Afternoon napping: Will you lose if you snooze?

• A number of studies point to the benefits of taking a nap in the afternoon — within certain parameters

Though the Mediterranean countries have long known the value of the after-lunch siesta, it hasn’t been as much of an institution in other, cooler parts of the world. In summer, temperatures of above 30 degrees, there is nothing for it but to pull down the shutters and pass out for two hours or more while the sun moves across the sky.

But even in these countries the afternoon nap is going out of fashion, says Stella Iacovides, a researcher at the Wits Sleep Laboratory and a senior lecturer in the department of physiology at Wits University.

“In recent years, there has been an increase in pressure to abandon the siesta,” she says.

“I believe this is due, at least in part, to the presence of big chain stores (for example Mango, Zara and H&M) with a different idea of working hours, that is staying open throughout the day. As such, siestas are probably less common now in the Mediterranean countries and there is some evidence of negative health outcomes.

“For example, in Greece a study that spanned six years reported that individuals who abandoned regular siestas had a 37% increase in risk of death from heart disease compared with those who maintained regular daytime naps.”

Many working people worldwide are finding it possible to take an afternoon nap because they are working remotely. And some companies, such as Google in Silicon Valley in the US, have introduced sleep pods, where staff can go for a brief quiet refuge from the buzz of the office. These pods, which retail between $8,000 and $12,000, are soundproof and temperature-controlled, and the reclinee is treated to ambient music and can set a timer.

Whether you are in a pod or just napping on your own sofa or bed, there are many health benefits, say the experts, but also a few reasons for caution.

According to Iacovides, daytime naps are recommended for management of disrupted sleep, and they have been shown to combat many of the negative effects of sleep deprivation.

“There are data to support that daytime napping results in improvements in memory, cognitive function, reaction times and mood. In our Sleep Laboratory at Wits we have conducted experiments that have shown a 30-minute afternoon nap helped restore sleep-deprivation-induced pain hypersensitivity in healthy, young individuals who habitually sleep well.

“Daytime napping is not for everyone, especially if it interferes with your sleep later. If a nap interrupts night-time sleep, then it’s certainly not recommended. Getting a good night-time sleep should certainly be prioritised.”

Regarding the length of the nap, she says the benefits are maximised with shorter naps, up to 30 minutes, “but even just 10 minutes can help one feel

refreshed and ready to continue with the remainder of the day’s activities”. The depth of sleep matters.

“A longer nap should be longer than about 90 minutes (a full sleep cycle), to avoid waking up in deep sleep which will increase sleep inertia and could make one feel less fresh and alert than before going to sleep even. So, waking up in a light sleep stage (stage 1 or 2) or in REM sleep will result in feeling more fresh and alert.”

When it comes to where you take a nap, it does not need to be a bed or a pod: “Lying down anywhere for a nap or short rest is beneficial even just shutting the eyes and not quite entering sleep, but perhaps just increasing the alpha brain wave activity, which happens as one enters sleep. Though I agree that a dark comfortable room is absolutely necessary for nighttime sleep, being too comfortable will increase the likelihood of oversleeping. Hence, even resting in the car or on two chairs or a couch in the office for a few minutes (even if one

doesn’t feel like they have gone to ‘sleep’), can be hugely beneficial for levels of cognitive function.”

Referring to a study published in the journal Sleep Medicine, and conducted by Dr Zhe Pan and others at the Guangzhou Medical University, Iacovides says there is a relationship between time spent napping and the risk of mortality, “but also between nap time and cardiovascular risks, meaning that the longer naps, over an hour, had detrimental health effects”.

Interestingly, regarding cardiovascular risks specifically, the authors also report that a shorter nap (30 minutes or less), may in fact reduce cardiovascular risk. “So the length of the nap matters. An extremely important factor to consider is night sleep duration (and quality), and the role that nighttime sleep plays in determining the relationship between napping and all-cause mortality. It may be that napping should be used mainly as a tool to compensate for reduced nighttime sleep. However, if daytime napping is interfering with sleep homeostasis and the circadian rhythm, it should probably be avoided. Shorter naps have less chance of interfering with these systems [as] one experiences less ‘sleep inertia’. Hence, after a short nap one feels more fresh and alert.”

There is some disagreement among experts on whether one can compensate for inadequate night-time sleep, or “sleep debt”. Zhe says his study challenges this notion.

The afternoon nap might be the answer to the problems companies are having with sleep-deprived employees. A study by Charles King, a previous MBA student at the University of Stellenbosch

Business School, showed that sleep-deprived employees are at higher risk of life-threatening chronic illness and disability, more likely to cause workplace accidents, less productive and more absent. The cost to just one medical scheme of treating the life-threatening diseases linked to sleeping less than the recommended eight hours is estimated at R22bn annually, according to the study.

According to King, twothirds of the people whose sleeping habits he tracked slept for less than seven hours a night, with men more likely to be sleep-deprived.

Naps are also not just for elderly people or slackers. The author of Take a Nap! Change your Life, Prof Sara Mednick of the University of California, says: “Napping is not what lazy people do. It’s what people who are really effective and creative and self-regulating and conscientious do.”

Mednick says she hopes companies will allow employees to work from home and take a nap after the pandemic.

DAYTIME NAPPING RESULTS IN IMPROVEMENTS IN MEMORY, COGNITIVE FUNCTION, REACTION TIMES AND MOOD

DAYTIME NAPPING IS NOT FOR EVERYONE, ESPECIALLY IF IT INTERFERES WITH YOUR SLEEP LATER