Updated: Jul 21, 2020
40% of adults get inadequate sleep
Why is sleep important?
Considered one of the most vital components of health and performance but often ignored, compromised sleep can negatively impact both health, performance and brain function (decision making, learning, psychological state and mental health). The reduction in immunity and compromised cognition and performance is a major concern for the corporate professional (overall health, missed work days through illness (psychological or physiological) and less day-to-day productivity) and the elite athlete (overall health (mental or physiological), lost training and competition days due to illness and reduced performance).
A reduction in total sleep and compromised sleep quality (a fast sleep onset latency and long duration of sleep do not automatically promise quality sleep and recovery) can influence a multitude of functions including (but not limited to) learning, memory, cognition, mood, stress, pain perception, immunity, recovery and inflammation with significant impact on wellbeing, daily life and athletic performance (especially submaximal and prolonged exercise) can be found with sleep deprivation. Metabolic changes in metabolism and neuroendocrine function have also been found in cases of chronic partial sleep deprivation which can result in alterations to glucose metabolism, appetite, food intake and protein synthesis, which may affect long-term performance and general wellbeing.
While we are awake, we have a consistent gradual increase is "Sleep Pressure" which is the result of adenosine, a molecule that builds up while we are awake and promotes sleep (note: the reason caffeine makes us feel alert is that it competes with adenosine at the location of the brain and stops it's impact of making us feel tired and drowsy. The resulting "caffeine crash" is due to caffeine being metabolised and adenosine having better access to the brain to exert its effect. Adequate sleep will remove this pressure and reduce the sleep debt; however, just like outstanding bills that roll over each month when not paid, inadequate sleep (duration or length) will cause an outstanding adenosine debt exerting tiredness.
Zeitgebers (meaning "time giver") are rhythmically occurring natural phenomenon which aids regulation of the body's internal circadian rhythms. As the human body has evolved over thousands of years sudden changes in the environment (crossing multiple time zones quickly to impact day/night cycle), digital devices emitting blue light, environmental noise, atmospheric conditions (i.e. heat or cold outside the thermal neutral zone), medication and stimulants, social interactions, exercise, eating and drinking patterns can impact the body's internal body clock.
How to improve sleep quality?
While we may not be able to impact duration, we can enhance behaviours to improve restorative quality. It’s not just blue light, alcohol and coffee – changes in the environment, light/time zones, noise, atmospheric conditions, medication, social interactions, psychological load, exercise, nutrition and drinking patterns can (for better or worse) impact our internal body clock.
1) Avoid blue light emitting digital devices before bed (reading a book is a better alternative) - use an analogue alarm clock and keep your phone out of reach).
2) Read before sleep, avoid work-related thoughts so you can switch-off once it is time to sleep.
3) Sleep in a dark room without lights or light disturbances after sunrise (a sleep blindfold can help).
4) Sleep in a room with minimal noise disturbances.
5) Sleep in the thermal-nuetral zone, approx 17-19 degrees celcius (use a thermometer).
6) Avoid strenuous exercise before bed (exercise can aid sleep, but too close too sleep can hinder sleep quality).
7) Caffeine and alcohol negatively impact sleep quality (if you feel you fall asleep quickly, the quality will be significantly impaired). Remove caffeine mid-afternoon due to it's ability to compete with adenosine receptors in the brain (we all metabolise caffeine at different rates, as well as different size individuals). Alcohol should also be kept to a minimum and avoid frequent consumption.
8) Use your bed for sleeping, and associate the environment with sleep. Do not associate bed with work (checking e-mails on the lap-top at night in bed).
9) Set a schedule, go to sleep and wake the same time each day.
This snapshot from a more extensive report which monitors stress, recovery, sleep, activity, training and occupational load shows alcohols impact. Both graphs show a 24hr timeline – which is linked with a digital diary (removed) to monitor what causes a stress response. On the bottom graph, the green colour on the right (signifying quality sleep) is significantly reduced due to alcohol – although self-reported quality was still moderate to high.
Areas of nutrition that can help?
(While research is minimal and somewhat inconclusive, several practical nutrition recommendations may also be suggested in addition to the above infographic):
1) High GI foods such as white rice, pasta, bread, and potatoes may promote sleep; however, they should be consumed more than 1 h before bedtime.
2) Diets high in carbohydrate may result in shorter sleep latencies.
3) Diets high in protein may result in improved sleep quality.
4) Diets high in fat may negatively influence total sleep time.
5) When total caloric intake is decreased, sleep quality may be disturbed.
6) Small doses of tryptophan (1 g) may improve both sleep latency and sleep quality. This can be achieved by consuming approximately 300 g of turkey or approximately 200g of pumpkin seeds.
7) The hormone melatonin and foods that have a high melatonin concentration may decrease sleep onset time.
8) Subjective sleep quality may be improved with the ingestion of the herb valerian; however, as with all supplements, athletes should be aware of potential contaminants as well as the inadvertent risk of a positive drug test.
How can I monitor sleep quality?
Unless you have laboratory/medical grade wearable tech (ideally not a wrist-worn device) you will have to use judgement. This is not as easy as it sounds and anecdotally it's common for people to have poorer quality sleep and self-rate the night's sleep as great.
A wellness questionnaire tracks markers of wellbeing and performance. A simple daily log of mood, energy, sleep quality, stress and muscle soreness marked out of five (one is worse and five is great) can allow you to see patterns. Acute fluctuations in numbers will appear, however, if sleep lowers and other markers (mood, energy) follow, there is a high probability that a stressor is negatively impacting sleep.