Many methods to improve your health are pretty straightforward: to lose weight, eat less and exercise more; to boost your energy, get more sleep; to prevent dehydration, drink more water. Others, however, are totally counterintuitive. The following tips really do work- but they may leave you scratching your head.

DRINK COFFEE TO HAVE A BETTER NAP
In a Japanese study that examined how to make the most of a nap, people who took a "coffee nap" - consuming about 200 milligrams of caffeine (the amount in one to two cups of coffee) and then immediately took a 20- minute rest-felt more alert and performed better on computer tests than those who only took a nap.

Why does this work? A 20-minute nap ends just as the caffeine kicks in and clears the brain of a molecule called adenosine, maximizing alertness. "Adenosine is a byproduct of wakefulness and activity," says Allen Towfigh, MD, medical director of New York Neurology & Sleep Medicine. "As adenosine levels increase, we become more fatigued. Napping clears out the adenosine and, when combined with caffeine, an adenosine-blocker further reduces its effects and amplifies the effects of the nap."

DON'T BRUSH AFTER EATING
Don't brush your teeth immediately after meals and drinks, especially if they were acidic. Acidic foods-citrus fruits, sports drinks, tomatoes, soda (both diet and regular)-can soften tooth enamel "like wet sandstone," says Howard R. Gamble, immediate past president of the Academy of General Dentistry. Brushing your teeth at this stage can speed up acid's effect on your enamel and erode the layer underneath. Gamble suggests waiting 30 to 60 minutes before brushing.

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