Pour it on
If you’re looking to maximize that 20-minute power nap, maybe a little coffee’s in order. OK, so it sounds counterintuitive, but hear us out. It’s called a “coffee nap,” and besides being another excuse to drink more coffee, there’s actually some science to it. According to Vox.com, if you caffeinate immediately before napping and sleep for 20 minutes or less, you can exploit a quirk in the way sleep and caffeine affect your brain.
That’s because sleeping clears from the brain adenosine, a natural byproduct of brain activity that makes us feel tired but also competes with caffeine for brain receptors. Meanwhile, it takes about 20 minutes for caffeine to get through the GI tract and reach the brain. So, if you slam a cup of joe and nap for 20 minutes, you'll reduce your adenosine levels just in time for the caffeine tsunami.
According to Stephen R. Braun’s book, Buzz: The Science and Lore of Alcohol and Caffeine, it's like "putting a block of wood under one of the brain’s primary brake pedals."
Researchers at Loughborough University in the UK found when tired participants took a 15-minute coffee nap, they went on to commit fewer errors in a driving simulator than when they were given only coffee, a decaf placebo or only a nap. This was true even if they had trouble falling asleep or just laid half-asleep during the 15 minutes.
Meanwhile, a Japanese study found people who took a coffee nap before performed significantly better on memory tests compared to people who solely took a nap, or took a nap and then washed their faces or had a light shone in their eyes.
There's even evidence that caffeine naps can help people go for long periods without proper sleep. As part of one study, 24 young men went without sleep for a 24 hours, taking only short naps. Twelve, who were given just a placebo, performed markedly worse on cognitive tests compared to their baseline scores. The 12 others, who had caffeine before their naps, managed scores roughly the same as their baselines.