What is a coffee nap - and can it make us more alert?

[Photo: Getty]

Words by Lydia Smith. 

Around one in three people have trouble sleeping and, as we all know, a restless night can leave us tired, frustrating and struggling to focus during the day.

Yet a build-up of sleeplessness can leave us with what experts call a “sleep debt” – when our hours of lost slumber clock up, leading to mental and physical fatigue.

Many of us rely on coffee to help perk us up during the day and if you find yourself fighting sleep during the day, a nap can help make up for lost slumber.

But, some people believe combining the two is great way to get a boost of energy.

A coffee nap is pretty much exactly as it sounds

You drink a caffeinated beverage and then settle down for a 20 or 30-minute nap, which is considered the ideal length to improve alertness, performance and mood, according to the National Sleep Foundation.

It is thought to boost energy levels because of its effect on adenosine, a chemical that promotes sleep.

“Adenosine is a chemical found in your body, which plays a part in regulating sleep by suppressing actions of the central nervous system associated with wakefulness,” says Abbas Kanani, pharmacist at Chemist Click. “Adenosine levels accumulate when you are awake, binding to adenosine receptors causing you to feel tired. When you fall asleep, adenosine levels drop, meaning you feel less drowsy.”

“Coffee helps to keep you awake by competing with adenosine to bind to adenosine receptors, without making you feel drowsy,” Kanani explains. “Taking a nap naturally lowers adenosine levels, and this effect combined with caffeine competing with adenosine to bind to receptors, can leave you feeling more alert during the day.”

You don’t need to worry about not being able to fall asleep right before drinking coffee, he adds, as the stimulating effects kick in around 20-30 minutes after consumption.

“In essence, adenosine levels are naturally lower after a nap,” Kanani says. “This effect in conjunction with caffeine competing with adenosine to bind to receptors (which don’t cause a drowsy effect), make it harder for adenosine to exert its sleepiness effect, which should end up leaving you more alert than a normal nap.”

In theory, therefore, you’ll feel more refreshed when you wake up

Your body will feel the effect of the caffeine hours later, as a moderate amount – a cup of coffee – takes up to five hours to leave your system.

Chloe Hall, a dietician with the British Dietetic Association, points out that it actually might be more beneficial to sleep first before having a caffeinated drink.

“Caffeine can improve alertness in the short-term, however it can, also, interfere with sleep so I would suggest that having a nap first and then having a cup of coffee may be more beneficial,” she says. “Some studies have looked at having a caffeinated drink and then a nap with beneficial results, however the studies were fairly small.”

There’s limited research to back the theory up

In 2003, a study suggested that a nap combined with caffeine reduced levels of sleepiness in participants more than a nap alone.

However, only 10 adults were involved in the study.

Research from 1997 also found consuming 200mg of caffeine before a 15-minute nap helped improve alertness in 12 sleepy participants taking part in a simulated driving experience.

Be careful not to overdo your caffeine intake

When we’re tired, it’s tempting to reach for the coffee pot every time we feel sleepy. It’s important not to have too much otherwise it will impact your sleep quality and can lead to health problems, Hall adds.

“Around 400mg of caffeine a day, equal to around 4 or 5 cups of coffee, is thought to be safe, however it does depend on the individual,” she says. “Pregnant women are advised to restrict caffeine to no more than 200mg a day and some people are, also, more sensitive to the effects of caffeine.

“Too much caffeine can affect people in different ways but it can result in anxiety, headaches, shakiness and gut issues such as diarrhoea.”

How good for us is napping?

Napping alone can be good for us, although relying on brief periods of sleep during the day might not address the underlying causes of insomnia at night, such as stress or too much screen-time.

Research has suggested naps not only make us feel less sleepy, but also improve our cognitive functioning, short-term memory and our mood.

Matt, who is 30 and works in events, says he often tried to get a few minutes of sleep during the day when he gets a break from work.

“It seems that everyone I know these days is constantly tired and feels like they haven’t slept enough each night,” he says. “If I get the opportunity during the day and my body feels like it could fall asleep, I take that as a sign that my body needs more sleep and I generally feel better after a short nap.”

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