It's known as the dreaded 2.30pm feeling.
You've had your eight hours of sleep, a very productive morning and a healthy lunch - but as the afternoon hits you start to fall into a post-lunch slump.
Feeling drowsy after lunch is completely natural, according to Dr Fiona Kerr, a neuro specialist from the University of Adelaide, who explains that humans are "built for two sleeps a day".
"Sleep deprivation in general has a number of negative consequences to the creative process and to general and mental health," she explains.
"The primary effect is the blocking of neurogenesis through increases in corticosterone levels but there is also a drop in attention capacity, executive function, working memory, quantification skills, logical reasoning, motor dexterity and mood."
She adds the slump in the afternoon occurs because our bodies are effectively "programmed to nap" at that time.
"A major reason for this is that human beings are biphasic (physically designed for two sleeps a day), with two major bodily rhythms (homeostatic sleep drive and circadian arousal) which pull us in different directions in terms of staying awake or sleeping, but they fascinatingly align in the middle of the day to create a 'nap zone'.
So how do you beat the workplace energy slump?
Dr Kerr suggests workers would benefit from a 15-minute midday nap, explaining it can offer a multitude of health benefits
They include increases in "cognitive function, memory, alertness, perception levels, stamina, mood, motor skills and creativity - along with decreased stress levels".
"The most common nap is 15 to 20 minutes (often called the Stage 2 nap) which refreshes the brain and increases alertness and motor performance," she adds.
"Having a nap of twenty minutes is also more beneficial than sleeping for an extra twenty minutes in the morning.
Research shows that a nap will temporarily improve mental operations, performance, reaction times and subjective feelings of alertness which can last up to 2 - 3 hours, according to Dr Kerr.
Why lack of sleep is bad for your health:
Regular poor sleep puts you at risk of serious medical conditions, including obesity, heart disease and diabetes – and it shortens your life expectancy.
Most of us need around eight hours of good-quality sleep a night to function properly – but some need more and some less.
As a general rule, if you wake up tired and spend the day longing for a chance to have a nap, it's likely that you're not getting enough sleep.
If you seem to catch every cold and flu that's going around, your bedtime could be to blame. Prolonged lack of sleep can disrupt your immune system, so you're less able to fend off bugs.
Lack of sleep can also make you put on weight
Chronic sleep debt may lead to long-term mood disorders like depression and anxiety.
Studies have suggested that people who usually sleep less than five hours a night have an increased risk of having or developing diabetes.
Long-standing sleep deprivation seems to be associated with increased heart rate, an increase in blood pressure and higher levels of certain chemicals linked with inflammation, which may put extra strain on your heart.
The Telegraph, London
