Humans Need More Sleep in the Winter: Say What?

 Humans Need More Sleep in the Winter: Say What?

During this time of year, it’s hard to not be jealous of the various squirrels, hedgehogs, possums, chipmunks¹, bats, skunks², lemurs, and other small mammals that lower their body temperatures and their metabolisms³ for the winter, napping in their burrows⁴ until the snow goes away. Bears don’t exactly hibernate⁵, but they do spend winters in their dens⁶, napping and caring for newborn cubs⁷. Even some species of reptiles⁸ and amphibians⁹ hibernate, remaining in a sluggish¹⁰ torpor¹¹ throughout the winter when there’s not enough heat to raise their body temperatures.

Humans, of course, do not hibernate, but it can feel much more difficult to get out of bed on a chilly¹² winter morning than it does in the height of summer. Some people take this as a welcome sign that being awake during the winter is an affront¹³ to nature. Or at the very least, they assume that humans need more sleep during winter. Is that true?

The Straight Talk

We don’t exactly need more sleep during the wintertime, but due to factors beyond our control, we definitely want it.

Humans’ sleep and wake cycles are regulated by light. Light suppresses the production of melatonin by the brain’s pineal gland¹⁴. As daylight fades, the pineal gland produces more melatonin, which causes us to feel sleepy. In the morning, the gland is instructed to stop producing the hormone¹⁵, which aids in waking up. We feel sleepier in the winter because there’s less daylight, hence more melatonin. We wake up when it’s still dark outside, before the pineal gland has been instructed to shut down, and it starts up again long before we’re actually ready to go to bed. That adds up to many lethargic¹⁶ mornings and evenings. 

Another dirty trick that makes us want more sleep is that wintertime affords us with prime sleeping conditions. It’s dark outside and the house is cool and still—a perfect recipe for a good night’s sleep. No wonder so many people have trouble leaving bed on a January morning.

Although many people end up waking later and retiring earlier during the cold, dark months, there’s no real biological need for getting extra sleep during the winter. There’s more variation in sleep needs among individuals than there is in a single individual between seasons. That is, some people naturally need more sleep than others need in order to function optimally¹⁷, and that number doesn’t change with the seasons.

Even though our body clock is triggered by light and dark, our sleep needs don’t correspond exactly with the length of the days. Think about it: in Scandinavian countries where there may be only a few hours of light per day in the winter, people don’t suddenly need eighteen or twenty hours of sleep per night. Likewise, in the summer when there are only a few hours of darkness, people aren’t suddenly able to get by on only two or three hours.

The imbalance of light and dark is a prime culprit in the development of seasonal¹⁸ affective disorder¹⁹ (SAD), a wintertime malaise characterized by fatigue²⁰, depression, and weight gain. Sound familiar? It’s no coincidence that treatment for SAD commonly includes light therapy to reset²¹ and regulate the body’s circadian rhythms.

The Takeaway

If you’re already getting your optimum amount of sleep, you don’t need extra just because it’s winter. But if you regularly don’t get enough, feel free to fight the freeze by staying snug²² in your bed as long as possible.

1 chipmunks   

n.金花鼠( chipmunk的名词复数 )

参考例句：

2 skunks   

n.臭鼬( skunk的名词复数 )；臭鼬毛皮；卑鄙的人；可恶的人

参考例句：

• Slim swans and slender skunks swim in the slippery slime. 苗条的天鹅和纤细的臭鼬在滑滑的黏泥上游泳。 来自互联网
• But not all baby skunks are so lucky. -We're coming down. 但不是所有的臭鼬宝宝都会如此幸运。-我们正在下来。 来自互联网

3 metabolisms   

n.新陈代谢( metabolism的名词复数 )

参考例句：

• Garden snails are evolving slower metabolisms. 花园蜗牛新陈代谢进化缓慢。 来自互联网
• Elite swimmers tend to be born with certain advantages, such as superefficient metabolisms. 精华的游泳者趋于与某个优点出生，例如superefficient新陈代谢。 来自互联网

4 burrows   

n.地洞( burrow的名词复数 )v.挖掘（洞穴），挖洞( burrow的第三人称单数 )；翻寻

参考例句：

• The intertidal beach unit contains some organism burrows. 潮间海滩单元含有一些生物潜穴。 来自辞典例句
• A mole burrows its way through the ground. 鼹鼠会在地下钻洞前进。 来自辞典例句

5 hibernate   

v.冬眠，蛰伏

参考例句：

• Bears often hibernate in caves.熊常在山洞里冬眠。
• Some warm-blooded animals do not need to hibernate.一些温血动物不需要冬眠。

