It’s getting easier and easier in the modern world to end up with a ruined sleep schedule. Some people are so overwhelmed with work obligations that they resort to sacrificing precious sleeping time to keep their affairs in order. Other people have to change shifts frequently and as a result, never seem to get enough rest when they’re supposed to. Maybe there are also underlying conditions that prevent someone from sleeping properly, typically sleep disorders or illnesses that cause a lot of pain and prevent the person from relaxing.
In these situations, a nap often seems like the best idea. Whether you want to dispel a headache or catch up on some of your missed sleep from last night, napping can offer some much-needed relief, but as with all things in life, moderation is key. It’s important to know how napping can affect your daily life and sleep schedule before you start including it in your routine and causing potential problems. That’s where we come in – we’ve prepared all the information you’ll ever need about napping, so you can get some extra sleep in without creating issues in your schedule. Let’s examine the topic together, shall we?
The Circadian Rhythm and Why It Matters
To understand the effects of napping and why it may or may not be a good idea depending on various factors, we have to dig into the topic of what the circadian rhythm is and how it affects our daily life. Try to think of it like this – you have a clock, located somewhere in your brain stem. This clock uses built-in photoreceptors to pick up on natural sunlight levels from your surroundings, and ultimately tell what time of day it is. Once it sees that it’s nighttime, it affects the production of sleep-related hormones like melatonin, slowly convincing your body to go to sleep. Once it’s time to wake up, your body produces cortisol and other chemical compounds that rouse you from your rest.
Now, the circadian rhythm isn’t only responsible for managing your sleep schedule. A whole host of other biological processes answer to this master clock, including your appetite, sex drive, daily energy levels, immune system, etc. While your circadian rhythm is balanced and functioning properly, your body is at peak performance, and you feel much more energized and ready to tackle incoming challenges. Your appetite is healthy, you’re less likely to get sick, and so on.
However, as you might have guessed by now, it’s not always that simple. This biological rhythm is incredibly easy to disrupt and can get thrown off-balance by anything from diet problems or bad sleeping habits (maybe as a result of shift work) to sleeping disorders and trauma. Once it falls out of rhythm, the consequences range from inconvenient to severe, and can seriously damage your performance in various fields during the day. Think of how many times you’ve seemingly been unable to feel rested after 7+ hours, which usually does the trick for almost everyone. Perhaps you’ve experienced trouble falling asleep at a reasonable time, only dozing off several hours later? These things are tied to the circadian rhythm, and this is why it’s essential to maintain a balanced sleep schedule.
The Structure of Sleep
It’s easy for an uninformed layman to imagine sleep as a binary thing, and separate a daily cycle into “hours we spend while awake” and “sleeping hours.” However, understanding sleep (and, by extension, napping) involves learning about how it transitions and alternates between different stages. As a whole, sleeping has us alternating between two broad sleep phases – REM and NREM (non-REM) sleep. Both of these are responsible for restoring our body and mind to prepare us for the coming days. Let’s examine what their rough purpose is, to put things into perspective and provide context:
- Stage 1 is the only stage that never gets repeated during any other sleep cycle, and it happens right as we’re falling asleep. It doesn’t last very long, with most people spending about 3% of their sleep in this stage, which roughly translates as 5-15 minutes. Your body temperature begins to drop slowly, along with your heart rate, and your breathing slows down. As you lose consciousness, you become less responsive to anything that’s going on around you. At some point, you will enter stage 2.
- Stage 2 begins roughly 15 minutes after stage 1 and is a more emphasized version of it. Your heart rate and breathing slow down even further, and your body temperature lowers. The movement of your eyes slows down as well, and signature light sleep brainwave patterns (called spindles and k-complexes) start showing up. Light sleep takes up around 50% of your overall time spent sleeping, although it doesn’t occur in one go. This stage is crucial for consolidating memories and learning, which is why college students are sometimes advised to take naps during their free time. Once your body is ready, you move into stage 3.
