By Rob Wilkins – Part 1 of 2
Special Assistant to the International Federation of Bodybuilders
In pursuit of the perfect body, many people focus on things like workout routines and supplements, however, many fail to consider another vital component of training-recovery. Remember that training is the stimulus to which the body adapts, but sufficient rest is essential to allow time for the adaptations to take place.
With adequate sleep athletes run better, swim better, and lift more weight. Exercise may be one of the best ways to achieve healthy sleep. A recent study (9) noted that people with minor sleep disturbances improved after four months of brisk walking 30 minutes four times a week. Another study (9) also reported that sleep improved in a group of seniors who exercised regularly.
WHY YOU NEED ZZZZ’S:
Sleep, a state that occupies about one third of our lives, is as basic a need as food, and vital to physical well-being. The main role of sleep is to restore the body’s energy supplies that have been depleted through the day’s activities. Factors that may influence human sleep patterns include physical size, muscle mass, brain size, and current level of physical fitness (12). Research indicates that people with a very high level of physical and intellectual activity need more sleep to fully recuperate. With that in mind, it is reasonable to think that the higher your activity level, the more sleep you need to restore your capacities.
Physical labor seems to increase the need for sleep more than intellectual work, a combination of both leads to the greatest sleeping needs, probably due to the fatigue of several systems of the body simultaneously.
Much of what is known about sleep stems from the groundbreaking 1953 discovery of rapid eye movement (REM) sleep (10). This is an active period of sleep marked in humans by intense activity in the brain and rapid bursts of eye movements. At the same time, scientists discovered that REM sleep is when dreaming occurs.
Before the 1950s, most scientists thought of sleep as an unchanging, dormant period, and considered it of little interest to science. During this time little was known about sleep or dreaming.
The earliest hints that sleep was a changing state came with studies showing that blood pressure, heart rate, and other body functions in humans rise and fall in a pattern during sleep. Because researchers had observed some eye movement during sleep, they recorded these movements by placing electrodes behind the eyes. They also recorded muscle activity and brain waves. They found regular periods of very rapid eye movement and rapidly changing brain waves that alternated with periods of deep, quiet, sleep marked by large, slow brain waves. Later, scientists found that the body is paralyzed during REM sleep (10).
Lack of sleep has major implications for public health, safety, productivity, and well-being. Little is known of the function or the role sleep plays in health and disease. It has been estimated that more than 60 million Americans, or approximately one in three adults, experience inadequate sleep that can interfere with daily activities (3). Excess sleepiness has been associated with accidents at work or at home, and at least three percent of serious automobile accidents and fatalities are due to a fatigued driver (3).
Sleep deprivation also affects us physically. Insufficient rest greatly reduces your recovery capacity, and thus your capacity to do physical work. Athletes undergoing an intense training program should sleep at least 9-10 hours/night and adding a short nap right after training is optimal. Each year sleep disorders add $16 billion to national health-care costs (e.g. by contributing to high blood pressure and heart disease). This figure does not account for accidents and lost productivity at work. The National Commission on Sleep Disorders estimates that sleep deprivation costs $150 billion a year in higher stress and reduced workplace productivity (US, 1999). 40% of truck accidents are attributable to fatigue and drowsiness, and there is an 800% increase in single vehicle commercial truck accidents between midnight and 8 am. Major industrial disasters such as Three Mile Island, Chernobyl, and the Exxon Valdez oil spill, have been attributed to sleep deprivation (5).
THE FIVE STAGES OF SLEEP:
Sleep is divided into REM and non-REM types (8). Non-REM sleep consists of the lighter stages–stage 1 and stage 2–and a deep form of sleep known as Delta (or slow-wave) sleep, which comprises stages 3 and 4. Most of the first third of the night, non-REM delta sleep predominates. After about an hour and a half in most normal people, the first REM period begins, and this alternates with non-REM sleep throughout the night. Most people have 4-5 REM periods in a given night. It is not known whether REM or delta sleep is deeper, but it generally requires more stimulation to arouse the sleeper from delta sleep. As people sleep they go through five different stages. These stages are broken down separately because there are changes in your brain waves. About every 90-100 minutes people pass through all 5 stages.
* In stage one of the sleep cycle brain waves are referred to as theta waves. They consist of a 4-7 cycle per second rhythm. (Non-REM Sleep)
* In stage 2 of sleep, the brain generates sleep spindles. Spindles are a 12-14 rhythm that lasts a half of a second. Sleep talking usually occurs during stages 1 and 2 of sleep. Sleep talking is mumbled and usually not understandable. (Non-REM Sleep)
* Delta waves are produced from the brain in the third stage of sleep. These brain waves become slower when the sleep cycle begins. During this cycle your heart rate, blood pressure, and arousal decline. (Non-REM Sleep)
* Stage four is very similar to stage 3 because Delta waves continue in the brain. During this stage of sleep most dreams and nightmares occur. (Non-REM Sleep)
* In stage five your breathing becomes irregular and more rapid. Your heartbeat rises and your eyes dart around in a momentary burst of activity while your eyelids are closed. This is called REM sleep (REM Sleep)
Even though REM sleep is a much deeper sleep it is not shown to be any better than Non-REM sleep. The reason for this is our bodies need for both kinds of sleep in order to be fully rested. Without one the other would never be as effective (8).