"THE BEST BRIDGE BETWEEN despair and hope," said Harry Ruby, "is a good night's sleep." When you don't get enough sleep, your body produces extra stress hormones, making you more vulnerable to anxiety and stress.

The authors of Painfully Shy: How to Overcome Social Anxiety and Reclaim Your Life wrote: "For people prone to social anxiety, adequate sleep is crucial. It can mean the difference between thinking about an issue realistically and becoming needlessly upset over something that's not really important. In other words, when you're overly tired, you're more likely to misread social situations and interpret them negatively."

A large percentage of people go day after day without enough sleep, causing themselves extra unnecessary stress and anxiety.

The question is, of course, what is enough sleep? The research can answer that question quite specifically. People are healthiest when they sleep about eight hours every night (somewhere between seven and eight hours). Health problems are associated with both more and less sleep than eight hours. Of course that is an average. Some nights you won't get enough sleep, but if you sleep extra the next night or two, you're getting eight hours sleep on average, and that is healthy.

Just to give you an example, a recent study at Yale University found that when people slept less that six hours a night on average, their risk of adult-onset diabetes doubled. When they slept more than eight hours, their risk of adult-onset diabetes tripled. This is typical of the findings. Too much sleep is bad. Too little sleep is bad. The right amount is good.

But seven to eight hours of tossing and turning won't do it. Researchers have also uncovered some useful information about how to get good quality sleep. You will sleep better if you:

Go to bed and get up at the same time every day.

Keep your feet are warm.

Eat three hours before going to bed. The closer to your bedtime you eat, the lighter the meal needs to be (especially light in fat, which takes the longest to digest).

Do something relaxing immediately prior to going to bed rather than doing something agitating. For most people, reading or stretching gently are relaxing; watching television or working on a computer are agitating (produce alertness and tension rather than relaxation, and therefore interfere with the going-to-sleep process).

Hormones that control wakefulness and sleepiness rise and fall in a cycle with regularity throughout the day. Most people feel sleepy around three in the afternoon, and if you take a nap then, you lower your risk of heart disease. Why? It is natural and healthy to sleep in two periods rather than one. It allows you reboot in the middle of the day. Not trying to power through "slump time," probably lowers your stress hormone level.

As Winston Churchill said, "You must sleep some time between lunch and dinner, and no half-way measures. Take off your clothes and get into bed…Don't think you'll be doing less work because you sleep during the day…You will be able to accomplish more."

It is important to sleep when you feel sleepy, and not force yourself to stay awake, because the opportunity will go away. It's not like hunger where you just get hungrier and hungrier. Your body cycles through ultradian rhythms (biological rhythms that cycle more than once a day) and you need to strike while the iron is hot. You may feel sleepy now and if you went to bed you would sleep well. But if you wait for forty-five minutes, the wake-sleep cycle has rebounded, and now it might be more difficult to fall asleep.

If you can fall asleep very quickly any time, by the way, that is a definite sign you are chronically sleep-deprived.

The sleep researcher and author of The Promise of Sleep: A Pioneer in Sleep Medicine Explores the Vital Connection Between Health, Happiness, and a Good Night's Sleep, William Dement, probably knows more about sleep than any other person. His research will give you a respect for sleep. It needs to be taken seriously. It effects your motivation level, your competence at your job, your likelihood of making a mistake while doing something dangerous, like driving a car. It effects your immune system. It obviously effects your mood.

Good sleep has been proven to be a better predictor of how long you will live than exercise, heredity, or diet. Amazing but true.

Did you get that? According to Dement, regular good sleep will help you live longer — and it will help you more reliably than even exercise, diet, or your genetic tendencies (all of which have a major impact on how long you will live).

One of the things Dement has discovered is that not getting enough sleep influences your motivation level, especially for creative people. It doesn't take a scientist to figure this out, although scientific research is the best way to sift fact from mistaken observations.

Another good way to find out what works is to only pay someone when they produce results. Under those conditions, there is a strong commitment to discover what works, regardless of anyone's pet theory. That's why salespeople often come up with so much practical information. When you're on commission and your entire income depends on your effectiveness, you lose your attachment to ideas that impair your abilities, or you don't make it.

W. Clement Stone wrote about sleep in The Success System That Never Fails. Stone worked his way up from a young man of limited means and no connections to an extremely wealthy man. He started out as a commission insurance salesman, selling door-to-door to businesses. In the process, he learned about the importance of sleep. He tried to get ten hours of sleep every night, plus a nap in the afternoon. This may be too much for optimal health, but it worked as a salesman putting out intense effort all day, and he said getting a lot of sleep gave him the energy he needed to keep at it, and it helped him maintain the high motivation he needed, to work his way to the top.

Sleep is important. When you feel tired or sleepy and you can sleep, you ought to. It's one of the best things you can do to lower your stress level, improve your health, and increase your ability to accomplish your goals.