Importance of Sleep
We all take sleep for granted until we have problems with it and then we quickly remember how desirable a good night's sleep is. The need to sleep is a fundamental human need. This is because all human abilities (like paying attention, memory recall and learning) are made worse by poor sleep and there is an intimate relationship between sleep and many psychological conditions for example, depression and anxiety.
Lack of Sleep
For the first 4 hours of sleep the body recovers mentally and for the next 4 hours the body recovers physically. If you are getting 5 hours sleep a night you are only recovering for 1 hour physically. During this physical recovery the body goes into a fat burning state while it regulates and repairs the body. These 4 hours of physical recovery are of great importance for people trying to lose weight and just live a healthy lifestyle. Poor sleep has been linked with cancer.
Sleep is neglected by most people and is one of the most important factors in regards to achieving your fitness goals, keeping energy levels high and being productive. There are five phases of sleep: stages 1, 2, 3, 4 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.
Sleep does not progress through these stages in sequence, however. Sleep begins in stage 1 and progresses into stages 2, 3 and 4. After stage 4 sleep, stage 3 and then stage 2 sleep are repeated before entering REM sleep. Once REM sleep is over, the body usually returns to stage 2 sleep. Sleep cycles through these stages approximately 4 or 5 times throughout the night.
On average, we enter the REM stage approximately 90 minutes after falling asleep. The first cycle of REM sleep might last only a short amount of time, but each cycle becomes longer, so REM sleep can last up to an hour as sleep progresses.
Why is Sleep important
In addition to affecting memory and learning, lack of sleep has been linked to body weight. In one 2005 study published in the Archives of Internal Medicine, overweight participants were found to sleep less than participants of a normal weight (Vorona et al., 2005). Brandon Peters, About.com's Guide to Sleep Disorders, reports that poor sleep at age 30 months can predict obesity at age seven. While researchers do not yet understand exactly how sleep disruption impacts appetite and metabolism, getting a good night's sleep certainly can't hurt your weight loss or weight maintenance efforts.
According to many experts, most people need between seven and eight hours of sleep each night. What happens when you don't get enough sleep? Symptoms such as moodiness, anxiety, aggression and increased stress levels can result. While sleeping more certainly won't eliminate all stress, it can help increase your readiness to cope with the stress of day-to-day life.