What is social jet-lag?


Social jetlag is the difference between the time we have to wake up and the time you would wake-up naturally. Like regular jetlag, social jetlag occurs when your internal clock and your social clock are misaligned. It’s like your work schedule running on Auckland time, while your body clock is on Sydney time, two hours behind. This makes it difficult to fall asleep and even harder to wake up the next morning. However, unlike regular jetlag, which usually subsides in a few days as one acclimates to the new time zone, social jetlag is a chronic condition that, if unaddressed, can continue indefinitely. It’s common for individuals suffering from social jetlag to sleep less during the week and try and pay back this sleep debt on weekends by sleeping in; however, several studies have linked this behaviour to serious health effects.


What causes “social jetlag”?

Our sleep/wake timing is influenced by three clocks: 1) our body-clock, or circadian rhythm influences our when we wake up and fall to sleep through the hormone’s cortisol and melatonin. 2) Our social clock is the time the time our watch or phone tells us. More broadly, social time relates to our commitment to others, such as what time we are expected to arrive at the office. 3) The solar clock refers to the sun’s position in the sky. Special receptors in our eye detect sunlight (or the lack of it) and shift our body-clock to match it with the solar time.


In the ideal person, our body-clock, our social clock, and the solar clock are in synchrony, meaning that you naturally wake up at the appropriate time for work without the need for an alarm clock. However, our modern lifestyles can interfere with this relationship, resulting in social jetlag. When you spend your morning indoors, with little sunlight, this sends a signal to our brain that the sun hasn’t risen yet, causing the body-clock to shift. On the other hand, when you are exposed to blue light at night, via traditional light sources and screen-based devices, this signals to the brain that the sun hasn’t set, causing the body clock to shift later still.


Side effects of “social jetlag.”

Aside from fatigue, social jetlag has been linked to several chronic health problems, including:

· Poor academic performance (Smarr, 2014)

· Greater chance of obesity (Roenneberg, et al., 2012)

· 33% high chance with each hour of social jetlag.

· Increased chance of addiction to nicotine and alcohol (Wittman et al., 2006)

· Increased risk of cardiovascular disease (Wong et al. 2015)

· Increased risk of metabolic disease (Scheer et al. 2009)

· An overall weakening of the circadian process (Jan-Dijk, 2012)


How to prevent “social jetlag.”

Although poor lighting is the problem, at OSIN we believe nutritional light is the solution.



Minimise exposure to blue light at night. By avoiding blue light at night, we send a signal to our brain that the sun has set, and that it is time to prepare the body for sleep. While there has been significant media attention surrounding blue light from devices and streetlighting, people often ignore the lightbulbs they have in their homes. You can minimise blue light at night simply by switching to Bedtime Bulb at night, and enabling a blue light filter and lowering the brightness of smart devices.


Get more natural light during the day. Exposure to natural light for as little as 30 minutes during the morning help bring the circadian rhythm forward, making it easier to get to sleep at night. Think of ways you can introduce more natural light into your lifestyle, such as taking a morning walk or biking to work.


For a more comprehensive list of sleep tips check out 4 habits for healthy sleep.

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