Sleep is the key lifestyle factor affecting all body systems and organs.

The sleep–wake cycle is the most overt circadian rhythm. Sleep is an orchestrated neurochemical process involving sleep‐promoting and arousal centres in the brain (Saper et al., 2005).
Sleep is essential in the restoration of brain energy, processing information acquired whilst we are awake. Learning, memory consolidation and 'pruning' of unused or surplus neuronal connections occurs during sleep. The activation of the recently discovered glymphatic system that is responsible for brain metabolite clearance (Musiek and Holtzman, 2016).

​These functions are critical for brain development, physical and mental health, and the maintenance of cognitive functions culminating in a sense of well‐being and daytime vigilance.
  • Sleep fine tunes the balance of insulin and blood sugar
  • Too little sleep increases the hormone that makes us hungry
  • Effects the immune system, in particular our Natural Killer Cells essential for fighting infections and cancer
  • Regularly getting <7 hours sleep a night has been shown to accelerate aging
  • Sleep affects our mental health - depression, anxiety, Alzheimer's & dementia etc.
  • Sleep disorders are in the background of most (if not all) diseases and mental health issues.

Are you getting enough quality sleep?

Neurologist Dr S Gominak has found that you can have a sleep disorder and not know it. So how can you tell if your quality of sleep is related to a seemingly unrelated issue or condition that you currently have? And if you do have a sleep disorder, what's the underlying reason behind that? This is what we will explore next...
To understand how sleep underpins and/or causes widespread body and brain issues we can take a look at what the research shows...
  • The specific stages of sleep allow for repair and healing in specific areas of the body.
  • When Vitamin D levels are insufficient it reduces, and in some cases completely stops REM stage sleep. Studies show that if you deny someone REM sleep they develop post traumatic stress disorder (PTSD).
  • Someone who only gets 5 hours sleep is 4 times more likely to catch a cold than those getting 8 hours sleep. This ties in with a Vitamin D deficiency and the resultant affect on sleep durations and quality.
  • After just 1 week of <6 hours sleep a night participant's blood sugar levels were disrupted to the point where they would be diagnosed as 'pre-diabetic'.
  • Exercise enhances the quality and quantity of deep sleep.

What is healthy sleep?

Dr Stasha Gominak describes here what should happen as a result of good sleep.

How to optimise your sleep - Quality & Quantity.

There are many practical lifestyle habits you can modify in order to give yourself the best chance of ensuring you get good sleep night after night. Living in Scotland we know that the number of hours of sunshine is less than in the south of Spain so getting your Vitamin D level tested is essential for giving you a 'benchmark' of where you're starting from.

Given the wealth of information studies have given us, it may well shed light on the health issue(s) you are currently experiencing.

10 Healthy Sleep Habits:
Circadian rhythm
Consistency - Get up, and go to bed at consistent times including weekends and holidays. Staying up late and getting up late the next morning shifts your body clock much like travelling to a different time zone, you will feel the effects of 'jet lag'. ​
Circadian rhythms are the biological processes or 'clocks' that exist in each one of our cells. Programmed to turn genes on or off at different times of day & night, they influence every aspect of our health, for instance; weight, energy levels, resistance to disease and infection and how well we sleep. To read more I recommend Dr Satchin Panda's book 'Circadian Code'. Watch his TEDx presentation on longevity.
Timing is key.
18 degrees celcius
To sleep well our core body temperature must drop by 2-3 degrees Fahrenheit to initiate and maintain good sleep says Matthew Walker the author of ​Why We Sleep. 
Bedroom temperature is optimal between 16-18 degrees celsius with fresh air coming in.

