Because of Triphasic's daytime and evening cores at often inconvenient hours, Triphasic is not very popular. The need for a core in SWS peak makes social life in the evening difficult. As it only has 4.5 hours of total sleep, Triphasic is quite inflexible even after adaptation for average sleepers. One person has reported being able to flex a Triphasic core by up to 30 minutes. With the limited flexibility, maintaining Triphasic long-term is difficult, even if the adaptation is successful. Intense exercise may also be detrimental to the schedule, because the increased SWS requirements from the exercise can lead to SWS wakes, and may cause oversleeps. Triphasic can create a sense of long days blurred together, with wake gaps all similar in length.
