How Magnesium influences sleep quality

 

– mechanisms of sleep

– biochemistry of magnesium in sleep physiology

– analysis of magnesium levels in the body

– supplementation protocols

 

 

 

The body is fascinating. Sleeping takes NO effort on our part, but our organism does an incredible job of reorganising our physiology during sleep.

 

Anti-Oxidation. When we experience darkness our body releases Melatonin. It is the strongest anti-oxidant of the human body. It neutralizes free radicals that accumulated during waking times and thereby reduces the risk of illness and reduces aging processes.

 

 

Defragmentation. At some points during sleep something really freaky happens. Our brain completely shuts down the connection to our muscular system for up to 6 periods of around 20-30 minutes each. Our muscle are completely paralysed. No muscle tension at all. Only our eyes move very fast from left to right. This stage of sleep is called the Rapid Eye Movement (REM) Stage of sleep. This is when we dream. Dreams are a series of simulations run by our consciousness to test some of our trusted propositions against “reality”. It would be terrible if we still had connection to our muscular system at that time. That would be a very heavy case of sleep walking. These simulations are important to keep us sane. There is strong association between loss of REM sleep and mental illness. REM sleep sorts out our conscious. Like cleaning a room. Every morning you wake up to a clean room if the REM Stage did its job right.

 

Tissue Regeneration. During sleep Human Growth Hormone and Testosterone get secreted in high amounts. These are very expensive and powerful hormones if you were to buy them on the black market. Pro athletes buy this stuff on the black market to recover faster from tissue damage caused by hard training or injury. You get them for free if you sleep right. And the hormones are very sensitive to sleep deprivation. It has been shown that only 5 nights of reduced sleep can drop a males testosterone levels by the same amount as if he were aged 10 years older. 

 

 

Memory Formation. Ever felt like taking a nap after some hours of studying? Better trust that instinct because memory formation is highly improved after sleeping. Mathematical information is better retained after sleeping and the same thing happens with motor learning. You will be better at a motor task after you slept a night.

 

 

The reality is that most peoples sleep is shit. About 60% of all athletes I have ever worked with have sub-optimal sleep. They will do anything to sleep better. But whatever they do, they will still wake up at night or just feel run over when they wake in the morning, even after they slept through.

 

 

Reasons for bad sleep quality range from environmental factors, emotional distress, toxicity, hormonal imbalances, radiation, to nutritional factors.

 

For this article let us focus on one of the micronutrients that is often out of balance when somebody experiences bad sleep quality. 

 

So lets get to it.

 

 

Waking up at night, Not being able to fall asleep, or feeling run over in the morning are all signs of bad sleep quality. Click To Tweet 

 

 

There are several reasons for magnesium deficiency :

1) Magnesium content of todays soil is far less than as recent as 30 years ago

2) Magnesium content of plants is far less than as recent as 30 years ago

3) Alcohol consumptions depletes magnesium stores in the body

4) Sympathetic Activation (Stressful work, Training) depletes magnesium stores in the body

 

Aside from possible major sleep disturbances magnesium deficient people also may show reduced speed&power, sugar cravings and reduced energy. 

 

 

 

Magnesium is a natural inhibitory modulator of N-methyl-D-aspartic acid (NMDA) receptors. NMDA receptors are excitatory receptors. That means they release dopamine when activated and thereby activity of the brain will increase. Think of the NMDA receptors as our brains “ON” switch. Activating NMDA receptors will wake us up. For example Ritalin and Adderall for ADHD treatment activate the NDMA channels. NMDA receptors are also activated by cholesterol from animal fats and from glutamate in foods like chips. This is not what we want when we want to sleep. So when sleeping we want the NMDA receptors to not be activated. Magnesium helps us accomplish that. Magnesium downregulates the excitatory threshold of NMDA receptors. That means the “ON” switch is now harder to push down. You know how you sometimes wake up from mini noises in your room? And sometimes you sleep like a baby when your bookshelf collapses? This has a lot to do with the excitatory threshold of your NMDA receptors at that time.

Alcohol inhibits NMDA as well. Thats why some athletes resort to alcohol to be better able to fall asleep. BUT acute alcohol consumption also reduces REM sleep, which reduces the sleeps ability to improve defragmentation and learning. And in chronic Alcohol consumption our body increases the amount of NMDA receptors over time to counter the effect of the alcohol. Eventually alcohol loses its sleep inducing effect and that is also why acute reduction of alcohol consumption leads to restlessness. Because then you have so many excitatory NMDA receptors without them being blocked. So better use magnesium than alcohol. 

 

 

In principle the biochemistry of alertness is governed by two chemical compounds in our brain. Glutamate is the principal excitatory neurotransmitter and wakes us up. Glutamate is the chemical key for the NMDA receptor. Like stated earlier NMDA is the “ON” switch in our brain. On the other hand we have GABA as the most important inhibitory neurotransmitter. GABA connects to the GABA receptor group, which is the most important inhibitory receptor group in our brain. GABA reduces alertness, which would allow us to sleep. Most heavy sleep medicines like Benzodiazepines (e.g. Valium) and Barbiturates (e.g. Thiopental) act directly on the GABA receptors. Magnesium reduces the excitatory threshold of GABA receptors. It makes it easier for GABA to trigger its receptors and thereby inhibiting overall brain activity. This makes us sleepy. So Magnesium reduces the effect of excitatory NMDA receptors, while at the same time increasing the effect of inhibitory GABA receptors.

