The Value of Z-z-z-z's
People nervous about a big presentation, test or athletic competition may be relieved to learn that losing a night's sleep is, in most cases, nothing to-well, to lose sleep over. So says the University of California at Berkeley Wellness Letter.
Individual results vary. Researchers have found, however, that moderate sleep loss causes no impairment of function in repetitive athletics (swimming, running), and theorize that top athletes may get more from the thrill of competition and applause than they might lose from a poor night's sleep.
Mentally, a bad night can cause more problems, but here the impairment seems to be limited to longer-term, less mentally demanding tasks-working on an assembly line, for instance, or watching a radar screen.
Studies show little significant impact on performance of short, interesting tasks, other than some irritability and mood shifts.
When it comes to creativity, however, researchers found a different story. Just one night's lost sleep, they say, can hinder spontaneity, flexibility and originality, and can make it harder for people to deal with unfamiliar situations.
More important to next-day performance than the amount of sleep may be the time of day of the presentation, test or athletic match. One study found that most people felt most alert at mid-morning and early evening, regardless of how much sleep they lost.