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It may seem obvious that sleep is beneficial. Even without fully understanding what sleep does for us, we know that going without sleep for too long makes us feel terrible, and that getting a good night's sleep can make us feel ready to take on the world.
Scientists have gone to great lengths to fully understand sleep's benefits. In studies of humans and other animals, they have discovered that sleep plays a critical role in immune function, metabolism, memory, learning, and other vital functions. The features in this section explore these discoveries and describe specific ways in which we all benefit from sleep.
Sleep is a necessary aspect of life and is essential to our health. It is recommended that we get 8 hours of sleep every night.
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The Harvard Women's Health Watch suggests six reasons to get enough sleep:
- Learning and memory ?Sleep helps the brain to commit new information to memory.
- Metabolism and weight?Chronic sleep deprivation may cause weight gain by affecting the way our bodies process and store carbohydrates and by altering levels of hormones that affect our appetite.
- Safety?A lack of sleep contributes to a greater tendency to fall asleep during the daytime. These lapses may cause falls or mistakes such as medical errors, air traffic mishaps, and road accidents.
- Mood?Sleep loss may result in irritability, impatience, inability to concentrate, and moodiness. Too little sleep can also leave you too tired to do the things you like to do.
- Cardiovascular health?Serious sleep disorders have been linked to hypertension, increased stress hormone levels, and irregular heartbeat.
- Disease?Sleep deprivation alters immune function, including the activity of the body's killer cells. Keeping up with sleep may also help fight cancer.
-Harvard Health Publications: Harvard Medical School
When we underestimate the importance of sleep we forget that sleep isn't a luxury, it's a biological necessity.
For all our sophistication and civilized way of living, we must remember that our brains and bodies are governed by biological functions and needs. Sleep plays a huge part in the way our bodies function - so big, in fact, that if we are totally deprived of sleep for an extended period of time, we will die.
There are?five stages of sleep, each stage has its own properties and benefits. Together, all stages enable our bodies to regenerate and rejuvenate themselves.
Every part of the body is affected - the brain, nervous system, immune system, hormones,emotions, heart, lungs, and the list goes on.
If we want to...
- live longer
- keep our bodies strong and healthy
- help our brain stay sharp and focused
- improve our memory
- keep our emotions positive and balanced
...then we need to recognize the importance of sleep.
Sleep, Learning, and Memory
It may not be surprising that it is more difficult to take in new information following a night of inadequate or disturbed sleep. What?s more surprising is that it is just as important to get a good night?s sleep after learning something new in order to process and retain the information that has been learned.?more
Theories of Why We Sleep
Inactivity Theory
One of the earliest theories of sleep, sometimes called the adaptive or evolutionary theory, suggests that inactivity at night is an adaptation that served a survival function by keeping organisms out of harm?s way at times when they would be particularly vulnerable. The theory suggests that animals that were able to stay still and quiet during these periods of vulnerability had an advantage over other animals that remained active. These animals did not have accidents during activities in the dark, for example, and were not killed by predators. Through natural selection, this behavioral strategy presumably evolved to become what we now recognize as sleep.
A simple counter-argument to this theory is that it is always safer to remain conscious in order to be able to react to an emergency (even if lying still in the dark at night). Thus, there does not seem to be any advantage of being unconscious and asleep if safety is paramount.
Energy Conservation Theory
Although it may be less apparent to people living in societies in which food sources are plentiful, one of the strongest factors in natural selection is competition for and effective utilization of energy resources. The energy conservation theory suggests that the primary function of sleep is to reduce an individual?s energy demand and expenditure during part of the day or night, especially at times when it is least efficient to search for food.
Research has shown that energy metabolism is significantly reduced during sleep (by as much as 10 percent in humans and even more in other species). For example, both body temperature and caloric demand decrease during sleep, as compared to wakefulness. Such evidence supports the proposition that one of the primary functions of sleep is to help organisms conserve their energy resources. Many scientists consider this theory to be related to, and part of, the inactivity theory.
