Health

Ross Edgley On The Study of Sleep

Ross Edgley explains the study of sleep, and how you can reap the rewards of a better nights sleep, with an exclusive extract from his new book – Blueprint.

Ross Edgley: Blueprint

An exclusive extract.

From world-renowned adventurer and bestselling author of The Art of Resilience and The World’s Fittest Book, comes the ultimate blueprint to building a bulletproof body.

Acclaimed as a veteran of ultra-endurance events having swam around the mainland of Great Britain in just 157 days, Ross Edgley is an athlete who continually questions the boundaries of fitness and how it is perceived. But what many of you don't realise, is that behind his madness is a lot (and we mean a lot) of scientific research.

Intrigued? Scroll on to read an exclusive extract from Ross's latest book: Blueprint, where you can explore more about:

. . .

The Study Of Sleep

Sleep is (and always will be) absolutely crucial to our survival.

This is why the sleep pioneer Allen Rechtschaffen noted that, “If sleep does not serve an absolute vital function, then it is the biggest mistake the evolutionary process ever made.”[1] This is because it would have made no sense for our paleolithic ancestors to spend 6 – 8 hours per day sleeping and unconscious making them vulnerable to predators, unable to hunt, eat and survive… unless it was an essential biological function.

What Is That Function?

Modern researchers don’t know exactly and have said, “Sleep has been one of the mysteries of biology” with many theories proposed.[2] But what we do know (based on hundreds of studies on the pathophysiological consequences of sleep deprivation) is without it we become ill, psychotic and could even die.

This is no exaggeration either, in 1894, Russian scientist Marie de Manaceine started experimenting on puppies to test the effects of sleep deprivation.

Obviously (and thankfully) for ethical reasons professional researchers have never pushed the deprivation process beyond this point with human subjects. However, there are horror stories from years ago where sleep deprivation was used as a form of torture.

Discovering it particularly effective because it attacks the deep biological functions at the core of a person’s mental and physical health, it was later adopted and adapted by “witch hunters” in Europe and North America who called this form of torture “tortura insomniae” and used it to integrate thousands of innocent women for alleged sorcery. American historian Andrew Dickson wrote, “In this way, temporary delusion became chronic insanity, mild cases became violent, torture and death ensued.”[5]

Basically, your own brain will begin to betray you.

Of course, not as extreme but the same happens in extreme sports too, take the Ultra-Trail du Mont-Blanc (UTMB) for example[6]. Considered one of the most difficult foot races in the world, it’s approximately 171km long (106 miles) with a total elevation gain of around 10,040 meters (32,940 ft.) and crosses the Alps through France, Italy and Switzerland. While the best runners complete the loop in slightly more than 20 hours, most runners take 32 to 46 hours to reach the finish and will have to run through 2 nights in order to complete the race. As a result, hallucinations (perceptual distortions[7]) are common and can take many forms.

All things considered, scientists believe, “Sleep is an important component of homeostasis, vital for our survival and sleep disorders are associated with significant behavioural and health consequences.”[8] This is because as we blissfully drift into a slumber your:

  • Muscles, tendons and ligaments repair and regrow.

  • Neurotransmitters - the chemical signals in the brain - are replenished to keep us motivated, focused and functioning.

  • Rejuvenating hormones like the Human Growth Hormone begin to naturally peak.

This last point is particularly important since the human growth hormone is a peptide hormone that stimulates cell reproduction, cell regeneration, growth and recovery. Which is why for all the energy bars and recovery shakes in the world, if you suspect your overtraining and under recovered, one of the best things you can do head to bed.

We’ve known this as far back as 1968 when research published in the Journal of Clinical Investigation[9] stated, “Sleep results in a major peak of growth hormone secretion.”

It’s basic biological “house maintenance”[10] and athletes can’t function without it.

This is based on research conducted at Stanford University who analysed the impact sleeping 10 hours a night had on player’s performance after 5 to 7 weeks. Previously the players had only been sleeping 6 to 9 hours and what the sleep scientists found was their performance dramatically improved[11].

Not just a little either, “shooting accuracy improved, with free throw percentage increasing by 9% and 3-point field goal percentage increasing by 9.2%,” and, “subjects also reported improved overall ratings of physical and mental well-being during practices and games.” What they concluded was, “improvements in specific measures of basketball performance after sleep extension indicate that optimal sleep is likely beneficial in reaching peak athletic performance.”

So Where Does This Nocturnal Magic Come From?

