It sounds backward, but research suggests a cup of coffee followed by a short nap could sharpen focus and fight fatigue.*

这听起来有点反常，不过研究显示，先喝一杯咖啡再小睡片刻，可能会让注意力更集中、对抗疲劳。*

In today’s caffeine-fueled culture, energy drinks and sleep hacks promise sharper focus and longer days. But one deceptively simple strategy keeps resurfacing: coffee with a nap.

在当下这个由咖啡因驱动的时代，能量饮料和各种“睡眠窍门”都承诺能让人更专注、把一天拉得更长。然而，有一种看似简单却颇为聪明的策略总在反复出现：咖啡加上一场小睡。

Of course, the so-called “caffeine nap” isn’t entirely novel. In Spain, for instance, it’s common to follow lunch with a coffee and a short siesta. But only recently have experts begun investigating whether there’s any scientific merit to this practice.

当然，所谓的“咖啡午睡（caffeine nap）”并不是什么新鲜事。以西班牙为例，人们常常在午饭后先喝一杯咖啡，再来一段短暂的午休（siesta）。不过，直到最近专家们才开始研究这种做法是否具有科学依据。

So, could a pre-siesta coffee give your brain a bigger boost than either alone? Endocrinologists and sleep experts discuss the molecular underpinnings and potential limitations of the caffeine nap.

那么，午睡（siesta）前来一杯咖啡，是否能比单独喝咖啡或单独小睡更能为大脑注入动力？内分泌学家（endocrinologists）和睡眠专家讨论了“咖啡因小睡”（caffeine nap）的分子机理及其潜在局限。

**THE YIN-YANG OF CAFFEINE AND ADENOSINE**

咖啡因与腺苷的“阴阳”关系

Sleepiness isn’t just a feeling—it’s chemical and biological processes at work.

困意不只是主观感觉——背后有化学和生物学过程在起作用。

In humans, one of the key players is adenosine, a neuromodulator that steadily builds up in the brain as our cells burn energy over the course of a day. As adenosine accumulates, it binds to a family of specialized receptors—A1, A2A, A2B, and A3—that help regulate critical cellular functions, including sleep.

在人类体内，一个关键“角色”是腺苷（adenosine），这是一种神经调质，随着一天中细胞消耗能量，会在大脑中不断累积。随着腺苷的堆积，它会与一组特化受体结合——A1、A2A、A2B 和 A3——这些受体帮助调控包括睡眠在内的关键细胞功能。

“When activated, [the receptors] slow nerve transmission and release of neurotransmitters,” says Scott Rivkees, a pediatric endocrinologist and professor at Brown’s School of Public Health. The effect is like a mental dimmer switch: the binding inhibits neural activity, making us feel sleepy. As we sleep, adenosine is broken down until the brain can resume normal functioning.

“当被激活时，[这些受体]会减慢神经传导和神经递质的释放，”布朗大学公共卫生学院的小儿内分泌学家兼教授Scott Rivkees说。其作用就像一个心理上的“调光开关”：这种结合会抑制神经活动，让我们感到困倦。随着我们入睡，腺苷会被分解，直到大脑恢复正常运作。

Caffeine exploits this system to keep us awake. “[Caffeine is] a potent adenosine antagonist that will block adenosine at each of the different receptor subtypes,” Rivkees says. With those receptors occupied, adenosine can’t dock and slow brain activity. Instead, nerve cells keep firing, neurotransmitters keep flowing, and we feel alert.

咖啡因利用这套系统让我们保持清醒。Rivkees 说：“[咖啡因]是一种强效的腺苷拮抗剂，能在各个不同的受体亚型上阻断腺苷。”当这些受体被占据时，腺苷就无法“对接”，也就不能减缓大脑活动。相反，神经元持续放电，神经递质不断释放，我们便感到清醒警觉。

“It’s this yin-yang relationship,” Rivkees says. The more caffeine you consume, the greater the number of receptors that are filled—though there is a physiological limit. “When you have really high concentrations of caffeine, you will block the majority of adenosine receptors.”

“这是种‘阴阳’关系，”Rivkees 说。“你摄入的咖啡因越多，被占据的受体就越多——不过这有生理上的上限。 当体内咖啡因浓度非常高时，你会阻断大多数腺苷受体（adenosine receptors）。”

This relationship isn’t static, however. As caffeine blocks adenosine receptors, the body compensates by generating more of them. Over time, it takes higher doses of caffeine to achieve the same effect—leading to tolerance and dependence at the molecular level.

然而，这种关系并非一成不变。随着咖啡因阻断腺苷受体，机体会通过生成更多受体来进行“补偿”。久而久之，需要更高剂量的咖啡因才能达到相同效果——在分子层面上导致耐受性（tolerance）和依赖性（dependence）。

**WHAT THE RESEARCH SAYS ABOUT CAFFEINE NAPS**

关于咖啡小睡（caffeine naps）的研究怎么说

Both naps and caffeine can reset the brain—naps by clearing out adenosine, caffeine by blocking it. But, some have long wondered, might a short nap after a cup of coffee amplify the stimulant’s effect?

小睡和咖啡因都能让大脑“重置”——小睡通过清除腺苷（adenosine），咖啡因则通过阻断它的作用。不过，长期以来人们一直在想：喝完一杯咖啡再小睡片刻，是否会放大这种兴奋剂的效果？

The idea has intuitive appeal. “A nap itself combats sleepiness. Caffeine itself also combats sleepiness. So, if we combine both, we could have a stronger effect,” says Seiji Nishino, a professor emeritus of psychiatry, behavioral sciences, and sleep medicine at Stanford. Conveniently, caffeine takes about 20-30 minutes to kick in, roughly the length of an ideal nap. “If we sleep longer than 30 minutes or an hour, we go into deep sleep,” Nishino says. Less than that provides the benefit of a mental boost, without the lingering brain fog.

