Focus on Fatigue

The Power of the Coffee Nap

By September 5, 2018 No Comments

Welcome to Focus on Fatigue,

Sometimes in life we have little choice but to keep on keeping on, even when we’re tired. Perhaps we’re in the car, still an hour away from home. Or maybe we need to finish a project and absolutely cannot miss the deadline. Is there an effective way to keep our alertness and performance levels up long enough to reach our goal safely? That is the question we’ll be investigating in this month’s Focus on Fatigue.

The FRMS Team



InterDynamics Pty Ltd
320 Adelaide Street Brisbane Qld 4000
Tel +61 7 3229 8300

Views expressed in articles and links provided are those of the individual authors, and do not necessarily represent the views of InterDynamics (except where directly attributed).


The Power of the Coffee Nap

In the midst of our busy working days (and working nights), many of us reach for a cup of coffee, or other caffeinated beverage, to counteract sleepiness. If the sleepiness reaches a high enough level, we may go even further and have a quick nap before returning to our task. But what would happen if we did both? Would combining the two techniques achieve an outcome greater than the sum of its parts?

What is a coffee nap?

Taking a coffee nap is a simple two-step process.

Step One: Drink a cup of coffee. This must be done quickly, so make sure it’s not too hot, or switch out your latte for an iced coffee, or a simple espresso shot. Drinking tea is not as good an option here simply because the caffeine content will not be high enough to achieve the desired effect.

Step Two: Take a nap. The nap itself should be no more than twenty minutes. This ensures you don’t enter the deeper stages of sleep, which would lead to grogginess (known as sleep inertia) upon waking. Setting an alarm on your phone is a great way to prevent oversleeping.

Why do coffee naps work?

Adenosine is a molecule produced by your brain when you’re awake and active. As adenosine builds up, it fits into receptors in the brain, making you tired. The caffeine molecule is similar in shape so, when you drink a cup of coffee, the caffeine makes its way to your brain and competes with the adenosine for access to the same receptors. The more caffeine molecules reaching the receptors, the greater the alerting effect.

Here’s where the nap can help. Sleep naturally flushes adenosine out of your brain, making way for more caffeine molecules to find available receptors. The caffeine takes about 30 minutes to be absorbed through your small intestine, pass into your bloodstream, and reach your brain. Therefore, if you have a 15-20 minute nap, the adenosine levels will be reduced just in time for the caffeine to sweep in and save the day. Hooray!

How well do coffee naps work?

The coffee nap has been found to be effective in a variety of situations, including:

  • preventing performance degradation on computer tasks for at least one hour
  • reducing sleepiness and improving performance in drivers during a monotonous afternoon drive in a car simulator for one hour
  • in a study of night shift workers, caffeine and naps were both found to improve performance on a vigilance task and decrease sleepiness, but the combination of the two had the greatest effect

It’s important to note that while coffee naps can alleviate sleepiness in the short term, they are not a replacement for adequate sleep, and the effects will wear off within a couple of hours.

What if I’m a bad napper?

Many people find it difficult to nap on command, especially during the day. However, the research has found that even a restful doze can help performance.

So, the next time you find yourself needing to go that extra hour or two before resting, try a coffee nap. It may just do the trick.


  • Hayashi, M., Masuda, A. and Hori, T. (2003) The alerting effects of caffeine, bright light and face washing after a short daytime nap. Clinical Neurophysiology, 114(12), 2268-2278.
  • Reyner, L. A. and Horne, J. A. (1997) Suppression of sleepiness in drivers: Combination of caffeine with a short nap. Psychophysiology, 34(6), 721-725.
  • Newman, R. A., Kamimori, G. H., Wesensten, N. J., Picchioni, D. and Baklin, T. J. (2013) Caffeine gum minimized sleep inertia. Perceptual and Motor Skills, 116(1), 280-293.
  • Schweitzer, P. K., Randazzo, A. C., Stone, K., Erman, M., and Walsh, J. K. (2006) Laboratory and field studies of naps and caffeine as practical countermeasures for sleep-wake problems associated with night work. Sleep, 29(1), 39-50.
  • Stromberg, J. (2015) Scientists agree: Coffee naps are better than coffee or naps alone. Vox. (Accessed: 1 August 2018)


In the News

Provided below are a selection of articles from around the web on the issues associated with fatigue. We hope you find them useful and interesting.

Article: Health Check: What are ‘coffee naps’ and can they help you power through the day

Chin Moi Chow, The Conversation (3 April 2017)

Caffeine and napping have something in common. Both make you feel alert and can enhance your performance, whether that’s driving, working or studying. But some people are convinced that drinking a coffee before a nap gives you an extra zap of energy when you wake up.

Video: Why do coffee naps recharge you so well?

SciShow, YouTube (23 June 2018)

A short video explaining the benefits of coffee naps, and why they work so well.

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