If you haven't heard of a coffee nap, it's the new fast fix for afternoon fatigue. Essentially, you drink a coffee, then take a 20-minute power nap, and when you wake up, you can expect to feel much more rejuvenated than either coffee or napping alone could make you. The latest sleep solution has been gaining some traction since researchers discovered that there may be some synergistic benefit to using caffeine and sleep in combination. It all has to do with a compound called adenosine, which is associated with drowsiness and promoting sleep. It seems that, when we typically drink a cup of coffee, the caffeine competes with the existing adenosine in the brain, so that some of the receptors that would respond to caffeine are blocked by the drowsy compound. But, in the 20 minutes it takes for a cat nap, your brain can clear that adenosine and make room for the caffeine that's on its way to your brain to give you that extra pick-me-up. Because of these biochemical processes happening in your brain, downing a cup of joe before your nap is actually more effective than just drinking coffee or just taking a nap. In a U.K. study in which fatigued patients were given either a coffee, a chance to nap, or a coffee then a nap, those who had the coffee nap performed better in subsequent tests. Of course, it's a good idea to be cautious about your caffeine consumption late in the day if you have trouble sleeping at night, because sleeplessness later on will just lead to further issues with fatigue. Check out another way to enjoy your cup of coffee with an extra energy boost. (Photography: Thinkstock)