From burning the midnight oil at work to partying until the early hours, most of us have cut corners when it comes to sleep. That can have a serious impact on our ability to function. According to at Harvard Medical School, being awake for 24 hours will leave you with the same level of cognitive impairment as having a blood alcohol volume of 0.1 per cent, which would push you over the drink-drive limit in several countries.
The areas of the brain involved in attention, judgement and sensory processing are particularly hard hit. Accident statistics bear this out: traffic accidents peak in the early hours when the circadian drive for alertness is at a low, and our drive for sleep is the strongest. The impact on abilities depends partly on age; lab tests show that young people鈥檚 reaction times suffer more than older people鈥檚 after being kept up all night. Lack of sleep also affects the parts of the brain in charge of emotions and decision-making, and .
Can you counter such effects? Stimulants like caffeine can mitigate the effects of sleep loss, but a better strategy might be to catnap your way to a more coherent state of mind. 鈥淵ou can certainly offset the impact of sleep loss by strategic napping,鈥� says at Boston Children鈥檚 Hospital. A short nap of just 10 to 30 minutes can improve alertness for 2 to 3 hours afterwards. A nap exceeding half an hour will have longer-lasting benefits, but is likely to leave you feeling even more groggy than before you nodded off, a phenomenon known as sleep inertia. An expert tip for avoiding that is to drink a cup of coffee just beforehand. The caffeine will kick in after about 20 minutes 鈥� in time to wipe away that hazy feeling when you wake.
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Trying to get away with lack of sleep over the long term is much more risky. For one thing, its effects are much more insidious. Sleeping for 6 hours a night instead of 8 for two weeks, for instance, produces the same cognitive deficits as going 24 hours without sleep. But you may not pick up on it 鈥� after the third or fourth day of sleep deprivation, even though their abilities are still deteriorating.
The effects of long-term lack of sleep are harder to get away with too, with elevated risk of diabetes, cardiovascular disease and some cancers. And if you have been repeatedly burning the candle at both ends, it can take weeks to recover, Czeisler says.
What about the idea that you can undo the damage with a very long recovery sleep? Probably not. 鈥淚t鈥檚 not like you can bank sleep,鈥� Owens says. 鈥淲e don鈥檛 know whether short sleep during the week and sleeping in at the weekends impacts people鈥檚 long-term cardiovascular morbidity. But the evidence we have so far suggests that it鈥檚 not a good way of dealing with it.鈥�
Read more: 鈥�Guilty pleasures: Which bad habits can you get away with?鈥�
This article appeared in print under the headline 鈥淕etting away with late nights鈥�
