Take a Coffee Nap: It's Better than a Coffee or a Nap Alone

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If you’re feeling a bit sleepy, a coffee nap could be just the thing. Half coffee, half nap, having a caffeine drink just before a nap gives you a little shuteye followed by the full benefits of caffeine. By happy coincidence, the amount of time it takes caffeine to affect the brain–about 20 minutes–makes for a nap that recharges your batteries without carrying you over into deep sleep, risking grogginess as a result of what scientists call “sleep inertia”.

Studies in the UK and Japan have found that individuals who take a coffee nap perform better on cognitive exercises and memory tests than those who take naps or drink caffeine alone. Recent advances in neuroscience help explain why. When caffeine hits the brain, it competes for space on neuro-receptors with similarly-shaped molecules called adenosine. A byproduct of brain activity, adenosine accumulates throughout the day and eventually makes you feel tired. Thus taking a nap can clear receptors of some adenosine, preparing the way for a fuller caffeine effect.

Because there is a small window of time to rest during coffee naps, concentrated caffeine is recommended, such as espresso or iced coffee. And despite decades of attempts to find something inherently bad about caffeine, humans metabolize it such that, for adults, there are no real problems, says NYU professor of nutrition Marion Nestle: