Think you can forgo a night--or even a couple extra hours--of sleep and still get by at work? Think again. According to Dr. Robert Oexman, director of the Sleep to Live Institute, there are numerous sleep myths that can get in the way of a good night's sleep--and your success.

Here, then, are Dr. Oexman's 9 sleep myths, and what you can do to fix them.

1. If I don't get enough sleep at night, I can make up for it with a nap during the day.

While naps can rejuvenate you enough to get through the day, they are not a permanent solution to sleep deprivation. If you must nap--avoid them after 3pm and limit to 15-20 minutes or you'll affect your ability to sleep at night, creating a vicious cycle.

2. The weekends are a great time to rest for a long week ahead.

You can't "bank" sleep and store it up for the future. Although being well-rested will help you cope a bit better with lost sleep, sluggishness will set in.

3. Eight hours of sleep is a luxury--six hours is realistic.

Sleeping should not be treated as a luxury, but as a necessary part of total health. People who get the proper amount of sleep feel better, look better, and are overall in better health. This is a major step to enjoying life more. It is hard to enjoy life when you are too fatigued to do what you like.

4. I'll learn more if I pull an all-nighter and cram for a test.

If you pull an all-nighter, your memory may fail you during that big test. It's during the REM stage of sleep that we consolidate memories from the day before. If we are trying to learn new information and skimp on sleep, we won't remember as much information.

5. Hitting the snooze button will give me a few extra minutes of rest I need to feel energized.

If you're snoozing--you're sleep deprived. Sleep does not come in 9-minute intervals, so be realistic about the time you need to get up. Consider hitting the snooze alarm just one time and doing light stretching with the light on. This gives you a gentle way to wake up.

6. If I wake in the middle of the night, I should read a book or watch TV until I become sleepy.

The bright light from your TV or lamp will only wake you up further. If you get up at night, go into another room and keep the room dark. You can pray, meditate, or do light stretching until you feel ready for sleep again.

7. Exercising near bedtime will keep me up at night because I'm too "energized."

Exercising near bedtime may keep you up at night, but that's because your body is too hot. Your core body temperature must cool down before you can have a restful sleep. The optimal time for exercise is four hours before you plan to sleep.

8. As I get older, my body requires less sleep.

Research has shown that as we get older we still need the same amount of sleep as when we were younger. In fact, older adults need to spend more time in bed to get the same amount of sleep--thanks to the aches, pains, and medications that wake them up at night.

9. Lack of sleep may make me feel tired, but it doesn't have a severe impact on my health.

The consequences of even one hour of sleep loss for one night can be an increase in heart attacks. The masses of the sleep-deprived have a higher risk of heart disease, type 2 diabetes, stroke, obesity, cancer, Alzheimer's, and depression.