From Polyphasic Sleep Wiki
Tri Core 1
chart link

Total sleep4 hours 50 minutes
Proposed byPolyphasic Sleep Discord Community
Specification3 single-cycle core sleeps, plus one nap.

Tri Core 1, or TC1, is a schedule with 3 single cycle cores and 1 nap, as a part of the Tri core schedule family.[1]


TC1 was created in 2017 by Discord user LichTerLoh with the goal to avoid the inconvenient daytime core on Triphasic.


All of the three cores on this schedule are placed during the night and morning hours, with a nap inserted in the day to maintain alertness. The first core and the last core are likely to primarily contain SWS and REM sleep, whereas the middle core is likely to contain mixed stages. The wake gap between the cores should be at least 2h to facilitate falling asleep in each core and avoid interrupted sleep.


Initially, it will be difficult to fall asleep in the core sleeps because they are placed close to each other. However, because there are 3 core sleeps around night hours, staying awake at night should be easier compared to Triphasic when adapting. However, compared to the daytime core in Triphasic, the night core in TC1 is likely to be more difficult to wake up from.

After adapting to TC1, one may slowly transition to DC3 by turning the third core into a nap and adding a third nap in the afternoon.


Little is known about the difficulty of this schedule, as there has been few attempts and only a few successes. It is likely to be more difficult than schedules with similar totals such as E2 and DC1, as the lack of a long core sleep necessitates the splitting of SWS, which can cause extremely difficult wakes.

Lifestyle considerations

Compared to Triphasic, it is much easier to schedule TC1, as it does not have the daytime core. However, the shorter gaps may be more limitng in terms of activities. For example, more mentally stimulating activities may not be advisable to avoid difficulties with falling asleep.

TC1 is likely to be slightly flexible after adaptation. Slightly flexing any one of the cores and/or the nap may be plausible, but so far no one has demonstrated this. TC1 provides a relatively large sleep reduction, and can be chosen by those who like the idea of having many short cores. However, DC1 and DC2 are more commonly attempted, and are likely easier to adapt to.


It is also possible to extend one TC1's core by an extra 90 m cycle, but so far few have attempted and no one has adapted to it. Either Triphasic-ext or one of the extended Dual core schedules would be preferable, as they avoid the short gaps that may make it difficult to fall asleep.


  1. "Tri Core Sleep Schedule". Retrieved 2020-11-20.