虎说百科丨不是所有人都适合睡午觉

Are naps harmful or helpful?

To nap or not to nap? Whether napping will work for you depends on a range of factors, such as lifestyle; sleep cycle length; culture; and, most importantly, the length of your snooze. 

午睡到底有害还是有益？

午睡还是不午睡，这是个问题。白天小睡是否适合你取决于一系列因素，比如生活方式、睡眠周期长度、文化，以及最重要的一点——小憩的时长。

If you like to nap, you are not alone. Napping is part of the culture in many countries: around 51 percent of people worldwide habitually enjoy 40 winks in the daytime. 

When it comes to napping, one size definitely doesn't fit all. If you are sleep deprived, a nap can be helpful or even essential for making it through the day. However, for those with other sleep issues, a nap may make it harder to fall asleep at night. For most of us, the timing and length of our nap will largely determine how beneficial it is to our sleep routine. 

如果你喜欢午睡，放心，你并不是一个人。很多国家都有午睡的文化：全球大约有 51% 的人习惯在白天小睡。

午睡这件事并不是对所有人都适用。如果你睡眠不足，白天小憩一会儿对你挺过这一天不仅很有帮助，甚至可以说是至关重要。但是，对于那些有其他睡眠问题的人来说，白天打盹儿就可能导致晚上更难入睡。于我们大多数人而言，午睡的时机和长度将从很大程度上决定它对我们的睡眠习惯有多大益处。

It's all in the timing

An ideal nap lasts one full sleep cycle—but in practice, this is hard to control. The most convenient and achievable option is a nap of 30 minutes or less, waking before the deep-sleep phase begins.     

一切尽在时机

最理想的午睡应该要经历一个完整的睡眠周期，但在实践中很难控制。一个最方便最好实现的选择是午睡不超过 30 分钟，这意味着在深度睡眠阶段开始之前醒来。

Between 1 p.m. and 4 p.m., most people experience an increase in sleepiness, triggered by a slight drop in core body temperature. A nap of 30 minutes or less around this time allows you to benefit from a burst of Stage 1 and 2 sleep, which is good for mental and physical alertness.  

多数人会在下午 1 点到 4点之间感到睡意增加，这是由身体核心温度略微下降引起的。此时眯上 30 分钟（或者更短），能让你从睡眠的第一和第二阶段受益。这有助于保持心理和生理上的清醒状态。

Napping for 30 minutes or less can reduce stress and lower the risk of cardiovascular problems like heart attacks and strokes. One study showed that napping three times a week for 30 minutes led to a 37 percent decreased risk of dying from heart disease.  

不超过 30 分钟的午睡可以缓解压力，同时还能降低心脏病和中风等心血管疾病的发病风险。一项研究表明，一周午睡 3 次、一次 30 分钟可将死于心脏病的几率降低 37%。

Naps can interfere with insomnia treatment, which involves restricting daytime sleep to increase the likelihood of sleeping solidly at night.     

午睡会干扰失眠治疗，这种治疗包含限制白天睡觉的措施，以便增加夜晚稳睡的可能性。

Beware of naps of more than 30 minutes. Waking from the deep-sleep stages results in sleep inertia, a super-groggy state where brainwaves are slow and it takes longer to adjust to the awake state.  

警惕长于 30 分钟的小憩。从深度睡眠阶段醒来会导致睡眠惰性，让人感到超级昏沉。在这种状态下，脑电波运动很慢，大脑需要更长时间才能调整到清醒状态。

A recent study has found that napping for more than 60 minutes a day increased the risk of type 2 diabetes by 50 percent. If you are in a high-risk category for this condition, avoid regular long naps.       

A 30-minute power nap gives an energy boost and is a healthier option than caffeine.   

最近一项研究发现，每天午睡超过 60 分钟会使 2 型糖尿病发病率增加 50%。如果你是 2 型糖尿病的高危人群，务必要避免午睡时间过长的习惯。

30 分钟的能量午睡不仅能提振精神，还是咖啡因的健康替代。