Are you a medieval sleeper? Why it's time to put the eight-hour night to bed 

In my 20s I’d fall asleep like a cat: on aeroplanes and trains and even – a lucky knack for a travel writer – the back of bumpy rickshaws. But wherever I lay my head, by 3am I’d be awake and pottering about for up to an hour before dozing off again until 6am. I now know I’m not alone.

Two thirds of women over the age of 40 wake at least once during the night, according to researchers at Harvard University, while a Sleep Council report found that a quarter of over 40s are natural ‘biphasic sleepers’. Biphasics, as we are known, tend either towards the ‘siesta structure’ of a five- or six-hour night-time sleep, plus a 30- to 90-minute daytime nap, or – like me – into a rhythm of two- to four-hour sleeps bridged by a waking period.

This isn’t something we can control – it is related to your age and circadian chronotype, which decides if you’re a night owl or up with the larks (or, in fact, a dolphin, lion, bear or wolf). Biphasics differ from insomniacs in that they do get enough sleep.

In fact, A. Roger Ekirch, author of At Day’s Close: A History of Nighttime, argues that biphasics or ‘medieval sleepers’ get closer to nature’s intention than the sleep we aspire to today (those precious eight uninterrupted hours).

‘For thousands of years until the industrial age, humans slept twice,’ Ekirch says. ‘A deeper first sleep from sunset until around 2am, followed by an interval of wakefulness, usually lasting an hour, then a lighter second sleep until around 6am, or later in the winter.’

The interval in the middle was used to visit neighbours, pray, or have sex, according to Ekirch. Only with the arrival of artificial lighting in the 1820s did sleep begin to compress into the pattern we now know.

For years I battled my ‘medieval’ sleep schedule, thinking it eccentric and antisocial. I tried meditation and melatonin hormone supplements.

I ignored the clock during my wakeful phase and counted my breaths and heartbeats. I tried sprinting and yoga, valerian roots, chamomile and blackout curtains. Back then, my sleeping patterns had a greater impact on my life. In a particularly hormonal phase in my late 20s, I’d sleepwalk, or rather ‘sleep cook’, at the tail end of my first sleep, jolting to wakefulness to find myself in the kitchen grilling something peculiar (once, sweet pickle and mayonnaise).

In my early 30s, my nocturnal activities caused tensions with a boyfriend who was  a light sleeper and, after I woke him up, he would pace the flat in his underpants accusing me of ‘Riverdancing’ in bed. 

More recently, with a husband who’s a rock-solid sleeper and a renewed gratitude for my wakeful hour, I’ve made peace with my medieval sleep patterns. Unbothered by my night-time wakings, Tim is grateful that I’m a morning lark to his night owl, making us compatible for shared parenthood.

Dr Bryony Sheaves, a clinical psychologist from the Sleep & Circadian Neuroscience Institute, concurs. ‘Some people will wake in the night and others won’t; some people are morning people and others are evening types. So abandoning strict rules about sleep can reduce the anxiety that often gets in the way of a good night’s sleep.’

But are there any other benefits to biphasic sleeping, beyond splitting childcare and achieving a neat sock drawer? Segmented sleepers often find they sleep fewer hours overall but that they wake feeling more refreshed.

According to a report in The Journal of Clinical Endocrinology & Metabolism, biphasics consolidate deep sleep (when your brain and body are restored) in their first block, then have REM sleep (when dreaming occurs) during their second, which boosts sleep quality. 

Nick Littlehales, a sleep coach to Premier League football teams, agrees we should think less in terms of an unbroken night’s sleep and more in terms of sleep phases. ‘We’re all up on exercise and diet these days, but when it comes to sleep we just trundle through our day until we only have seven or eight hours left until we have to  do it all again,’ he says.

Instead, he advises people to think in terms of four to five 90-minute blocks of sleep over a 24-hour period. ‘Why not get up at 2am after your first two or three sleep cycles and do some ironing, or make your lunch for the next day, before heading back to bed?’ he says. 

Since I stopped worrying about my own unusual way of sleeping, I’ve harnessed  the time for my benefit. I find my ironing pile greatly reduced as a result of my night-time waking periods. And I’m  less anxious during the day when I’ve made the most of that precious middle-of-the-night hour for thinking over my problems and working out how to  tackle them.

So maybe it is time to stop aspiring to that maddening myth of eight uninterrupted hours’ sleep at  night, in order to have a really good night’s (or day’s) sleep.

Illustrations by Giacomo Bagnara