Biphasic sleep involves dividing daily rest into two distinct periods, such as a long night’s rest paired with a daytime nap.
Understanding the Biphasic Sleep Pattern
Monophasic sleep consists of one continuous block of rest, whereas the biphasic approach splits sleep into two phases. While many people now sleep once per night, historical evidence suggests humans previously followed a segmented approach. Before the industrial era and the rise of artificial lighting, people often slept for a few hours after sunset, woke around midnight to tend to children or fires, and then returned to sleep for a second phase.
This differs from polyphasic sleep, which requires three or more sleep periods. While infants naturally follow this pattern, unplanned polyphasic sleep in adults can sometimes indicate sleep disorders or neurodegenerative diseases.
Common Biphasic Sleep Schedule Examples
These routines vary, provided the total rest time remains at least seven hours per 24-hour period:
- Siesta: Common in Spain and Italy, this involves a 60- to 90-minute afternoon nap and five to six hours of nighttime sleep.
- Midday Nap: A shorter 20- to 30-minute nap during the day paired with six or seven hours of sleep at night.
- First/Second Sleep: The traditional preindustrial method of sleeping from 9 or 10 p.m., waking for one or two hours at midnight, and then sleeping again.
Biphasic Sleep Benefits and Risks
This routine can increase alertness and reduce daytime sleepiness for some. Short naps provide immediate cognitive boosts, while naps longer than 30 minutes offer more lasting cognitive improvements, though they may cause initial grogginess.
Potential drawbacks exist. Some researchers argue that external factors, such as eating habits or heat, drive these patterns rather than biology. The most significant risk is sleep deprivation. Insufficient total sleep increases the risk of obesity, diabetes, stroke, high blood pressure, and kidney or heart disease. In preschool children, daytime napping has been linked to lower nighttime sleep quality, poorer vocabulary, and shorter attention spans.
Tips for Starting Biphasic Sleep
Consider these steps when transitioning to this routine:
- Choose a Biphasic Sleep Schedule: Pick a style and set a fixed wake-up time to ensure you achieve seven hours of total rest.
- Maintain Consistency: Keep bed and wake times steady to avoid long-term health issues like hypertension.
- Manage Light: Avoid screens and dim the lights 30 to 60 minutes before any sleep phase. Use dim reddish or yellowish bulbs if waking at midnight.
- Improve Hygiene: Limit caffeine before resting, exercise regularly, and keep the bedroom dark and cool.
FAQ
Did humans used to have biphasic sleep?
Yes, this is believed to have been a common pattern throughout human history until the industrial age. Many birds and mammals also sleep in two phases.
Is biphasic sleep good for students?
It may be beneficial if the student maintains a consistent schedule, as short daytime naps can improve focus. However, traditional school schedules often hinder consistency, and napping may reduce the quality of a child’s nighttime sleep.
What is a biphasic sleep schedule?
It is any routine where sleep is divided into two segments per day, such as two separate nighttime periods or a long nighttime stretch and a midday nap.
When to See a Doctor
Consult a healthcare provider before making a radical change to your sleep routine. Seek medical attention if you experience:
- Randomly timed waking and sleeping (which may indicate a circadian rhythm disorder).
- Chronic sleep deprivation.
- Excessive grogginess that impairs daily functioning.
Disclaimer: This content is for informational purposes only and does not provide medical advice, diagnosis, or treatment
Related articles
- Using Levels of Ikhfa to Improve Sleep Quality
- The Ferber Method Sleep Training: A Complete Guide
- Why Do You Have Blurry Vision in the Morning?
- Restless Legs Syndrome Causes: Diagnosis and Symptoms
- More about Sleep & Sleep Disorders
Illustration: AI-generated
approved by: Medica Health team