You probably know: the best time to nap is when it comes naturally—usually sometime during the mid-afternoon circadian dip between 3 p.m. and 5 p.m. After you snooze, chances are you'll be more alert, perform better on cognitive tests, have faster reflexes, and feel more "on" that you would otherwise. (Sadly, most of us don't/can't nap, which is why traffic accidents peak in these hours.) One thing to keep in mind: the sweet spot is shockingly short—10 minutes—but has benefits that last as long as 2.5 hours, finds an Australian study. A longer nap leads to drowsiness after waking.
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