According to research published in Frontiers of Systems Neuroscience[12] it’s closely related to our previously mentioned neurotransmitters. Neurotransmitters are the chemicals that work to transmit signals from a neuron to a target cell across a synapse within the body. Pretty much every function within the body is controlled (or impacted) by neurotransmitters, from emotional states to mental performance and our perception to fatigue and pain. They’re the brain’s little chemical messengers and if they’re not working correctly due to lack of sleep you can’t expect to run, swim, cycle or compete to the best of your ability.

In summary, never underestimate your need for sleep. If you do (based on hundreds of studies in sleep deprivation) you will be physically tired[13], mentally exhausted[14], not optimally recovering[15] and the decisions you make will be flawed and impaired[16].

So how do we get better at sleep during your Recovery Macrocycle? Put simply, you must learn to schedule it according to the natural laws that govern human biology.

6 Steps To Better Sleep:

  1. Morning Sun Sets Your 'Body Clock'.

  2. Learn To 'Digital Detox'.

  3. Cut Out Caffeine.

  4. Train To Sleep

  5. Find 65 Degrees Fahrenheit (18.3°C)

  6. Supplement Your Sleep

Morning Sun Sets Your 'Body Clock'.

Studies show that morning sunlight reinforces your natural circadian rhythm. This is because by exposing your eyes to this bright (natural) light early in the morning, you signal to your brain that bedtime is over, it’s time to suppress melatonin production and get up and attack the day. It also does this by increasing cortisol production since cortisol and melatonin operate indirectly to each other as research reveals, “These hormones can be considered to be stable markers of the circadian time structure and therefore useful tools to validate rhythms' synchronisation of human subjects.”[1]

Therefore, understand the best thing you can do to start (and therefore end) your day is set your “biological clock” by going for a morning run, swim or cycle and exposing your eyes to bright, natural sunlight like mother nature intended for your hypothalamus.

Learn To 'Digital Detox'.

Closely related to your morning (sunrise) rituals should be a conscious effort to manage and monitor the amount of light you’re pumping into your eyes from smartphones, computers and other electronic devices in the evening. This is because studies show, “Modern light exposure patterns contribute to late sleep schedules and may disrupt sleep and circadian clocks”[2] since the blue light that’s emitted from these screens can delay the release of sleep-inducing melatonin, increase alertness, and reset the body’s internal clock (or circadian rhythm) to a later schedule.

For all these reasons try imposing a daily “digital detox” on your evenings by abstaining from smartphones and computers and basically getting too up close to anything with a screen from 7pm onwards as you prep the brain (and therefore body) for bed.

Cut Out Caffeine

As discussed caffeine is a stimulant so it’s no surprise it can badly impact on our sleep if too much is consumed at the wrong time of day.[3] This is why research reveals there is a strong association between daily intake of caffeine and reduced sleep quality and quantity[4]since caffeine consumption by day causes a reduction in 6-sulfatoxymelatonin (the main metabolite of melatonin) which interferes with our natural sleep-wake cycle (circadian rhythm).[5]

Now worth noting is the effects of caffeine on sleep vary from person to person since research reveals individuals respond differently based on a variety of factors, including age, sensitivity levels, regular coffee and caffeine intake, time of consumption and genetic variability[6]. But with this said, studies show even if taken 6 hours before bedtime, a moderate dose of caffeine (100mg which is about one home-brewed 8 oz. cup of coffee) can have disruptive effects on sleep[7]. Which is why I would advise to err on the side of caution and avoid coffee, tea and/or energy drinks at least 6 hours before getting tucked up into bed.

Train To Sleep

In 2007 a study published in the Journal of Neuroscience wrote, “The present results are in agreement with findings from other authors and suggest that depletion of cerebral energy stores and accumulation of the sleep promoting substance adenosine after high intensity exercise may play a key role in homeostatic sleep regulation.”[8]

Or (put more simply) exercise can help you sleep by making you feel tired. This is because it’s believed exercise can lead to a build-up of adenosine which (as we discussed before) helps monitor fatigue within the body as it inhibits neural activity, causes drowsiness, and essentially tells our body to rest, recovery and rebuild our energy reserves.

Also, studies show it doesn’t have to be a savage, superhuman session to induce sleep either. Research from The International Journal of Behavioural Nutrition and Physical Activity showed, “Moderate intensity exercise programs, with a frequency of three times per week and a duration of 12 weeks showed the highest number of significant improvements in different sleep outcomes.”[9] Whilst other studies show the type of exercise doesn’t matter[10] since everything from strength training to yoga was shown to have sleep enhancing benefits.[11]

Find 65 Degrees Fahrenheit (18.3°C)

A study published in the Journal of physiological anthropology found that, “The thermal environment (temperature of the room) is one of the most important factors that can affect human sleep.”[12] This has been supported by numerous studies over the year, but a large-scale analysis of 765,000 survey respondents and found that most people experience abnormal sleeping patterns during the hotter summer months when it may be more difficult to keep sleeping quarters at an optimal temperature[13].

