Sleep quality is just as important and sleep quantity. In general terms, when we sleep, a healthy pattern would be to be asleep about 85% of the time that we are in bed. While waking is normal, you shouldn’t take too long to get back to sleep. If you are trying to go to sleep for greater than 20 minutes, or you are waking often, the quality of your sleep will be affected.
Sleep quality is just as important and sleep quantity. In general terms, when we sleep, a healthy pattern would be to be asleep about 85% of the time that we are in bed. While waking is normal, you shouldn’t take too long to get back to sleep. If you are trying to go to sleep for greater than 20 minutes, or you are waking often, the quality of your sleep will be affected.
4 stages of deep sleep 1-4 (4 being the deepest).
First 20 minutes of sleep are usually typified by stages 1 & 2. Your heart rate begins to slow down, and your brain waves also begin to slow down. You then drop into stages of deeper sleep (3 & 4) where your heart rate continues to drop (really drops to lower levels). Brain activity does some unusual patterns where large amounts of neurons activate together and then switch off together in waves. Muscle tone also drops significantly. By now you are about 60-70 minutes into the first sleep cycle. You will then rise back up to stage 2 for about 10 minutes and then you will have your first period of REM sleep activity.
You then continue to go through regular 90-minute cycles where you drift from 1-4 and experience periods of REM. In the first hours of sleep, most of these 90-minute cycles are comprised of deeper non-Rem stages of sleep. These deeper stages are restorative for musculature and motor-learning; and dream content tends to be less emotional. Autonomic storms where shifts in ANS (PNS/SNS) activity occur randomly in terms of timeframe and duration. There are corresponding shifts in BP, HR and hormone levels like Growth Hormone, Insulin and Testosterone.
If for example, you went to sleep much later than normal or these first hours of your normal sleep cycle were disrupted, you would essentially miss this period and the associated benefits. You would essentially fast track or skip through the deeper stages and move through to the latter half of your sleep cycle. By doing this, you may feel like HR, BP, Insulin is less regulated the next day.
In the second half of the night, there are longer periods where you are in REM stages of sleep during those 90-min cycles. Rem sleep is vital for several cognitive functions. Sleep can be described as a self-generated therapy and in particular, REM is vital for consolidating learning and memory and is critical in aspects of emotional and mental health. Surprisingly, it is hard to see a difference in neural activity between REM Sleep and Wakefulness. The two key differences are muscle activity. In Rem sleep, muscles are essentially paralysed so you don’t play out the activities in your dreams, and your eyes are shut and move horizontally rapidly in Rem sleep, whereas your eyes during wakefulness and obviously moving in every plane based on what is happening in your environment.
If you are deprived of the second half of your sleep, you will typically miss out on the higher levels of REM sleep, this is when dream content is more emotional and the emotional centres are more active. Sleep or lack of sleep alters empathy and decreases your ability to resolve conflict in relationships. Testosterone and Growth Hormone are higher, so you will miss out on the benefits of growth and repair features of these hormones. Rem Sleep out of all the stages of sleep is highly predictive of your longevity (good REM sleep equals good longevity; poor REM sleep equals poor longevity).
Even though in both examples above, you might get 4-hours sleep for example, the quality of sleep is different, and it affects different functions. There are some obvious things that can disrupt our sleep patterns. Most people understand that caffeine will prevent us having a good night’s sleep. Caffeine blocks the receptors for adenosine, which means we feel less sleepy. The effects of caffeine can have an effect for 10-12 hours after ingestion. You should therefore aim to have your last drink of caffeine >10 hours before bedtime. Even if you go to sleep after drinking caffeine, your quality of sleep is likely to be reduced.
Alcohol is another substance that can affect our sleep patterns. Alcohol is a sedative, but not a sleep aid. When you have a drink, your cortex is put under sedation, so it might feel like you are falling asleep easier, but it can be seen as losing consciousness easier (not going to sleep easier). Alcohol, via the activation of the SNS will lead you to wake more often, thereby creating a more fractured sleep. These period of being awake may not be consciously remembered. Alcohol also blocks REM patterns, meaning that this part of your sleep is less effective. This is like missing out on ‘Emotional First Aid’ / overnight therapy. Memory and cognitive functions are also inhibited when you miss REM sleep.
There are other practical tips that you can put into practice that might help you improve the quantity & quality of your sleep. Here are some simple tips:
- Artificial Light / Screens:
- Promote: Create a ‘wind-down’ routine. Aim to dim the lights an hour before you go to bed so your system registers that the sun has gone down and it’s time to sleep.
- Avoid: Aim to avoid computers, iPad’s, TV’s and phones in the hours before sleep. The light from the screen and the stimulation the various media have on your system can may it harder to go to sleep.
- Noise:
- Promote: Aim to set up your bedroom so it is as quiet as possible.
- Avoid: If there is anything that causes distraction like a ticking clock, a rustling curtain or squeaky fan, aim to find a solution before it is time to go to sleep.
- Relax (Brain & Body)
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- Promote: Relax Mind & Body before you go to bed (meditation / stretch / breathing / visualisation). Write down all the things that might keep you awake ‘worrying’ about an hour before you go to bed (not straight before).
- Avoid: Thinking or planning while you are in bed. Rumination, worrying or irrigational thoughts can be more active in the dark, when you are tired and perhaps disorientated in the middle of a night’s sleep.
- Practical
- Promote: Create a sleep routine that works for you. Biology likes consistency. Predictable sleep timing, meal timing and routines that signal to your system that you are ‘winding down’ to sleep time are helpful to develop and reinforce each night.
- Avoid: Contrary to past advice, don’t ‘count sheep’. This is likely to stimulate cognitive activity rather than to ‘quieten’ it down in preparation for sleep. Remove all clock faces from your room. These add external feedback that can be counterproductive. Aim to avoid judgement. If you take longer to go to sleep than usual, or you wake more often than usual, that is fine. You will drift off to sleep eventually providing that you don’t get caught up into any overthinking or frustration.