If you're not sleeping well, you probably don't need anyone to tell you it's bad for you -- your own body lets you know loud and clear. But feeling crummy the next day is just the tip of the iceberg when it comes to the ramifications of poor sleep. Sleep, scientists now know, is one of the keys to healthy aging, helping protect your body from pretty much every major health threat. Studies show sleep protects your brain from Alzheimer's and dementia, while lack of sleep can shorten your life. And it's not called "beauty sleep" for nothing -- research shows that sleeping poorly can prematurely age your skin as well as boost appetite and slow metabolism, leading you to gain weight.
But knowing you need to improve your sleep isn't the same thing as doing it, right? Here are ten science-proven secrets to deep sleep.
1. Set a Sleep Schedule -- and Stick to It
There's a good reason why previous generations went to bed early and woke with the sun. Our bodies follow internal clocks known as circadian rhythms, and they don't like to be frequently reset. That's the conclusion from a spate of recent studies linking irregular sleep schedules with conditions including heart disease, diabetes, stroke, and cancer. One study even found that irregular sleep patterns cause permanent changes to our genetic code, with the potential to trigger a host of major illnesses and conditions.
What to do: Work out a compromise schedule that you can stick to (at least without enormous variation) both weekdays and weekends. When you need to make changes to your sleep schedule, do it by changing your wake-up time gradually over several days -- your bedtime will follow naturally as you get tired earlier or later.
One more trick: Create a bedtime routine for yourself, just as you would for a child -- a series of steps that you do every night just before bed. (At least when your schedule permits.) These can be whatever works for you -- listen to music, straighten up your room, take a hot bath, read. Once they become habit, they signal to your brain that it's time to wind down.
2. Embrace the Darkness
We live in a bright world -- we stay up late under bright lights, then tumble into bed and expect to be asleep in minutes. But here's the problem: Light tricks your brain into thinking it's time to wake up, causing it to stop production of melatonin, the hormone that triggers sleep. Even very small amounts coming from, say, cracks in the blinds or a lighted clock can make it harder to fall asleep or can affect how deeply you sleep.
What to do: Start with a thorough room check. Are there streetlights outside your windows? Use blackout curtains or shades and make sure they fit the windows tightly so no light seeps in around the edges. Are you charging your phone, tablet, or computer in your bedroom? Move devices to another room or cover the charging lights. Use an alarm clock without a lighted dial, or turn it to face the wall. Never use night-lights -- instead, keep a book light or mini flashlight next to your bed and use it when you get up to use the bathroom or let the dog out, rather than turning on the overhead light. (Be careful to point it away from yourself so you don't look into the beam.)
One more trick: Make sure you're exposing yourself to bright light during the day. Get outside in the sun if you can, or at least sit in the light from a window. When that's not possible, try using a lightbox or light visor to supplement your exposure to bright light.
3. Make Bedtime Tech-Free
If the last thing you do before bed is check your e-mail, you're not alone. Bringing our laptops and tablets to bed with us has become a national habit. But not all habits are good ones, and this is one worth changing. The problem: Computers and tablets are designed with backlit screens, so the light shines directly in your eyes when you look at them. And that's not all -- the type of light used in electronic devices is a close relative of sunlight, so it's even more disruptive to circadian rhythms than other types of light.
What to do: Make the last hour before bedtime screen-free. If you must use a laptop or tablet, turn the screen brightness as low as you can tolerate and prop it as far away from you as your typing arms will reach. If you love eReaders, try a Kindle or other device with a screen that's not backlit.
4. Use Your Ears Wisely
No matter how sound your sleep, your brain continues to process sound through an area called the auditory cortex. And while some sounds startle us awake or disturb us into tossing and turning, there are other types of sound that can actually help you sleep more deeply.
