Generally, it has been assumed that the need for sleep does not decrease with age, but rather that other factors gradually come to interfere with our ability to sleep through the night.

Older individuals, for instance, are at greater risk not only for developing medical and psychiatric disorders but also for taking medications that can disrupt sleep. In spite of these influences, however, it may be that an actual biological deterioration of the sleep drive might also be playing a role.

A new study published in the journal Current Biology has been able to shed some light on this puzzle of sleep and aging. The researchers, who wanted to determine the maximal sleep capacity of both young and older persons, arranged for groups of younger adults (ages 18 to 32 years) and older adults (ages 60 to 76 years) to lie in bed for 12 hours during the night and for another 4 hours in the afternoon.

The subjects tended to sleep significantly longer at the beginning of the experiment, presumably because they were making up for a sleep debt accrued during their usual daily sleep routines. When the sleep patterns stabilized, however, the younger adults were capable of sleeping for much longer times — an average of 8.9 hours daily — than were the elderly people, who got only 7.4 hours daily. This 1.5-hour difference in maximal sleep capacity is impressive.

If your biological drive for sleep seems to have decreased, make sure that you are following the kinds of routines and behaviors that will give you the best chance of getting as much refreshing sleep as possible. Here are some examples of good sleep hygiene:

* Make sure that you're going to bed early enough to allow yourself to get an adequate night's sleep.
* As your bedtime approaches, develop a relaxing routine in the evening — don't keep busy until the moment before you expect to fall asleep.
* Avoid watching TV in bed.
* Sleep in a cool, relatively dark room.
* Consider going to sleep to the sound of white noise, either from a bedside fan or a machine that generates calming sounds.
* Increase your exercising, but don't do it so near to bedtime that it gets your adrenaline flowing and keeps you awake.
* Limit your daily intake of caffeinated beverages and avoid them completely after lunchtime.
* Avoid alcoholic beverages.

一般來說，假定睡眠所需的時(shí)間不會(huì)因年齡的增加而減少，而是其他因素逐漸干擾了我們整夜酣睡不醒的能力。

老年人，例如，有更大的風(fēng)險(xiǎn)，不僅在不斷發(fā)展的醫(yī)療和精神失調(diào)，而且因?yàn)榉帞_亂睡眠。不計(jì)這些影響，然而，它可能是一個(gè)實(shí)際的生物惡化的睡眠驅(qū)動(dòng)器也可以發(fā)揮作用。

發(fā)表在現(xiàn)代生物學(xué)雜志上的一項(xiàng)新研究，已經(jīng)能夠闡明睡眠與衰老之迷。研究人員，想要確定年輕人和老年人最大的睡眠能力，安排成組的年輕人（年齡18至32歲）和老年人（ 60歲至76歲）夜間躺在床上12個(gè)小時(shí)，另外下午4個(gè)小時(shí)。

實(shí)驗(yàn)開始時(shí)試驗(yàn)者的睡眠時(shí)間明顯偏長(zhǎng)，大概是因?yàn)樗麄冊(cè)趶浹a(bǔ)日常睡眠期間累積的債務(wù)。當(dāng)睡眠模式穩(wěn)定下來了，然而，年輕人睡眠的時(shí)間更長(zhǎng)——平均每天8 .9小時(shí)-比老人——只有7. 4小時(shí)每天。這1.5小時(shí)的最大睡眠能力差異令人印象深刻。

如果您睡眠的生物性驅(qū)動(dòng)看起來有所下降，請(qǐng)務(wù)必遵循下面的各種慣例和行為，這會(huì)給你帶來最好的改變，越來越多耳目一新的睡眠。下面是一些好的睡眠保健例子：

1.請(qǐng)務(wù)必要早點(diǎn)上床，使自己獲得足夠的睡眠。
2.快要睡覺的時(shí)候，晚上制定一個(gè)相對(duì)輕松工作計(jì)劃——不要忙碌到你希望入睡之前的那一刻。
3.避免在床上看電視。
4.睡在一個(gè)涼爽，相對(duì)黑暗的屋子里。
5.考慮在無噪聲中睡覺，無論是從床頭風(fēng)扇還是機(jī)器產(chǎn)生平靜的聲音。
6.加強(qiáng)鍛煉，但不是在臨近睡覺的時(shí)候，因?yàn)樗鼤?huì)使您的腎上腺素流動(dòng)，讓你清醒。
7.控制您每日攝取含有咖啡因（茶精）的飲料，午飯后要完全避免他們。
8.避免酒精飲料。