Like most people, my brain starts to fizzle out between 2 and 3pm. According to science, this isn't due to a lunch hangover but rather a part of our circadian rhythm.
To preempt the inevitable afternoon slothfulness, author Dan Pink proposes to take a nappuccino. He recommends that before you take your 20-minute nap (science shows that more than 20 minutes can make you feel drowsier), you should drink a cup of coffee.
Writes Pink in his new book When: The Scientific Secrets of Perfect Timing:
The caffeine won't fully engage in your bloodstream for about 25 minutes, so drink up right before you lie down.
The pre-nap caffeination will give you an extra boost when you wake up. Your brain will be sharper and more focused. You'll also receive all the benefits of a nap: lower blood pressure and a stronger heart.
You can read more about the nappuccino productivity hack here.