生活常识篇之午睡

正常情况下的午睡必须以半个小时为上限。因为长时间的午睡，会让人进入deep sleep。而从deep sleep回复到正常状态的过程中会有半个小时左右的头疼和智力下降等现象。这是由于人体的生物钟的保护机制，所以午睡前闹上闹钟，半个小时后准时起床。

Why do I always have terrible headaches after taking an afternoon nap?

Naps are only beneficial if they are around 20-30 minutes. It’s a Power nap! If you sleep longer, your allowing your body to go into a deeper, more restful sleep. That’s great if you planning on sleeping the whole night. But when you cut it off short and get up, your body is even more groggy then when you planned on having a nap. Your disturbing your body’s biological clock. Your head hurts because your dramatically taking your body out a very relaxed state which it usually stays in for hours.