Dorveille Sleep: Is It a Good Idea to Split The Night's Rest Into Two 'Shifts'?

Common health guidelines promoted by the World Health Organisation (WHO) and US' Centers for Disease Control and Prevention (CDC) say that adults need to 7 to 8 hours of sleep at night. But it turns out that's not how humans have always slept.

There are theories that, long before humanity introduced the solid eight-hour sleep session at night as a norm, people used to sleep in two "shifts", in a method that is also known as "biphasic sleep" or "dorveille sleep".

It seems that evidence of people adopting such a habit can be found in literature and old medical records, but are there any actual health benefits to this practice?

"Individuals say they have found it has made them more productive and calmer throughout day, particularly if the segmented sleep fits in with the rest of their life’s schedule," sleep expert James Wilson told Metro.

According to him, most people who opt to "sleep in shifts" prefer dividing their night into sessions of four hours.

"This generally gives you most of your deep sleep and some of your REM sleep, the sleep that is important to physical and mental health, so it feels like a good minimum amount to aim for in the initial segment," he said, adding that the waking period between the shifts is generally two hours.

However, should you switch to biphasic sleep, be ready for short-term after-effects as it can affect both physical and mental health.

"If you have – to your knowledge – always been a monophasic sleeper in your adult life, then changing to a biphasic sleep schedule can initially have adverse effects especially if it results in sleep deprivation which could cause serious health issues," said Colin Aston-James, creator of SleepHub - a device to improve sleep quality.

Those who switch from monophasic sleep to biphasic might feel "jet-lagged", according to Aston-James, and it could be difficult to concentrate at certain times of the day - but at the same time, they might feel more energetic during parts of the day where they felt drowsy before.

"Some found it strange to be wide awake and have energy at night when most others in their surroundings were fast asleep," he said.

Aside from this, biphasic sleep can pose additional difficulties when you try to adjust it to the common working day, when the majority of colleagues and family members prefer monophasic sleep.

So maybe good old naps are a better idea if you want to get a quick rest and increase productivity in the modern bustle.