Since E1 provides a relatively high amount of sleep, transition to this schedule from monophasic sleep is recommended to be done straight from monophasic (i.e., cold turkey). However, unlike other polyphasic schedules with less total sleep, learning to nap on E1 may take up to several weeks because humans have been observed to get used to sleeping monophasically for only 6 hours per night, sometimes for extended periods. Thus, it may take time for sleep pressure to build enough to induce sleep in naps. However, experienced nappers or those with high natural ability to fall asleep may still be able to fall asleep for the nap within a few days, or even right away in a few cases, albeit likely with high sleep onset.
