Many of us feel tired after hitting the books for extended hours, and most of us either go for a caffeine shot or a 20-minute nap before continuing the task. However, scientists recommend that you try both at the same time – drink a cup of coffee and then take a quick nap.
It actually exploits a quirk in your brain that maximises alertness.
The Coffee Nap
Everybody knows that caffeine interferes with sleep, but it’ll need to be absorbed through your small intestines and bloodstream in order to work. Once it gets to the brain, it fits into receptors there are normally filled with a molecule called adenosine which is responsible for making you feel tired. With caffeine blocking the receptors, it’s unable to do so.
However, caffeine doesn’t block every single adenosine receptor – the best way to clear all of it is with sleep. If you nap for 20 minutes or more, your brain enters a deeper sleep state which can take some time to recover from (you feel even sleepier). However, nap shorter than 20 minutes, enough adenosine will be cleared from your brain and the caffeine will have time to kick in through your bloodstream.
Experiments have shown that coffee naps are more effective than coffee or naps alone in maximising alertness. Loughborough University (UK) and a Japanese study conducted separate experiments and found that tired participants committed fewer errors in a driving simulator and performed significantly better in memory tests after taking a coffee nap.
How to do the Coffee Nap
First, drink coffee or another caffeinated beverage (here’s a good database of the amount of caffeine in many types of drinks).
Second, drink it quickly so you have a long window of time to sleep.
Third, try to get to sleep immediately – even if it’s just a half-sleep, it can be helpful.
Finally, set your alarm clock to wake you up within 20 minutes; you don’t want to enter a deep sleep an you want to be awake when the caffeine hits your brain.