If you’re still feeling shattered, despite getting seven hours’ sleep most nights, you might be missing the final piece of the energy puzzle: sleep regularity.
You don’t have to be a full-on hedonist to find going to sleep at the same time every evening a challenge. One evening you might be in bed by 10pm, hands moisturised, and ready for sleep; the next, you’re schlepping home from a mid-evening gym class or pub quiz which puts your regime back an hour or two.
The question then is: should you be pushing your alarm back an hour so you’re always sleeping the same number of hours every night? I have a friend who regularly goes out ‘til 3am on the weekend, and who (unless there’s an emergency) always sleeps in ‘till midday the next day – the same number of hours he gets in the week. And guess what? He’s less of a shivering mess than the rest of us who gym early in the morning and stumble home from the pub at 11pm. Has he cracked the key to regular socialising and energy maintenance?
“What many people fail to recognise about sleep is that sleep is inexorably linked to our circadian rhythms,” says Dr Deborah Less from Dr Fox Online Pharmacy. “This is the body’s natural clock – a group of specialised cells called the suprachiasmatic nucleus (SCN) which sits just behind the optic chiasm (the place where optic nerve fibres from each eye cross behind the eyes). It is highly sensitive to the perception of light which enters each eye through the retina.”
Cross that body clock, and you’re in trouble. “Human beings are likely to thrive best when we live in synchronicity with our body clock. This means flooding the brain with natural light first thing in the morning, which switches off melatonin production, and allowing the body to sleep at night when it gets dark, when melatonin levels are high.
“If we disrupt this pattern, this has numerous negative consequences for health. Among other medical conditions, it increases the risk of cognitive impairment, psychiatric illness, obesity, and metabolic syndrome.”
That SCN that Dr Lee mentions contains a metronome-like ‘master pacemaker’ which ensures that our cells’ metabolic processes are correctly timed. Everything is ruled in time with the 24-hour clock, with darkness promoting the production of melatonin – something that’s often overridden with screens and artificial lighting.
It’s because of this that Dr Lee recommends setting a bedtime and sticking to it. “Also, set your alarm clock and get up at the same time every morning – your brain will learn to recognise the pattern. You should try and mimic your circadian rhythms as far as possible. This will help ensure you get the best possible quality of sleep, and give your body the best opportunity to cleanse, refresh, replenish and restore your cellular function.”
What’s more important: sleep regularity, quantity or quality?
That’s all very well in theory but in practice, many of us haven’t been able to stick with the same bedtime since school. If you’re getting a good amount of sleep or a shorter but deeper snooze, that surely doesn’t matter… right?
Wrong. Dr Guy Meadows, co-founder and clinical lead at Sleep School tells Stylist that “keeping an irregular sleep schedule confuses our body clock, which can lead to a condition known as social jet lag. Like regular jet lag, it can cause insomnia, fatigue, nausea and brain fog.”
Dr Lee says that sleep regularity is a ‘vital’ component of sleep quality, even if quality is “probably more important than sleep quantity”. She points to a 2021 review of sleep studies which concluded much the same thing while flagging the fact that while measuring sleep quantity is relatively easy, there are no agreed standards for classifying sleep quality.
Saying that, we can assess poor sleep. Dr Lee says: “Sleep disturbances, such as difficulty falling asleep and waking at night are linked to high blood pressure and raised cholesterol levels. In a 2020 Japanese study of nearly 2 million adults, the risk of cardiovascular disease – angina, heart attacks, heart failure and atrial fibrillation – were all significantly lower in those who reported restful sleep. Improving sleep quality should be a priority in the management of those with established cardiovascular disease.
“Better sleep quality is also linked to a lower BMI. Poor sleep has also been found to be associated with an increased risk of type-2 diabetes.”
Dr Lindsay Browning, psychologist, neuroscientist and sleep expert at And So To Bed suggests thinking of sleep like “eating a healthy, balanced diet”. “You need to have protein, carbohydrates, fats and vegetables – you wouldn’t be healthy if you only ate protein or only carbohydrates. Similarly we need all the different stages of sleep to be healthy.
“At the beginning of the night we tend to proportionately have more deep sleep and as the night progresses we tend to proportionately get more and more REM sleep. If you only get a small amount of sleep (say three or four hours) because you are woken up much too early, you’re likely not to get the right proportions of the different kinds of sleep because you probably won’t have had enough dreaming sleep (which happens increasingly towards the end of the night).
How to offset poor sleep regularity
So, what are you supposed to do if you just can’t commit to a regular bedtime? Is it possible to offset any of the damage associated with poor sleep regularity?
“It’s not always possible to go to bed every night at the same time, but you should try to do this as a rule and deviate from the pattern as infrequently as possible,” Dr Lee suggests.
“If you don’t get your full seven hours every night you will start accumulating a sleep debt. Research shows that it can take up to four days to recover from one hour of sleep debt – as assessed by a variety of neurological and endocrine tests, tests of metabolism, measuring stress hormone levels, and assessing levels of daytime sleepiness.”
Dr Meadows stresses that keeping to a regular sleep-wake cycle is just one of the body clock time keepers: “When we choose to eat, move, work and expose ourselves to light also influence the body clock. Keeping these as regular will help to minimise the impact of an irregular sleeping pattern.” That means aiming to go for a run around the same time throughout the week, having your breakfast and dinner around the same times and sticking to a coffee timetable.
Going back to my mate who sleeps in ‘til 12pm on a Saturday, Dr says that sleeping in may help undo some of the damage done by late nights, although this has not been proven beyond reasonable doubt. If you’re only getting five hours’ kip a night, there’s no concrete evidence to suggest that you can make up that debt later. And if you’re a shift worker, we know that there are plenty of health issues associated with nighttime working and irregular hours. Short of quitting, there’s not a whole lot you can do about that.
5 tips for boosting sleep quality and energy
However, our experts do have a few tips for improving the quality of the shut eye you do manage to get:
- If you feel sleepy, go to sleep if you can, whenever it is. You need to listen to your body and respond to the cues.
- Naps can add up to help complete the seven-to-nine hours we need but they either need to be very quick naps (20 minutes) or the full 90-110 minutes, Dr Browning says. “Anything in between will cause grogginess as you are interrupting the sleep cycle.”
- If you know you have a late night or a shift coming up, have a daytime sleep in advance.
- Make sure you have the best possible sleep hygiene – proper blackout blinds or curtains to keep the room dark, keep it cool, quiet and well ventilated.
- Don’t compensate for poor sleep by over indulging in caffeine. Try to avoid having a cup of coffee as soon as you wake up in the morning because that’s when your body has a natural cortisol spike. “Instead, wait until you have been up for an hour to an hour and a half before grabbing that cup of coffee,” Dr Browning recommends.
Miranda Larbi is the editor of Strong Women and Strong Women Training Club. A qualified personal trainer and vegan runner, she can usually be found training for the next marathon, seeking out vegan treats or cycling across London on a pond-green Tokyo bike.