这个想法直观上就很有吸引力。“小睡本身能对抗困倦。咖啡因本身也能对抗困倦。所以，如果把两者结合起来，可能会有更强的效果。”斯坦福大学精神病学、行为科学与睡眠医学名誉教授西野诚二（Seiji Nishino）说。巧的是，咖啡因大约需要20—30分钟开始起效，这大致就是理想小睡的时长。“如果我们睡超过30分钟或一个小时，就会进入深睡期，”西野说。短于这个时长的小睡，既能带来精神提升，又不会留下挥之不去的‘脑雾’感。

“Part of the reason for combining these things is that sort of sleep inertia problem,” says Siobhan Banks, professor and director of the Behaviour-Brain-Body Research Centre at the University of South Australia, referring to the grogginess that persists after a nap. “If you could have coffee in conjunction with a nap, it could perhaps improve your performance.”

“把这两件事结合起来的部分原因，是所谓的‘睡眠惯性’问题，”南澳大利亚大学Behaviour-Brain-Body Research Centre的教授兼主任Siobhan Banks说。这里的“睡眠惯性”指的是小睡后持续存在的那种昏沉感。“如果你能把喝咖啡与小睡结合起来，或许能提升你的表现。”

Despite its buzz, the caffeine nap remains understudied. A 1997 study observed improved driving ability among participants who combined caffeine with a short nap, and a 2001 study described the benefits of caffeine in reducing post-nap sleepiness. But evidence is thin, and experts like Nishino remain cautious. “Conceptually it’s correct,” he says. “But I don’t know if it works or not.”

尽管话题热度不低，“咖啡因小睡”仍研究不足。1997年的一项研究发现，将咖啡因与短暂小睡结合的参与者，其驾驶能力有所提升；而2001年的一项研究则指出，咖啡因有助于减轻小睡后的困倦。不过，相关证据仍然薄弱，像Nishino这样的专家依然保持谨慎。他说：“从概念上看这是对的，但我不知道它是否真的有效。”

Now, scientists like Banks are starting to test the theory more rigorously. Her research has focused on using caffeine more strategically, particularly in the workplace. Early results are promising. In a pilot study published in 2020, Banks and her team found that a caffeine-nap—200 mg of caffeine immediately before a 30-minute rest—reduced fatigue and boosted cognitive performance.

现在，像 Banks 这样的科学家正开始以更严格的方式检验这一理论。她的研究重点是更有策略地使用咖啡因，尤其是在职场环境中。初步结果令人鼓舞。在2020年发表的一项先导性研究中，Banks 及其团队发现，“咖啡因小睡”——在30分钟休息前立即摄入200毫克咖啡因（约相当于两杯普通咖啡）——能降低疲劳感并提升认知表现。

While Banks says the initial findings “confirm that there’s some benefit to the concept,” she concedes that the studies are relatively small and laboratory-based. Other researchers have noted similar shortcomings, calling for more studies that test caffeine naps in a wider range of real-life scenarios.

尽管Banks表示，初步结果“证实这一概念确实有一定益处”，但她也承认这些研究样本规模较小，且主要基于实验室环境。其他研究者也指出了类似的不足，呼吁开展更多研究，在更广泛的真实生活场景中检验“咖啡因小睡”（caffeine nap）。

“These studies have limitations,” says Nora D. Volkow, director of the National Institute on Drug Abuse at the National Institutes of Health. “One is that most involved healthy volunteers in their early 20s and 30s. So, people who are middle-aged and older, or those with sleep disorders, may not see the same benefits.”

“这些研究存在局限性，”美国国立卫生研究院（NIH）下属的美国国家药物滥用研究所（National Institute on Drug Abuse）所长Nora D. Volkow说。“其中之一是，大多数纳入的是二十出头和三十多岁的健康志愿者。因此，中年及以上人群，或有睡眠障碍的人，可能看不到同样的益处。”

There are also individual differences to consider. Some people are more or less prone to napping, while others have unusually high sensitivity to caffeine. No matter what the research shows about the efficacy of caffeine naps, it ultimately “depends on the person and on the situation,” Nishino says.

还要考虑个体差异。有些人更容易（或不太容易）打盹，而另一些人对咖啡因的敏感性异常高。Nishino说，无论研究对“咖啡因小睡”的效果显示什么，归根到底都“取决于个人和具体情境”。

And as effective as caffeine is for improving attention and alertness, Volkow cautions that caffeine naps will never be a productivity silver bullet—or replacement for a good night’s rest.

尽管咖啡因在提升注意力和警觉性方面很有效，Volkow 警告说，“咖啡小睡”（caffeine nap）绝不可能成为提高生产力的万能灵药——也不能替代一晚高质量的睡眠。

Still, Banks believes some at-home experimentation is worthwhile and recommends starting with smaller doses. “Play and have a cup of coffee before a nap,” she says. “I think there’s enough evidence to give it a go and see if it works.”

尽管如此，Banks 认为在家里做些小实验是值得的，并建议从较小剂量开始。她说：“不妨‘玩一玩’，在小睡前喝一杯咖啡。” “我认为已有的证据足以值得一试，看看这办法是否对你有效。”