During sleep, our consciousness is suspended and the body is restored. The hypothalamus, a section of the brain, is the sleep and wakefulness center. It controls the body’s sleep cycle and functions in five stages. The first four stages, or 80 percent of sleep, fall under the non-rapid eye movement (non-REM) sleep. The last function is the rapid eye movement (REM) stage of sleep.
The REM and non-REM sleep stages change in cycles of 90 minutes. During the non-REM sleep, especially the last two stages of sleep, growth hormone levels increase and tissues are repaired and grow. Also, the immune system rejuvenates making the body less prone to illnesses.
REM sleep is greatly associated with memory functions. Some scientists believe that during REM sleep, short-term memory is stored into long-term memory. This would explain why people have better memory retention after a good night’s sleep. Also, the majority of dreams are experienced during this stage of sleep.
Staying awake for 24 hours causes reduced hand-eye coordination. It increases reaction time that is similar to having a blood-alcohol level content equal to 0.1. For this reason, many road accidents and work-related incidents are caused due to lack of sleep. Chronic sleep deprivation may also be linked to depression and emotional problems, as well as prolonged fatigue and mood swings.
Sleep is of great importance when it comes to physical activity. As little as 20 hours without sleep can begin to deter mental functioning. This can make activities involving coordination and agility much more difficult since the control of muscles by the nervous system will diminish. During sleep, muscles and bones are repaired and grow. Therefore, to notice improvements in physical performance and avoid injuries, the body needs adequate sleep.
Newborns sleep anywhere from 11 hours to 18 hours a day. Children age three to five need from 11 hours to 13 hours of sleep, whereas teenagers require nine to 10 hours. Adults should get about eight hours of sleep per night. These are general guidelines since some people can function adequately with less hours of sleep. However, research shows that people averaging less than four hours or more than nine hours of sleep per night have a shorter lifespan than those who sleep four to nine hours.
There are a few steps that are necessary to ensure a good night’s sleep. One should purposefully go to bed early enough to get the adequate amount of hours of sleep. Adjusting room temperature and having a comfortable bed will also make sleep more enjoyable. Avoid coffee and other caffeinated drinks since caffeine can remain in the body for up to eight hours. Also avoid nicotine during the hours before going to sleep because it has a similar stimulating effect. Both caffeine and nicotine increase alertness making it harder to fall asleep.
Avoid using suppressants to fall asleep. Each stage of sleep has a distinct function. Sleeping pills and alcohol may help a person fall asleep by causing the loss of consciousness but they also suppress some of the natural sleep stages mentioned earlier. For this reason, some physiological functions will not be fulfilled by chemically induced sleep.
In general, people spend almost 200,000 hours, or 8,303 days sleeping during their lifetime. Even though the scientific world is still in debate over why we require it, the importance of sleep is certainly vast. Exercise is known to improve the quality of sleep. So, if you are one of those individuals who has trouble falling or staying asleep, NEIU’s Campus Recreation facility offers many options for a good workout. Just don’t forget to set your alarm clock because you might oversleep and miss that 8:00 a.m. class.
Dejan Slavnic is a personal trainer at NEIU, certified through the American College of Sports Medicine (ACSM).