By Dr Luisa Dillner/London
If you’re yawning while you’re reading this you are either already bored (how rude) or tired. And if you’re tired, you’re also likely to feel frustrated, impulsive and a bit miserable.
Sleepiness is also often accompanied by finding it hard to remember things, an inability to concentrate and a tendency to bump into things. Thank goodness there’s a cure – even on the busiest of days. It’s the midday nap.
A small study in the journal Personality and Individual Differences of 40 volunteers aged between 18 to 50 who’d all had the same average amount of sleep found that those who had an hour’s afternoon nap spent longer on an impossible task without getting frustrated than those who didn’t nap.
But who wants to get better at coping with an impossible task? What this translates to in ordinary life is that napping not only reduces tiredness, but the impulsive decision-making and short-temperedness that goes along with it.
The nap, arguably, is underused in modern life, especially among grumpy, tired people. Previous research has found it increases “positive emotions”, “energy”, “motivation” and “joy”. So should everyone go back to being a toddler and have a kip after lunch?
Naps commonly last between 30 and 90 minutes and it’s estimated that regular naps are taken by between a third to two-thirds of people worldwide. Studies show naps are more effective than caffeine in increasing alertness and improving verbal memory.
Even a brief nap of 7 to 10 minutes (nodding off) can have immediate benefits lasting up to three hours. However, longer naps, of two hours, can lead to sleep inertia producing feelings of disorientation, especially if you had a high sleep “debt” before you nodded off.
Between 1pm and 4pm is the time most conducive to napping – Japanese research puts the best time to nap at 2pm, for 20 minutes. This produced the greatest feelings of alertness and well being for the longest time.
A review of napping in pilots (called strategic napping) found that those who took naps (yes, sometimes in the cockpit, according to the research) during the cruising phase of long-haul flights improved their alertness and performance. Fatigue in pilots can manifest itself in poorer reaction times and reduced awareness of peripheral vision.
One review article in Sleep Medicine did find a relationship between daytime napping and an increased risk of dying from any cause but the authors point out that sick people are more likely to take daytime naps anyway, so don’t let this put you off. It’s more of a concern that you’ll snore or dribble in front of colleagues.- Guardian News and Media
♦ Dr Luisa Dillner, a writer and doctor, heads BMJ Group Research and Development
