After starting a new sleep schedule, some time is necessary for the body to adapt. In general, the complete adaptation usually takes over four weeks, greatly depending on schedule, adherence and will vary from person to person. The whole adaptation process comprises roughly of four main stages with 6-10 days for each. Adaptation is a gradual process, and improvements in sleep deprivation symptoms can be seen as one adheres to their schedule. This will be especially noticeable in individuals new to polyphasic sleep.

Stages of Adaptation

First stage:

Assuming one hasn’t changed the start of the SWS core, falling asleep for the core should be easy during this stage. Falling asleep during naps can however prove to be tricky if one does not have prior napping experience.

Sleep quality is the same as in monophasic sleep as the sleep stages have not repartitioned. Cycle compression has not begun, so the sleep cycle lengths are still the same (90m per cycle, presumably). During this time, you might get a glimpse of what it will feel like post-adaptation, as long as you’ve gone into the adaptation process without prior sleep debt. This stage gets shorter on extreme schedules with a low total amount of sleep.

Second stage:

In this stage it is common to start feeling tired during the day, for some periods of time. Waking up becomes harder, as total sleep is reduced. The feeling of sleepiness becomes more apparent as sleep debt is accumulated. During this stage, falling asleep generally becomes much easier in many of the nap(s) and core(s). Random waves of sudden tiredness happen during the day, until they eventually align with the designated sleep times. This stage is shortened in more difficult schedules.

Third stage:

The third stage is the most problematic stage where a substantial amount of people fail. Sleep debt has accumulated enough to cause oversleeps. It is extremely important to set appropriate alarms ahead of time in order to minimize the chance of oversleeping. The difficulty of this adaptation stage greatly depends on the total sleep reduction where more extreme schedules are going to be significantly harder. This stage gets longer with respect to the previous two on more extreme schedules.

Important:  Read more about handling sleep deprivation, oversleeps, and microsleeps here.

Many people experience an improved ability to remember dreams in the naps or cores, but falling asleep becomes very hard for some sleeps (due to the body realigning the BRACs, energy dips etc.) and easy for others (but it becomes so much harder to wake up from those successful sleeps). Gradual improvements are expected during this stage as the body gets used to the new sleeping schedule and as sleep efficiency improves, but the tiredness only increases to finally peak at the end of this stage. Random premature wakes are common in this stage, but they should subside eventually. Sleep debt is starting to get repaid during this stage. Undersleeping (skipping naps and cores) will drag this stage out!

Some observations suggest that the sleep stages become more stable during naps and cores and that the sleep cycle length can shorten. These are the key improvements in sleep efficiency that make reduced sleep possible on a polyphasic schedule. If waking up before the alarm becomes consistent altering the alarms to accommodate this is wise.

Fourth stage:

Provided you get this far without significant oversleeping, you should reach stage four. Gradual improvements can be seen during the course of this stage, as time progresses, where people often start to experience natural awakening before the alarm rings, have more vivid dreams, and fall asleep easily and consistently. Waking up becomes easier, and alertness is improved during the day. Feelings of tiredness will rise sharply before nap times, but you will feel fresh again upon waking. This stage can take a very long time to complete. Compared to stage three there is a clear drop in tiredness, almost like returning to stage 2, which should decrease as time passes. Undersleeping during this stage might kick one back to stage 3 for a while, as this is also a stage where sleep debt is being repaid. Some people occasionally experience stage four symptoms during previous stages. It is important to not mistake them as signs of completed adaptation as that can lead to oversleeping if the present level of sleep deprivation is underestimated.

Fast adaptations

In the past, some people have suggested that it might be possible to adapt to extreme schedules such as Uberman in a short time span of only two weeks weeks with most sleep deprivation symptoms disappearing after only a week of adaptation. In reality, this seems like a very atypical experience as a significant portion of people oversleep during the first week of adaptation. Those who last do not experience signs of improvements after the 7 days. On more extreme schedules, it is common to experience extreme ups and downs in alertness and sleepiness that can give a false temporary sense of adaptation, which commonly ends with a sleep crash after a swing from extreme alertness to extreme sleepiness. This is common on day 5-10 on these schedules, and this is where the actual hard part starts, so the idea of being adapted in one week is fanciful. In reality, extreme schedules like Uberman and Dymaxion are more likely to require at least 3 weeks of persistence before sleep deprivation symptoms start to dissipate.

It is debatable whether adaptation to these extreme schedules is even possible for the vast majority of people, since it would require 120 minutes of total sleep to account for 90m of both REM and SWS, not even considering the necessary light sleep. Whether the body switches over to a ‘deeper’ form of SWS and REM sleep (indicated by increase in REM density in REM sleep or delta waves power in SWS, or similar) to account for this is yet to be shown.

There have been instances of people being able to stick to these schedules for a long time, but it has eventually led to them having a crash, a massive oversleep of several hours, which is detrimental to the adaptation progress. It is unclear if extreme schedules leave long-lasting damage.

Adaptation success

Signs to recognize when you have adapted to a schedule, in order of importance:

  1. Feel energized and productive when awake, no memory loss, elevation in mood and good appetite.
  2. Wake up feeling refreshed, whether from the nap or the core. No sleep inertia.
  3. Fall asleep quickly in all sleeps, even if you don’t prepare some time beforehand to sleep.
  4. Wake naturally without the need for alarms. This requires long entrainment with a sleep cycle; often months for it to be consistent.
  5. The naps feel long and drawn out. Each nap can feel like up to 2 hours have passed in just a single 20 minute nap.
    You might also remember more dreams from your sleeps, and more vivid dreams (the dreams can come from the end of your core sleep, or you can even dream right when you fall asleep shortly). Some people remember fewer dreams, due to consistently waking from light sleep as an adaptation to rigid sleep times.

It has previously been thought to be possible to adapt within a very short amount of time. This is because people had only counted remembering dreams in the naps as the necessary requirement for adapting. Via gradual adaptation remembering dreams in the naps takes a very short amount of time to do, however the core will still have to be repartitioned, so it is invalid to claim to be adapted just by remembering dreams alone.

On more extreme schedules (such as Uberman) it is also common to experience all of these signs prior to a successful adaptation. The difference is that they often do not last. These schedules are notorious for rapid swings in tiredness which cause uncautious individuals, who misidentify the temporary signs as adaptation, to fail when they get caught off guard by sudden feeling of extreme tiredness.


While forcing your body to go through the long process of adaptation you have to take time to understand your body better. Everyone has their own challenges that they must learn to overcome, and while many first-time adapters fail, it is important to learn from that experience and try again. This article can not prepare you for what your individual adaptation will feel like, but with a general understanding of the ins and outs of adaptation and the support of the polyphasic community, you’re bound to go far. Log your experience, compare with others logs and develop your sleep deprivation coping skills. There are people who have gone through the same process as you are and are willing to help and support you on your road to adaptation. Their experience is the basis for the Adaptation Methods and you can always reach them on our social media. Good luck!

Main author: Crimson

Page last updated: 8 October 2019