- Stage 3 is commonly known as deep sleep, and this is where you start becoming entirely unresponsive to almost anything that goes on in your surroundings. While light sleep is easy to break, it’s much, much harder to rouse you from deep sleep, hence the name. Your muscle movement slows down to the point of stopping, which is why people rarely move in this stage. Deep sleep is when a lot of bodily repairs take place. Toxins are flushed out of your body, and tissues are mended. Deep sleep occupies around 20% of our total sleeping time and leads into stage 4 after a while.
- Stage 4 is normally called REM sleep, but has properties that lead some people to call it “paradoxical sleep.” When you examine the brainwave readings of a person in REM sleep, it bears a striking resemblance to the readings an awake person would produce. Certain parts of the brain are dormant, while others show more activity than while you’re awake. As a whole, REM sleep is where your mind is “repaired” and prepared for the following day. People who regularly have issues concentrating or remembering important information might just struggle to get enough REM sleep. Stage 4 becomes more and more prevalent as the night goes on until, eventually, the person wakes up. It takes up around 25% of your total sleeping time, assuming you’re not interrupted.
An Overview of Napping
So how does napping play into all of this? Well, the first thing you should remember is that light sleep is the only stage where it’s easy to wake someone up without creating a very unpleasant period of sleep inertia. For those of you that aren’t aware of sleep inertia, it’s just a fancy term for that groggy feeling you get when you wake up, especially if you haven’t had enough rest overall. The problem with sleep inertia is that is causes a massive drop in performance for many actions you wish to perform before that grogginess subsides, including maths or memorization.
If you are roused from a deep sleep, that sleep inertia hits you so much harder and takes way longer to pass. It means that if your daytime nap comes right before something important, you want to take care of, and you allow yourself to enter stage 3, you’re far more prone to errors than if you had simply avoided the nap altogether – a potentially life-threatening scenario if you plan on driving anytime soon. Logically, this would mean that naps are best left within the realm of light sleep, which usually limits your resting time to around 20 minutes at most. But this isn’t the only reason to impose that kind of time limit – we have to talk about sleep onset latency.
Sleep onset latency represents how long it takes you to fall asleep once you are in bed and trying to doze off. The lower the sleep onset latency, the easier it is for you to start sleeping. Many disorders tend to drastically increase this latency, causing periods of insomnia that can last for hours, and seriously impact your overall sleeping schedule and health. Simply dipping into deep sleep is enough to increase your sleep onset latency in the future – mainly, when you have to go to bed in the evening. The problem can then loop back into itself – if you don’t get enough rest during the night, you will be more willing to take a nap, and can easily set yourself back on later sleep, which makes you tired the following day, and so on. However, staying in light sleep dampens this issue, even if it doesn’t remove it altogether – another reason why your naps should last 20 minutes tops.
During 2006, a study was published in the official journal of the Sleep Research Society (or SRS for short) where they had groups of subjects nap for predetermined periods, and then report any cognitive improvements or impairments they experienced after waking up. The goal was to narrow down the optimal nap duration and help people get some rest without risking their entire sleeping schedule. They used a control group of subjects that didn’t take a nap and then compared it to the results from people who slept for 5, 10, 20, and 30-35 minutes. The results were clear as day.
The group that had slept for five minutes reported very little cognitive improvement, which meant that five minutes of napping doesn’t accomplish much compared to just not sleeping. Subjects who had taken 30-minute naps as part of the study had to deal with a period of unpleasant grogginess but reported noticeable cognitive improvements for almost three full hours after their sleep inertia subsided. Meanwhile, subjects who had slept for 10-20 minutes performed better than either of these two categories. Their cognitive improvements were easy to notice and lasted two or more hours without almost any sleep inertia.
When and Where Should You Take Your Naps?
