The Intriguing World Of Biphasic Sleep: Twice-Daily Dozing

Sleeping twice a day is known as biphasic sleep. This involves a person sleeping in two segments, or phases, per day. This can take the form of a longer nighttime sleep and a shorter daytime nap, or two nighttime sleep segments with a waking period in between. Biphasic sleep is distinct from monophasic sleep, which is the more common sleep pattern of one period of sleep within a 24-hour period, and polyphasic sleep, which involves multiple sleep periods over a 24-hour cycle.

Biphasic sleep involves two sleep periods, one longer at night and a shorter daytime nap

Biphasic sleep involves two sleep periods in a 24-hour cycle. This is in contrast to monophasic sleep, which is one period of sleep within 24 hours, and polyphasic sleep, which involves multiple sleep periods.

Biphasic sleep typically consists of a longer period of sleep at night, followed by a shorter daytime nap. This might be a 20-minute nap in the middle of the day, alongside six to seven hours of sleep at night. Alternatively, it could be a longer nap of 60 to 90 minutes, with five hours of sleep at night.

The practice of biphasic sleep is not a new phenomenon. In pre-industrial times, it was common to get up for a couple of hours in the middle of the night. Historian Roger Ekirch, author of 'At Day's Close: Night in Times Past', found references to a segmented sleeping pattern in over 500 documents from ancient, medieval, and modern history. Other historians, such as Craig Koslofsky, have endorsed Ekirch's analysis.

According to Ekirch's argument, adults would typically sleep in two distinct phases, with an intervening period of wakefulness of about an hour. This time was often used for reflection, prayer, or interpretation of dreams, which were more vivid during this period.

In modern times, biphasic sleep is still practised in various cultures. The tradition of the siesta, a nap taken in the early afternoon, is common in Spain, Greece, China, India, South Africa, Italy, and several Latin American countries.

Some people adopt a biphasic sleep schedule to increase productivity and reduce the effects of sleep loss. However, there are potential downsides to biphasic sleep. It may not be feasible for those with strict work schedules or family commitments. Additionally, there is a risk of sleep deprivation if the total sleep time across the two periods is insufficient.

Monophasic sleep is one block of sleep, usually at night, and is the most common sleep pattern

Monophasic sleep is a sleep pattern where a person attains all their sleep in one block of time, usually at night. It is the most common sleep pattern, with most modern Americans and the global population being monophasic sleepers.

The custom of sleeping for one 6- to 8-hour segment per day is thought to have been shaped by the modern industrial workday. The invention of artificial lighting meant that humans could stay awake past sunset, and the workday could be extended. This compressed the amount of time available for sleeping, and most people didn't have the luxury of sleeping twice a day.

Monophasic sleep is typical of most of the population, but biphasic and polyphasic sleep patterns are also known to manifest naturally in some people. Biphasic sleep involves two sleep periods, usually a longer nighttime sleep and a shorter daytime nap. Polyphasic sleep involves multiple sleep periods over a 24-hour cycle, usually in the form of short naps.

Some people intentionally adopt biphasic or polyphasic sleep schedules to increase productivity and improve cognitive function. However, for most people, following a non-monophasic sleep schedule can lead to sleep deprivation and associated negative health outcomes.

Polyphasic sleep is sleeping multiple times over 24 hours and is common in infants and animals

Polyphasic sleep refers to sleeping multiple times over a 24-hour period. This is in contrast to monophasic sleep, which involves one period of sleep within 24 hours. Polyphasic sleep is common in infants and animals and is believed to be the ancestral sleep state for mammals.

Polyphasic sleep can take various forms, including biphasic sleep, which involves two sleep periods, and triphasic sleep, which involves three sleep periods. For example, a person might sleep for a few hours in the early evening, wake up for a couple of hours in the middle of the night, and then sleep for several more hours until dawn. Alternatively, they might sleep for several hours during the night and take a short nap in the afternoon.

Polyphasic sleep was common in pre-industrial societies, with people typically sleeping in two distinct phases, bridged by a period of wakefulness. This time was often used for reflection, interpretation of dreams, creative work, or social activities. The invention of artificial lighting and the Industrial Revolution led to a shift towards monophasic sleep patterns, as people could work for longer stretches of time and socialize at night.

While polyphasic sleep can offer benefits such as increased alertness and cognitive function, there is limited scientific evidence supporting its effectiveness. Additionally, it may not be feasible for everyone due to work or family commitments. It is important to prioritize getting sufficient sleep, as sleep deprivation can have negative physical and mental health outcomes.

Segmented sleep is sleeping in shifts, with a couple of hours awake in the middle of the night

Segmented sleep, also known as biphasic sleep, is a sleep pattern that involves sleeping in two segments or phases per day. This means that a person sleeps for two separate periods within a 24-hour period, in contrast to monophasic sleep, which involves a single continuous block of sleep, usually at night.

Segmented sleep can take different forms. One common approach is to have two sleep sessions at night. This involves sleeping for a few hours starting in the early evening or at night, then waking up for a couple of hours, and finally sleeping for several more hours until dawn or later. This typically results in a total of six to eight hours of sleep.

Another way to structure segmented sleep is to have one session at night and one during the day. This is often referred to as "siesta sleep" and is common in cultures such as Spain and Greece. People may sleep for a longer period at night (around six hours) and then take a short nap of about 20 minutes in the afternoon. Alternatively, they may sleep for a shorter period at night (around five hours) and take a longer nap of about 1 to 1.5 hours during the day.

Segmented sleep was actually the norm in pre-industrial times, according to historian Roger Ekirch. People would typically sleep for their first sleep in the early evening, wake up for a couple of hours in the middle of the night, and then have their second sleep until morning. This period of wakefulness was often used for activities like praying, smoking, or visiting neighbours.

Some people in modern times also follow a segmented sleep schedule, using the middle-of-the-night awake period for creative pursuits, thinking, reading, or meditation. However, maintaining a segmented sleep schedule can be challenging for those with family or work commitments.

There are mixed views on the health impacts of segmented sleep, as there has been limited research on its long-term effects. While some people report feeling more rested and energetic with this sleep pattern, others caution that it may disrupt your circadian rhythms and lead to sleep deprivation if not managed properly.

Siesta sleep is a biphasic sleep pattern common in Spain, Greece, and many Latin American cultures

Siesta sleep is a biphasic sleep pattern where a person sleeps twice in a 24-hour period. This type of sleep pattern is common in Spain, Greece, and many Latin American cultures. It is characterised by a longer nighttime sleep and a shorter daytime nap.

The siesta sleep schedule usually involves a 60- to 90-minute nap during the day, typically in the afternoon, followed by five to six hours of sleep at night. This type of biphasic sleep pattern is also known as "segmented sleep" or "siesta sleep".

Siesta sleep is just one variation of biphasic sleep. Another common approach is to have two sleep sessions at night. With this approach, a person might sleep for a few hours starting in the early evening or at night, wake up for a couple of hours, and then sleep for several more hours until dawn. This style of biphasic sleep yields approximately six to eight hours of sleep in total.

Biphasic sleep is different from monophasic sleep, which is the more common sleep pattern where a person sleeps for only one extended session, usually at night. It is also distinct from polyphasic sleep, which involves sleeping for more than two sessions in a 24-hour period.

While biphasic sleep may offer benefits such as improved cognitive function, productivity, and stress reduction, it may not be feasible or suitable for everyone. For example, it can be difficult to maintain a biphasic sleep schedule with strict work schedules or family commitments. Additionally, there is limited research on the long-term effects of biphasic sleep, and it may increase the risk of sleep deprivation if not properly managed.

Frequently asked questions