Table of ContentsView AllTable of ContentsBiphasic SleepTypes of SleepWho Should Avoid It?

Table of ContentsView All

View All

Table of Contents

Biphasic Sleep

Types of Sleep

Who Should Avoid It?

Biphasicsleep is asleep schedulethat involves two periods of sleep over 24 hours, which is often sleep at night plus a nap. Monophasic sleep is a schedule that involves one period of sleep, and polyphasic sleep is a schedule that involves two or more periods of sleep.

Nappinghas benefits such as increasing the total amount of sleep per day to alleviatesleep deprivationand improve physical health, mental health, and brain function. However, there are serious health risks if sleep periods are too short, interrupted, or do not allow for quality sleep.

Learn about biphasic sleep, how to get on this type of sleep schedule, who should (or shouldn’t) do it), and more.

A photo composite of the same woman awake and also asleep for a biphasic sleep concept.

Biphasic Sleep: Breaking Up Sleep in Two

Biphasic sleep is any sleep schedule that includes two periods of sleep during 24 hours. This may be two nighttimesleep phaseswith a break between them or a longer sleep phase at night with a nap at another time during the day.

Benefits of napping include:

Even though there can be benefits, it is important for each person to follow the sleep schedule that is best for them. Everyone is different, and theideal sleep scheduledepends on many things, such as work, household dynamics, and other lifestyle factors.

Throughout History

While many people today practice monophasic sleep habits, this has not always been the case. Biphasic sleep schedules were more common before industrialization.It used to be more common for people to go to sleep with the sun, wake up for a while in the middle of the night, and then return to sleep.

When electricity and artificial light became available and more widely used, people began to stay awake later in the evenings, lengthening the day. This led to decreased time spent awake in the middle of the night. More people adopted monophasicsleephabits.

Is Biphasic Sleep Relevant Today?

Biphasic sleep is still relevant today, and many people follow this type of sleep schedule.

People caring for babies must often wake up during the night. Babies have a polyphasic sleep schedule, sleeping and waking multiple times every 24 hours.This allows them to eat and rest, not going too long without either. As they grow and develop, they take fewer naps and are able tosleeplonger at a time.

Additionally, napping is sometimes used as a way to get out of the sun and heat in the middle of the day, enjoy more evening hours, or catch up on reduced hours of nighttime sleep.

For example, people who work a night shift or aresleep-deprivedmay sleep two or more times in a 24-hour period in an attempt to get more sleep.These sleep habits may or may not be consistent each day.

Am I a Monophasic, Biphasic, or Polyphasic Sleeper?

While there may be a genetic component, and people may feel a more natural tendency to monophasic, biphasic, orpolyphasic sleep, lifestyle plays a significant role.

Anyone who typically sleeps once per 24-hour period is a monophasic sleeper. Anyone who consistently sleeps twice is a biphasic sleeper, and more than twice is a polyphasic sleeper.

It is also possible to shift to adifferent sleep schedule, even in adulthood. For example, a monophasic sleep schedule may work well until a new job with different hours or demands shortens nighttime sleeping hours. In this case, it may be beneficial to start napping daily to get enough total sleep.

How to Get on a Biphasic Sleep Schedule

When shifting to a biphasic sleep schedule, it is important to follow goodsleep habitsin order to get the right amount of quality sleep.One of the keys to achieving a biphasic sleep schedule is to keep it consistent. It is best to sleep and nap at the same time every day.

Exercise during waking hours can improvesleep qualitybut may make it difficult to fall asleep right afterward.So, it is important to schedule the day in a way that allows for enough time between exercise and sleep.

Sincecaffeine can interfere with sleep, it should be avoided to make it easier to fall asleep.Having a bedtime routine that includes dimming the lights and getting relaxed can help to adjust to a biphasic sleep schedule.

12 Sleep Hygiene Tips for a Better Night’s Rest

Should Anyone Skip Biphasic Sleep?

Biphasic sleep is not ideal for everyone. There are risks, such as sleep inertia, which is when a person feels less than their best after waking up from sleep.This may include feeling tired, groggy, or disoriented and having decreased performance in areas such as information processing and reaction time.

