Naps have gotten a bum rap.
D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008875:Middle Aged; D012146:Rest / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D007319:Sleep Initiation and Maintenance Disorders / Q000503:physiopathology; D013997:Time Factors