what is nap

A nap is a short period of sleep that usually occurs during the day. Napping can help to maintain alertness or overcome daytime fatigue. Nap needs and the benefits of napping can vary, and although there are a variety of benefits to napping, naps may have drawbacks for certain people. For example, for older adults, napping during the day is associated with self-reported sleep problems such as waking up frequently during the night. Napping may be too much if it interferes with sleep at night. A power nap, also known as a Stage 2 nap, is a short slumber of 20 minutes or less which terminates before the occurrence of deep slow-wave sleep, intended to quickly revitalize the napper. The power nap is meant to maximize the benefits of sleep versus time. It is used to supplement normal sleep, especially when a sleeper has accumulated a sleep deficit. The greater the sleep deficit, however, the more effective the nap. Twenty- to thirty-minute naps are recommended for adults, while young children and elderly people may need longer naps.