Additionally, sleeping more than once per day may make it more challenging to fall asleep, stay asleep, or get quality sleep. Napping and biphasic sleep may not be ideal for anyone who experiencesdifficulty sleeping, such as those withinsomnia.

Does Sleeping Too Much Affect You?

A Word From VerywellSleep deprivation can lead to serious consequences, including worse mood and struggles with job or school performance. A consistent sleep schedule allowing enough time in bed can help you avoid sleep deprivation.—DANIEL COMBS, MD, MEDICAL EXPERT BOARD

A Word From Verywell

Sleep deprivation can lead to serious consequences, including worse mood and struggles with job or school performance. A consistent sleep schedule allowing enough time in bed can help you avoid sleep deprivation.—DANIEL COMBS, MD, MEDICAL EXPERT BOARD

Sleep deprivation can lead to serious consequences, including worse mood and struggles with job or school performance. A consistent sleep schedule allowing enough time in bed can help you avoid sleep deprivation.

—DANIEL COMBS, MD, MEDICAL EXPERT BOARD

Daniel Combs, MD

Summary

Biphasic sleep is any sleep schedule with two sleep phases each day, over a 24-hour period. It may happen with one long sleep phase plus a short nap or in two sleep phases that are closer to even in length. It has benefits, such as increasing total sleep time for those who are prone to not getting enough total sleep, but it is not for everyone.

Biphasic sleep is not new. It was more common before artificial light became widespread, lengthening the days and condensing nighttime sleep into one phase. It is relevant today, especially for those caring for babies and those who do not get enough sleep in a single sleep phase.

Regardless of how many sleep phases per day, it is important to follow good sleep habits in order to get enough total quality sleep.

10 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Weaver MD, Sletten TL, Foster RG, et al.Adverse impact of polyphasic sleep patterns in humans: report of the National Sleep Foundation sleep timing and variability consensus panel.Sleep Health. 2021;7(3):293-302. doi:10.1016/j.sleh.2021.02.009Sleep Foundation.Siestas.Flaskerud JH.The cultures of sleep.Issues in Mental Health Nursing. 2015;36(12):1013-1016. doi:10.3109/01612840.2014.978960Nunn CL, Samson DR, Krystal AD.Shining evolutionary light on human sleep and sleep disorders.EMPH. 2016;2016(1):227-243. doi:10.1093/emph/eow018Dashti HS, Daghlas I, Lane JM, et al.Genetic determinants of daytime napping and effects on cardiometabolic health.Nat Commun. 2021;12(1):900. doi:10.1038/s41467-020-20585-3Souabni M, Souabni MJ, Hammouda O, et al.Benefits and risks of napping in older adults: a systematic review.Front Aging Neurosci. 2022;14:1000707. doi:10.3389/fnagi.2022.1000707Johns Hopkins Medicine.Exercising for better sleep.O’Callaghan F, Muurlink O, Reid N.Effects of caffeine on sleep quality and daytime functioning.Risk Manag Healthc Policy. 2018;11:263-271. doi:10.2147/RMHP.S156404National Aeronautics and Space Administration.The benefits of napping for safety.Robbins R, Grandner MA, Buxton OM, et al.Sleep myths: an expert-led study to identify false beliefs about sleep that impinge upon population sleep health practices.Sleep Health. 2019;5(4):409-417. doi:10.1016/j.sleh.2019.02.002

10 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Weaver MD, Sletten TL, Foster RG, et al.Adverse impact of polyphasic sleep patterns in humans: report of the National Sleep Foundation sleep timing and variability consensus panel.Sleep Health. 2021;7(3):293-302. doi:10.1016/j.sleh.2021.02.009Sleep Foundation.Siestas.Flaskerud JH.The cultures of sleep.Issues in Mental Health Nursing. 2015;36(12):1013-1016. doi:10.3109/01612840.2014.978960Nunn CL, Samson DR, Krystal AD.Shining evolutionary light on human sleep and sleep disorders.EMPH. 2016;2016(1):227-243. doi:10.1093/emph/eow018Dashti HS, Daghlas I, Lane JM, et al.Genetic determinants of daytime napping and effects on cardiometabolic health.Nat Commun. 2021;12(1):900. doi:10.1038/s41467-020-20585-3Souabni M, Souabni MJ, Hammouda O, et al.Benefits and risks of napping in older adults: a systematic review.Front Aging Neurosci. 2022;14:1000707. doi:10.3389/fnagi.2022.1000707Johns Hopkins Medicine.Exercising for better sleep.O’Callaghan F, Muurlink O, Reid N.Effects of caffeine on sleep quality and daytime functioning.Risk Manag Healthc Policy. 2018;11:263-271. doi:10.2147/RMHP.S156404National Aeronautics and Space Administration.The benefits of napping for safety.Robbins R, Grandner MA, Buxton OM, et al.Sleep myths: an expert-led study to identify false beliefs about sleep that impinge upon population sleep health practices.Sleep Health. 2019;5(4):409-417. doi:10.1016/j.sleh.2019.02.002