Restorative Theories
Another explanation for why we sleep is based on the long-held belief that sleep in some way serves to "restore" what is lost in the body while we are awake. Sleep provides an opportunity for the body to repair and rejuvenate itself. In recent years, these ideas have gained support from empirical evidence collected in human and animal studies. The most striking of these is that animals deprived entirely of sleep lose all immune function and die in just a matter of weeks. This is further supported by findings that many of the major restorative functions in the body like muscle growth, tissue repair, protein synthesis, and?growth hormone?release occur mostly, or in some cases only, during sleep.
Other rejuvenating aspects of sleep are specific to the brain andcognitive function. For example, while we are awake, neurons in the brain produce?adenosine, a by-product of the cells' activities. The build-up of adenosine in the brain is thought to be one factor that leads to our perception of being tired. (Incidentally, this feeling is counteracted by the use of?caffeine, which blocks the actions of adenosine in the brain and keeps us alert.) Scientists think that this build-up of adenosine during wakefulness may promote the "drive to sleep." As long as we are awake, adenosine accumulates and remains high. During sleep, the body has a chance to clear adenosine from the system, and, as a result, we feel more alert when we wake.
Brain Plasticity Theory
One of the most recent and compelling explanations for why we sleep is based on findings that sleep is correlated to changes in the structure and organization of the brain. This phenomenon, known as brain plasticity, is not entirely understood, but its connection to sleep has several critical implications. It is becoming clear, for example, that sleep plays a critical role in brain development in infants and young children. Infants spend about 13 to 14 hours per day sleeping, and about half of that time is spent in REM sleep, the stage in which most dreams occur. A link between sleep and brain plasticity is becoming clear in adults as well. This is seen in the effect that sleep and sleep deprivation have on people's ability to learn and perform a variety of tasks.
Bookshelf
- Siegel JM. 2005. Clues to the functions of mammalian sleep. Nature. 437:1264-1271.
- Porkka-Heiskanen T. 1999. Adenosine in sleep and wakefulness. Annals of Medicine. 31:125-129.
- Frank MG. 2006. The mystery of sleep function: current perspectives and future directions. Reviews in the Neurosciences. 17:375-392.
This theory and the role of sleep in learning are covered in greater detail in?Sleep, Learning, and Memory.
Although these theories remain unproven, science has made tremendous strides in discovering what happens during sleep and what mechanisms in the body control the cycles of sleep and wakefulness that help define our lives. While this research does not directly answer the question, "Why do we sleep?" it does set the stage for putting that question in a new context and generating new knowledge about this essential part of life.
Good for:?Preventing neck and back pain, reducing acid reflux, minimizing wrinkles, maintaining perky breasts
Bad for:?Snoring
The scoop:?Sleeping on your back makes it easy for your head, neck, and spine to maintain a neutral position. You?re not forcing any extra curves into your back, says Steven Diamant, a chiropractor in New York City. It?s also ideal for fighting acid reflux, Dr. Olson says: "If the head is elevated, your stomach will be below your esophagus so acid or food can?t come back up."
Back-sleeping also helps prevent wrinkles, because nothing is pushing against your face, notes Dee Anna Glaser, MD, a professor of dermatology at Saint Louis University. And the weight of your breasts is fully supported, reducing sagginess.
Good for:?Preventing neck and back pain, reducing acid reflux, snoring less, sleeping during pregnancy
Bad for:?Your skin and your breasts
The scoop:?Side-sleeping is great for overall health?it reduces snoring and keeps your spine elongated. If you suffer from acid reflux, this is the next best thing to sleeping on your back. The downside: "Sleeping on your side can cause you to get wrinkles," Dr. Glaser says. Blame all that smushing of one side of your face into the pillow.
This pose also contributes to breast sag, since your girls are dangling downward, stretching the ligaments, says?Health?s Medical Editor Roshini Rajapaksa, MD.
HOW MUCH SLEEP DO YOU NEED?
Over time, chronic sleep deprivation may lead to an array of serious medical conditions including obesity, diabetes, heart disease, and even early mortality.
While sleep requirements vary by individual, the National Institute of Neurological Disorders and Stroke reports that most adults need seven to eight hours a night. Though, some people may need as few as 5 hours per night and others may need up to nine or ten hours of sleep each day for proper functioning.