So we’ve established the ideal duration for your daytime nap, one that leaves you refreshed and ready to perform without having to slog through a period of grogginess. But that still doesn’t answer all of our questions. It can be easy to think that you can just take your nap whenever, and get the same results as the ones we’ve mentioned above. When you take your nap can be just as important as its duration, and our body gives us subtle hints during the day.
Assuming you have a normal sleep schedule, your body will start producing melatonin during the period between 2 PM and 4 PM. For most people, this coincides with lunchtime and seems specifically hard-coded into our system to offer some mid-day relief. We’re naturally sleepier during this time of day and will wake up even more refreshed if we end up taking a nap (as long as it lasts between 10 and 20 minutes). Even if you have to take a nap outside of this specific period, make sure to leave at least 3 hours between that nap and the point where you go to bed for the full night.
The location is also important. It’s not difficult to imagine what kind of place helps you sleep the easiest. You want to establish a temperature that hovers between 60-67 degrees Fahrenheit (which translates as 15 to 19 degrees Celsius) and lie down in a dark room. Natural sunlight is easy to get rid of, but you also want to remember that electronic devices can interfere with your relaxation, especially ones that create a large amount of artificial light. If you let sunlight creep into your bedroom during nap time, you risk throwing your circadian rhythm off-balance due to how it responds to natural light.
Note: Insomniacs are advised to avoid naps whenever possible since napping can amplify their problems with falling asleep at night by extending their sleep onset latency. If you’re worried that naps would be unhealthy for you, consult your primary care physician.
What are Coffee Naps?
Coffee naps are a recent thing, a method many people have been using to ensure they feel refreshed and energized after their daily nap. If you drink a cup of coffee right before you take a 20-minute nap, you create the optimal conditions for yourself. As soon as you wake up from the nap, the caffeine kicks in, jumpstarting your body and mind in a way that improves your performance throughout the rest of the day. This combination is so potent that it’s been skyrocketing in popularity in recent years.
Napping is great for removing excess adenosine from your body. This chemical compound causes drowsiness, and would normally neutralize the coffee, as they have opposite effects. However, when it’s gone, there’s nothing to stop that coffee from zapping you full of energy as soon as the nap ends. Try to drink the coffee as quickly as possible, to make sure the caffeine boost comes at the ideal time.
Tests that were done on subjects who have attempted this method showcase an improvement in the subjects’ ability to perform in cognition and memorization tests. Subjective feelings of improvement were reported as well, suggesting that a coffee nap can also subtly affect a person’s confidence and overall comfort during the day.
How to Take a Short Nap Without Oversleeping
Controlling the duration of your nap is easier said than done. When we’re tired, our body wants nothing more than to sleep for 7 or so hours straight. If we do that, however, we ruin our sleep schedule and create health-related complications in many cases. Luckily, there are methods you can rely on to help you control how long your mid-day naps are. Let’s list the most prominent ones:
- Drink a cup of coffee right before your nap. We mentioned this above, but the effectiveness of a caffeine kick should not be underestimated. Not only will it energize you for the rest of the day, but it will make it easier to wake up if your nap extends 5 minutes past the intended limit. Try to avoid putting any sugar or milk in the coffee, just in case.
- Set an alarm for when you’re meant to wake up. It may be self-explanatory, but exhausted people tend to forget even simple things. To make sure you have a reason to get out of bed, put the source of that alarm on the other side of the room, especially if it’s a smartphone. By forcing yourself to walk across the room to turn off the alarm, you’re putting yourself in a position where you’re already up and running. Try to make the ringtone an aggressive or upbeat song, something you can’t easily sleep through.
- Ask anyone else in your home to help you wake up at the designated time. If you somehow miss your alarm ringtone, you want to have a backup plan, and family members or your partner can help you shake off the sleep inertia and get back into the action.
Michael is a professional writer based in Boston and someone who has always been fascinated with the mysteries of sleep. When he’s not reading about new sleep studies and working on our news section, you can find him playing video games or visiting local comic book stores.