Siesta

A siesta (Spanish pronunciation: ) (Spanish, meaning 'nap') is a short nap taken in the early afternoon, often after the midday meal. Such a period of sleep is a common tradition in some countries, particularly those where the weather is warm. The siesta is historically common throughout the Mediterranean and Southern Europe. It is the traditional daytime sleep of Spain and, through Spanish influence, the Philippines, and many Hispanic American countries. In Dalmatia (coastal Croatia), the traditional afternoon nap is known as pižolot (from Venetian pixolotto). The Spanish word siesta derives originally from the Latin word hora sexta 'sixth hour' (counting from dawn, hence 'midday rest'). Factors explaining the geographical distribution of the modern siesta are high temperatures and heavy intake of food at the midday meal. Combined, these two factors contribute to the feeling of post-lunch drowsiness. In many countries that practice the siesta, the heat can be unbearable in the early afternoon, making a midday break at home welcome. The timing of sleep in humans depends upon a balance between homeostatic sleep propensity, the need for sleep as a function of the amount of time elapsed since the last adequate sleep episode, and circadian rhythms which determine the ideal timing of a correctly structured and restorative sleep episode. The homeostatic pressure to sleep starts growing upon awakening. The circadian signal for wakefulness starts building in the (late) afternoon. As Harvard professor of sleep medicine Charles A. Czeisler notes, 'The circadian system is set up in a beautiful way to override the homeostatic drive for sleep.' Thus, in many people, there is a dip when the drive for sleep has been building for hours and the drive for wakefulness has not yet started. This is, again quoting Czeisler, 'a great time for a nap'. The drive for wakefulness intensifies through the evening, making it difficult to get to sleep 2–3 hours before one's usual bedtime when the wake maintenance zone ends. Taking a long lunch break including a nap is common in a number of Mediterranean, tropical, and subtropical countries. The Washington Post of 13 February 2007 reports at length on studies in Greece that indicate that those who nap have less risk of heart attack. Siesta is also common in Italy, where it is called riposo in Northern Italy and pennichella or pisolino in Southern Italy. Many museums, churches and shops close during midday (from 12:00–1:30 pm to 2:30–4:00 pm) so that proprietors can go home for lunch and sometimes a nap during the day’s hottest hours. In the United States, the United Kingdom, and a growing number of other countries, a short sleep has been referred to as a 'power nap', a term coined by Cornell University social psychologist James Maas and recognized by other research scientists such as Sara Mednick as well as in the popular press. Siesta is also practiced in some still colder regions, such as Patagonia.