April 27, 2021
Why on earth is a physio interested in and talking about sleep? Well, not only is it vital for survival, it is imperative for repair and recovery; it allows us to learn new movement patterns when undergoing rehab from an injury and helps us deal with pain. Sleep deprivation is in fact a form of torture, as those of you with small children already know!
First a bit about the science that explains why we are rendered unconscious for several hours a day, why teenagers stay up late and what happens when we don’t get enough sleep (including poor decision making and reduced productivity) and then some practical tips to improve how well you sleep.
WHY DO WE NEED TO SLEEP?
Sleep has an effect on our whole body.
- Sleep allows us to learn facts and memorise experiences we have encountered through the day – read something through, or practice/ visualise a technique before you go to sleep
- We recalibrate our emotional brain circuits to give us a perspective on our thoughts and emotions
- Because we have been able to add perspective to our experiences we are better able to make logical decisions and choices – hence the expression ‘ to sleep on it’
- It is during the dreaming period of our sleep that we enter a personal ‘virtual reality’ where even painful or frightening experiences can be compared to past experiences so that we can face new challenges with more confidence, or to inspire creativity to problem solve
- We recalibrate our insulin and circulating glucose levels that enable us to make better food choices
- Our gut biomes maintain and re-set themselves
- Our blood pressure lowers and we are able to give out heart a rest
- Our repair and immune system are restored
WHEN DO WE FALL ASLEEP?
Our bodies are controlled by circulating chemicals and hormones that regulate our systems. Our sleep is guided by our Circadian Rhythm which is regulated by a balance of hormones and the effect of the light spectrum on a part of our brain called the pineal gland that receives light from our eyes.
1 – Melatonin. This is our trigger to sleep and is affected by changes in the light spectrum, from the brighter ‘blues’ of daylight to the softer ‘reds’ of the evening. It is produced in the pineal gland of the brain when you find yourself in a dark environment. The change in light causes messages to be sent from the eye to the brain telling it that more melatonin should be produced. The melatonin winds the body down to a more lethargic and sleep-ready state.
2 – Adenosine. This is the hormone that makes us feel sleepy and builds up during the time we are awake.
3 – Serotonin. Not only is this our feel good hormone that increases positivity and relaxation but it also keeps us energised. This energy is particularly important because we all need it to get us going in the morning and wash away the lethargy that would otherwise keep us in bed. It too reacts to light and needs bright natural light for its best production.
Our bodies create different amounts of melatonin at different stages in our lives, this is why BABIES and young children will fall asleep on the sofa even when they are trying hard to stay up, as melatonin levels peak between the ages of 1- 3 years but ADOLESCENTS shift their circadian rhythm by 1- 2 hours as melatonin production decreases around the age of puberty into the early 20’s.
NB Caffeine in coffee, energy drinks and fizzy drinks blocks the effects of adenosine on the body so we feel more alert, however the adenosine will continue to build up in our system leading to a ‘caffeine crash’ when the caffeine leaves our system.
Caffeine takes around 5-7 hours to be metabolised and excreted, so there is still 50% in our system between 2 – 3 hours after we have had the drink. So avoid caffeine in the afternoon if you possibly can. Also remember there is still around 15% caffeine in decaffeinated coffee and the effect is accumulative. Think of the NASA experiment when spiders were given caffeine when you reach for you next cup! ( The effect on a spider may not exactly replicate that on humans but a good visual to think of never the less).
WHAT HAPPENS TO US WHEN WE ARE ASLEEP?
When we fall asleep we move though cycles of about 90 to 120 minutes moving through Non Rapid Eye Movement sleep (NREM) and Rapid Eye Movement (REM) levels in each cycle.
If you have a sleep app on your smart watch/fit bit it may analyse your sleep into these levels
NREM sleep manages file transfer from short term to long term storage; gets rid of duplicates and strengthens memory.
NREM is divided up into:
N1 = 1- 5 mins dozing;
N2 = 10 -60 mins; deeper more relaxed sleep with gentle brainwave patterns
N3 = 20 – 40 mins; is our deepest level of sleep where we produce of growth and repair hormones
REM = 10 – 60 mins;
We are paralysed apart from our eyes and breathing, but our brainwaves are as if we are awake. This is when we dream. It is a safe virtual reality – reinforcing what is important to us by integration of new with past experiences to problem solve or create new ways to deal with different situations.
We spend longer in NREM sleep at the beginning of our sleep pattern and more REM sleep towards the end – which is why we can sometimes remember our dreams. Both ends of the spectrum are important. We sometimes loose out when woken by pain, children disturbing our sleep, needing the loo or a morning alarm.
Losing any stage of our sleep cycle can impact on our mental and physical health and our ability to fight infection/ inflammation and repair.
HOW TO SLEEP WELL
1 ROUTINE: Make sure you have a bed time routine. This is called sleep hygiene. Aim to get away from a screen for at least 30 minutes before you go to sleep or at least use an app for a blue light filter. Keep your bedroom as dark and cool as you can (around 18 C is optimal) when you are asleep. Try to aim for the same bed time each night, including weekends, and to sleep without an alarm waking you.
2 NUTRITION: Research shows that eating foods with a higher GI index can help you get to sleep. This period is called sleep onset latency. You can shorten this period by trying some jasmine rice with your evening meal, which should be 3-4 hours before aiming to sleep or a drink of tart cherry juice which can increase your melatonin levels. Avoid caffeine after lunch if at all possible.
3 EXERCISE & LIGHT: Blue light can build up in our system when we sit at a screen all day, or work under artificial light so aim to get outside for a ‘good’ light source that boosts your serotonin to lift your mood. Even a short walk will help. However aim for at least 2 hours break after cardio-vascular exercise before you go to sleep to lower your heart rate and body temperature.
4 RELAXATION: Find a method that suits you be it a contrast, visualisation, breathing or mindfulness technique.
5 PAIN RELIEF: Make sure your mattress isn’t sagging, check your pillow height or use a rolled up towel in your pillowcase to support your neck. Inflammation can lead to pain as the inflammatory chemicals build up as your circulation slows down as you sleep – so get that injury looked at or seek help for that chronic condition you haven’t had time to deal with. You will sleep better, and repair better, and feel better for it.
BWT Physio – we understand your body.