Why it’s crucial to switch off at 5pm

11th August, 2017

Ever find yourself putting the final touches on a powerpoint presentation as midnight draws closer? Well, you could be part of a problem that costs nearly $66.3 billion per year.

Earlier this week, Deloitte Access Economics together with the Sleep Health Foundation released an exhaustive (geddit?) report on the economic cost of poor sleep [PDF].

The report points out one fundamental truth unique to the modern workplace: we’re not switching off.


The ability to work from home means that often we take our work home with us and blur the lines between the final bell and our own time.

Given that Australians and New Zealanders fought so hard for the eight-hour working day, it’s ironic that we’re so eager to give those gains right back.

As more people bring a connection to the workplace into their home, we’re unwittingly making the eight hours we’re supposed to be resting worse for the sake of the eight hours we’re supposed to be working.

And it’s making both worse.

The blue screen of death (or at least poor sleep)

You’ve probably seen a lot written about the role of ‘blue light’ in sleeping patterns.

It turns out that the blue light emitted from things like smartphones, televisions and laptops are having a negative effect on our circadian rhythms, which are the physical, mental and behavioural patterns in our biology that follow a roughly 24-hour cycle.

A 2014 study [PDF] looked at two control groups – one group reading a book the old-fashioned way before they went to sleep and the other using an e-reader to read the same book.

The study found that the group that read the old-fashioned way felt more sleepy at night and woke up more refreshed, while the e-reader group felt more ‘wired’ at night but woke up horribly.

What happens in the course of normal events is that the pineal gland releases melatonin a couple of hours before you go to bed.

The introduction of melatonin into the system reduces alertness and basically sets the scene for sleep.

But blue light can keep the pineal gland from releasing melatonin, which means those who have been exposed to blue light start the chemical process of sleep later.

The same thing happens to people feverishly typing out emails approaching midnight.

While the time it takes to fall asleep changes, the expected work hours the next day don’t – meaning they end up more sluggish and unable to perform during the day.

The mind also has less time to rest, meaning a key plank of creativity is being cut off.

READ: Are you burning the midnight oil?

The role of rest in creativity

Each night, unbeknownst to us, a human mind compiles all the data presented to it that day to try to make sense of it.

The part of the brain which is active when we are at rest is referred to as the ‘default mode network (DMN)’ – the part of the brain which kicks into life when we’re daydreaming.

When there are no screens demanding our attention, our brain kicks into DMN mode to make sense of all the data that has been presented to it.

Studies have found that this network is more active than is typical in creative people – which is why they can seem off with the fairies.

By continuing to work into the night and exposing ourselves to blue light, we are shortening the time between closing our eyes and waking up with the alarm.

The melatonin release from the pineal gland takes more time to kick in, and the time our minds are in DMN mode is lessened.

This has a very real consequence the next day.

Productivity losses

The gains we’re making by getting that highly critical presentation done by 9am tomorrow is to the longer-term detriment to our work performance.

The report noted that poor sleep habits played a huge role in the effects of both presenteeism and absenteeism.

READ: Why your staff should stay home when you’re sick

It indicated that the cost of productivity losses due to inadequate sleep reached a whopping $17.8 billion.


Those who sleep poorly are simply not as productive during peak times.

It’s why sports teams are now actually hiring sleep experts, viewing sleep through the prism of peak performance.

Sleep is clearly a pretty big deal – if not for peak performance then for health more generally.

By bringing our work home with us we’re robbing ourselves of the best opportunity for quality sleep.

Tapping out that quick email may seem harmless – but it’s probably doing more harm than good.