Which Type of Nap is Best?

‍Reviewed by Sahil Chopra, MD, and Stacey Gunn, MD.

Research by Savit Malhotra.

In this fourth and final article of our napping mini-series, we will end our discussion on naps by talking about the different types of naps and which one tends to be the best and causes the fewest negative effects. Specifically, we will be looking at power naps, “cat naps,” non-sleep deep rest, and “nappuccino.”

Introduction

Now that we have explored what napping is, when it can be helpful, and when it might be doing more harm than good, it’s time to conclude our series by discussing the different types of naps that people can take. Contrary to popular belief, napping isn’t a “one-size-fits-all” solution. Power naps, “cat naps,” non-sleep deep rest, and “nappuccino” are all examples of these different types of naps. In this final article, we will start by breaking down what each of these naps is, the best use for each nap, and how you can choose which nap is the right fit for you. 

Power Naps

When people think of taking a nap, they often think of a power nap, even if they don’t exactly know what it is. A power nap is typically defined as a short, 10 to 30-minute sleep where your body is able to rest without falling into the deeper stages of sleep.^[1] The reason why power naps tend to be so effective is that, since they avoid deeper sleep stages, they avoid sleep inertia (a temporary state of disorientation and declined performance).^[2] Typically, deep sleep occurs after about 30 minutes of being asleep.^[1] 

Research has shown that generally, those who take a nap in the afternoon do see improved cognitive performance, specifically in alertness. This study also mentions that naps should be kept short in order to avoid sleep inertia, and when this is followed, the benefits of the nap may last up to 2.5 hours (however, this is a topic that still requires further research).^[3] Here, we see that short power naps do provide benefits so long as sleep inertia is avoided. It is a good idea to keep these to about 20 minutes, because timing sleep stages can become tricky, and you may unknowingly slip into deeper sleep closer to the 30 minute mark. A study published in SLEEP looked at the effects of 10-minute naps versus 30-minute naps (especially in the case of a simulated night shift) and found that the 10-minute nap caused the least sleep inertia and mitigated a performance decline after the nap. However, those who took a 30-minute nap did suffer from considerable sleep inertia and performance decline after they woke up due to the 30-minute nap having more associated slow wave sleep.^[4] 

Figure 1: The graph above shows the difference in cognitive performance for the different control groups in the aforementioned research study. The 10-minute nap group was associated with the smallest decline in performance post-nap, while the 30-minute nap group saw a sudden decline in performance post-nap. All credit belongs to the original authors. (Hilditch et al.)

Based on these studies, we can see that shorter power naps do tend to be better in terms of maximizing performance while minimizing sleep inertia. 

“Cat Naps”

A “cat nap” is often thought of as quick, light doze.^[5] When it comes to these types of naps, they are often unplanned and just happen due to a person being overwhelmingly tired. Thus, it is not unusual for a person to take a cat nap without setting an alarm.  Sometimes people wake up quickly from these, but other times the nap can inadvertently extend past the ideal < 20-minute nap time. A person may then experience sleep inertia and cognitive impairment upon waking, making their day even harder than before they went to bed. We often recommend that when a person decides to take a nap, they do so with intention. That is to say, they know why they are taking a nap (for example, in order to boost cognitive function for the last half of their work time) and time it correctly by setting alarms and actually getting up when the alarm rings. 

If a person is taking cat naps often and is regularly experiencing these unplanned sleeps, it could point to some greater issue. As we talked about in the last article, feeling tired during the day could be a sign of some other issue with nighttime sleep. This raises questions like whether a person is sleeping enough at night or if they may have some other issue, like sleep apnea, that is disrupting their nighttime sleep and thereby causing them to need to take naps in order to get through their day. 

Non-Sleep Deep Rest

Non-sleep deep rest (NSDR), a term coined by neuroscientist Dr. Andrew Huberman, is a method in which a person is able to rest and relax without actually falling asleep.^[6] When a person practices NSDR, they are able to enter a state of deep relaxation through relaxation techniques like breathing, visualization, and attention exercises.^[7] These techniques were first explored in Yoga Nidra, otherwise known as yogic sleep, where a person combines imagery and specific posture to achieve this state of deep relaxation, where their mind can rest while they are still aware of their surroundings.^[8]

By practicing the different relaxation techniques mentioned above, it is believed that a person is able to decrease their sympathetic nervous system activity (the part of the nervous system responsible for the human “fight or flight” response) while increasing the activity of their parasympathetic nervous system (the part of the nervous system that is responsible for “rest and digest” functions).^[11] Additionally, NSDR/Yoga Nidra helps reduce anxiety symptoms, both the cognitive and physiological symptoms.^[7,9] 

