From Polyphasic Sleep Wiki

Naps are short blocks of sleep, typically under 45 minutes. They are used to gain REM and alertness during the day, often to compensate for the lost REM time from having shorter cores.

30m naps vs 20m naps

Although 30m naps can be placed in any polyphasic schedules, scheduling them outside of non-reduced Biphasic patterns is often heavily discouraged. As such, only the "-maxion" family of schedules capitalizes on 30m naps right from the beginning of the adaptation. Over the years, there have been more discoveries on the pros and cons of a 30m nap compared to the ubiquitous 20m nap.

  • The most noticeable difference is that these naps are longer than 20m naps by 10 minutes. It has been concluded that naps beyond 25m (up to any duration below ~70-90m) will most likely lead sleepers to an SWS wake, following the regular/standard/non-repartitioned progression of vital sleep stages in a certain sleep duration. When adaptation first begins, sleep cycles remain as they are, and in the naps, light sleep (NREM1 and NREM2) will initiate the transition from wake to sleep in the process. After roughly ~25m asleep, SWS, the deepest stage of sleep, will start to enter the nap. Thus, the odds of waking in SWS increase when a 30m nap is scheduled. This is the primary reason that makes 30m naps unpopular because of the requirement of extra willpower to wake from it.
  • The longer duration of these naps also potentiate more recuperative effects than a 20m nap would. When sleep is fully repartitioned, a 30m nap may contain a higher percentage of REM sleep, or give some amount of SWS if homeostatic pressure is high enough.
  • Together with 20m naps, 30m naps are considered short naps, and their duration makes it easy for them to fit into a normal daily lifestyle. However, a 20m nap may be preferred in the event that the noon breaks do not allow for a 30m nap; all in all, the slightly longer duration is only considered a slight loss of a 30m nap to a 20m nap, but this largely depends on personal lifestyles.
  • On a non-reduced Biphasic pattern, 30m naps actually have a lot of viability. The main idea is that most, if not all of SWS has been provided in the main nocturnal core sleep, the nap duration often contains a trace amount of SWS, and there have been a few reports of natural wakes around the 30m mark. It is believed that SWS pressure is very low when sleep is not reduced, and the nocturnal sleep setup is the same as the monophasic core, so for the most part, SWS exerts little effects on wake, making it easier to handle 30m naps (especially if they are a result of a natural awakening). It is also very possible that since sleep pressure is low on non-reduced Biphasic conditions, it may take some more minutes to actually fall asleep in the nap - this immediately reduces the chance for an SWS wake because of the longer sleep onset (and partially turns the nap into a ~20-25m nap instead).
  • A 30m nap may be at a disadvantage with the dream recall opportunities, because of the SWS wakes. This suggests that lucid dreaming may not be as strong on a 30m nap than on a regular 20m nap. However, adaptation to Bimaxion or any reduced polyphasic schedule can turn a 30m nap into a huge reservoir for dreaming if the nap is scheduled to be in early daytime hours (dawn to early afternoon). Excluding pronaps that last for 30m long, the first nap on Bimaxion, for example, can proliferate a lot of REM sleep once SWS repartitioning has been stabilized in the core(s) and/or the second nap.
  • On an "-AMAYL" polyphasic schedule (e.g, Sevamayl, Ducamayl), a 30m nap can be occasionally added to the schedule, replacing the usual 20m naps occasionally, if it is still early in the day. The whole purpose is to simply avoid SWS wakes through this nap extension, without worrying about a great chance to oversleep the nap and turn it into a core. Because of the nap flexibility of these polyphasic schedules, it is expected that sleep onset for nap(s) is longer than on fixed, scheduled nap time on a schedule with the same sleep times everyday. As a result, in conditions that sleepers do not have adequate time to cool down and get ready for a certain nap, they can utilize a 30m nap to buffer the time it takes to fall asleep, while still granting them recovery from the nap. As an "-AMAYL" polyphasic sleeper takes a 30m nap, they can then effectively skip their next nap for the rest of the day, or schedule fewer naps later on to accommodate their commitments, strategically abusing the longer nap duration that a 30m nap offers. For this reason, a 30m nap can be considered a "compound 20m nap".
  • In rare cases, some polyphasic sleepers may be more prone to 30m naps as they feel more "natural" than 20m naps. It is unknown as to why and probably comes down to preference and exposure to both nap durations.

With all things considered, on Bimaxion, a very reduced sleep total that causes very intense repartitioning of sleep stages, the Dymaxion naps' behavior do not follow the logic of the regular 30m nap on biphasic sleep or any casual 30m naps taken when needed.