If a 20-minute nap, a cup of joe, and more shuteye at night were in a cage match, who would win for reducing that classic afternoon "dip"? The answer is: (in order of effectiveness)

二十分钟的小睡，一杯咖啡，晚上多睡一会，这三样哪种能更有效地减轻下午的瞌睡？答案如下(根据有效度排序)：

1. Nap 小睡

2. Caffeine 咖啡

3. Then more nighttime sleep 晚上多睡会儿

A new study just released proves the power of a nap over a jolt¹ of caffeine and even more sleep at night. It's actually the first such study to look at all three methods for combating the afternoon lull² that's commonly experienced-and which is a very normal physiological³ response to the body cycling through its natural rhythms during the day。

一项新研究刚刚证明小睡的威力强过一罐咖啡甚至是晚上多睡一会儿。这实际上是第一次让三种对抗下午犯困的方法同台竞技。事实上，下午犯困是一天之中人体生理节律导致的非常正常的生理反应。

Just because you feel sleepy at some point in the afternoon doesn't actually mean you're sleep deprived. About eight hours after you wake up, the body's temperature dips a little, triggering that oh-so-annoying drowsiness⁴ after lunch and smack⁵ dab⁶ in the middle of your attempts to focus and get more done in the late afternoon。

其实下午犯困并不是意味着你缺觉。大概在醒后八小时，身体的体温会出现小幅回落，这会导致午餐之后昏昏沉沉的瞌睡，并且恰好这时你还想多做点事情，就更难集中注意力了。