Nap skeptic......................

     Naps also improve our overall health.  A large study in Greece, which followed more than 23,000 people over six years, found that, controlling for other risk factors, people who napped were as much as 37 percent less likely as others to die from heart disease, "an effect of the same order of magnitude as taking an aspirin or exercising every day."  Napping strengthens our immune system.  And one British study found that simply anticipating a nap can reduce blood pressure.
     Yet, even after absorbing this evidence, I remained a nap skeptic.  One reason I so disliked naps is that I woke up from them feeling as if someone had injected my bloodstream with oatmeal and replaced my brain with oily rags.  Then I discovered something crucial:  I was doing it wrong.
     While naps between thirty and ninety minutes can produce some long-term benefits, the come with steep costs.  The ideal naps - those that combine effectiveness with efficiency - are far shorter, usually between ten and twenty minutes.   For instance, an Australian study published in the journal Sleep found that five-minute naps did little to reduce fatigue, increase vigor, or sharpen thinking.  But ten-minute naps had positive effects that lasted nearly three hours.  Slightly longer naps were also effective.  But once the nap lasted beyond about the twenty-minute mark, our body and brain began to pay a price.   That price is known as "sleep inertia" - the confused, boggy feeling I typically had upon waking.   Having to recover from sleep inertia - all that time spent splashing water on my face, shaking my upper body like a soaked golden retriever, and search desk drawers for candy to get some sugar in my system - subtracts from the nap's benefits ...

-Daniel H. Pink,  When:  The Scientific Secrets Of Perfect Timing