6 dens   

n.牙齿，齿状部分；兽窝( den的名词复数 )；窝点；休息室；书斋

参考例句：

• Female bears tend to line their dens with leaves or grass. 母熊往往会在洞穴里垫些树叶或草。 来自辞典例句
• In winter bears usually hibernate in their dens. 冬天熊通常在穴里冬眠。 来自辞典例句

7 cubs   

n.幼小的兽，不懂规矩的年轻人( cub的名词复数 )

参考例句：

• a lioness guarding her cubs 守护幼崽的母狮
• Lion cubs depend on their mother to feed them. 狮子的幼仔依靠母狮喂养。 来自《简明英汉词典》

8 reptiles   

n.爬行动物，爬虫( reptile的名词复数 )

参考例句：

• Snakes and crocodiles are both reptiles. 蛇和鳄鱼都是爬行动物。 来自《简明英汉词典》
• Birds, reptiles and insects come from eggs. 鸟类、爬虫及昆虫是卵生的。 来自《现代汉英综合大词典》

9 amphibians   

两栖动物( amphibian的名词复数 )； 水陆两用车； 水旱两生植物； 水陆两用飞行器

参考例句：

• The skin of amphibians is permeable to water. 两栖动物的皮肤是透水的。
• Two amphibians ferry them out over the sands. 两辆水陆两用车把他们渡过沙滩。

10 sluggish   

adj.懒惰的，迟钝的，无精打采的

参考例句：

• This humid heat makes you feel rather sluggish.这种湿热的天气使人感到懒洋洋的。
• Circulation is much more sluggish in the feet than in the hands.脚部的循环比手部的循环缓慢得多。

11 torpor   

n.迟钝；麻木；（动物的）冬眠

参考例句：

• The sick person gradually falls into a torpor.病人逐渐变得迟钝。
• He fell into a deep torpor.他一下子进入了深度麻痹状态。

12 chilly   

adj.凉快的，寒冷的

参考例句：

• I feel chilly without a coat.我由于没有穿大衣而感到凉飕飕的。
• I grew chilly when the fire went out.炉火熄灭后，寒气逼人。

13 affront   

n./v.侮辱，触怒

参考例句：

• Your behaviour is an affront to public decency.你的行为有伤风化。
• This remark caused affront to many people.这句话得罪了不少人。

14 gland   

n.腺体，(机)密封压盖，填料盖

参考例句：

• This is a snake's poison gland.这就是蛇的毒腺。
• Her mother has an underactive adrenal gland.她的母亲肾上腺机能不全。

15 hormone   

n.荷尔蒙，激素，内分泌

参考例句：

• Hormone implants are used as growth boosters.激素植入物被用作生长辅助剂。
• This hormone interacts closely with other hormones in the body.这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。

16 lethargic   

adj.昏睡的，懒洋洋的

参考例句：

• He felt too miserable and lethargic to get dressed.他心情低落无精打采，完全没有心思穿衣整装。
• The hot weather made me feel lethargic.炎热的天气使我昏昏欲睡。

17 optimally   

最佳

参考例句：

• In the classic script for a Cartel, the group sets a unified optimally exploiting price structure. 按照卡特尔的传统范本，这个集团制定出一个统一的最有利于剥削的价格结构。 来自辞典例句
• RF power LDMOS with a trench drift region is optimally designed. 对射频功率LDMOS槽形漂移区的结构进行了优化设计。 来自互联网

18 seasonal   

adj.季节的，季节性的

参考例句：

• The town relies on the seasonal tourist industry for jobs.这个城镇依靠季节性旅游业提供就业机会。
• The hors d'oeuvre is seasonal vegetables.餐前小吃是应时蔬菜。

19 disorder   

n.紊乱，混乱；骚动，骚乱；疾病，失调

参考例句：

• When returning back,he discovered the room to be in disorder.回家后，他发现屋子里乱七八糟。
• It contained a vast number of letters in great disorder.里面七零八落地装着许多信件。

20 fatigue   

n.疲劳，劳累

参考例句：

• The old lady can't bear the fatigue of a long journey.这位老妇人不能忍受长途旅行的疲劳。
• I have got over my weakness and fatigue.我已从虚弱和疲劳中恢复过来了。

21 reset   

v.重新安排，复位；n.重新放置；重放之物

参考例句：

• As soon as you arrive at your destination,step out of the aircraft and reset your wristwatch.你一到达目的地，就走出飞机并重新设置手表时间。
• He is recovering from an operation to reset his arm.他做了一个手臂复位手术，正在恢复。

22 snug   

adj.温暖舒适的，合身的，安全的；v.使整洁干净，舒适地依靠，紧贴；n.（英）酒吧里的私房

参考例句：

• He showed us into a snug little sitting room.他领我们走进了一间温暖而舒适的小客厅。
• She had a small but snug home.她有个小小的但很舒适的家。