Want to Be More Productive? Stop Working at This Time
Each person has a high point and a low point every day.
There's generally a period when you're full of energy (say 8am-10am). There's also a time when you have zero energy, probably between 2pm-4pm, a time when you're full to busting of things to do and people to please. When this low point inevitably hits, stop working. Do this instead.
Every given country or people group has their own way of handling this low point during the day. The Spanish are famous for their siesta. Dozens of other nations, including Portugal, Philippines, China, India, Greece, and Italy also take advantage of this time to rest. But America?
We just power through. How do we power through? With coffee, of course! But to get the most benefit, and therefore be the most productive, you should really do both.
Depending on body mass, what you've had to eat, etc., it will take between 30-45 minutes for the caffeine to take effect. So do this. Drink your cup of coffee, and then take a 20-minute power nap.
Find a quiet place, sit in your car, put your head down, crawl under your desk. Do whatever works for you in your situation, but close your eyes and force yourself to rest for 20 minutes. Even if you "can't fall asleep like that," 20 minutes is just enough time to get into stage 2 of sleep (even if you don't realize it, you'll probably enter stage 1).
Physicians swear by the 20-minute power nap to get them through long shifts, and dozens of experiments verify that it helps you rest just enough to be active again with the same amount of determination as before. Here's where it gets really good.
You drink your coffee. While the caffeine is taking its jolly sweet time coming to your rescue, you're giving your body and mind the boost it needs via power nap.
As you wake up and resume your duties, the caffeine will also kick in. Now you're unstoppable! The productivity boost from this coffee/nap combo will far outweigh the time you took to rest.
We all naturally have a high point and a low point during the day. If you want to be more productive, stop working when you feel your afternoon start to slip away from you. Drink a cup of coffee, and follow it up with a nap.