Winning the Afternoon: The Secret Science of Coffee Napping

This scientifically-tested hack keeps you on your A-game and holds the key to defeating the afternoon slump.


We’ve all experienced the afternoon slump, right? There you are, doing what you do, and frankly you’re smashing it; productivity is not the word. You’re swallowing to-do lists whole as you bend the laws of time to achieve more in one morning than should be humanly possible (sounds like you’ve been meditating), and you’re intent on riding this magnificent wave all day.

And then, sometime after lunch, it strikes. A lack of energy so sudden and severe that your attention, motivation and productivity drop through the floor and obliterate the office/flat/pet store below. The afternoon slump. Aka the Netflix and duvet compulsion. Aka, no longer smashing it.

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I know the sinking feeling of the afternoon slump all too well. In the final weeks before my university deadlines, when the proverbial fan was a mess and time was not an ally, I would get up painfully early each day and get straight to work on essays and music projects. Progress was made, word counts rose and inoffensive singer-songwriter melodies began to sparkle. But for all that the mornings were a goldmine of productivity, afternoons were the equivalent of prospecting in the Thames.

According to the good folk of the National Sleep Foundation, sometimes the afternoon slump is our own fault. For example, eating too many simple carbohydrates for lunch (think: white bread, white rice or chips) results in a sugar crash. Likewise, sitting still for too long or getting dehydrated in the morning can lead to afternoon sleepiness. However, there’s also a key cause that’s beyond our control – namely, that we experience a natural drop in body temperature between 2pm and 4pm as part of our body’s circadian rhythm.

Therefore, it seems that even if we adjust our diets or work habits to reduce the risk of an afternoon slump, it’s likely to happen anyway. With that in mind, perhaps there’s something to be said for a more reactive approach, especially when an unproductive afternoon is simply not an option. I think I’ve found the ideal response for these occasions, for the times when you don’t want to waste time befriending the afternoon slump in the hope he’ll stop being mean in the playground; you just want to hit him back and be done with it.

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We already know that taking a quick snooze in the afternoon can bestow a host of benefits (if you didn’t, go and read this, I’ll wait), including the one we’re most concerned with here, alertness. But what if I told you there’s a way to supercharge your nap? A secret ingredient to help you tick off to-dos like there is a tomorrow, and it’s got ‘deadline day’ written all over it? Thankfully, there is such an ingredient, and it tastes great: coffee.

“That’s not exactly a startling revelation”, I hear you cry, before clicking away in disgust. “Have a nap, wake up, grab a coffee and get on with it, right? It’s not rocket surgery”.

Well, here’s the shocker: you drink the coffee before taking a nap. Now, common sense tells us that caffeine and sleep do not make the best of bedfellows. In fact, it’s been shown that consuming caffeine as much as six hours before bed is likely to disrupt your nighttime sleep. As such, I’m fully aware that consuming a steaming cup of the world’s favourite stimulant directly before attempting to catch some shuteye sounds somewhat counterintuitive. But there’s trick to this, and it’s scientifically supported.


It’s not new science either. Researchers at Loughborough University’s Sleep Research Laboratory have been experimenting with ‘coffee naps’ since the ’90s. Their research has mostly been concerned with preventing drivers from falling asleep at the wheel, but the results could equally be applied to the potential car crash of your impending deadline; they’ve found that the caffeine/nap combo is more effective at boosting alertness than either caffeine or napping independently. Similarly, a Japanese study found that the alertness of people working at computers benefited more from the caffeine/nap combo than from naps combined with face washing or exposure to bright light.

More recently, a report that looked into ways to combat the drowsiness experienced shortly after waking from a nap (a potentially massive safety-hazard in certain industries) found that caffeine ‘administered prior to sleep’ is still the best-known option.

So how does it work?

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According to Vox, it’s all down to a substance called adenosine. This is a by-product of brain activity that accumulates throughout the day, and eventually makes you feel tired. Now, the reason caffeine is so effective at preventing tiredness is that it blocks the brain’s adenosine receptors. This is pretty neat, but the really clever part is that sleep also clears adenosine from the brain, which effectively removes the competition and allows the caffeine to get to work.

Therefore, to reap the maximum energy boost from your cup of coffee, it makes sense to combine it with a nap. In a further twist of fortuitous chemical coincidence, the length of time that coffee takes to be absorbed is pretty much exactly the same as the optimum length that your nap should be if you want to avoid ‘sleep inertia’ (drowsiness when you wake up): 15-20 minutes. By the time you come round from your micro-sleep, all that adenosine will have been cleared and the caffeine will be well and truly kicking in; the afternoon slump has no chance.

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Quick note: A common response to my lengthy and honestly-not-boring speeches regarding the benefits of short naps is, “There’s no way I can get to sleep that quickly”. This is an understandable concern, but the good news is that most studies agree that even lying there and dozing without properly nodding off is beneficialAnd you never know; I’ve often surprised myself by sleeping so deeply that fifteen minutes felt like hours (a similar effect can be achieved by listening to Donald Trump). 

So, that’s the science. Do you think you’ll give it a go? If so, here are a few practical considerations:

  • In most experiments, participants were given 150-200mg of caffeine. That’s roughly equivalent to the two shots of Espresso that go into a small Americano or a medium Latte at CostBucks. However, because you’re probably planning to try this out somewhere a little more private, I’ll add that the equivalent dosage in instant coffee is about three teaspoons (as someone with a low caffeine tolerance, I don’t need anywhere near that much…go with what works for you).
  • You need to drink the coffee quickly; remember that once you start drinking, you’ve only got a twenty-minute window to get some sleep. Therefore I recommend going for an Espresso-sized concentration, or letting a full cup cool sufficiently that you can drink it fast. And don’t get distracted between finishing your drink and lying down!


  • I find that napping on a bed or sofa is dangerously comfortable. If you’re too comfy, the temptation to snooze beyond the allotted twenty minutes is going to be strong, despite the caffeine. Don’t forget, you’re not doing this for enjoyment, but because there’s work to do, and even a few extra minutes can result in sleep inertia when you eventually get up. Therefore I tend to nap on the floor, lying on my back with a cushion behind my head. This is probably either great or horrendous for my spine, I don’t know (ask me in twenty years).
  • You’ll want to set an alarm for 15-20 minutes. To ensure that you get up and back to work promptly, I recommend placing this far enough away that you have to stand up and walk over to turn it off. By this point you’ll be on your feet and raring to go, with none of that irritating sleep inertia to slow you down.

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  • If you wake up before your alarm – which is fairly common – gauge how you feel. If you feel particularly fresh and alert, then make the most of it and get back to work – coffee nap complete! Otherwise, I find it’s worth staying put; you may well drift back into a light sleep for a few more minutes, which will greatly contribute to the energising effect of the coffee nap.

And that’s it – the secret weapon in the war against the afternoon slump is coffee plus sleep, in an unexpected order. Tested by scientists, pilots, drivers, students and that cute fox halfway down this article, coffee napping potentially holds the key to the highest-performing afternoons of your life. Indeed, I can’t overstate the extent to which this little hack helped me finish my degree. So go, take this knowledge and use it well, experiment with the formula, and let me know in the comments how you got on. Happy napping!

Thanks for reading! Words by Alexander MJ S. Images from Pexels and Pixabay.