 

 

The third pathway of how Magnesium improves our sleep is that it is involved in Melatonin synthesis via the Serotonin-N-acetyltransferase (AANAT) enzyme. This enzyme makes melatonin from serotonin in our pineal gland. The primary trigger for activity of AANAT is darkness. When our retina is exposed to complete darkness AANAT activity is increased 100-fold and makes a lot of melatonin. Some investigations found Magnesium to be involved in AANAT activity with reduced magnesium levels associated with reduced AANAT activity. 

Its important to note that especially the light wavelengths of 460 to 480 nanometers (blue light) are responsible for suppressing AANAT activity and thereby reducing melatonin levels. Our ancestors had only a fire after the sun went down. Fire emits a red/yellow light, which does not include blue light wavelengths. The same holds true for the old fashioned light bulbs. So melatonin was still being produced while sitting by a fire or a yellowish light bulb. Sleeping in was easier with that. Only the newer energy-saving bright light bulbs emit blue light. Same with televisions and computer screens. They emit a lot of blue light, which suppresses melatonin levels and makes it harder to fall asleep. It could be speculated that this higher confrontation with „blue“ light in recent times could have something to do with the mysterious calcification of the pineal gland. Maybe the calcium layer is the „oakley shade“ of the pineal gland. But lets stick to the evidence for now.

It is not quite clear yet how melatonin makes us sleepy. The current scientific hypothesis is that it decreases core body temperature, while at the same time acting on the GABA receptors and thereby reducing brain activity.

 

 

The base compound our body uses to synthesise Serotonin is tryptophan. It is found mostly in white meats. My first impactful encounter with tryptophan was in the fall of 2008 when I went to visit my college roommates family in northern Wisconsin and we had the most brutal turkey coma. After eating a lot of thanksgiving turkey me and the whole family just feel asleep for several ours in the living room while the Minnesota Vikings played Thursday night football . Magnesium plays a key role in activating the TPH enzyme responsible for making serotonin out of tryptophan. 

 

 

– If you want to sleep avoid things that activate the NMDA receptors via glutamate (e.g. glutamate in food, cholesterol (high animal-fat foods)).

– Consider a craving for high-fat foods (cholesterol) or highly processed foods (glutamate) as your bodies attempt to stay awake via activation of NMDA receptors. So instead of indulging into chips or fries give your body what it really needs….Rest.

– Magnesium down regulates NMDA activity, and upregulates GABA activity. It doesn’t trigger directly. It just decreases/increases their respective sensitivity. 

– Alcohol and Benzodiazepines (e.g. Valium) have a similar but more powerful mechanism of action on the NMDA and GABA receptors as magnesium has. 

– Chronic use of Alcohol or Benzodiazepines leads to your body increasing the amount of NMDA receptors, and decreasing the amount GABA receptors. That is why you build a tolerance to both alcohol and benzodiazepines until you have to increase the dose to achieve the same effect. This also leads in part to restlessness associated with withdrawal.

– Darkness increases AANAT activity in the pineal gland and thereby increasing melatonin levels.

– Melatonin increases sleepiness by reducing core body temperature and acting on GABA receptors

– Therefore darkness is vital for proper sleep quality. Avoid blue-light emitting light sources like screens and bright light bulbs after sunset. The melatonin effect on core temperature also helps us understand why a room temperature of around 16-18°C seems optimal for sleep quality.

– Never eat too much turkey when you want to stay awake for the Thanksgiving football game

 

 

 

See how Magnesium doesn’t influence the levels of Tryptophan, Serotonin, Melatonin or GABA directly. It just modulates the affinity of the NMDA and GABA receptors and increases conversion from tryptophan to serotonin to melatonin.

 

 

 

 

Magnesium diagnosis is very elusive as 99% of all of bodies magnesium is found intracellularly. Blood serum levels are very stable, while intracellular levels and tissue levels fluctuate a lot. Serum diagnosis is easy, but inconclusive. You will have stable and normal serum magnesium levels if you are not on the edge of death. Intracellular (red blood cells, oral epithelial cells) and tissue (brain tissue) analysis would be more conclusive as it varies more but its close to impossible to measure it accurately. There are some promising approaches to look at intracellular magnesium from epithelial cells of the mouth, but these are not broadly available yet.

At the same time magnesium is very cheap and cannot be overdosed. That is why I recommend to just take it and see if it improves sleep. Sounds unscientific but if you really think all aspects through this is the most scientific and evidence-based approach.

