So, what is sleep? Sleep is a state of mind that involves muscle relaxation, reduced interaction
with surroundings, and minimal sensory activity. And what happens when we sleep? Well, when we sleep we
go through cycles of sleep, which lasts about 90 to 110 minutes. Each cycle has two different states of
sleep and four stages of sleep. The two states of sleep are often classified as NREM, non REM sleep,
and REM sleep, REM means rapid eye movement. Non REM sleep has three stages, and REM has only one
stage of sleep. Non REM stages are typically noted as n1 through n3, stage n1 is a light sleep where
you drift in and out of sleep and can be awakened easily. The eyes move slowly and muscle activity
slows. During the stage brain waves usually have an alpha wave appearance, as shown on this chart.
Stage n1 accounts for 5 to 10% of sleep. In stage n2 sleepers become harder to awaken, muscular
activity decreases even more, and conscious awareness disappears completely, brain waves
take on a theta wave pattern with sleep spindles and K complexes appearing on the brainwave chart.
Sleep spindles are believed to be periods where the brain is trying to keep the sleeper in a
tranquil state, researchers believe that these spindles are associated with refreshment of our
ability to learn, K complexes are large waves and often occur after an environmental stimuli such as
a sound in the bedroom. 45 to 55 percent of sleep is in stage n2. In stage n3 slow brain waves called
Delta waves begin to appear, as this stage goes on the brain produces almost exclusively delta waves,
this is considered deep sleep, where there is no eye movement or muscle activity. People awaken from
this stage do not adjust immediately, as this stage continues it is made up almost entirely
of Delta waves and it is believed that this stage is the most restful form of sleep. Stage
n3 accounts for about 15 to 25% of sleep. In the REM stage muscles become paralyzed, heart rate and
breathing become more rapid and irregular, and the eyes jerk rapidly, brain waves increase to a
pattern that is similar to that of someone who is awake. 20 to 25% of sleep is spent in the REM
stage. As stated earlier, a sleep cycle usually lasts 90 to 110 minutes and then the sleeper
cycles through the stages again, but the earlier sleep cycles have shorter REM sleeps and longer
periods of deep sleep, whereas later in the night REM periods lengthen and deep sleep decreases. So
how much sleep do we need? The chart on your screen lists the sleep recommendations based on age, these
are the recommendations from the National Sleep Foundation. As you can see, the sleep range for
adults ranges from 7 to 9 hours, however, there are adults that can function on 6 hours and there are
some that need 10 hours. Women in the first three months of pregnancy often need several more hours
than usual and the amount needed increases if you have been deprived in previous days. Now let's take
a look at some of the effects of lack of sleep. Lack of sleep has been linked to obesity, type 2
diabetes, cardiovascular disease, hypertension, and poor immune function. It can also lead to
car accidents, learning deficiency, lower sex drive, depression, decreased memory, ages your skin more,
impaired judgment, and less productivity at work or school. Over sleeping can also be problematic,
research suggests over sleeping can lead to weight gain, headaches, depression, heart
disease, and back pain. So what are the benefits of consistent quality sleep? Good quality sleep
has been shown to improve memory, decrease stress, decrease anxiety, increase creativity and increase
athletic performance. During deep sleep, growth hormone is released, which stimulates tissue
growth and muscle repair. There are many experts that believe getting enough high-quality sleep
is just as important to health and well-being as nutrition and exercise. How do we get good quality
sleep? It's often hard to get a good night of sleep, some things that have been shown to increase the
quality of sleep include, regular exercise, creating a good sleep environment, such as having a pleasant
room temperature and maybe having a soothing sound with soft music or a fan running, avoiding caffeine,
avoiding alcohol and sleeping pills, as they both can disrupt sleeping patterns, having a relaxed period
prior to sleep with no stressful affairs, and not watching TV in bed, as it can increase alertness.