When you go to bed and when you get up are keystones to restful, refreshing sleep. Once you learn to synchronize your body's biological clock, your body will know when to sleep and when to be alert.

1. Wake at the Same Time Every Day.A good night's sleep actually starts in the morning. The second your eyes flutter open, light shoots down the optic nerve and into the brain's biological clock. There it stimulates the production of a smorgasbord of hormones that regulate growth, reproduction, eating, sleeping, thinking, remembering -- even how you feel from minute to minute."Sunlight activates the brain," says Frisca L. Yan-Go, M.D., medical director of the UCLA Sleep Disorders Center. And activating it at the same time every morning synchronizes your body's biological clock. Then your body has a clear direction that at midnight it's supposed to be asleep and at noon it's supposed to be awake.Wake up at a different time every day and the clock is out of sync. You feel groggy and hungover for hours, and even when you start to feel a bit more alert after that first Starbucks, you really never achieve the mental edge of which you're capable.

2. Hit the Sheets Only When Sleepy. No, not just tired. Sleepy, as in your eyes are droopy and you keep losing track of what people are saying to you.

3. Get Up. Sleeping from 11:30 P.M. until 2:00 A.M., tossing and turning until 4, then sleeping until 6 gives you eight hours in bed but only 4 1/2 hours of sleep. That's a huge mismatch that can actually inhibit your sleep drive and cause insomnia all by itself. To prevent that from exacerbating your sleep issues, when you wake at 2:00 A.M., get up and go read a book in the living room. Being up increases your sleep drive -- which just could make you sleepy enough to actually fall asleep when you return to bed.One caveat: Don't stay in bed when you're awake. A part of your mind will begin to associate the bed with being awake rather than being asleep. And that can turn on a nasty "I'm-not-going-to-sleep!" anxiety that will rev your engines whenever you get into bed. It's one of the most insidious -- and potent -- causes of chronic insomnia.

4. Give Yourself an Hour. The one right before bed. You need it to wind down and transition from the woman-who-can-do-everything into the woman-who-can-sleep. Unfortunately, most women are not giving themselves one single second. According to the 2007 National Sleep Foundation poll, during the hour before bed, around 60 percent of us do household chores, 37 percent take care of children, 36 percent do activities with other family members, 36 percent are on the Internet, and 21 percent do work related to their jobs.

5. Beware Sunday Night Insomina. Staying up late on Friday and Saturday nights and sleeping in on Saturday and Sunday mornings is frequently the gift we give ourselves on weekends after a hard week at work. Yet that little gift -- small as it is -- is enough to screw up our biological clocks. Even if you get to bed early on Sunday night, you will not be ready to sleep, and you will not end up being the happy camper you were expecting come Monday morning.

何时睡觉和何时起床是获得使人休息充分、精神焕发的睡眠的关键。一旦你学会了如何调整身体的时钟，你的身体就知道什么时候睡觉、什么时候要清醒。

1 每天定时醒来

一宿好觉实际上从清晨开始。你眼睛睁开的那一刻，光线照射在视神经上，传入大脑的生物钟里。在那里它刺激一种瑞典自助餐式的荷尔蒙生产，荷尔蒙能调节生长、生殖、饮食、睡眠、思考、记忆－－甚至你每一分钟的感觉如何。“阳光激活大脑，”加州大学洛杉矶分校睡眠障碍中心的医学主任，弗里斯卡·L·严戈博士说。每天早晨在同一时刻激活大脑就校对了人的生物钟。于是你的身体就获得了明确的指示，在半夜它应该睡觉，在中午它要清醒。每天起床的时间不同，生物钟就会紊乱。你会几个小时感觉眩晕、像宿醉一般难受，即使你在喝了一杯星巴克咖啡后感觉好点，你也决不能表现出你的最佳状态。

2 只有当困倦的时候才就寝

光是累了不行，只有困倦得眼皮也睁不开，别人对你说什么都听不进去时才去睡。

3 睡不着时就起床

从夜里11点睡到凌晨2点，然后翻来覆去睡不着到4点，接着又睡到6点，你在床上待了8个小时却只有4个半小时的睡眠。这种严重的不一致，本身就很可能抑制你的睡意，导致失眠。要预防你的睡眠问题恶化，当你在凌晨2点醒来的时候，起床到起居室看一会书。起来不睡会增加你的睡意－－这就能使你困得在回到床上时倒头就睡。有一点要注意：醒着的时候不要待在床上。你的一部分意识会把床同清醒而不是睡意相联系，这会引发一种危险的“我睡不着觉”的焦虑，无论何时你上床，它都会使你的马达倒转。这是一种最不为人觉察的－－也是潜在的－－慢性失眠的原因。

4 给自己一小时时间放松

上床前一小时，你需要放松发条，把自己从什么都能干的女人变成想睡觉的女人。不幸的是，多数妇女连一秒钟也不给自己。根据2007年国家睡眠基金会的一次调查，在睡觉前的一小时内，大约60％的妇女做家务，37％的人照顾孩子，36％的人和家人一起做事，36％的人上网，还有21％的人在干与工作有关的活。

5 小心周日晚上的失眠症

周五、周六晚上待到很晚不睡，周六和周日早上睡过头，经常是我们在一周辛苦工作之后奖励自己的小礼物。然而，这份小礼物－－尽管它不大－－也足够把我们的生物钟全毁掉。即使你在周日晚早早上床，你也没准备好睡觉，当周一来临的时候，你也不能像自己期待的那样，像个快活的露营者。