You know the feeling. You've been staying up late studying or you've picked up the early morning shift. Whatever happened, you've skipped out on precious sleep hours.
No matter though, your weekend is coming up and you sleep in a couple of hours to refill the tank.
But the following week you're feeling lethargic, unfocused, maybe even a little grumpy.
You may have put your body into what's called, social jetlag.
It's a term coined by German researcher Till Roennenberg in 2006 and is basically a mismatch between your internal circadian rhythm (body clock) and the outside world.
According to UQ Professor of Sleep and Health Simon Smith, being in social jetlag for a prolonged period could have adverse effects on your health.
"One reason for this is that almost all important body functions act according to your body clock, and work best when these functions are synchronised," Mr Smith told ABC News
"Disrupting the clock seems to disrupt these functions, and it can take time to re-establish the best timing."
But in order to take yourself out of social jetlag, first you need to understand your sleep chronotype.
What is a sleep chronotype?
Inside all of us is an internal body clock that aligns our behaviour and physiology to the earth's night and day cycle, Professor Russell Foster, head of the Sleep and Circadian Neuroscience Institute at the University of Oxford told Radio National.
"But we don't always align our internal clock to the earth in the same way, some people will get up earlier and go to bed earlier and some people will go to bed later and get up later," he said.
"That's largely referred to as our sleep chronotype and that comes from our internal body clocks."
According to Professor Foster, there's three main sleep chronotypes;
- Larks – those who wake up early and go to sleep early
- Doves – those who wake up and go to sleep at moderate times
- Owls – those who go to sleep late and wake up late
Sleep chronotypes are constantly changing, dependent on three factors;
- Studies have identified particular genes that will predispose people to be a morning type or an evening type.
- Age e.g. a person in their 20s will go to bed around two hours later than someone in their 60s
- When a person sees light after they wake up.
What is social jetlag and is it bad for your health?
Professor Smith says that social jetlag is very similar to regular jetlag.
"It is a mismatch between your internal circadian rhythm and the outside world. This can happen in regular life when your chronotype conflict with your body clock," he says.
"One measure of social jetlag is the difference in wake up time between days of work or study, and ‘free’ days (e.g. weekdays versus weekends for some traditional work hours)."
While jetlag from a holiday can be annoying, social jetlag can lead to health problems, according to Professor Foster.
"On the more immediate end you have the failure to process information, frustration, increased irritability, the failure to communicate with others and the loss of empathy," he says of the complications social jetlag can have short term.
"If you do this over years and decades it can lead to real problems such as cardiovascular disease, heart disease to even cancer and big metabolic events. So, the greater the social jetlag the greater the chance of type two diabetes."
This is why it's so important to align your sleep chronotype with your working habits to the point where it needs to be at the forefront of employer's minds.
"Employers need to show a duty of care like 'I can chronotype my workforce and let those individuals who are the late types do the late shift and the early types do the early shift', then the employee needs to mitigate some of those problems," Dr Foster says
"I think there can be accommodation from both employer and employee."
Why can't I sleep?
Professor Smith says there are many reasons you might not be getting the shut-eye you need.
"Some people experience specific sleep disorders, such as insomnia and sleep apnoea. Conditions such as depression, anxiety, and stress can impact sleep, as can pain and a range of chronic conditions,' he says.
"However, many more experience poor sleep or insufficient sleep because when it seems there is just not enough time in the day, sleep is often given up first."
When falling asleep seems impossible, Professor Smith says that your environment can also become a factor.
"An increasing issue of concern is the external environment. This can be seen as traffic or aircraft noise interrupting sleep, excessive street lighting beaming into homes, increased temperature in bedrooms without air-conditioning, and other factors that make sleep difficult," he says.
"The use of artificial lighting in homes has extended the virtual day. This means that the biological signal for sleep – melatonin – may be suppressed, making getting to sleep and regulation of the body clock more difficult," he says.
Then there's the issue of the omnipresent smartphone.
"Social media can be very engaging but the content, timing, and nature, may often conflict with the state of safety and calm needed for sleep."
How much sleep should I be getting?
Bad news if you're waiting for a magical number that will leave you feeling refreshed every day — the amount of sleep needed varies from person to person.
"People do vary in the ‘natural’ amount of sleep they need, and this need can vary across our lives. For most adults, this might be between 7 and 9 hours," Professor Smith says.
"Many people think that 8 hours is the ‘right amount’. While for some that’s plenty, for others it is just not enough sleep. Losing an hour a sleep a night for a week is a lot of lost sleep"
Professor Smith says taking notice of the time that you're getting up every day — including the weekends — could help confirm a healthy sleep schedule.
"Really, the amount of sleep you need is the amount that leaves you refreshed and energised in the morning, and alert and calm during the day," he says.
How do I sleep better?
The best way to get better sleep, according to sleep experts is to stop worrying about it.
"Sleep will happen if we let it. Setting aside enough time for sleep, creating an environment that doesn’t conflict with sleep, and establishing routines that signal sleep to the body and mind will all help," Professor Smith says.
Professor Smith also suggests the following steps to improve sleep:
- Reducing the intensity of household lighting in the evenings
- Making sensible decisions about technology use at night
- Keeping to a fixed wake-up time (at least most of the time)
- Regular exercise
But he also acknowledges that for some people, these small changes are not enough.
"In that case, there are well trained sleep experts — such as Psychologists and Sleep Physicians — who can provide more focused methods to improve sleep," he says.
Professor Foster is in agreement that the best way to improve your sleep is to embrace the shut-eye you get.
“At the turn of the century people realised that sleep is incredibly important but now we’re at the point where people are anxious about sleep rather than embracing the sleep they get," Professor Foster says.
“Hopefully in the coming years we’re going to relax about our sleep, realise that it’s incredibly diverse and stop worrying about it.”