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Weaver MD, Sletten TL, Foster RG, et al.Adverse impact of polyphasic sleep patterns in humans: report of the National Sleep Foundation sleep timing and variability consensus panel.Sleep Health. 2021;7(3):293-302. doi:10.1016/j.sleh.2021.02.009Sleep Foundation.Siestas.Flaskerud JH.The cultures of sleep.Issues in Mental Health Nursing. 2015;36(12):1013-1016. doi:10.3109/01612840.2014.978960Nunn CL, Samson DR, Krystal AD.Shining evolutionary light on human sleep and sleep disorders.EMPH. 2016;2016(1):227-243. doi:10.1093/emph/eow018Dashti HS, Daghlas I, Lane JM, et al.Genetic determinants of daytime napping and effects on cardiometabolic health.Nat Commun. 2021;12(1):900. doi:10.1038/s41467-020-20585-3Souabni M, Souabni MJ, Hammouda O, et al.Benefits and risks of napping in older adults: a systematic review.Front Aging Neurosci. 2022;14:1000707. doi:10.3389/fnagi.2022.1000707Johns Hopkins Medicine.Exercising for better sleep.O’Callaghan F, Muurlink O, Reid N.Effects of caffeine on sleep quality and daytime functioning.Risk Manag Healthc Policy. 2018;11:263-271. doi:10.2147/RMHP.S156404National Aeronautics and Space Administration.The benefits of napping for safety.Robbins R, Grandner MA, Buxton OM, et al.Sleep myths: an expert-led study to identify false beliefs about sleep that impinge upon population sleep health practices.Sleep Health. 2019;5(4):409-417. doi:10.1016/j.sleh.2019.02.002

Weaver MD, Sletten TL, Foster RG, et al.Adverse impact of polyphasic sleep patterns in humans: report of the National Sleep Foundation sleep timing and variability consensus panel.Sleep Health. 2021;7(3):293-302. doi:10.1016/j.sleh.2021.02.009

Sleep Foundation.Siestas.

Flaskerud JH.The cultures of sleep.Issues in Mental Health Nursing. 2015;36(12):1013-1016. doi:10.3109/01612840.2014.978960

Nunn CL, Samson DR, Krystal AD.Shining evolutionary light on human sleep and sleep disorders.EMPH. 2016;2016(1):227-243. doi:10.1093/emph/eow018

Dashti HS, Daghlas I, Lane JM, et al.Genetic determinants of daytime napping and effects on cardiometabolic health.Nat Commun. 2021;12(1):900. doi:10.1038/s41467-020-20585-3

Souabni M, Souabni MJ, Hammouda O, et al.Benefits and risks of napping in older adults: a systematic review.Front Aging Neurosci. 2022;14:1000707. doi:10.3389/fnagi.2022.1000707

Johns Hopkins Medicine.Exercising for better sleep.

O’Callaghan F, Muurlink O, Reid N.Effects of caffeine on sleep quality and daytime functioning.Risk Manag Healthc Policy. 2018;11:263-271. doi:10.2147/RMHP.S156404

National Aeronautics and Space Administration.The benefits of napping for safety.

Robbins R, Grandner MA, Buxton OM, et al.Sleep myths: an expert-led study to identify false beliefs about sleep that impinge upon population sleep health practices.Sleep Health. 2019;5(4):409-417. doi:10.1016/j.sleh.2019.02.002

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