However, as NREM 2 gets reduced, the ability to stay awake for long periods diminishes. This is why schedules with less total sleep time (TST) need more sleeps spread throughout the day to be sustainable. Taking a ~20-minute nap or a ~90-minute single-cycle core helps a polyphasic sleeper sustain wakefulness. Maximum wake gaps are dependent on the schedule, time of day, as well as the sleeper's individual needs. With gaps too large, one will always experiences bouts of tiredness during it and be unable to fully adapt to the schedule.
然而，随着NREM2的减少，长时间保持清醒的能力也会减弱。因此，总睡眠时间（TST）较短的时程需要有更多睡眠段落分布在一天中。约20分钟的小睡或约90分钟的单周期主段有助于多相睡眠者维持清醒状态。最大的觉醒间隔取决于你所选的时程、日程安排以及睡眠者的个人需求。如果间隔太大，你在这期间将会总是感到阵阵疲惫，进而无法完全适应时程。
