Why holidays can make you more sleepy

For many of us, the holiday months are a chance to indulge in a precious and increasingly rare commodity: non-time-limited, good quality, satisfying sleep.

But sometimes, despite sleeping more than usual every night, a holiday can bring a surprising level of tiredness.

You might be just lying around at home, or if you’re lucky, perhaps on a towel by a beach or pool. Still you find that all you want to do is, well, more of the same.

You may find it hard to keep your eyes open. Just getting up for a cup of tea or to look for that novel you planned to read can feel just too damn exhausting.

If you had planned on being a bit more energised, it can be a mysterious (not to mention frustrating) phenomenon.

How can being on holidays without the normal limits on your sleep possibly leave you feeling more tired?

End-of-year burnout

If your fatigue hits you just in the first few days of your holidays, it might simply be that you’re still in a catch-up sleep phase, sleep psychologist Professor Dorothy Bruck suggests.

The demands of the festive season can leave people “over-revved”.

When you finally slow down, you may be registering for the first time a level of sleep deprivation that has been entrenched, but previously masked by the stimulation of having adrenaline constantly surging through your body.

In fact, for many of us, holidays are a wake-up call as to just how little sleep we’re getting.

“If you haven’t been fully rested for a while, you can forget what it feels like,” Dr Bruck says.

“People can lose their frame of reference. The average amount of sleep [adults have] is 7.2 or 7.3 hours.

“But when we let people sleep until they can’t sleep anymore, the average is 8.25 hours.”

So with a lot of us potentially an hour short of shut-eye every day in our normal routines, the end of the year might be a time to pay homage to sleep’s remarkable restorative powers.

“People think sleep is just a knockout time, when nothing happens,” Dr Bruck says.

“But we know that certain parts of the brain use more oxygen and glucose when you’re asleep than when you’re awake.”

It’s a time when our brains “make new connections, file things away, chuck things out, and put things in their right place so you can find them later”.

“Sleep is as important as healthy food and exercise. I think people need to prioritise sleep a little more,” Dr Bruck says.

Dr Bruck points out that if your fatigue is persistent and unrelenting then it may be more of a psychological issue — a reaction perhaps to burnout from work — than a problem with the quality of your sleep.

“It’s not something I’d say is necessarily a sleep issue,” Dr Bruck says.

“What we perceive as fatigue may not be sleep deprivation. Feeling sleepy is a desire to go to sleep. Feeling fatigued is more complex and doesn’t always involve sleepiness.”

Why your holidays can make you tired

Tiredness after sleeping well is different from tiredness from not sleeping well. Aspects of seasonal festivities can upset your slumber in a number of ways including:

Alcohol

You might be surprised to know booze can impact on your sleep for some time after you’ve consumed it.

“Often when people go on holidays, they drink a lot more alcohol and this can have a really detrimental effect on the quality of your sleep,” Dr Bruck says.

If it’s just a couple of drinks, the disruptive impact will be limited to that night.

“[The alcohol] might help you go to sleep and for the first half of the night, your sleep can be dead to the world. But the second half of the night, [sleep] is much more fragmented,” Dr Bruck says.

To minimise this, try leaving some time — ideally a few hours — between having a couple of alcoholic drinks and going to bed.

But if you let your hair down and have a bit of a binge (five or more standard drinks in one night is classed as a binge) you may find your sleep is sabotaged for up to a week after the booze is out of your system.

“Binge drinking can muck up melatonin, the hormone that makes us feel sleepy, for maybe the next five or seven days [and nights],” Dr Bruck says.

If you consider that a standard drink is usually a smaller volume than most people pour themselves, this level of drinking and the subsequent sleep impairment would not be uncommon.

Tummy troubles

The holiday season is also a time when we tend to eat a bit more — or let’s face it, a lot more — than normal. We also tend to feast on a wider variety of foods; some of which may disagree with us.

Discomfort in your digestive system can be a sleep killer, with chilli and other spicy foods a particular problem, according to Central Queensland University sleep researcher Charli Sargent.

“Anything that’s going to cause reflux or indigestion might indirectly interrupt your sleep, so if you’ve eaten a meal that’s quite spicy then it might be having an effect your sleep,” Dr Sargent says.

But a sugary dessert (or other high-sugar food) just before bed can be a problem too — leaving you with “a sugar high” that can make you feel stimulated and not sleepy, Dr Bruck says. The effect should not last longer than an hour or so, however.

This is why if you’re sleep deprived in the day and wanting a boost, you’re better off having complex carbohydrates — grainy bread for example — and protein, like lean meat or some cheese, than a sugary donut or chocolate bar.

With the latter, “for the first half hour, you’re firing on all cyclinders”, Dr Bruck says. But an hour to an hour and a half later, you crash and may find it hard to function.

Daytime naps

Afternoon siestas when you don’t have to work can be one of the nicest parts of being on holidays.

We often link an afternoon lull in our alertness to the effects of eating lunch. But the “mid-afternoon dip”, is actually a normal feature of our circadian rhythm — the biological clock that influences when we feel wakeful or want to sleep — and can happen whether you’ve had food or not, Dr Bruck says.

Without the pressure of a looming afternoon work deadline, or just a generally higher state of relaxation, staying awake all day when you’re on holidays can be even more difficult than usual.

While you can enjoy the treat without guilt at these times, napping too long in the day can weaken your body’s “drive” to sleep at night, which might mean you’ll be tossing and turning and unable to drop off until the wee hours.

All too often, this restlessness can trigger anxiety that can further impede sleep. If a weaker night time sleep drive bothers you, it’s best to keep any snoozing in the day to no more than 20 minutes.

(Set an alarm on your phone when you feel yourself start to nod off, Dr Bruck suggests.)

And hopefully you’ll still sleep like a baby — or at least an adult on a very happy holiday — at night.

This post originally appeared on the ABC and has been republished here with full permission.