A power nap is a short sleep, typically lasting between 10 to 30 minutes, designed to boost alertness and enhance performance. This brief rest can help improve mood, increase focus, and reduce fatigue without causing sleep inertia, which is the grogginess that can occur after longer naps. Power naps are most effective when taken in the early afternoon, aligning with the body's natural circadian rhythms. They can be particularly beneficial for individuals who experience sleep deprivation or need a quick energy boost during the day, making them popular among students and professionals alike.