is logged on her YouTube channel. She eventually quit because she was gaining weight despite attempting different diets. This coincides with research linking increased risk of obesity to night-time eating on regular sleep schedules, suggesting polyphasic sleep is no different in this aspect34. Whether keeping an intermittent fast during the night period would completely mitigate this issue is unclear, but the direct link of obesity to night time eating suggests that reduction in night time eating could significantly help people affected by this issue. Energy from food intake is known to counter sleepiness that might otherwise occur from having low volumes of sleep, which may require a diet based on energy sources with slower release (namely protein and low GI food) and possibly increased food intake during the adaptation period as that generally more demanding than maintaining the schedule afterwards.
Daylight saving time
In most parts of the world the clocks move forward in the spring and then backwards again in the autumn. This can interfere slightly with polyphasic scheduling. In general you should try to stick to all of your sleep times during the DST changeover. Sleep blocks should be kept to the same length, and sleep blocks which are near to or overlap the border might need to have their timings tweaked to alleviate excess sleep deprivation. Most polyphasers do not find this to be a considerable issue.
If the DST changeover is just after you start your schedule, you might want to start sleeping on the new timezone early in order to make sure the adaptation period keeps consistent scheduling, or to stay on the old scheduled time until adaptation. If you plan on doing the DST change it is recommended to switch cold turkey, as some people have reported grogginess and malaise from doing a slow transition of only a few minutes a day.
Being on a polyphasic schedule while also travelling is possible but hard to pull off. If time zones are switched while the travelling happens during adaptation there are three recommend options;
- Sticking with the original schedule
- Rotating the schedule to fit the new timezone
- Returning to monophasic sleep
The optimal route is to stick with the original schedule during the travel (the dark period and a daylight lamp should make this manageable), but depending on the duration and nature of the stay, rotating the schedule should also be possible. Note that rotating the schedule will cause adaptation to be set back (around a week for each rotation is a good estimate, but it is dependent on several factors). During adaptation it is important to stick to all sleeping times, which is why many delay starting their adaptation until after they’ve traveled. After being adapted for at least a month flexing is likely the best logical choice if nap times are missed (see flexing). Starting a gradual adaptation could also be an option if it is possible, or temporarily switching over to a harder schedule.
Jet lag happens when you travel through different time zones. If you change your schedule during the stay, you will initially struggle to fall asleep fast in the new time zone, and your schedule will suffer. Depending on how long your trip is, how long you stay in the new region, and how long you have been polyphasic, the travel can be hard or relatively easy to handle. This will reflect on the need to re-adapt to the schedule during and after the trip. Another factor to consider is the possibility to be able to maintain the schedule when on the plane and in the airport.
If you have decided to return to monophasic sleep, just rest when you feel sleepy enough. If you’re on a plane, try to get a core sleep, or a nap, and time it so that when the plane lands, you wake up.
If sticking to the schedule with minor setbacks is your choice of action, try minimizing the over- and undersleeps. Make smart use of alarms in the plane. Mechanical alarm clocks as backups are smart, as there could be problems with phones. Nap in the airport if necessary. Try not to core in the airports, as you will be vulnerable to thefts and such. Optimally your flight aligns with your core so you manage to sleep most of it during the flight. Preparing a “do not disturb” sign, with a sleeping mask and airplane pillow is wise.
Tactical oversleeps could possibly be an idea during this critical time. Your safety and well being should be a higher priority than adapting quickly, so if you have to skip several naps or parts of the core sleeping one or a few extra naps could benefit you despite prolonging adaptation.