Understanding Importance of Sleep
What is Sleep? Sleep is an important part of our daily routine, you spend one third of your day asleep. Without sleep we cannot form or maintain the pathways to our brains that let us learn and create new memories and you may find it harder to concentrate and respond and react quickly. Sleep is important for a number of brain functions, including how nerve cells communicate with each other. Sleep affects almost every type of tissue and system in the body-from the brain, heart, and lungs to metabolism, immune function, mood and disease resistance.
In this modern day and age with it’s technological advances, we find that we are getting less sleep now than ever. A study done in 2013 showed that the average American sleeps 6.8 hours a night with 40% sleeping less than 6 hours a night. Comparing this to a study done by the same research group in 1942, The typical American average 7.9 hours of sleep a night with only 11% sleeping less than 6 hours a night. Going further back to 1910, the average american sleeps just over 9 hours a night. Let us delve deeper into the topic of sleep by first understanding what is sleep?
Sleep has the following characteristics which in many ways define sleep:
- Sleep is a period of reduced activity
- Sleep is associated with a typical posture, such as lying down with eyes closed (for humans)
- Sleep results in a decreased responsiveness to external stimuli
- Sleep is a state that is relatively easy to reverse
There are two basic types of sleep, rapid eye movement (REM) and non-REM sleep (which has three different stages):
- Stage 1 (N1): non-REM sleep is the changeover from wakefulness to sleep.
- Stage 2 (N2): a period of light sleep before you enter deep sleep.
- Stage 3 (N3): the period of deep sleep that you need to feel refreshed in the morning. It occurs in longer periods during the first half of the night.
Each sleep cycle contains five distinct phases, which exhibit different brain wave patterns. It suffices to say that one sleep cycle lasts an average of 90 minutes: about 65 minutes of normal/non-REM sleep, 20 minutes of REM sleep and a final 5 minutes of non-REM sleep. REM or deep sleep makes up 20-25% of your sleep each night.
Most dreaming occurs during REM sleep, although some can also occur in non-REM sleep; usually notable when you wake up and go back to sleep and have intense or vivid dreams. When you are in the REM phase of your sleep, your arms and leg muscles become temporarily paralyzed, which prevents you from acting out your dreams. On average, we need four (6 hours sleep) or five (7.5 hours sleep) cycles in a 24 hour period. Most adults need 7-9 hours of sleep a night, but after the age of 60, night time sleep tends to be shorter, lighter and interrupted by multiple awakenings. Elderly people are also more likely to take medications that interfere with sleep. In general, people are getting less sleep than they need due to longer work hours and the availability of digital entertainment and other activities.
As a general rule, if you wake up tired and spend the day longing for a chance to have a nap, it is likely that you are not getting enough sleep. Prolonged lack of sleep can disrupt your immune system so you are less able to fend of bugs and viruses. Lack of sleep can lead to weight gain or make wake loss difficult. Chronic sleep debt may lead to mood disorders like depression and anxiety and studies have suggested that people who usually sleep less than five hours a night have a higher risk of having or developing diabetes. Sleep deprivation has also been associated with increased heart rate, an increase in blood pressure and higher levels of certain chemicals linked with inflammation.
So what are you waiting for? Get your 4-5 cycles of quality sleep each night.The secret is not the amount of sleep but rather the number itself; a multiple of 90 minutes will change your life!
Written by Ian MacLeod
Co-Founder & Head Coach at Nirvana Strength