So, what is the optimal temperature? Sleep scientists believe it’s between 60 and 67°F (15.6 and 19.4°C). This is because your body’s internal temperature changes during a 24-hour period due to your circadian rhythm. It begins to cool down when you go to bed and continues to drop until reaching its low point near daybreak (roughly 5am). But if the room temperature is too hot or cold, it may affect the drop in your body’s internal temperature and cause you to have disrupted sleep as your circadian rhythm malfunctions.

This doesn’t mean you have to take a thermometer to bed every night, but instead just be conscious of how hot or cold the room is and perhaps try setting your home’s thermostat to drop during your sleeping hours or open windows or turn on air conditioning or heat if the temperature rises or falls outside of the ideal sleeping range.

Supplement Your Sleep

As we’ve discussed melatonin is crucial to a good night’s sleep, which is why ever since scientists discovered it in 1958 there has been increasing scientific attention to the relationship of melatonin to diet. Cherries are one food known to be naturally high in melatonin which is why a study published in the European Journal of Nutrition[14] looked at whether drinking tart cherry juice would improve melatonin levels and sleep. Among the tart cherry-juice drinkers, melatonin levels and serotonin levels rose significantly which in turn improved the quality and quantity of their sleep.

What was even more interesting for me in my Recovery Mesocycle (in my fit yet fatigued state) was research published in the European Journal of Neurology found, “Melatonin supplementation may be an effective treatment for patients with chronic fatigue.”[15]

Finally, it’s important to mention that supplementing with melatonin is by no means a single solution or a ‘silver bullet’ sleep remedy. But studies show that once (and only once) you’re properly scheduling sleep, snoozing at 65°F (18.3°C), working in harmony with your circadian rhythm, exercising and cutting out caffeine (6 hours before bed) then supplementing your sleep with melatonin could be the proverbial cherry on top of your nighttime routine.

. . .

This is an exclusive extract from Blueprint: Build a Bulletproof Body for Extreme Adventure in 365-Days - Ross Edgley's third book .

Featuring a selection of tailored workouts, digestible sports science, and interspersed with a look into Ross' own adventures across the world, Blueprint is the ultimate guide to optimising your time and training to make the impossible possible.

. . .
References:

[1] Brahim Selmaoui and Yvan Touitou (2003) “Reproducibility of the circadian rhythms of serum cortisol and melatonin in healthy subjects: a study of three different 24-h cycles over six weeks” Life Sciences Volume 73, Issue 26, 14 November 2003, Pages 3339-3349

[2] Wright, Kenneth P Jr et al. “Entrainment of the human circadian clock to the natural light-dark cycle.” Current biology : CB vol. 23,16 (2013): 1554-8.

[3] Ninad S. Chaudhary, Michael A. Grandner, Nicholas J. Jackson, Subhajit Chakravorty (2016) “Caffeine consumption, insomnia, and sleep duration: Results from a nationally representative sample” Nutrition. 2016 Nov-Dec;32(11-12):1193-9.

[4] Roehrs T. et al. (2008) Caffeine: sleep and daytime sleepiness.Sleep Med Rev, 12:153-62.

[5] Shilo L, Sabbah H, Hadari R, et al. The effects of coffee consumption on sleep and melatonin secretion. Sleep Med. 2002;3(3):271–273

[6] Clark I. and Landolt H.P. (2016) Coffee, Caffeine, and Sleep. Sleep Med Rev, 31:70-78.

[7] Drake C; Roehrs T; Shambroom J; Roth T. Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. J Clin Sleep Med 2013;9(11):1195-1200.

[8] M. Dworak, P. Diel, S. Voss, W. Hollmann, H. K. Strüder (2007) "Intense exercise increases adenosine concentrations in rat brain: implications for a homeostatic sleep drive." Neuroscience. 2007 Dec 19; 150(4): 789–795. Published online 2007

[9] Vanderlinden, J., Boen, F. & van Uffelen, J.G.Z. Effects of physical activity programs on sleep outcomes in older adults: a systematic review. Int J Behav Nutr Phys Act 17, 11 (2020).

[10] Brupbacher, G., Gerger, H., Wechsler, M. et al. The effects of aerobic, resistance, and meditative movement exercise on sleep in individuals with depression: protocol for a systematic review and network meta-analysis. Syst Rev 8, 105 (2019).

