Sleep is a nightly elixir. Ironically, it’s one you only truly appreciate when you don’t have enough of it. Have you ever lain wide awake at 3 a.m., desperate to sink back into sleep and stop the thoughts racing through your head? And then the next morning, you get up incapable of clear thought, devoid of energy and forced to drink large quantities of coffee just to make it through the day.
Sadly, this scenario is all too common. You often sleep less when the heat is on at work — precisely when you need to be on top form. A vicious circle can develop: more stress leads to less sleep, and so it goes on.
To perform well in the workplace, we clearly need sufficient sleep. Yet stress and insomnia are intimate bedfellows. “Stress directly impacts our ability to fall asleep at night, which results in lack of sleep,” says Sofia Axelrod, a sleep researcher at Rockefeller University, New York, who works in the lab of Michael Young, winner of the Nobel Prize for his work on circadian rhythms.
Sleep deprivation triggers elevated stress hormone levels, perpetuating the problem. If you sleep poorly, your brain will work more slowly and you will have fewer resources to handle stress, adds Torbjörn Åkerstedt, senior professor at the Stress Research Institute, Stockholm University.
Just how much stress are we talking about? The good news is that day-to-day worries don’t have much of an effect: stress has to be at quite a high level to impair sleep. Stress is at its worst when you’re working at your limit, resulting in burnout — a state of extreme fatigue due to long-term stress. Different people react differently to stress. Those with high work-related ambitions are the most vulnerable. Individuals with a relaxed approach towards work and whose self-worth comes from outside the workplace are less affected.
Unfortunately, stress has escalated since the late 1990s, when the wheels of the economy started to roll again following a period of recession, says Åkerstedt. “A lot of companies increased their demands on personnel and let people who weren’t essential to company performance go. The people who provided support, such as secretaries and assistants, were simply removed from the workplace and those remaining took on their workload alongside their main responsibilities.”
Turn it off
Digital technology may have reduced the workload but it’s not necessarily conducive to a good night’s sleep. Staring at a screen in the evening plays havoc with our circadian clock — light tells our bodies what time it is and regulates our physiology, explains Axelrod. “Evening light exposure strongly suppresses the sleep hormone melatonin and thereby makes it hard to fall asleep. TVs, iPads and mobile phones, even regular light bulbs, all emit blue-enriched light, which is extra potent at keeping us awake.”
Heavy drinking or smoking are also taboo if you want a good night’s rest. A lack of exercise won’t help either. The experts advise that you try to stay physically and mentally active, reduce your caffeine intake from lunchtime onwards and relax before bedtime.
So, just how much sleep do we actually need? It varies between individuals, but as a rule of thumb, seven hours appears to be the norm for an average 25- to 35-year-old. The young need even more sleep, as their developing brains require more energy. Older people, meanwhile, need less sleep: the average 65-year-old needs only six hours.
But what about those individuals, like Margaret Thatcher or Barack Obama, who claim to need only four hours’ sleep per night? The majority of short sleepers are, in essence, poor sleepers, says Åkerstedt. A subgroup, however, really do require less sleep. Some may cheat: Churchill said he barely slept, but he normally took afternoon naps.
The clock strikes midnight
Once upon a time, midnight really was the middle of the night, with hours of sleep extending from 8 p.m. to 4 a.m. Ideally, humans should still sleep around midnight, with a few hours’ sleep before 3 a.m. to 4 a.m. and a few hours’ sleep thereafter. That is when our circadian clock suppresses our metabolism, creating the ideal conditions for sleep, says Axelrod.
The invention of the light bulb in the 19th century, and then later the introduction of television and the internet, has pushed bedtime later and later. Realistically, it can’t be pushed much further, though — we simply aren’t made for sleeping during daylight hours, says Åkerstedt. “We’re diurnal animals — we need the light, we need the sun, so we’ve reached the end of this type of adjustment.”
We can adapt to earlier bedtimes, however. Research shows that if you take a couple of night owls, deprive them of their mobile phones and electricity and take them camping, within a couple of days, they will start sleeping between 8 p.m. and 4 a.m.
We should forget that weekend lie-in, too, as it upends bodily rhythms and results in sleep deprivation on Monday. A well-trained bodily rhythm allows the sleep hormone melatonin to increase in the evening, making it easier to fall asleep. And we wake up feeling refreshed thanks to the natural release of cortisol, which goads us into action.
Some of us are clearly early birds, while night owls operate best after dusk. It’s all down to the so-called clock genes in our bodies, which determine our chronotype and interpersonal differences. Those of us with teenagers know all too well what a struggle it is to get them out of bed in the morning. In fact, they’re not simply lazy — they have biology on their side. Teenagers have a delayed circadian rhythm leading to a late chronotype, with melatonin rhythms that encourage them to go to bed late. Their sleep hormone is still high in the morning, making them sleepy. Having to wake up at 6 a.m. to get ready for school is the equivalent of getting up in the middle of the night for teenagers.
Sleeping on the job
Fancy a siesta in the office? Some companies now promote the idea of a quick power nap at work to increase productivity. Google, for example, has nap pods for its employees. For the moderately sleep-deprived, a nap can substitute for an hour or two of light sleep. What’s more, you’re more alert and have a higher IQ after a short nap. For insomniacs, though, naps are a bad idea, as they offset your sleep need, which normally builds up during the day and makes you tired at night.
So, what are the affects of impaired sleep on your work? Studies show that a poor night’s sleep will reduce your performance by ten per cent. Globally, the US has the biggest financial losses (up to $411 billion, or 2.28 per cent of its GDP) and most working days lost (1.2 million) are the result of sleep deprivation. This is closely followed by Japan (up to $138.6 billion, which is 2.92 per cent of its GDP, and around 600,000 working days lost). Sleep loss is also a major cause of accidents at work.
Complete sleep deprivation will kill faster than starvation. A lack of sleep has a negative impact on temperature regulation, digestion and metabolism, causing an increased risk of obesity, diabetes, stroke and cancer.
The brain needs sleep to function properly, and insufficient sleep means that memory, decision-making, vision, balance and motor coordination all suffer. Night-shift workers show impaired cognitive performance equivalent to alcohol intoxication.
Poor sleep worsens people’s mood and increases the risk of developing anxiety disorders and depression. Working late into the night might boost your productivity for a while, but the downsides just aren’t worth it: a higher risk of health and mood disorders, lower cognitive performance and lower life expectancy. Work hard, but make sure you to go to bed on time — every single night.