What to do: If your bedroom lets in street noise or other loud, sudden sounds and can't be soundproofed, earplugs are going to be the best solution. But silence is not necessarily golden -- studies have found that "white" and "pink" noise promote deep, restful sleep. White noise occurs when sounds of different frequencies are combined into a muted blend; it's the type used in most sound machines. Pink noise, a more recent discovery, occurs when every sound is of a consistent frequency -- think of falling rain or a steady breeze in the trees. Test out different types of sounds and see what works for you.
5. Cool It: Lower the Temperature
Just as outside temperatures drop throughout the night, your body and brain want indoor temperatures to drop, too. In fact, feeling cool is so closely linked with restful sleep that the sleep hormone melatonin not only makes you feel drowsy, it lowers body temperature. (And of course becoming overheated during the night is an even bigger problem for women in the midlife perimenopausal and menopausal years.)
What to do: Don't overdress for bed, and choose natural fabrics that breathe, like cotton. If you're chilly when you first get into bed, wear socks or sweats but jettison them just before you drift off. Open the window nearest the bed for a fresh breeze, or use a fan, which has the additional benefit of creating white noise. If it's hot out, cooling your head with a cold washcloth or ice pack has been shown to help you fall asleep faster.
6. No More Late-Night Gym
Exercise raises your heart rate and boosts overall metabolism, which is the opposite of what you want before bed. In fact, sleep researchers have demonstrated that exercising within three hours of bedtime causes you to sleep restlessly, waking up frequently during the night.
What to do: If you prefer to exercise at the end of your workday, stop at the gym on the way home. Then enjoy dinner and a couple of hours of relaxation to let your system settle back down.
7. Cut out the After-Dinner Drink
Alcohol is deceptive when it comes to sleep. Because it's a central nervous system depressant, you may feel relaxed and even sleepy right after having a drink. But research shows alcohol interferes with the deeper sleep state known as REM sleep, causing restless sleep or middle-of-the-night insomnia.
What to do: Enjoy your glass of wine or beer with dinner, but put the bottle away several hours before bed. And make sure to drink plenty of water with alcoholic drinks, as dehydration amplifies sleep problems.
8. Skip the Smokes, Too
You may think of smoking as something you do to relax, but the fact remains that nicotine is a stimulant, just like caffeine.
What to do: Try to put as much time as possible between your last cigarette of the day and bed. Substitute a different relaxing habit, such as a warm bath. (Better yet, quit smoking, and add as much as nine years to your life.)
9. Eat a Midnight (or 10 p.m.) Snack
You've always heard you shouldn't eat a big meal close to bedtime, and that's true, experts say. But the same doesn't hold true for a small carb-heavy snack, which can actually help you sleep. Carbohydrate-rich foods trigger your body to produce insulin, which speeds up the release of tryptophan and serotonin, two brain chemicals that relax you and make you feel sleepy.
What to do: One of the best combinations for instant drowsiness is toast or a small bowl of granola or oatmeal topped with bananas or dried cherries. The whole grains in toast and cereal are easily digested complex carbs, triggering insulin production, while oats have the added benefit of containing melatonin, which many people take as a sleep aid. Bananas are rich in potassium and magnesium, which relax the muscles, as well as the amino acid L-tryptophan. And, like oats, cherries (both fresh and dried) contain significant amounts of melatonin.
One more trick: Avoid protein, which is takes much longer to digest and therefore keeps your metabolism active when it should be in shut-down mode.
10. Put Your Worries to Bed
You know the drill -- you wake up in the middle of the night and your mind starts going a mile a minute. It's a natural instinct to problem solve when you can't sleep, but it's extremely unproductive, experts say, because everything seems bigger and more urgent at night and yet we can't take anxiety-relieving action until morning.
What to do: Keep a pad and pen next to the bed so you can jot down a "worry list" of the things that are bothering you. But that's not the important part -- what's critical is to banish each worry from your mind once it's written down. As you list each item, tell yourself that it's now on the list and will be a top priority the next day. Then let it go, and let yourself get some much-needed zzzs.