Your holiday travel might be over, but do you nonetheless feel ‘jet lagged’? Or perhaps you’re knackered without having gone anywhere near an airport? You might be experiencing ‘social jetlag’; when your work or study schedule is out of synch with your body clock, your internal rhythm that affects when you feel sleepy and when you feel awake. Your body clock is regulated by structures in the brain and it is influenced by light. Light striking your eyes triggers changes associated with wakefulness. But for a variety of reasons, our wake time is often shifted later during holidays. So when the time comes for us to go back to our normal (earlier) work or study routine, we’re forced to undersleep. And this can make the “back to the grind” feel even uglier than it otherwise would. If you’ve had a nice dark place to sleep while you’ve been on holidays, your social jet lag is likely to be more pronounced, says Victoria University sleep psychologist Professor Dorothy Bruck. But the good news is the cure is usually right outside your bedroom blinds daylight. We all have a body rhythm that runs on about a 24 hour cycle, Bruck says. “But it actually runs a bit more than 24 hours; it’s about 24.5 or 25 hours for most people.” That means if you follow your body’s natural rhythm which is more likely when you’re on holidays you start going to bed a little bit later every night and sleeping in a little bit more every morning. Holiday socialising at night is another force that pulls you in this direction. “People do stay out later and they’re less likely to feel sleepy earlier on because their body’s running a bit faster than 24 hours all the time. And they know they don’t have to get up for that 7am alarm.” The need to get up and moving of a morning normally keeps this drift in check: “As soon as you wake up in the morning, you get the light in your eyes and that’s a very strong cue [to tell your body clock it is daytime]. And that helps us keep a little bit closer to a 24-hour rhythm.” But if you haven’t had to get up and moving because you’ve had a lovely holiday without commitments thankyou very much you may well have ended up with a body clock that’s shifted by several hours. Some who lead a very passive indoor lifestyle in darkened rooms while they’re on holidays might actually come close to completely inverting their day night cycle, Bruck says. This takes a big effort to reverse. For most of us, however, the end of January just means getting used to waking up a few hours earlier. Nonetheless it can still take our bodies several days to adapt. To reprogram your body clock to be in synch with an earlier school or work day, and help it stay in synch, here are some tips. Expose yourself to bright sunlight shortly after getting up. (Daylight is best, as even the natural light on a cloudy morning is brighter than most artificial light.) This bright light will suppress morning levels of the sleep-inducing melatonin hormone and reset your body clock. While wake time has the most impact, what you do at night matters too. You want a pre-bed wind-down routine that allows you to hit the sack in time to get the sleep you need before that morning alarm sounds. A warm bath or shower, chatting or reading are good pre-bed activities. Avoid watching television or using computers, mobile phones and other electronic devices in the bedroom in the hour before going to sleep as research has shown this leads to taking longer to fall asleep. As well as the stimulation effect, the blue light from computer screens suppresses the hormone melatonin, which normally helps to make you feel sleepy. If you struggle to sleep well or find being sleep deprived hits you especially hard, it’s worth trying to maintain your week day schedule as much as possible on Saturdays and Sundays, the Sleep Health Foundation advises. “Sleep is as important as healthy food and exercise,” says Dorothy Bruck. As sleep physician Dr Keith Wong has told us in the past, not getting enough sleep impairs your reaction time, problem solving ability, mood and immune system; and over time might lead to long-term health problems such as heart disease and diabetes. Poor sleep has also been linked to weight gain and can impair children’s ability to learn at school. “Research has shown that students who don’t get enough sleep have difficulty understanding lessons, and struggle to complete assignments, class tests and exams, ” says Sleep Health Foundation president Dr David Hillman. The Australasian Sleep Association says most adults need 6.5 to 8.5 hours sleep a night to “function and feel they can manage life adequately.” Nine hours is recommended for teenagers and more for five to 12-year-olds, the Sleep Health Foundation says.
ABC Health News, 28 January 2015 ;http://www.abc.net.au/news/ ;