A tip for exercising in the evening: If you have found it difficult to sleep after evening exercise this can be for 2 reasons; exercise increases metabolic rate and circulating levels of cortisol which will keep you alert and awake for several hours afterwards, and exercise raises your core body temperature, which as we know must be able to drop. A way to help 'dump' the heat is by having a hot bath or shower before bed. This dilates blood vessels in the periphery and serves as a way to lose the excess heat.
Blackout blinds
Light waves penetrate the body, not just through the eyes. If light is still able to reach the pineal gland in the brain during the night you can't completely 'power down' for the night. Remember humans have been wandering the planet for the last 100,000 years or so and only until relatively very recently have we had the technology to artificially light our homes after sundown and beyond candle light.
We now know much more about the effect of exposure to blue light in the evening has on the human brain and overall health. and it's shown to be massively disruptive to all systems.
no caffiene at least 10 hours before bed
Caffeine is a psychoactive drug which has a half-life* of 6-8 hours (and can be as many as 10 hours for some people) in the body. This means that there will still be 1/4 of the caffeine, from a cup of coffee at noon, going around in your brain at midnight.
For those of us who like an espresso after dinner without ever feeling like it affects sleep... Sleep studies have shown a 20% reduction of deep sleep when you drink one shot of espresso in the evening. So we're not taking about being consciously aware of having a poor night's sleep, especially if you sleep right through the night. 

It is worth taking a look at how much caffeine you're consuming on a daily basis. This includes tea, green tea, energy drinks, chocolate and painkillers that contain caffeine. Start by replacing each cup with a caffeine-free alternative and give your body a minimum of 10 hours to metabolise it before bed.
*The half-life is the time it takes for your body to eliminate half of the drug.
alcohol
Alcohol has a very similar effect for getting us to sleep like sleeping pills. It rather 'knocks you out' rather than allowing normal restorative sleep. Have you ever found yourself waking up between the hours of around 2-4am? The effect alcohol has on impairing regulation of blood sugar levels.
If you find you're waking up repeatedly at a specific time of night you will find it interesting to look at the Chinese Body Clock. What could be going on for your body in terms of stress and it's ability to heal given the environment* you're placing it in.
*environment - this term encompasses all areas of lifestyle, physical, chemical and emotional.
blue light
no food or drink other than water 3 hours before bed
Giving your digestive system 3 hours to deal with your evening meal before bed allows your body to wind down for restful, restorative sleep. It typically takes blood sugar levels to come down to a baseline 2 hours after eating. The moment you have a snack or drink anything other than water digestive enzymes and insulin etc are released and metabolism is revved up again, 

If you eat a meal late and go to bed shortly afterwards your meal will not be fully digested as body systems are winding down for the night. Similar to drinking alcohol, you may find yourself waking up in the small hours with a full feeling in your stomach. Again these conditions are not conducive to a good, quality night's sleep.
aim to be asleep before 10pm
.Asleep by 10pm is all about our circadian clock and diurnal secretion of melatonin.
production of melatonin conveys the message of darkness to the body clock and induces night‐state physiological functions, for example, sleep/wake blood pressure and metabolism

Melatonin levels begin to rise after the sun goes down and starting from 8pm. Over the following 2 hours you start to feel sleepy as the sleep pressure begins to reach a threshold.
avoid catnaps
Napping during the day reduces sleep pressure and can create a catch-22 when you would really rather sleep through the night instead of repeatedly getting sleepy and fatigued during the day.
nasal breathing
The discussion of nasal breathing and the effect on sleep is vast. I have so much amazing information to share with you I almost don't know where to start!
As I discuss in the section 'Breathe' to restore and ensure you are exclusively breathing through your nose and have clear, open airways is paramount for good quality sleep.

If you snore at night this indicates that you have a sleep disorder, commonly linked to an underlying Vitamin D deficiency as it relates to an inability to maintain open airways during sleep. They therefore collapse and gurgling, snoring and, at worst, sleep apnoea are the results.
If you sleep alone you may be unaware of any altered breathing patterns. A good indication is if you wake up with a dry mouth, wake up tired like you haven't slept well. If you know that your nose and airways are stuffy or difficult to nasal breathe through during the day or with moderate exercise and find yourself habitually mouth breathing, you can be certain you are mouth breathing at night too.
In addition to the breathing exercises I discuss in the 'Breathe' section to clear your airways you can use a nasal dilator device at night (and cardiovascular sport for better oxygen exchange efficiency).