The mono-phase sleeping is the most common sleeping pattern. It happens usually from late evening until morning. Most of the daily activities of this civilization are tailored in order to fit around it. Sleeping during the night is most normal time for sleeping.
Our physiological function ( metabolism, heart rate, secretion, digestion, etc. ) are naturally programmed to perform at reduced rate, in order to make the sleep and rest as easy and effective as possible.
The duration of sleeping during the night depends from one individual to the other. Infants sleep up to 16 hours per day. Children sleep up to 10 hours. The adults are sleeping around 8 hours, while elders tend to sleep less. The duration of the sleep is not the only indication of the sleep quality. The other factors play a considerable role.
During the sleep the human brain wave functions are lowering to the frequency between 0 and 4 Hz. During the sleep the eyes shows pattern known as rapid eye movement ( REM ) happens during dreaming. It is considered that is necessary to have four or five REM cycles during the night, in order to complete the sleeping cycle and needs for recovery. The total REM time is usually from 90 to 120 minutes.
The mono phase sleep pattern is the easiest to comply with daily requirements, since it is common for most of the population. Simply during the night everybody sleeps ( well, almost everybody ). The day is remaining for daily activities.
Therefore, adherence to night mono phase sleep pattern is socially most accepted, since meets the expectation of majority. Therefore, planning the nigh mono phase sleep pattern is relatively easy to conduct.
On the other side, mono phase sleep pattern have some drawbacks. If somebody is sleeping 8 hours per day, that means that 16 hours is dedicated to other activities.
The 16 hours of various activities, without a break, can be quite exhausting. In that term, individual with 16 hours of activities may have change in energy levels and, consequently, change of mood. These variations can reflect to the individual productivity and quality of life.