Does Napping Affect Your Sleep at Night?


Do you take a nap during the day? Whether they call it a siesta, a catnap, a power nap, or simply a day-off, a lot of people take naps. If you need to take a nap, there’s nothing wrong with that. In fact, in 2008 British researchers reported results of a study that compared getting more nighttime sleep, taking a nap, and using caffeine as ways to combat afternoon drowsiness. They found that taking a nap was the most effective choice. However, did you know that taking a nap could affect how you sleep at night?

To understand if your naps are negatively affecting your sleep at night we first need to understand the role circadian rhythms play as it relates to napping.

Circadian Rhythms and Napping

The term circadian rhythm is is derived from Latin circa, meaning “around” (or “approximately”), and diēm, meaning “day”, and refers to the metabolic cycle of a living organism. It includes both sleep and wakefulness. Circadian rhythms are controlled by a region of the brain called the suprachiasmatic nucleus and they follow an approximate 24-hour cycle. The repeated day-to-day rising and falling in levels of certain chemicals (such as cortisol) in the body help control this circadian rhythm.

A person’s circadian rhythm can be impacted by many factors. For instance, jet lag, shift work, sleep deprivation, and other triggers of circadian misalignment influence our sleep cycles. However, the most powerful determinant of our body’s sleep-wake cycle is sunlight exposure. The light spectrum that hits the retina is primarily comprised of wavelengths in the reds and oranges. Blue light is a relatively short wavelength that gets absorbed by the eye more rapidly than its longer wavelength red/orange counterparts.

While each person is different it is common for our circadian rhythm to dictate a period of sleepiness or decreased alertness after lunch. Though it is quite normal for people to feel a bit sleepy in the afternoon, this can be the result of or be exacerbated by things such as sleep disorders, medical conditions, stress, poor nutrition, or simply not getting enough sleep. You should seek medical assistance to rule out any medical conditions if you have a sudden change or increase in your level of tiredness during the day.

So while it might be perfectly normal to feel tired and want to take a nap during the day, but that doesn’t necessarily mean it is a good idea. To answer that question we need to look at when you are napping and how long the nap is.

When You Take A Nap is Important

Many experts suggest that if you take a nap you should do it earlier in the day, preferably before 3 p.m., because if you take a nap later in the day it could negatively affect your sleep later at night.

You might be thinking that it seems odd that the time of a nap matters especially if the length of your nap is the same regardless of when you take it.

So is there a specific reason why taking a nap later in the day might make it difficult to fall asleep at night? Actually, yes there is a reason…

The Effect of Napping on Your Homeostatic Sleep Drive

The reason why sleeping later in the day may not be a good idea is because of something related to circadian rhythms called homeostatic sleep drive, which refers to a natural process that increases feelings of sleepiness as the day goes on. Your sleep drive refers to the probability of your being able to fall asleep at a certain time. This is caused by the gradual accumulation of a neurotransmitter called adenosine throughout the day. The chemical gradually decreases while you sleep.

Simply put, if you take a nap too late in the day, your sleep drive may not be that great when it is time to go to bed at night. This lack of sleepiness is because the adenosine in your system hasn’t had enough time to rebound to its normal end of the day levels, which is what makes it hard for you to fall asleep at night. That is why many sleep experts suggest napping earlier in the day so you can avoid this disruption of your sleep cycle.

It is also important to note that every situation is unique and each person has their own internal clock. So there probably isn’t a one-time-fits-all answer, so just try to nap earlier in the day if you can.

Pay Attention to How Long You Nap

A lot of people wonder, “How long can you nap without messing up your sleep schedule?” and that is a valid concern.

Depending on your individual needs experts will recommend that to awake feeling alert and refreshed the ideal nap should be between 10 to 30 minutes. This is because many people find that when they take a nap for too long, they wake up groggy and tired.

In addition to trying to avoid waking up feeling like you are in a fog another reason why most experts recommend taking a short nap is because if you were to take a longer nap it may actually impair your ability to fall asleep when you are ready to go to bed at the end of the day. This is because, during long periods of sleep, the brain can get into the deeper sleep stages, which in addition to being harder to wake up from, but also reduces sleep pressure that we discussed earlier, making it more difficult for your to fall asleep at your normal bedtime.

Does this mean that we should never take longer naps? Not at all. There are multiple reasons why you may want or need to take a long nap. Maybe you are sick, dealing with sleep deprivation, or maybe you are going to be working the night shift and want more energy. In fact, the CDC suggests that taking a multiple-hour nap before working the night shift can be a good idea for nurses because during a long nap “the brain can progress into the deeper stages of sleep and, as a result, can reduce the buildup of pressure for sleep. This can help reduce the drop in alertness during the night shift.”

While we just talked about examples of when taking a longer nap might make sense, the truth of the matter is that the vast majority of people who feel a little drowsy in the afternoons aren’t in one of these situations where they need a long nap.

So it is important to keep an eye on how long you take your naps. If you want to get the full restorative benefits of your naps, try to limit them to 20 minutes or less to ensure that when you wake up from your sleep your quality of life remains high and you will still be able to fall asleep at night.

What If I Suffer From Insomnia, Is It Safe for Me to Nap?

Insomnia is a condition where you have trouble falling asleep at night and/or staying asleep. Insomnia is also often associated with difficulty in waking up in the morning. Frequently, one seeks professional help to treat insomnia. Many people who suffer from insomnia are told that napping will negatively affect their ability to fall asleep at night and/or stay asleep during the night. If you suffer from insomnia it is possible that napping may not be a good option for you even if you pay close attention to when and how long you are napping.

Final Thoughts

For many of us, the urge to nap is perfectly normal. In fact, taking a nap can be very restorative and allow you to finish your day on top of your game. However, taking naps the wrong way can negatively impact your sleep at night, but if we don’t nap too late in the day and don’t nap for too long most of us will still be able to sleep well at night. So you most likely can go ahead and take that nap without fear of it impacting your sleep tonight.