As As travel restrictions ease, we're waving goodbye to lockdown insomnia and embracing sleep retreats for a well-earned dose of circadian recalibration.

After months of lockdown, we're finding that camomile tea, lavender oil and curling up with a good book just aren't cutting it when it comes to winding down.

According to a study by King's College London, half the population has struggled with getting to sleep during the COVID crisis. What's more, two in five of the 2,300 participants reported that they're sleeping for fewer hours a night on average. It's small wonder that the hashtag #cantsleep has been trending on Twitter since the start of lockdown.

If you're reading this and wondering what you can do to snatch back those precious hours of slumber, a circadian reboot may be in order.

But what does "circadian" mean?

Technically, "circadian" refers to biological processes that run on a 24-hour cycle, our wake-sleep cycle being one of them. It's easiest to think of these rhythms as your body clock. These control a whole array of vital biological systems from our mood, heart rate, blood pressure and performance levels to our metabolic, immune and reproductive cycles.

When those rhythms experience significant disruptions (such as the stress from, say, a global pandemic), there can be concerning knock-on effects to our health and wellbeing, some of which can include being at a higher risk of heart disease, gut disorders, some cancers, obesity, allergies and premature ageing. "There's not one function of the body that is not adversely affected by sleep deprivation; the list is endless," says Anandi, founder of The Sleep Guru. To put it bluntly: it's important to stay in sync.

What does all this have to do with our lockdown sleeping habits?

Anandi advises that maintaining daily rituals is vital for circadian function and notes how lockdown has thrown many of these rituals off-kilter. She lists "adapting lighting, exercising at certain times [and] diets, like intermittent fasting" as lifestyle changes that can help restore the balance.

One of the most important factors in sustaining a constant circadian rhythm is light exposure - more specifically, the right type of light at the right time of day. The regular rising and setting of the sun provide our bodies with the essential "time cues" they need to activate different biological processes, but our modern lives have upturned the basic rules of circadian biology.

Even before the pandemic, we were all guilty of flagrantly defying our natural rhythms by dowsing our eyes every evening in the bright blue lights from our phone, television and computer screens, tricking our brains into thinking it's still daytime, so they work to keep us alert. Ideally, we need to be exposed to the sun's blue light during the day and wind down in the evenings, either in darkness or with warm-hued lights - think campfire. Other factors like the amount of exercise we get (and when) as well as our caffeine and alcohol consumption (which, for us at least, has gone up quite considerably) also play an essential role in healthy circadian function - and these problems have only been amplified in lockdown.

Many of us who have been working remotely have become bound to the always-on work culture while our daily commutes have been reduced from, perhaps, a 20-minute brisk walk outside to a three-second trot down the corridor without a glimmer of sunlight. Similarly, for our key workers, who often do shift work in places with unnaturally bright lights (hospitals, supermarkets, etc.) they, too, have become further disconnected from their normal circadian cycles. All this is playing havoc with our sleeping patterns.

Where did the idea of circadian travel come from?

Long before COVID interrupted our peaceful slumbers, some weary travellers were using circadian science to help mitigate the effects of jet lag, particularly for long-haul journeys, when body clocks are drastically thrown off course in a very short period of time.

To combat the issue, strategies like restricting light exposure, rest and food intake at certain times were used to help travellers recover and adjust faster. Intermittent fasting was also encouraged, as it's a circadian-based diet (eating within a timed window). Hydrotherapy, timed exercise and taking small doses of the hormone melatonin also proved beneficial. This considered approach to recalibrating the body clock after some significant disruption is what inspired the wider philosophy behind circadian travel.

Et voilà! Circadian science is much more than a nap abroad with a glass of warm milk. But is circadian travel for you?

What does circadian travel involve?

Circadian travel involves attending sleep-focused retreats, where sleep specialists have devised a tailored programme around resetting your circadian rhythms.

The approach each centre takes varies in both style and intensity with some adopting holistic methods; some take science-based approaches while others incorporate tailored medical plans and advice. These techniques may include analysing your sleeping habits, oxygen therapy, full-body MOTs, homoeopathic remedies, timed meals and exercise, Ayurvedic massages, mood-boosting music and sounds, as well as light-exposure therapy. You don't have to be a chronic insomniac to go to one, but if you are, this might just be the thing for you.

Below, you'll find a selection of hotels that offer specialised sleep retreats, each offering a different approach. You may be after new lifestyle changes, a few days' escapism, or a detailed plan to help you work through your disturbed lockdown sleep. Wherever you go, rest and relaxation are guaranteed.

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