Current research mostly surrounds the practice of Yoda Nidra as opposed to NSDR, yet the results of either can be generalized and applied to different scenarios. For example, one paper found that when physically active people practiced NSDR, they saw a significant increase in their performance due to improvements in their physical readiness, recovery state, and mood states. These same participants also saw a decrease in their stress levels, showing both the physical and cognitive benefits of NSDR.^[10] For more information on how to practice NSDR, we have included a link to Dr. Huberman’s guide to NSDR as well as an article on the steps to practicing Yoga Nidra.

“Nappuccinos”

Finally, we will now talk about the “nappuchino,” otherwise known as the coffee nap. This technique involves taking a power nap immediately after drinking a cup of coffee. The thought behind this is that after approximately 20 minutes, the caffeine from the coffee will kick in and help you wake up, preventing your nap from extending past 20 minutes and helping to increase your alertness.^[12] We talked earlier about optimal sleep time, and the coffee nap is a great way to abide by this, as it takes roughly 20 minutes for caffeine to travel through the bloodstream to the brain.^[13] 

We have often talked about why drinking coffee before sleeping can result in poor nighttime rest. As a quick refresher, this is because caffeine saturates our adenosine receptors, which are the binding spots for the neurotransmitter adenosine. Adenosine serves an important role in the regulation and maintenance of sleep. So it may seem counterintuitive to drink caffeine, a stimulant, right before sleeping. The key here, however, is that we aren’t trying to maintain our sleep at all; in fact, we want our sleep to become disrupted so that we may wake up from our nap. Research has shown that blocking the adenosine receptors not only allows us to wake up but also helps us feel refreshed while experiencing reduced drowsiness and increased performance. One study found that taking a nap after drinking caffeine led to fewer sleep-related incidents than those who took a placebo or only a large amount of caffeine.^[14] A similar study also found that caffeine and a nap were associated with performance maintenance as opposed to a placebo group.^[15] 

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Figure 2: The chart above shows the significant differences in the number of sleep-related incidents of a group that had high caffeine levels, caffeine and a nap, and a placebo. The caffeine and nap group saw the fewest incidents during all of the time intervals after the break. All credit belongs to the original authors. (Reyner et al.)

Conclusion

So, which type of nap is best? Immediately, we can eliminate cat naps from the running due to their vast unpredictability. Cat naps can be indicative of some other problem, and so those who are regularly taking these types of naps should consider taking a deeper look into their sleep. NSDR is a great practice for someone to become productive during later times of the day. Since a person is not actually falling asleep when they practice NSDR, it is unlikely that it will significantly hinder their circadian rhythm, and the benefits of NSDR are unparalleled. For this reason, it remains one of the best techniques when it comes to boosting daytime productivity, even though it is not, by definition, a nap. The other benefit of NSDR is that it can be completed in as little as 10 minutes, or can be extended to 30-60 minutes if needed to combat a loss of sleep from the night before.^[6]

However, some people may not be able to achieve this deep state of relaxation in 10 minutes and really are crunched for time. In this case, a power nap would remain a reasonable option. These naps have been scientifically proven to boost productivity even though they are short in length. But if you struggle to stick with the recommended amount of time (about 20 minutes) or find yourself sleeping through your alarms, a “coffee nap” can be a great way to build on this style of napping. This style of nap is essentially just a power nap combined with caffeine, so your body is forced to wake up after 20 minutes. This option also remains a well proven method of boosting your daytime productivity, however, depending on how you time the nap, you may disrupt your circadian rhythm if you take this nap too late in the day or when your sleep drive is low (for more information about how naps can impact your nighttime sleep, read our article on when napping becomes harmful).

At the end of the day (pun intended), ensuring your nighttime rest is up to par remains the best option when it comes to optimizing your day. If you want the most productivity, the fewest naps, and the least grogginess during the day, it is important to always make sure you are getting enough high-quality sleep every night. If you ever suspect that your nighttime rest is not where it should be, consult with a sleep doctor so that they can help you get back on track! 

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This concludes our napping mini-series. Next week, we will begin a new series where we talk about the different bidirectional relationships between sleep apnea and your body. We have previously released an article on the bidirectional relationship between obstructive sleep apnea and obesity, and this will serve as our starting point. We will next look at the relationship between obstructive sleep apnea and diabetes. 

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