Part of the chapter explains why us human folk will sometimes wake up feeling just grand and sometimes waking up feeling like a grand piano has landed on us (and may still be there). It's all to do with body clocks, circadian rhythms, sleep cycles, and goes something a little like this.
We all have a sleep cycle that we move through each time we close our eyes to rest. There are five stages to the sleep cycle; each cycle lasting approximately 90 minutes. Four stages are non-REM (rapid eye movement) and one stage is REM sleep, when we do most of our active dreaming and our eyes tend to move – hence the name.
Getting good, restorative sleep is not just a matter of spending enough hours in bed. The amount of time you spend in each of the stages of sleep matters. A normal adult spends approximately 50% of total sleep time in light sleep, 20% in REM sleep, and 30% in the remaining stages, including deep sleep.
Each stage of sleep in the sleep cycle offers benefits to the sleeper. However, deep sleep and REM sleep are particularly important.
The most damaging effects of sleep deprivation are from inadequate deep sleep. Deep sleep is a time when the body repairs itself and builds up energy for the day ahead. It plays a major role in maintaining general health, stimulating growth and development, repairing muscles and tissues, and boosting your immune system. In order to wake up energised and refreshed, getting quality deep sleep is key. Being woken in the night during the deep sleep or REM stages can impact significantly on the quality of sleep had each night and can contribute to an increase in the symptoms experienced from lack of sleep.
After telling a friend about this aspect of sleeping, she shared with me that she has an app on her iPhone that monitors your sleep cycles and wakes you up at some point within a half-hour window, but at an appropriate pace and time to coincide with what part of your sleep cycle you are in. The app is called Sleep Cycle.
It's a reasonably priced app and I really quite like it. As well as having very calming sounds to wake me, it does do the whole 'work out where I am in my sleep cycle and wake me appropriately' thing, but best of all - you get a very cool graph of your sleep pattern each night, a record of how long you have slept, and an average sleeping time over the nights you use it.
Example of sleep graph
I'm not on commission to sell the app - just wanted to share with any like-minded geeks who think that seeing your sleep pattern and knowing how long you have slept each night (and average sleeping times) will add value to your life.
It is certainly keeping me 'appy at the moment.
BTW - avg sleeping time over 19 nights is 7hrs 22mins.