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's the science behind the idea.

Interesting!  I've tried a nap, immediately followed by coffee. This is even better!

<yawn><stretch> Works!

Very cools thanks for the lifehack, Geege!

But here's the trick of the coffee nap: sleeping naturally clears adenosine from the brain. If you nap for longer than 15 or 20 minutes, your brain is more likely to enter deeper stages of sleep that take some time to recover from. But shorter naps generally don't lead to this so-called "sleep inertia" — and it takes around 20 minutes for the caffeine to get through your gastrointestinal tract and bloodstream anyway.

So if you nap for those 20 minutes, you'll reduce your levels of adenosine just in time for the caffeine to kick in. The caffeine will have less adenosine to compete with, and will thereby be even more effective in making you alert.

Awesome stuff! I have noticed this phenomenon even with regular sleep. If I drink some coffee at night (not too much), I have no problem falling asleep, but I am more alert the next morning. Not sure why...

Probably a variation on the same effect that some caffeine remains in your bloodstream when you awake. The main difference being that you went through the path of a much deeper, longer sleep.

geege, have you tried this? does it work?

genius!!

I'm terrified of becoming addicted to coffee naps ( maybe the perfect polyphasic sleep hack )

It's likely that coffee naps are no more addictive than coffee.