A few months after the release of our short online course, the Sleep Recovery Specialist, Academic Press published a significant scientific reference book titled Sleep and Health, edited by Michael Grandner PhD. This naturally caught our attention on the subject as previously there has not really been a single book to refer to across such a wide range of important topics related to sleep and human health. We contacted Dr Grandner directly expressing our interest and as a result, we were pleased to be given the opportunity to review the full book. The book has 37 chapters, so it seemed only right to share 37 fascinating facts about sleep, one drawn from each chapter. Here is our book review.
It has been quite a mission to read this 512-page book, but the insights and information contained within have been fascinating! Essentially the book is a compilation of 37 different chapters that have been written by a combined total of 84 different expert authors from around the world. Something that became apparent in our research into the Sleep Recovery Specialist was the extensive volume of scientific research that has been completed on the subject of sleep. It can certainly be overwhelming to trawl through such vast levels of information. Sleep and Health does a superb job of pulling the existing research together into one helpful and well-organized resource. If sleep is a subject that you are keen to have a more in-depth understanding of, then you would do well to turn to the extensive, yet concise bank of knowledge found in Grandner’s book, Sleep and Health.
37 fascinating facts about sleep
To be honest, it would be impossible to try and cover the full scope of this book in a single blog post, so perhaps the best way to give you a flavour of what is available to learn is to share a single fact or principle found within each of the 37 individual chapters contained within the book. So, enjoy these 37 fascinating facts about sleep and health:
- Sleep need is defined by individual genetics and physiology and does not change after losing a night of sleep or oversleeping on the weekends.
- The age-adjusted estimated prevalence of insufficient sleep (≤6 h) was reported to be 35.1% of the US population.
- The sex differences in subjective sleep complaints are amplified with ageing, with middle-aged women demonstrating an increased risk of insomnia, poorer sleep quality, and more frequent awakenings, despite reporting earlier bedtimes and longer sleep duration compared to men.
- Approximately 80% of older adults aged 71 and older had obstructive sleep apnea and the incidence increased 2.2 times for each 10-year increase of age.
- Previous studies have shown associations between sleep-related beliefs and sleep health … Those who express generally positive attitudes about sleep are more likely to experience better quality sleep in general.
- Most existing data suggest more disruptive and less efficient sleep in lower social-economic status individuals.
- Those living in areas that are brighter at night have a later bedtime. Thus, city dwellers often sleep less than their rural counterparts as a result of these physical features of urban neighbourhoods.
- Human health can be negatively affected due to inhibited melatonin production because of exposure to bright light at night, especially green and blue spectrum light.
- There is a growing body of evidence that the mental engagement (and distraction) that electronic devices provide, may interfere with sleep.
- Sleep tracking devices now boast the capability to monitor physiologic data previously unavailable outside the clinic, including movement, respiration, body position, heart rate variability, and even EEG.
- There are two recommendations associated with exercise in the context of sleep hygiene: (i) exercise is good for sleep and should be encouraged but (ii) exercise too close to bedtime is detrimental to sleep and should be discouraged.
- Objective scientific validation is well behind evaluating sleep tracker technology at the pace in which new technology is introduced to the public. In general, the quality of the data and the consumer usability of the devices are in opposition.
- Younger adults were more likely to use mobile phones at night than older adults, and were more likely to have shorter sleep duration, and increased tiredness. Symptoms of depression, anxiety, and stress were associated with the use of mobile phones at night.
- People’s attitudes about health and their health behaviours do not exist in isolation; they effect, and are affected by, the attitudes and behaviours of others. The more two individuals interact, the greater role this social context will have on their health behaviours.
- Late sleepers exhibit a shorter sleep duration, consume more calories at dinner and after 8pm, consume more fast food and full-calorie soda, and have a higher BMI compared to normal sleepers.
- A large epidemiologic study on short sleep duration (sleep <6 h) showed an increase in the risk for elevated blood pressure by 8% in a population of 162,121 adult men and women free from major diseases including obesity.
- Individuals who report poor sleep quality have a 40% increased likelihood of having diabetes. This risk is comparable with family history, being overweight, and higher than physical inactivity.
