If you are really tired it helps to take a nap or drink a cup of coffee. But who would have thought that combining the two produces optimal results. It turns out that you drink coffee for the perfect nap. Vox writes about coffee naps.

If you’re feeling sleepy and want to wake yourself up – and have 20 minutes or so to spare before you need to be fully alert – there’s something you should try. It’s more effective than drinking a cup of coffee or taking a quick nap.

It’s drinking a cup of coffee and then taking a quick nap. This is called a coffee nap.

It might sound crazy: conventional wisdom is that caffeine interferes with sleep. But if you caffeinate immediately before napping and sleep for 20 minutes or less, you can exploit a quirk in the way both sleep and caffeine affect your brain to maximize alertness.

Here is how it works.

Caffeine and Adenosine

When you drink coffee and it enters your blood stream it eventually arrives in your brain which is where it exerts its wake up effect. Caffeine fits onto chemical receptors that normally accept the molecule adenosine. Adenosine is a byproduct of activity in the brain and when it accumulates in the receptors you get tired. Caffeine blocks the ability of adenosine to build up in the receptors and make you feel tired!

Naps and Adenosine

The body’s natural way to clean adenosine from the “tired” receptors is to sleep. When you take a nap your body starts clearing adenosine from the receptors and when you drink coffee before the nap you further clear out the adenosine as caffeine competes for the receptor sites. So what are the results of using coffee for the perfect nap?

Testing the Nap and Caffeine Hypothesis

Researchers report in Psychophysiology that caffeine and a nap improved performance in a driving simulator in a paper titled Counteracting driver sleepiness: effects of napping, caffeine and placebo.

Caffeine and nap significantly reduced driving impairments, subjective sleepiness, and electroencephalographic (EEG) activity indicating drowsiness.

So if you want wake up refreshed and able to do your work more effectively consider coffee for the perfect nap.

Coffee, Nap and Better Memory

Japanese researchers looked at the alerting effects of caffeine combined with a nap followed by bright light and face washing.

The effects of a short nap against mid-afternoon sleepiness could be enhanced by combining caffeine intake, exposure to bright light, or face washing.

Although all measures were useful the best combination was a cup of coffee immediately followed by a nap.

But Not Too Long a Nap

The one pitfall in using coffee for the perfect nap is that if you sleep past twenty minutes or so you enter deeper stages of sleep and rather than waking up refreshed and able to perform better at the task at hand you wake up later on not remembering where you are and why you are there! Coffee provides the perfect nap but make sure it is just a nap.