What percentage of the night is typically spent in N2 sleep?

In a typical sleep cycle, the second stage of non-REM sleep, known as N2, constitutes a significant portion of the total sleep time. It is during N2 sleep that the body begins to relax more fully, and heart rate and body temperature decrease. On average, individuals spend about 40-50% of their entire sleep period in this stage.

N2 sleep is characterized by the presence of sleep spindles and K-complexes on an electroencephalogram (EEG), indicating a transition into deeper sleep and an important part of the sleep architecture. Therefore, the correct representation of the percentage of night typically spent in N2 sleep aligns with this understanding, confirming that it encompasses a substantial portion of sleep for most individuals.