[11] D'Aurea, Carolina & Poyares, Dalva & Passos, Giselle & Santana, Marcos & Youngstedt, Shawn & Lino de Souza, Altay & Bicudo, Juliana & Tufik, Sergio & De Mello, Marco. (2018). Effects of resistance exercise training and stretching on chronic insomnia. Brazilian Journal of Psychiatry. 41.

[12] Okamoto-Mizuno, Kazue, and Koh Mizuno. “Effects of thermal environment on sleep and circadian rhythm.” Journal of physiological anthropology vol. 31,1 14. 31 May. 2012

[13] Obradovich, Nick et al. “Nighttime temperature and human sleep loss in a changing climate.” Science advances vol. 3,5 e1601555. 26 May. 2017.

[14] Howatson, G., Bell, P.G., Tallent, J. et al. Effect of tart cherry juice (Prunus cerasus) on melatonin levels and enhanced sleep quality. Eur J Nutr 51, 909–916 (2012).

[15] R. O. van Heukelom, J. B. Prins, M. G. Smits, G. Bleijenberg (2006) "Influence of melatonin on fatigue severity in patients with chronic fatigue syndrome and late melatonin secretion." Eur J Neurol. 2006 Jan; 13(1): 55–60.

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[1] Rechtschaffen (1998) Current perspectives on the function of sleep. Perspect Biol Med 41(3): 359 (32).

[2] Samson Z Assefa, Montserrat Diaz-Abad, Emerson M Wickwire, Steven M Scharf. The Functions of Sleep. AIMS Neuroscience, 2015, 2(3): 155-171.

[3] Kovalzon VM (2009) “Some notes on the biography of Maria Manasseina” Journal of the History of the Neurosciences, 2009 Jul;18(3):312-9

[4] Bentivoglio M and Grassi-Zucconi G (1997) “The pioneering experimental studies on sleep deprivation” Sleep. 1997 Jul;20(7):570-6.

[5] Louis Jolyon West, Herbert H. Janszen, Boyd K. Lester and Floyd S. Cornelisoon Jr (1962) “THE PSYCHOSIS OF SLEEP DEPRIVATION” Volume 96, Issue 1 Some Biological Aspects of Schizopherenic Behaviour January 1962 Pages 66-70.

[6] Rémy Hurdiel, Thierry Pezé, Johanna Daugherty, Julien Girard, Mathias Poussel, Laurence Poletti, Patrick Basset & Denis Theunynck (2015) Combined effects of sleep deprivation and strenuous exercise on cognitive performances during The North Face® Ultra Trail du Mont Blanc® (UTMB®), Journal of Sports Sciences, 33:7, 670-674.

[7] Babkoff, H., Sing, H. C., Thorne, D. R., Genser, S. G., & Hegge, F. W. (1989). Perceptual Distortions and Hallucinations Reported during the Course of Sleep Deprivation. Perceptual and Motor Skills, 68(3), 787–798.

[8] Chrousos G, Vgontzas AN and Kritikou I (2016) “HPA Axis and Sleep” [Updated 2016 Jan 18]. In: Feingold KR, Anawalt B, Boyce A, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK279071/

[9] Takahashi Y, Kipnis DM and Daughaday WH (1968) “Growth hormone secretion during sleep.” Journal of Clinical Investigation, 1968 Sep;47(9):2079-90.

[10] Serge Brand, Johannes Beck, Markus Gerber, Martin Hatzinger & Edith Holsboer-Trachsler (2010) Evidence of favorable sleep-EEG patterns in adolescent male vigorous football players compared to controls, The World Journal of Biological Psychiatry, 11:2-2, 465-475.

[11] Mah, C. D., Mah, K. E., Kezirian, E. J., & Dement, W. C. (2011). The effects of sleep extension on the athletic performance of collegiate basketball players. Sleep, 34(7), 943–950. doi:10.5665/SLEEP.1132.

[12] Susanne Diekelmann (2014) "Sleep for cognitive enhancement" Frontiers in Systems Neuroscience, 02 April 2014.

[13] June J. Pilcher and Allen I. Huffcutt (1996) "Effects of Sleep Deprivation on Performance: A Meta-Analysis" Sleep, volume 19 Issue 4 June 1996.

[14] K.A. Honn, J.M. Hinson, P. Whitney, H.P.A. Van Dongen (2019) “Cognitive flexibility: A distinct element of performance impairment due to sleep deprivation” Accident Analysis & Prevention Volume 126, May 2019, Pages 191-197.

[15] Alhola, P., & Polo-Kantola, P. (2007). Sleep deprivation: Impact on cognitive performance. Neuropsychiatric Disease and Treatment, 3(5), 553-567.

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