Sleep deprivation is linked to an increased risk of high blood pressure, stroke heart disease, CVD, diabetes and kidney disease. Being deficient in sleep is also linked with an increased risk of obesity; in fact some studies have shown that for each hour of sleep lost your risk of obesity increases.
Each night when we drop off to sleep and our conscious mind switches off, our brain and body start to work on all the functions we take for granted. A lot of these neural and cognitive functions cannot be provided by wakefulness and hence the need for us to sleep. Some of these functions include our brain coding newly acquired information, leading to better memory during wakefulness. The brain processes, sorts, consolidates and commits to memory the days events.
There are a number of stages that must occur and repeat in sequence to provide a quality sleep experience. During an average 8 hour nightly sleep, you will go through approximately 5 sleep cycles. The chart below shows the duration of sleep and cycle stages across an average night sleep.
During the stages of NREM sleep, muscles are completely relaxed, blood pressure drops and breathing slows. Blood supply to the muscles is increased, energy is restored, tissue is repaired and growth hormone production takes place.
At the end of deep sleep you enter into REM sleep. During REM sleep, your eyes move quickly in different directions. That doesn’t happen during non-REM sleep. (Check out your pets sleeping; you will easily see when they enter into a REM sleep stage).
Usually, REM sleep happens 90 minutes after falling asleep & lasts around 5 minutes in length. Each REM cycle occurs every 70-120 minutes and its duration progressively lengthens from the initial 5 minutes upwards to an hour in length. Your heart rate and breathing quickens. REM sleep is where the brain is most active and dreaming takes place. Just as deep sleep renews the body and tissues, REM sleep renews the mind by playing a key role in learning and memory. REM sleep consolidates and processes the days events and information. It is important in strengthening memory and replenishing the feel good neurotransmitters, like serotonin and dopamine.
If you aren’t getting enough deep sleep, your body will try to make that up first, at the expense of REM sleep.
The amount of sleep the body requires for full restoration and function, changes over the lifecycle (see graphic). A newborn will require on average 15 hours of sleep each day, where as a senior 65+ will require an average of around 7.5 hours a day.
During the day get some exercise and be mindful of caffeine and alcohol, they can negatively affect sleep quality and shorten sleep cycles.
To get more mind and mood-boosting REM sleep, try sleeping an extra 30 minutes to an hour in the morning, when REM sleep stages are longer. Improving your overall sleep will also increase your REM sleep.
With our busy lifestyles people don’t consider sleep as a priority. However, if you wish to live a longer, happier, healthier life, then getting your ‘nightly 8 hours’ is most beneficial. Ensure sleep is scheduled into your daily routine, just like, gym, work, and walking the dog etc, that way sleep is made a priority.
The following ten true/false questions (courtesy of www.sleepfoundation.org) test your sleep IQ. How much do you know really know about sleep? Perhaps you’ll be surprised. The answers are at the bottom of this article.