The 5 Stages of Sleep
Sleep is such an important part of health but it is undervalued as a vital component being healthy. As you read in the post about sleep, it is one of the primary ways to be healthy. Lack of sleep is a primary cause of poor health. I think many people view sleep as a necessary waste of their valuable time. They think of sleep as a certain period of forced unconsciousness and resist it mightily; even though their health is not at its best. I am astounded at the money people will throw at health products and disease ‘cures’ when all it takes to recover health is the discipline to follow several simple strategies.
One of the biggest neglected strategies is to get the proper rest and enough restorative sleep. The majority of adults should be getting at least 7 hours of sleep a night. However, we’ve all heard of the few people who only sleep for 4 or less hours and wake refreshed and ready to take on the day. I’d like to show you why that is possible for them and is not a good idea for most of us normal folk.
Below is a description of the different stages of sleep that we cycle through every time we sleep. Normally there are definite time periods where beneficial sequentially triggered processes happen to prepare the brain and body for restoration and repair that occur during the next level of sleep.
So if you’ve run into one of those people who boast about only needing 4 hours or less of sleep; one of two things are happening. One, they are lying to themselves and others about their need for sleep. They are using rugged discipline to take a small time period out of their ‘productive” day. They see sleep as a time waster and are driven to keep producing. They are human “doings” instead of human “beings”. Two, they validly need only a small window of sleep time. Their brain cycles through the stages of sleep faster than the average person and they awake refreshed after an abbreviated nighttime of sleepy bye-bye.
The true short sleep cycle individuals are at one end of the need for sleep distribution curve. Just remember that there are other people who fall onto the other side of the curve who require more than the normal amount of sleep to be healthy. We must pay attention to our body’s needs and the subtle messages it sends us. Utilizing all of your healing powers by listening to your body’s wisdom is a lost art that needs to be valued and re-discovered as a valid tool to use. Listen to your body’s needs for sleep. It is one of the best and easiest ways for nurture health.
There are five phases of sleep: stages 1, 2, 3, 4 (NREM – non rapid eye movement) and REM (rapid eye movement). Usually when you are sleeping, you begin at stage 1 and go through each stage until reaching REM sleep, and then you begin the cycle again. Each complete sleep cycle takes from 90 to 110 minutes. Your brain acts differently in each stage of sleep. In some of the stages, your body may make movements, but in others your arms and legs will be immobile.
Stage 1
Stage 1 sleep is light sleep. You experience a drifting in and out of sleep. You can be easily woken up. Your eye movement and body movements slow down. You may experience sudden jerky movement of your legs or other muscles. These are known as hypnic myoclonia or myoclonic jerks. These “sleep starts” can give a sensation of falling. They are caused by the motor areas of the brain being spontaneously stimulated.
Stage 2
Around 50 percent of your time sleeping is spent in stage 2 sleep. During this stage, eye movement stops and your brain waves (a measure of the activity level of the brain) become slower. There will also be brief bursts of rapid brain activity called sleep spindles.
Stage 3
Stage 3 is the first stage of deep sleep. The brain waves are a combination of slow waves, known as delta waves, combined with faster waves. During stage 3 sleep it can be very difficult to wake someone up. If you are woken up during this stage, you may feel groggy and disoriented for several minutes.
Stage 4
Stage 4 sleep is the second stage of deep sleep. In this stage the brain is making the slow delta waves almost exclusively. In this stage it is also very difficult to wake someone up. Both stages of deep sleep are important for feeling refreshed in the morning. If these stages are too short, sleep will not feel satisfying.
1 through 4 stages are also known as Non-REM or NREM stage of sleep. During the deep stages of NREM sleep, the body repairs and regenerates tissues, builds bone and muscle, and appears to strengthen the immune system. As you get older, you sleep more lightly and get less deep sleep. Aging is also associated with shorter time spans of sleep, although studies show the amount of sleep needed doesn’t appear to diminish with age.
Stage 5 REM Sleep – Rapid Eye Movement
REM sleep is the sleep stage in which dreaming occurs. When you enter into REM sleep, your breathing becomes fast, irregular and shallow. Your eyes will move rapidly and your muscles become immobile. Heart rate and blood pressure increase. Men may develop erections. Adults REM sleep is about 20 percent of total sleep time.
REM sleep is also the phase of sleep in which you dream. Intense dreaming occurs during REM sleep as a result of heightened brain activity, but paralysis occurs simultaneously in the major voluntary muscle groups. A part of the brain (pons) shuts down motor signals to keep the body safe from violent activity while you are dreaming. REM is a mixture of encephalic (brain) states of excitement and muscular immobility. For this reason, it is sometimes called paradoxical sleep. This sleep phase begins about 70 to 90 minutes after you fall asleep. The first sleep cycle has a shorter phase of REM sleep. Toward morning, the time spent in REM sleep increases and the deep sleep stages decrease.
Researchers do not fully understand REM sleep and dreaming. They know it is important in learning and the creation of long-term memories. If a person’s REM sleep is disrupted, the next sleep cycle does not follow the normal order, but often goes directly to REM sleep until the previous night’s lost REM time is made up.
Source: Brain Basics: Understanding Sleep, National Institute of Neurological Disorders and Stroke (NINDS)
How Much Sleep Do You Need?
The amount of sleep a person needs depends on the individual. The need for sleep depends on various factors, one of which is age. Infants usually require about 16-18 hours of sleep per day, while teenagers need about 9 hours per day on average. Most adults need about 7-8 hours of sleep per day. The amount of sleep a person needs also increases if he or she has been deprived of sleep. People do not seem to adapt to getting less sleep than they need.
