If you’ve ever felt the need to rest your head on your work desk to secretly get a few minutes of post-lunch shut-eye while the boss wasn’t watching, it turns out you’re not lazy or disinterested. In fact, you are very normal.
According to Moira Junge, sleep psychologist and member of the Sleep Health Foundation, we were designed to require an afternoon kip to get through the day.
“We are all pre-programmed to need a little nap in the afternoon, explains Junge. “What happens with our body’s sleep mechanisms is that we have a post-lunch dip in our system and have a propensity to sleep.”
Junge explains the ‘post-lunch dip’ in our 24-hour circadian rhythm is like a sleepy switch that just flicks on in the afternoon. It’s independent of what we eat and of the amount we’ve slept the night before. This dip also gets repeated at night around 11pm and is the reason why some of us ‘crash out’ around that time.
“We are all pre-programmed to need a little nap in the afternoon. What happens with our body’s sleep mechanisms is that we have a post-lunch dip in our system and have a propensity to sleep.”
But, says Junge, what’s unique about this afternoon napping signal is that it’s temporary. It lasts 30 minutes to 1.5 hours before we go back to feeling alert again.
“If you don’t get an opportunity for sleep, say if you are at work, you can cycle through this dip quickly as your body’s systems will rise again, with or without a sleep if you can just manage to stay awake through it.”
Professor Leon Lack from the School of Psychology at Flinders University is pro-power napping and says if we can, we should. He reminds me that our need to nap in the afternoon is the reason why siestas are an accepted practice in many countries and explains that napping is a natural human habit dating back hundreds of years.
“We’ve become so fixed in our cultural habits of having a single nighttime sleep,” Prof Lack tells SBS. “This idea is a reasonably recent cultural adaptation from the industrial revolution and because of the advent of electric lights.
“Over 300 years ago, when most people were rural farmers, you probably had naps in the middle of the day and stayed up a little later at night but only so long as the fires burned in your house.”
So let’s say one day, our workplaces radically changed to become pro-napping zones. How long a kip should we have on our desk before the alarm rings? Junge says the trick is for the nap to be very short: 20 minutes is ideal, with time dedicated for you to fall asleep.
“If you sleep more than 20 minutes, you get into that deep slow wave of sleep where you can’t hear anything or wake up and don’t know where you are,” says Junge.
“That’s because the first 20 minutes of sleep are very light, stage one and two of sleep, and if you sleep for longer, you are more likely to have sleep inertia, where you wake up and feel worse or take a long time to ‘wake up’ and get going. Longer naps might also affect your sleepiness and ability to sleep at night. So short, sharp naps are recommended.”
Prof Lack goes even further to suggest that the average adult should be having 10 minute power naps in the afternoon, as needed, with a few minutes added to fall asleep.
He co-conducted research in 2006 comparing no naps with naps of five, 10, 20 and 30 minute durations. The 10-minute adult nap gave participants the biggest rise in alertness with the minimal amount of post-nap grogginess.
“With the 20 and 30 minutes sleeps, performance was impaired a little bit immediately after waking up for the first half hour or so,” says Prof Lack. “But the 10 minute naps produced significant benefits in cognitive performance.”
"Stop the struggle and have a quick kip so you can be more productive at work for the rest of the day.”
The moral of this dreamy story, Prof Lack suggests, is that if someone is really struggling with sleepiness in the afternoon, it’s likely they will continue on struggling for up to 90 minutes until they come out of ‘that dip’.
“So managers should find out what’s better for the worker. Is it better for them to be below par at work for 1.5 hours [during their afternoon dip] and potentially make mistakes? Or allow them 15 minutes – five minutes to relax and fall asleep and 10 minutes of napping – to increase the productivity for the remainder of that 1.5 hours?
“Napping could be considered beneficial if you are struggling with sleepiness in the day, commonly in afternoon and have a decline in alertness. Stop the struggle and have a quick kip so you can be more productive at work for the rest of the day.”
Both experts stress that this advice is general and that sleep needs vary according to individual needs and circumstances. They recommend that people with sleep disorders consult a GP and, if needed, see a sleep specialist.
Catch up on Insight's Sleep special on SBS On Demand: