So, why are you always tired?

所以為什麼你總是感覺疲累?

If you know the number of hours of sleep isn't the problem, the second most common cause of fatigue comes from lack of physical activity and a poor diet.

若問題不在睡眠時間長短，第二常見導致疲勞的原因便是運動量不夠和不健康的飲食習慣。

Study after study finds that adults who began light exercise a few times a week reported more energy after six weeks.

許多研究接連指出，成年人每週進行幾次輕度運動，6週後就能更有精神。

People who exercise more regularly also report sleeping better, even though studies show that they aren't sleeping any longer.

研究也指出，規律運動的人睡得比較好，就算他們睡眠時間並沒有比較長。

But if that doesn't help, don't go straight for your cup of joe.

假如運動無法消除疲勞，也別馬上灌咖啡。

While many studies show coffee is good for your health, research shows that your reliance on it can make you more sleepy.

儘管多項研究顯示咖啡有益健康，但太依賴咖啡會讓人更想睡。

Caffeine blocks adenosine in your brain which normally accumulates through the day and makes you sleepy at night.

咖啡因阻卻大腦腺苷傳遞，這些神經傳導物通常會累積一整天並讓你晚上產生睡意。

But consuming coffee or energy drinks less than six hours before bed can ultimately affect your sleep quality.

但是睡前6小時內攝取咖啡或能量飲會影響你的睡眠品質。

As a result people who don't use caffeine often report feeling less tired in the morning.

因此，沒攝取咖啡因的人早晨通常較無疲勞感。

You might consider making sure you're fully hydrated with some water first too.

此外，還需要確保攝取足夠水分。

One study found that a drop of 1.5 percent in our bodies normal water levels can cause difficulty concentrating.

一項研究指出，體內水份若低於身體正常含水量 1.5%，會導致注意力難以集中。

Your blood thickens which slows down nutrients and oxygen getting to your muscles and organs.

濃稠的血液會減緩養分和氧氣進入肌肉與器官。

However, a 2 percent drop is enough to make you feel thirsty so while there's no need to gulping down gallons of water, staying hydrated throughout the day will certainly help.

不過，體內水分只要低於 2% 就能會讓人自然感到口渴，所以雖然沒必要牛飲一堆水，終日保持水份充足對身體絕對有幫助。

Urine should be pale yellow.

尿液應該呈淡黃色。

Any darker, and it's time for some water.

若顏色加深，就表示該喝水了。

Those glasses of wine or beers before bed may also be affecting your day.

睡前小酌幾杯也會影響白天的生活。

Studies have found that after becoming intoxicated (that) while test subjects would fall asleep faster their quality of sleep was actually much lower, particularly during the second half of their night's sleep.

研究發現，酒醉後受試者可能更容易睡著，但他們的睡眠品質也下降許多，特別是後半段的夜間睡眠。

Ultimately, alcohol reduces the amount of REM sleep you get.

酒精最終會縮短快速動眼睡眠。

And, if you're binge drinking and sleeping in on the weekends be aware that a consistent sleep schedule is key.

若是你喜歡在週末狂飲然後很晚起床，就要注意規律的睡眠時間是重要的關鍵。

Try waking up close to your normal time on weekends and having short 20-minute naps in the day.

要試著在週末維持正常時間起床，並且在日間小睡 20 分鐘。

These will still recharge your body without going into deep sleep and making you more tired.

小睡可以讓身體重獲能量，但不需要進入深層睡眠，以免搞的自己更加疲勞。

You're also more likely to fall asleep at a correct time on Sunday evening, making Monday morning easier.

這樣一來，週日晚上也比較能夠在正確時間入睡，週一早晨就更容易起床。

Of course your mental well-being plays a role too.

當然，心理健康也很重要。

Anxiety is a big one.

焦慮是一大問題。

Worrying what people think, always feeling tense about work or being overly concerned about every decision can be physically exhausting.

在意別人的看法、工作總處於壓力狀態或是對每個決定都過於擔心，都會讓身體筋疲力盡。

And fatigue is one of the main symptoms of generalized anxiety disorder.

而疲勞是廣泛性焦慮症的主要症狀之一。

Not only that, but anxiety may be affecting your sleep quality.

不僅如此，焦慮也會影響睡眠品質。

On another serious end, depression can cause both physical, and emotional fatigue which more sleep won't necessarily relieve.

更嚴重的話，憂鬱會造成的身心疲勞，再多睡眠也不一定能有效紓緩。

For some it causes insomnia or the inability to fall asleep in the first place.

有些情況還會造成失眠或一開始就難以入睡的情形。

Unfortunately, there's no quick fix for the 10 percent of Americans who do suffer from depression.

很遺憾，目前並沒有應急之計可以幫助那 10% 深受憂鬱之苦的美國人。

So if you think you may be depressed see your physician or psychologist.

若你覺得自己可能陷入憂鬱，務必尋求醫師或心理醫師的協助。

Finally, you might also simply be a night owl.

最後，疲勞也可能僅因你是個夜貓子。

Around 20 percent of population have genetics making them predisposed to staying up late.

約有20%的人體內的基因讓他們傾向於熬夜。

But living in our 9-to-5 world may make it difficult for you to get the proper amount of sleep.

但生活在朝九晚五的世界，熬夜讓你難以獲得適當的睡眠而造成疲勞。

In fact, scientists call this phenomenon social jet lag.

科學家稱此現象為社會性時差。

Well, night owls feel like they're living in the wrong time zone every day.

夜貓子每天都覺得自己住錯時區了。

If nothing seems to help, there may be an underlying medical condition causing your fatigue which should be talked about with your physician.

若以上對你毫無幫助，也許有個潛在病因導致你疲勞，你該找醫師談談了。

Got a burning question you want answered?

有問題憋在心裡難受想解嗎?

Ask it in the comments or on Facebook and twitter.

在留言處、臉書或推特發問吧！

And subscribe for more weekly science videos.

歡迎訂閱，收看更多的每週科學。