In many corners of our productivity-obsessed society, naps are associated with laziness. Everyone should sleep eight hours at night,the thinking goes, and work all through the day.But that's backward. Most people routinely woke up for several hours in the middle of the night, and supplemented their "segmented" sleep with a nap in the afternoon.In other words, napping is natural. A short nap can also produce all sorts of benefits.

在我们这个崇尚效率的社会，午睡在多数情况下和懒惰联系在一起。普遍认为，每个人都应晚上睡八小时，然后工作一整天。然而，这种想法已经过时。多数人夜晚通常会照例醒过来几小时，然后下午的时候小睡一会，补充他们“支离破碎”的睡眠。换言之，午睡再自然不过，小睡也益处颇多。

1) Nap in the afternoon.

下午小睡一会。

Some researchers even think the afternoon urge to nap is evolutionary:It seems nature definitely intended that adults should nap in the middle of the day, perhaps to get out of the midday sun.Regardless of the biological reason, this afternoon lull¹ is the perfect time to take a quick nap.

研究人员甚至认为力促下午小睡具有革新意义：成年人就该中午小憩，这似乎是天性所致，也许就为了躲避日中的太阳吧。除却生理原因，下午的间歇时间小睡一下再合适不过。

2) Find a dark, comfortable, quiet place.

个光线暗、 安静舒适的地方。

You may feel tired enough to fall asleep anywhere, but sleep researchers find that these controllable factors play a huge role in how easily and quickly people can fall asleep.

也许你累到哪里都能入睡，但睡眠研究人员发觉这些可控因素很大程度决定你是否可以轻松快速入睡。

3) Figure out how long to nap.

计算下要午睡多久。

Because your brain progresses through a series of distinct stages after you fall asleep, naps of different lengths can have surprisingly different effects.

因为你的大脑在你入睡后逐步进入一系列不同的阶段，午睡时长不等，效果也惊人的不同。

4) Set an alarm.

定好闹钟。

This might seem obvious, but for most people it's really hard to wake up when you intend to, and longer naps can backfire.

这看似显而易见，但多数人打算起来时往往醒不来，午睡时间过长往往事与愿违。

5) Optional: Drink some coffee first.

可选择先喝点咖啡。

Quickly downing a cup of coffee and then napping for 20 minutes or less can have some surprising benefits.

飞速灌下一杯咖啡，然后小睡约摸20分钟会有令人惊喜的效果。

The reason is that it takes around 20 minutes for caffeine to move through your gastrointestinal tract² and your bloodstream, to enter your brain. What's more, caffeine makes you feel more energetic by displacing a chemical called adenosine, which produces a feeling of tiredness — and sleep naturally clears adenosine from your brain.That means when you wake up after 20 minutes and the caffeine arrives, it has less adenosine to compete with, amplifying³ the effect of the caffeine.

原因在于，咖啡因要花大约20分钟才能进入肠胃道和血液，再进入大脑。此外，咖啡因会替换掉一种叫腺甘酸的化学物质，这种物质还会产生疲劳的感觉，从而让你活力更充沛。而睡觉可以彻底让腺甘酸从你大脑里清除。这意味着20分钟后你一觉醒来，咖啡因起效，没有太多腺甘酸相抵触，增强了咖啡因的效果。