Woman drinking coffee in bed

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"If you want to nap, lay off the caffeine."
As a caffeine addict juggling multiple deadlines, O'Connor noticed that downing an espresso before a planned nap didn't prevent him from falling asleep, and it also seemed to help him feel more refreshed when he woke up. He found a series of studies by sleep researchers in England that supported his hypothesis: Drinking a cup of coffee and then immediately snoozing for 15 minutes was more effective at reviving a wiped-out person than either of those strategies on its own. The researchers believe that the short nap helps clear the brain of the sleep-inducing compound adenosine and gives the coffee just enough time to kick in (caffeine takes about 20 minutes to have a physiological effect).

Sip, sleep, snap to attention: These studies involved sleep-deprived drivers, but O'Connor says that if this trick can make someone alert, coordinated and focused enough to handle a vehicle without delays in reaction time, then it would also help any of us who need an afternoon energy boost.