Newborns (0-2 months old) | 12-18 hours |
Infants (3-11 months old) | 14-15 Hours |
Toddlers (1-3 years old)l | 12-14 Hours |
Pre-schoolers (3-5 years old) | 11-13 Hours |
School-aged Children (5-10 years old) | 10-11 Hours |
Teens (11-17 years old) | 8-9 Hours |
Adults | 7-9 Hours |
?Studies show that people who get the appropriate amount of sleep on a regular basis tend to live longer, healthier lives than those who sleep too few or even too many hours each night. This underscores the importance of making sleep a top priority.
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BENEFITS OF SLEEP
Following are some of the benefits of sleep and how it improves the quality and the length of your life.
Your body produces extra protein molecules while you're sleeping that helps strengthen your ability to fight infection and stay healthy.Sleep helps to repair your body.?
These molecules help your immune system mend your body at a cellular level when you are stressed or have been exposed to compromising elements such as pollutants and infectious bacteria.
Sleep helps keep your heart healthy.?
Your cardiovascular system is constantly under pressure and sleep helps to reduce the levels of stress and inflammation in your body. High levels of "inflammatory markers" are linked to heart disease and strokes. Sleep can also help keep blood pressure and cholesterol levels (which play a role in heart disease) in check.
Sleep reduces stress.?
A good night's sleep can help lower blood pressure and elevated levels of stress hormones, which are a natural result of today's fast paced lifestyle.
High blood pressure can be life threatening and the?physical effects of stress?can produce "'wear and tear" on your body and degenerate cells, which propel the aging process. Sleep helps to slow these effects and encourages a state of relaxation.
Sleep improves your memory.
That 'foggy' feeling that you struggle with when deprived of sleep makes it difficult to concentrate. This often leads to memory problems with facts, faces, lessons, or even conversations. Sleeping well eliminates these difficulties because, as you sleep, your brain is busy organizing and correlating memories.
One of the great benefits of sleep is that it allows your brain to better process new experiences and knowledge, increasing your understanding and retention. So, next time you hear someone say "why don't you sleep on it," take their advice.
Sleep helps control body weight issues.
Sleep helps regulate the hormones that affect and control your appetite. Studies have shown that when your body is deprived of sleep, the normal hormone balances are interrupted and your appetite increases.
Unfortunately this increase in appetite doesn't lead to a craving for fruits and veggies. Rather, your body longs for foods high in calories, fats, and carbohydrates.
Sleep reduces your chances of diabetesSo, if you're trying to lose those stubborn few pounds that just keep hanging around, consider the benefits of sleep on weight control and make sure that getting enough sleep each day. For more information on sleep and body weight.
Researchers have shown that lack of sleep may lead to type 2 diabetes by affecting how your body processes glucose, which is the carbohydrate your cells use for fuel.
The Division of Sleep Medicine at Harvard Medical School reports that a study showed a healthy group of people who had reduced their sleep from eight to four hours per night processed glucose more slowly.
Other research initiatives have revealed that adults who usually sleep less than five hours per night have a greatly increased risk of developing diabetes.
Sleep reduces the occurrence of mood disorders.
With insufficient sleep during the night, many people become agitated or moody the following day. Yet, when limited sleep becomes a chronic issue, studies have shown it can lead to long-term mood disorders such as depression or anxiety.
The benefits of sleep are extensive and can make a difference in your quality of life, as well as the length of your life. Therefore, it is vital to place a priority on getting ample, consistent sleep.
Bookshelf
- Siegel JM. 2005. Clues to the functions of mammalian sleep. Nature. 437:1264-1271.
- Porkka-Heiskanen T. 1999. Adenosine in sleep and wakefulness. Annals of Medicine. 31:125-129.
- Frank MG. 2006. The mystery of sleep function: current perspectives and future directions. Reviews in the Neurosciences. 17:375-392.
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- See more at: http://www.better-sleep-better-life.com/benefits-of-sleep.html
Source: http://thefitnessfairy.com/?p=2396
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