A 90-120 minute nap can restore alertness for how many hours?

A 90-120 minute nap can significantly enhance alertness, providing a restorative effect that often lasts for an extended period. Research indicates that a nap of this duration allows an individual to enter deeper stages of sleep, including REM and slow-wave sleep, which are crucial for cognitive restoration and memory consolidation.

As a result, the alertness gained from such a nap can potentially withstand fatigue for about 12-15 hours. This extended alertness is particularly beneficial for those who may experience sleep deprivation or fatigue during the day, making a longer nap an effective strategy to combat drowsiness and improve focus for a substantial time after waking.

Options suggesting shorter or longer durations, such as 6-8 hours or 15-18 hours, do not align with the typical effects of napping, as naps cannot extend alertness beyond a certain threshold, nor can they replace the need for a full night's sleep, which is generally recommended for optimal functioning.