Need to know
Napping is back in vogue
You’re back from lunch and ready to get back to work except… you feel sleepy. Should you force yourself to stay awake, or should you let yourself doze off? Would it help, or would it ruin your night’s sleep? We are sleep scientists and we’re going to walk you through the science of napping and how to nap in a way that is of maximal benefit.
Naps are short periods of sleep that occur outside a main nocturnal period. It is critical to distinguish these planned periods of daytime sleep from episodes of irresistible sleep that are not intended. The latter could signify significantly inadequate nighttime sleep, jetlag, a sleep disorder, or a neurological condition that requires medical attention.
Toddlers, young children, and younger adolescents nap regularly, but with brain maturation comes a reduced tendency to nap from mid-adolescence to midlife. Afternoon napping used to be a fixture in Mediterranean, Middle Eastern and East Asian societies, providing a respite from high outdoor temperatures and to accommodate for sleep patterns, such as waking up very early in the morning for prayers. However, with economic development, air-conditioning and the emergence of work schedules aligned to those in Western Europe and North America, the practice has declined in many countries where it was once common. In most Western societies, a nap would mean sleeping at the workplace, but this is often frowned upon and carries the connotation that one is not putting in effort or is being slovenly – for instance, in 2019 the US government formally banned any federal employees from napping at work.
There has been a recent rekindling of interest in napping – as reflected in a rise in research papers, media coverage and even companies offering at-work nap facilities. This has happened for at least two reasons. The first relates to many people’s impression that they are not obtaining adequate nocturnal sleep. This can cause them tiredness and a lack of motivation to work, particularly in the afternoon. For these people, a mid-afternoon nap can help boost cognitive function.
Consider our research with adolescents, who were allocated either five or six-and-a-half hours of sleep at night over successive nights. We found that a 60- or 90-minute nap restored their alertness and ability to pay attention almost to the level of control participants, who were averaging nine hours of sleep a night. Although we don’t recommend using napping as a daily remedy to compensate for lack of nocturnal sleep, our findings clearly suggest that napping is an effective countermeasure when applied sparingly.
A second reason for the new spate of interest in napping relates to people who obtain adequate or near-adequate sleep at night, but who have become interested in using naps as a performance-optimisation tool. Their interest is justified by a recent research review showing that, even with adequate nighttime sleep, naps can boost productivity and learning.
For instance, one study compared people’s ability to memorise facts, depending on which of three conditions they were in: the first group had two learning episodes separated by a 60-minute nap; the second group had two learning episodes separated by a 60-minute break; and the third group continued cramming through the 60-minute break. You can imagine these as representing some of the ways students choose to spend their afternoons during a semester. All the groups were tested 30 minutes after the second learning session. At this point, both the cramming and the napping groups outperformed the group that simply took a break, but crucially only the napping group showed this memory advantage when tested again a week later. Such findings suggest that, instead of forcing oneself to continue learning without a break, taking a nap between learning sessions might result in greater productivity. Indeed, several companies are beginning to provide facilities for napping to achieve this.
Most research in this field has focused on using sleep to aid memory-consolidation after a period of learning – this is the process by which information is made more durable to forgetting and interference from similar material. However, naps can also benefit initial encoding of information. Our own work has demonstrated that naps prior to study can facilitate fact-learning and the building of new knowledge. Related research shows that naps are linked to subsequent increases in brain activation in the hippocampus, a structure crucial for supporting memory.
Naps: worth giving them a try
Despite all these reasons to nap, only about half of adults report regularly taking naps. While for some the barrier may be opportunity, for others it may be the feeling that they are incapable of napping. If you find yourself in this category, don’t brush off napping just yet. In this Guide, we will share advice on napping that will help you give it another go. In particular, we will address questions on timing and duration: how long to nap for, at what time of day, and we’ll give you evidence-based reasons for our recommendations.
Even if you feel confident about settling down for a nap, perhaps you’ve had the unpleasant experience where a nap has lasted too long, or you did it too late and it’s affected your nighttime sleep. Or perhaps you started a set task too soon after waking from your nap and were set back by ‘sleep inertia’ – the grogginess immediately after waking. This Guide is for you, too – in fact, it’s for anyone who has wondered about napping better, how napping can be beneficial, or for those who want to try napping for the first time.