Biphasic sleep is a pattern that is followed for 24 hours, where a person sleeps in two cycles or segments. Also known as bimodal sleep, it is a concept that divides nighttime sleep into two blocks. It includes a shorter sleep period at night, and a nap during the day, which should last for half an hour to an hour at max. While this may seem tiresome, this sleep pattern comes naturally to many people, who may feel tired during the afternoon. This way of resting your body comes with its positive and negative points. While it may help in better memory and cognitive function and improve productivity, the biggest drawback is that it has the potential to disrupt sleep patterns.

What is Biphasic Sleep?

Biphasic sleep refers to a sleep pattern where sleep is divided into two periods within 24 hours. A study published in the journal Nature and Science of Sleep, states that this sleep pattern includes a long sleep duration at night of 6–7 hours, with a short nap during the day, which is less than one hour. This is common among school or college-going youngsters, homemakers and senior citizens who sleep primarily for specific periods at night and also have a secondary, shorter sleep or often a nap during the day, mostly in the afternoon. “Historically, this sleep pattern was common, with people having a ‘first’ and ‘second’ sleep separated by a wakeful period during the night, to keep a watch, forage, hunt, socialise or for other domestic activities,” explains internal medicine specialist Dr Rahul Tambe.

Earlier biphasic sleep would happen with both sleep segments during the night, divided by a time gap in between. Image courtesy: Adobe stock

Benefits of Biphasic Sleep

This sleep pattern has several potential benefits, including:

1. Increases productivity

A short nap during the day can improve alertness, focus, and cognitive function. By breaking up the day with a short sleep, or a power nap, you can maintain productivity levels and reduce fatigue. A study, published in the journal Progress in Brain Research, states that short naps ranging from 5 to 15 minutes are beneficial. They are linked with better cognitive function, as were naps of longer than 30 minutes. A midday nap can reduce fatigue and increase alertness for the rest of the day, especially for students, potentially boosting productivity,” says Dr Tambe.

2. Improves mood

A short nap, during the day, can help alleviate stress and anxiety, leading to a more positive mood. Adequate sleep is crucial for emotional well-being, and biphasic sleep can contribute to improved mood stability. “The division of sleep can further improve the consolidation of memories, particularly if the second sleep episode includes REM sleep, which supports learning and memory retention,” says Dr Tambe.

3. Promotes overall health

Even physiologically, the sleep pattern can help eliminate natural dips in alertness during the afternoon. It can help people people adapt better to their circadian rhythms, or the way their body adapts to changes during the day, says Dr Tambe. It helps you get adequate sleep, and that is linked to a reduced risk of heart disease, states this study published in the journal, Current Cardiology Reviews. The study observed that mortality rates from ischemic heart disease, cancer, and stroke, were the lowest for people who were sleeping seven to eight hours per night. Additionally, adequate sleep helps boost the immune system, making you less susceptible to illness.

Biphasic Sleep: How to do it?

• Set a regular schedule: Establish a primary sleep phase at night. This can be six to seven hours, and a secondary sleep phase which will be one hour, in the afternoon so you get an 8-hour rest during the day.
• Gradual adjustment: If you're not used to napping, introduce it naturally in your schedule. Shorten night-time sleep slightly over time to incorporate the afternoon nap without losing total sleep duration.
• Optimise your sleep environment: You need to be well rested for this to work for you. Ensure both sleep periods take place in a dark, quiet, and comfortable setting.
• Monitor and adjust the pattern: It is important to note if this is working for you or not. So make sure to track your energy levels and alertness to fine-tune sleep duration in each phase.

Variations in Biphasic sleep patterns

Here are some ways you can twist this sleep schedule to suit your needs:

1. Siesta sleep schedule

A siesta sleep schedule involves taking a short nap, usually around 60-90 minutes, in the early afternoon. This way of resting is common in many cultures, particularly in warm places. However, if you are practising biphasic sleep, then you can change the long siesta into a short nap, capped at 60-90 minutes. Here, nighttime sleep would be five to six hours per night.

2. Midday nap sleep schedule

A midday nap, typically lasting 20-30 minutes, can be a powerful tool for boosting energy, improving mood, and enhancing cognitive function. An ideal nap is between 1 PM and 3 PM. This timing allows for a refreshing nap without interfering with nighttime sleep. In the case of biphasic sleep pattern, this nap is also not beyond 20- or 30-minutes. In this variation, you can sleep upto 7 hours during the night.

3. First/second sleep schedule

This has been happening for ages. Here, people would typically retire early, around 9-10 PM, and sleep for a few hours. Then, they would wake up for an hour or two. After this, they would return to sleep until morning. The original way of following a biphasic sleep schedule was also the same. Your nighttime sleep was split into two segments, during the night itself. People would wake up around midnight, for an hour or two, and then go back to sleep.

Biphasic sleep: What to keep in mind?

Though this sleep pattern is helpful and comes with a host of benefits, it needs to be done carefully as well. Here is what to keep in mind:

• Routine is important Maintain a consistent schedule that will gradually adjust to the body's natural rhythms.
• Napping too late can interfere with night-time sleep, so aim for early to mid-afternoon naps.
• The total sleep time should meet personal sleep requirements so you are not sleeping for too long or too little to prevent cumulative sleep debt. With each sleep schedule, the person should still obtain a total of at least seven hours of sleep per 24-hour period.

Are there any side effects of Biphasic sleep?

Here are some ways that this sleep pattern might not work for you:

• Difficulty falling asleep: Delayed afternoon naps may keep you awake late in the night, prolonging the nighttime sleep onset for some individuals. Check out other reasons why you can’t sleep at night.
• Reduced REM sleep: If not balanced correctly, this sleep pattern could reduce REM sleep, which is crucial for memory and mood regulation. REM (rapid eye movement) sleep is important for our physical health as well as our mental health and memory.
• Increased sleep fragmentation: Dividing sleep might lead to more periods of waking, which could reduce overall sleep efficiency.
• Circadian Disruption: An inconsistent sleep schedule could disrupt circadian rhythms or the physical, mental, as well as behavioural changes that happen to us. A disruption in these can lead to fatigue and difficulty in maintaining focus.

While practicing biphasic sleep, it's important to make sure that you get atleast 8 hours of sleep everyday. Image courtesy: Freepik

Frequently Asked Questions (FAQs)

1. Is Biphasic Sleep Right for Everyone?

While this sleep pattern offers benefits, it's not suitable for everyone. It may disrupt your daily routine and social life. It's essential to consider your individual needs and lifestyle before adopting this sleep pattern.

2. Is it better to sleep continuously or in intervals?

While segmented sleep has its benefits, it is important to do it only if you require it. If your regular sleep pattern is giving you adequate rest, then it is important to stick to that.

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