Learning how to hack your own body clock

Have you ever won­dered why some peo­ple leap out of bed first thing in the morn­ing, instant­ly ready to tack­le the day ahead, while oth­ers only start feel­ing pro­duc­tive late in the day? If so, you might be inter­est­ed to know that much of the vari­ance is con­trolled by genes – or, to be pre­cise, a pro­tein-cod­ing gene called peri­od cir­ca­di­an reg­u­la­tor 3 (PER3). This helps to reg­u­late our body clocks, con­trol­ling the sleep/wake cycle or cir­ca­di­an rhythm. 

Muta­tions in PER3 have led to the exis­tence of “extreme larks” and “extreme owls”. These make up 27% and 9% of the pop­u­la­tion respec­tive­ly, accord­ing to a 2018 study of 433,268 peo­ple pub­lished by Kris­ten Knut­son and Mal­colm von Schantz in The Jour­nal of Bio­log­i­cal and Med­ical Rhythm Research. Most peo­ple, who sit some­where along a con­tin­u­um between these two chrono­type groups, are known as “hum­ming­birds”.

Evo­lu­tion­ary psy­chol­o­gists posit that the emer­gence of larks and owls start­ed as a trib­al pro­tec­tion mech­a­nism. Night was the most dan­ger­ous time for ear­ly humans. It made sense to have peo­ple who were able to stay alert, main­tain the fire and keep watch overnight. They could then be relieved at dawn by the ear­ly ris­ers. 

An individual’s chrono­type can fluc­tu­ate with age. While young chil­dren and the over-60s would gen­er­al­ly be described as larks, teenagers tend towards owlish before sta­bil­is­ing into their adult chrono­type in their mid-20s.

PER3’s influ­ence doesn’t ful­ly account for how our body clocks are set. The suprachi­as­mat­ic nucle­us – locat­ed close to the optic nerve in the hypo­thal­a­mus region of the brain – also plays a role in reg­u­lat­ing cir­ca­di­an rhythms by respond­ing to light and dark­ness. This means that our cir­ca­di­an rhythms are affect­ed by the vary­ing lengths of day and night over the year too.

A third influ­ence is our own habits. Dr Guy Mead­ows, clin­i­cal direc­tor and man­ag­ing part­ner at Lon­don-based clin­ic Sleep School, explains: “Beyond genet­ics, our every­day behav­iour also has a strong impact on our sleep/wake tim­ing, espe­cial­ly now, when peo­ple are work­ing for longer and lat­er, while expos­ing them­selves to a lot of light-based stim­u­la­tion from elec­tron­ic devices for longer and lat­er too.”

The problems of being a night owl

While the times at which we’re at our most effec­tive are part­ly genet­i­cal­ly dic­tat­ed, there is lit­tle acknowl­edg­ment for this fac­tor in a civil­i­sa­tion that tends to be organ­ised around ear­ly ris­ing.

“Vari­a­tions on the phrase ‘the ear­ly bird catch­es the worm’ can be found in every lan­guage on the plan­et,” Mead­ows says. “By con­trast, there’s a huge stig­ma asso­ci­at­ed with being a night owl, as we live in a world that is, com­plete­ly erro­neous­ly, set up for those of us who fare bet­ter in the morn­ing.”

While peo­ple are only just start­ing to appre­ci­ate that point, the Covid-19 lock­downs have actu­al­ly helped some night owls who’ve been oblig­ed to work at home. “The fact that they haven’t had to get up ear­ly to com­mute means that they’ve been able to sleep in for a bit longer, which is more aligned to their nat­ur­al rhythms,” Mead­ows explains.

This idea of align­ment is impor­tant. For peo­ple whose lifestyles aren’t in har­mo­ny with their nat­ur­al rhythms, any resul­tant sleep depri­va­tion can harm their men­tal and phys­i­cal health. Their con­cen­tra­tion and mem­o­ry can suf­fer and they may be vul­ner­a­ble to high­er lev­els of stress and anx­i­ety. They may also be at greater risk of heart dis­ease and type 2 dia­betes. Stud­ies indi­cate that night owls are more prone to all of these prob­lems.

While most peo­ple require between six and eight hours of sleep a night, as many as half of all peo­ple in the West are “out of phase”, accord­ing to Dr Sari­ta Robin­son, deputy head of psy­chol­o­gy and com­put­er sci­ence at the Uni­ver­si­ty of Cen­tral Lan­cashire. This means that they’re get­ting up before they want to or going to sleep lat­er than they should. This is usu­al­ly down to the effects on the suprachi­as­mat­ic nucle­us of the blue light emit­ted by com­put­er screens and mobile phones.

How to work with your body clock

So, what can peo­ple, and night owls in par­tic­u­lar, do to improve their well­be­ing? Mead­ows’ advice is to at least try to get the right amount of sleep most nights of the week.

“Keep a reg­u­lar wake/sleep cycle,” he says. “If you’re incur­ring sleep debt from going to bed too late, take mea­sures to repay it by going to bed ear­li­er or sleep­ing lat­er one night a week.” 

Anoth­er fac­tor that can ben­e­fit sleep-deprived peo­ple is to work effec­tive­ly with light, says Dr Lind­say Brown­ing, author of Nav­i­gat­ing Sleep­less­ness and sleep ambas­sador for bed retail­er And So To Bed. For night owls, this could mean open­ing the cur­tains first thing in the morn­ing to get as much light into their eyes as pos­si­ble. Doing so inhibits the pro­duc­tion of mela­tonin, the sleep hor­mone, and acti­vates cor­ti­sol, which makes them feel more awake. Sun­rise alarm clocks, which wake peo­ple with a grad­u­al­ly bright­en­ing light, are a use­ful alter­na­tive dur­ing the dark­er win­ter months.

Mean­while, larks who want to stay more alert in the evening should stim­u­late their brains with the blue light of an elec­tron­ic device and refrain from dim­ming the lights in their homes.

Anoth­er option, Brown­ing says, is for peo­ple to learn to work effec­tive­ly with their own body clock and its nat­ur­al peaks and troughs.

“It makes sense for larks to per­form impor­tant tasks ear­ly in the day and for owls to save more com­plex activ­i­ties for lat­er,” she says. “While you can’t change your chrono­type, you can recog­nise what it is and so make your day work more effec­tive­ly for you.”