- Several studies suggest that humans’ metabolic systems do not adapt to disrupted sleep-wake patterns.
- Tart cherries have been shown to improve sleep quality and reduce insomnia symptoms. This may be explained, in part, by the rise in circulating melatonin concentrations that occurs after daily ingestion of tart cherry juice.
- Multiple cross-sectional studies have reported that greater sedentary behaviour is associated with lower sleep efficiency, higher daytime sleepiness, and greater odds of having short sleep duration, poor sleep quality, and sleep problems.
- Binge drinking, of ≥5 standard alcoholic beverages, has been associated with insomnia symptoms in multiple populations, including adolescents, young adults, college students, older adults, Veterans, and firefighters.
- Current smokers accrued 24% more stage 1, light sleep, but a significantly lower percentage of stage 3 deep sleep than never smokers; this would indicate shallower, more disturbed sleep.
- Those who had a circadian preference for evening time were three times more likely to consume high dose caffeinated energy drinks and report daytime sleepiness compared to those with a preference for morning time.
- Accumulating evidence points to the role of short sleep in the development and progression of age-related diseases, many of which include alterations in immune functioning.
- Among the most reliable effects of sleep deprivation is the degradation of attention, especially vigilant attention.
- In one study, a single night without sleep was associated with fewer creative responses and greater difficulty letting go of unsuccessful strategies.
- Bedtime procrastination has been associated with lower overall self-control as well as poorer sleep habits and lower self-reported sleep duration.
- Up to 90% of individuals with Major Depressive Disorder experience insomnia. Those with insomnia, compared to those without, are twice as likely to develop depression. These rates have been shown to be 4 times greater in adolescents.
- Multiple studies to date suggest a shift toward a predominance of sympathetic (stress) modulation during both wake and night time periods in individuals with chronic insomnia, due to decreased parasympathetic (relaxation) activity that occurs during sleep.
- Both dietary weight loss and exercise have been shown to improve and even cure sleep apnea. Avoidance of sedating medications and abstinence from alcohol are encouraged in all patients with obstructive sleep apnea.
- Sleep restriction (1.5 h less than habitual sleep duration) in children for 1-week is associated with a significant increase in calorie intake per day as well as alterations to the hunger hormone, leptin.
- Among 8–12-year old children, shorter sleep durations are associated with heightened emotional responses, including sadness, anger, fear and disgust.
- Contrary to popular belief, adolescents require just as much sleep as they did when they were a few years younger with 9.25h of nightly sleep being considered optimal through the teen years.
- Demands from both the work domain and from the family domain can restrict the time available for sleep. Studies describe sleep as the “victim” that suffers due to time-based conflict between work and family roles.
- Sleep health is a multidimensional pattern of sleep-wakefulness, adapted to the individual, social, and environmental demands, that promotes physical and mental well-being.
- Disruptions during sleep due to sleep apnea can confer symptoms of daytime sleepiness, fatigue, and inability to sustain attention – these deficits are amplified under mundane conditions or while doing overlearned activities that require sustained attention, such as, for example, driving long distances.
- There is an epidemic of sleep disorders among police, firefighters, and emergency medical service providers. Efforts to improve sleep have the potential to vastly improve the safety, health, and performance of this vulnerable group, benefiting not only them but the public that they serve.
Find out more about sleep and health book
If you enjoyed these 37 fascinating facts about sleep, one from each of the chapters in Sleep and Health, and are really looking to study the deeper details on the subject, then please find out more about the book by visiting the publisher’s page at Academic Press, or by visiting the Amazon page. The purchase price is quite high, even for an academic book, although the level of knowledge and detail provided is probably a fair reward for the cost invested.
Find out more: Sleep Recovery Specialist course
Sleep is so integral to the goals of health and fitness professionals, both personally and for their clients, that we decided to create an online course targeted specifically to personal trainers, fitness instructors, strength coaches, sports specific trainers, and fitness professionals more broadly. This course has many, many more fascinating facts about sleep, health and exercise that makes it well worth completing! We invite you to find out more about our innovative online course, the Sleep Recovery Specialist.