What are Sleep cycles
There are 4 stages that occurs in our brain during sleep. When we have entered different stages, we call that a cycle. As we repeat different stages throughout our sleep we are constantly going into multiple cycles
What are the stages?
Stage One: Light Sleep (N1) - This should count for approximately 5% of sleep
Stage Two: Stabilised Light Sleep (N2) - This should count for approximately 45% of sleep
Stage Three: Deep Sleep (N3) - This should count for approximately 25% of sleep
Stage Four: REM Sleep (N4) This should count for approximately 25% of sleep
There are way to track the quality of these sleeps, smart watches from Garmin do a terrific job to ensure as well others decides such as Whoop bands.
Each stage has an important role, some more than others. So what does each stage do for us?
Light Sleep
This is stage occurs when our brain wave length slow down. The brain waves change of to theta waves from alpha waves. This when our bodies start to relax and tension dissipates from our muscles, which is why on occasion you can be drifting off and feel that hypnic jerk from our muscles twitching. This is our gateway into becoming asleep
Stabilised Light Sleep
So our brain wave length remains in theta but everything else’s starts ramping up our sleep. This stage is when our body temperature drops, our heart rate slows down. This then leads us into more of a relaxed state allowing our brain to strength neuropathways from any new skills or movement we have learnt that day. This will account for up to half of our sleeping time.
Deep Sleep
When we enter deep sleep our brain waves transform from theta to delta waves. For our body this mean our body isn now fully relaxed and incredible hard to wake us up. This stages of sleep is when the body goes to work in recovery. This is the stage when muscle tissues are being repairs from strain or injury, when immune systems are strengthen, our brain start to dump out ‘waste’. The fluid that flushes the brain cleans out toxic proteins such as beta-amyloids as well metabolic byproducts and excesses neurotransmitters. The fluid is able to clean our brains as our cells slightly shrink during sleep…the human body is truly a miracle.
Rapid Eye Movement (REM) Sleep
The brain starts resemble being awake, its a temporarily in a state of paralysis to stop your body reenacting dreams that are occurring this is also when vivid dreams can also occur which can sometimes leave you baffled in the morning. This allows us to emotionally process things they may have occurred, solving problems in our subconscious as well as memory consolidation. This is a super critical stage to enter into
What influences our sleep the most and how likely we are going to enter into a perfect night of rest. It the circadian rhythm. This is a 24 hour cycle that our body runs off and should in in-tuned with sunrises and sunsets. This is how we have lived for hundreds of thousands of years.
We should start to fell tired a couple of hours after the sunset due to it as well as our body’s sleep pressure adenosine. This builds up the more you are awake which is why after being awake for over 12 hours you’ll start to feel tired.
Now not to sound like a nagging mum, it is importantly to go to bed at a reasonable hour. We know from studies that earlier in the night we go to bed the more Deep and REM sleep will occur. So going to be around midnight will simply wipe that out leaving you waking up feel groggy and sometimes depressed. It’s paramount to have a consistent bed time that not too late in the night to unsure you sleeping 8-9 hours a night.