Here, the principles of daytime sleep, optimized to achieve four different outcomes:
There are five stages of sleep, each one reflecting the body and brain's progressive relaxation. Stage one and two are lighter phases of sleep that will leave you refreshed. You'll reap the benefits after as few as eight minutes, but be sure to limit your nap to less than half an hour. The effects of a quickie post-lunch nap like this can last at least three hours, just long enough to get you through the 3 p.m. doldrums.
Drink 150 milligrams of caffeine, roughly an 8-ounce cup of coffee, immediately before napping. Caffeine takes 15 to 30 minutes to kick in, so it's a natural alarm clock, and you'll be juiced upon waking.
After 45 to 90 minutes, snoozers enter stage three and four sleep, which improves memory by about 20 percent for tasks including word association and navigating mazes. Emotions rooted in memory become more balanced, too. The upshot? You'll be calmer and less prone to overindulgence (e.g., no more overdosing on cookies in the conference room). Allow 15 minutes after waking to shake off grogginess, which adds slightly to the overall time you should budget.
Set up an incentive. Harvard University researchers report that among subjects whose bedtime occurred before memory testing, those promised a monetary reward for each correct answer did better than those who weren't. (Post-deadline facial, anyone?)
After 90 minutes, you'll enter deep REM (rapid eye movement) sleep, or stage five, which boosted performance on creative problem-solving in a 2009 University of California, San Diego study. The researchers were at pains to point out that the advantage wasn't due to improved memory; they attributed it to REM sleep's ability to "assimilate new information into past experience" in the brain.
Think about key points you want to accomplish in your project before nodding off. While you sleep, or upon waking, your brain will dredge up potentially helpful information that might otherwise be discarded.