Sleep. It’s a basic necessity of life, as important to our health and well-being as air, food, and water. The way we sleep at night has a great impact on our general health as well as our daily mood, behavior, and performance. It also has a huge impact on the overall quality of our lives.

According to recent National Sleep Foundation (NSF) Sleep in America polls, more than one-third of American adults get less than seven hours of sleep weeknights, nearly three-quarters experience a sleep problem a few nights a week or more, and more than one-third are so sleepy during the day it interferes with daily activities. In addition, nearly one-quarter of the adults in this country don’t get even the minimum amount of sleep they say they need to be alert the next day, putting themselves at risk for injury, health, and behavior problems!

In the past century, we have reduced our average time asleep by 20 percent and in the past 25 years, we have added a month to our average annual work/commute time. While our society has changed, our bodies have not. Our national sleep debt is affecting all of us, and we are paying the price.

How much is enough?
Getting enough sleep refers to the amount of sleep you need to not feel sleepy the next day. Adequate sleep is when you awaken naturally without an alarm clock. Quality sleep means it is continuous and uninterrupted.

Sleep requirements vary over the life cycle. Newborns and infants need a lot of sleep and have several periods of sleep throughout a 24-hour period. Naps are important to them as well as to older infants and toddlers who may nap up to the age of five. In adolescence, sleep patterns shift to a later sleep-wake cycle, but teens still need around nine hours of sleep. As we get older, sleep patterns may change, but the need for sleep remains the same. Sleep experts generally recommend an average of seven to nine hours per night for adults; some people can get along with less while others may need more.

You are how you sleep
American adults say that when they don’t sleep enough, they have more negative moods—they are more irritable, stressed, and tired. Studies show that lack of sleep leads to problems completing a task, concentrating, making decisions, and unsafe actions. More recent research ties sleep deprivation to signs of aging and symptoms of diabetes. Certain hormones are released during sleep; when you don’t sleep long enough to allow these hormones to be released, weight gain and lack of fitness can result. Other serious consequences of sleep deprivation include the approximate 100,000 vehicle crashes and 1,500 deaths that occur each year as a result of drowsy driving.

Nature’s biological clocks
Sleep occurs naturally in response to how long we are awake. The need for sleep accumulates, and the longer we are awake, the stronger is the drive to sleep. Our circadian biological clock, located in the brain, regulates when we feel sleepy and when we are alert. It is influenced by light, so we naturally tend to get sleepy when it is dark and be alert when it is light. Body temperature, which lowers throughout the night, and hormones that are secreted during sleep, also play a role with our “clock,” which runs on a 24-hour cycle. This cycle often causes dips in its rhythm, resulting in sleepiness around 2:00-4:00 in the morning and 1:00-3:00 in the afternoon.

Sleep stages
There are various states and stages of our sleep that follow a predictable pattern of REM (rapid-eye movement) and NREM (Non-Rapid Eye Movement) sleep throughout a typical eight-hour period. Each of these states alternates every 90 minutes; the time spent in each of these states and stage varies by age.

NREM – 75 percent of the night
We enter NREM sleep as we begin to fall asleep; there are four stages:
Stage 1 Light sleep; between being awake and entering sleep
Stage 2 Onset of sleep; disengaged with environment; regular breathing and heart rate; body temperature falls.
Stage 3 & 4 Deepest and most restorative sleep; muscles relaxed; blood pressure drops; breathing slower; energy regained; hormones released for growth and development

REM – 25 percent of the night
Occurs increasingly over later part of night; provides energy to brain and body; brain active and dreams occur as eyes dart back and forth; bodies immobile and relaxed, muscles shut down; breathing and heart rate may be irregular.

Tips for Good Sleep
There are several things you can do to help ensure a good night’s sleep:
• Establish a regular bed time and wake time schedule to help set your body’s internal clock.
• Avoid caffeine and nicotine products close to bedtime.
• Avoid alcohol close to bedtime.
• Exercise regularly but avoid doing so at least three hours before bedtime.
• Establish a regular relaxing, non-alerting bedtime routine.
• Create a sleep-conducive environment that is dark, quiet, and cool.