Everyone naps, but not everyone naps well. In the eternal quest for the perfect nap, researchers, scientists, and journalists explore everything from the problem of grogginess to productivity-boosting power naps to the ability to learn while asleep. Here's what you should know before you decide to doze.

  • Learn While You Dream  The New York Times' Tara Parker-Pope explains that if you go to bed frustrated by a problem, your brain will keep at work while you sleep. "Struggling with a task might be the trigger that prompts the sleeping brain to focus on the subject and work on getting better," she writes. "Dreams don’t necessarily have to make sense or be obvious to the awake mind in order to have a learning benefit."
  • How to Sit  Economist Austin Frakt examines a study. The further you lean back the better. Lying down is best. Leaning forward is the least beneficial but better than not napping at all. He adds, "The most important consideration for me is neck alignment. Leaning my head back may find a stable surface for it, but it can irritate my neck. Best results seem to occur with folded arms and head slightly slumped forward."
  • Why Naps Make You Smarter  Mental Floss' Ranson Riggs writes, "It all happens in the hippocampus, which is a part of our brain which temporarily stores 'fact-based memories.' 'It's as though the email inbox in your hippocampus is full and, until you sleep and clear out those fact emails, you’re not going to receive any more mail. It’s just going to bounce until you sleep and move it into another folder,' Dr Matthew Walker, a Berkeley psychologist said. Even more fascinating, the study found that small children who are learning to construct words into sentences are unlikely to remember their lessons unless they sleep soon afterward."
  • ...Unless They Make You Groggy  The Washington Post's Ezra Klein doesn't see a net benefit. "When I nap, there's at least a 50-50 chance that I'll wake up feeling groggy and awful. Whatever cognitive benefits naps offer, they're vastly outweighed by the period of time in which I'm useless and unhappy and desperate to go back to sleep."
  • How Long To Nap?  Ten minutes, Eric Barker reads from a scientific study. Five-minute naps are useless, thirty-minute naps are useful but cause "a period of impaired alertness and performance immediately after napping, indicative of sleep inertia." The twenty-minute nap is good too, although not significantly more effective than the ten-minute one.
  • ...Don't Nap Too Long  Economist Austin Frakt says to those who complain that naps are counter-productive, "They are more than likely too long. For most people optimal nap length is less than 30 minutes (for me it is 20). The trick is to enter the first few lighter stages of sleep and then exit before experiencing the deeper ones. Going deep risks sleep inertia, that horrible, groggy feeling."
  • ...But 90-Minute Naps Make You Smarter  So concludes ArsTechnica's Casey Johnston from a study that shows "participants who were able to take naps long enough for dreams to occur were able to perform a previously learned task more quickly than others who had had to stay awake."
  • You Should Nap at Work  The Atlantic's Eleanor Smith makes the case. "Depending on their length, naps are said to boost productivity, creativity, memory, and problem-solving abilities -- not to mention enhance weight loss, reduce stress, and lower the risk of heart disease. Naps are also said to be more effective than drinking caffeine for stimulating alertness. And yet, sleeping during the workday, for the most part, remains a taboo." But allowing employees to nap would make them more productive and benefit the company. Here's more insight on napping at work.
  • ...Fixing The Fluorescent Light Problem  Lifehacker reader Mitondsolves suggests, "Need a nap but it is too bright in the office? Get an old pair of sunglasses and put black tape behind the lenses. Works well on an airplane instead of those odd looking eyeshades."
  • ...How To Sneak It  Mental Floss' Miss Cellania gives 7 tips for the clandestine office nap. Number three gives a special iPhone app that makes the noises that would normally come from a productive, non-sleeping office worker: Pencil sharpeners, tapping keyboards, etc.
  • ...What If You're Slow to Fall Asleep?  Lifehacker's Daniel Tenner jumps that hurdle to napping. "Napping is not sleeping. To get the benefit of a refreshing power nap, you don't need to fall asleep. It's enough to relax yourself and let your thoughts drift off, even while remaining mostly awake. If you can do this properly (it does take some practice), you can power nap even if you find it impossible to fall asleep quickly." Tenner explains how to develop this skill.