 

 

 

It can take up to three months of (heavy) magnesium supplementation to improve sleep in highly deficient people. With some of the athletes I work with we attack the issue on several fronts:

 

1) We use oral magnesium supplementation via Magnesium-Threonate. This is the form of magnesium which is most readily absorbed by the brain. We have been using the “Neuromag” product by Designs for Health for that purpose. We use between 2-4g of Magnesium-Threonate per day, which equals to around 150 to 300mg of elementary magnesium per day. Magnesium-Glycinate is another very good form of magnesium for musculoskeletal symptoms of magnesium deficiency, but is not well absorbed across the blood-brain barrier, that is why I prefer Magnesium-Threonate for sleep disturbances.

 

 

2) Several times per week we use Epsom Salt baths. Epsom salt is Magnesium-Sulfate. This stuff is very cheap and you can buy it in big buckets of 10kg. Just pour around a kilo of it into the bathtub and take a 45 minute bath. Magnesium in this form is very well absorbed through the skin.

 

3) We spike massage oil with magnesium. We discuss with the physios the possibility of mixing magnesium into the massage oils to further improve magnesium exposure. Sometimes we are able to mix the massage oil with magnesium powder, and sometimes we just have the physios finish off every massage with magnesium oil. As most athletes get massages 4-5 times per week that is great way of increasing magnesium. BUUUT beware of ITCHING! A lot of magnesium oils have the tendency to itch A LOT. I haven’t quite figured out what makes it itch and what the hallmarks are of an oil that doesn’t. 

 

 

4) Another obvious way is to increase magnesium via natural foods. Dark leafy greens are usually very high in magnesium. As are nuts and seeds and avocado. Also dark bitter chocolate is good for the sweet tooth. Sodas and milk reduce magnesium absorption for their high content of phosphoric acid. These are not recommended.

 

 

 

 

 

 

 

1. Peuhkuri K, Sihvola N, Korpela R. Dietary factors and fluctuating levels of melatonin. Food Nutr Res. 2012;56(0):1–9.
2. Zeng Y, Yang J, Du J, Pu X, Yang X, Yang S, et al. Strategies of Functional Foods Promote Sleep in Human Being. Curr Signal Transduct Ther. 2015;9(3):148–55.
3. Uygun DS, Ye Z, Zecharia AY, Harding EC, Yu X, Yustos R, et al. Bottom-Up versus Top-Down Induction of Sleep by Zolpidem Acting on Histaminergic  and Neocortex Neurons. J Neurosci. 2016 Nov;36(44):11171–84.
4. Fawcett WJ, Haxby EJ, Male DA. Magnesium: physiology and pharmacology. Br J Anaesth Br J Anaesth. 1999;83(83):302–20.
5. Serefko A, Szopa A, Poleszak E. Magnesium and depression. Magnes Res. 2016 Mar;29(3):112–9.
6. Rondanelli M, Opizzi A, Monteferrario F, Antoniello N, Manni R, Klersy C. The effect of melatonin, magnesium, and zinc on primary insomnia in long-term care facility residents in Italy: a double-blind, placebo-controlled clinical trial. J Am Geriatr Soc. 2011 Jan;59(1):82–90.
7. Chollet D, Franken P, Raffin Y, Henrotte JG, Widmer J, Malafosse A, et al. Magnesium involvement in sleep: genetic and nutritional models. Behav Genet. 2001 Sep;31(5):413–25.
8. Boomsma D. The magic of magnesium. Int J Pharm Compd. 2008;12(4):306–9.
9. Durlach J, Pages N, Bac P, Bara M, Guiet-Bara A. Biorhythms and possible central regulation of magnesium status, phototherapy, darkness therapy and chronopathological forms of magnesium depletion. Magnes Res. 2002 Mar;15(1–2):49–66.
10. Wienecke E, Nolden C. [Long-term HRV analysis shows stress reduction by magnesium intake]. MMW Fortschr Med. 2016 Dec;158(Suppl 6):12–6.
11. de Baaij JHF, Hoenderop JGJ, Bindels RJM. Magnesium in man: implications for health and disease. Physiol Rev. 2015 Jan;95(1):1–46.
12. Nielsen FH, Johnson LK, Zeng H. Magnesium supplementation improves indicators of low magnesium status and inflammatory stress in adults older than 51 years with poor quality sleep. Magnes Res. 2010 Dec;23(4):158–68.
13. Santos DA, Matias CN, Monteiro CP, Silva AM, Rocha PM, Minderico CS, et al. Magnesium intake is associated with strength performance in elite basketball, handball and volleyball players. Magnes Res. 2011;24(4):215–9.
14. Kass LS, Skinner P, Poeira F. A pilot study on the effects of magnesium supplementation with high and low habitual dietary magnesium intake on resting and recovery from aerobic and resistance exercise and systolic blood pressure. J Sport Sci Med. 2013;12(1):144–50.
15. Brilla LR, Haley TF. Effect of magnesium supplementation on strength training in humans. J Am Coll Nutr. 1992;11(3):326–9.
16. Cinar V, Mogulkoc R, Baltaci AK, Nizamlioglu M. Effect of Magnesium Supplementation on Some Plasma Elements in Athletes at Rest and Exhaustion. Biol Trace Elem Res. 2007;119(2):97–102.
17. Abbasi B, Kimiagar M, Sadeghniiat K, Shirazi MM, Hedayati M, Rashidkhani B. The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial. J Res Med Sci. 2012;17(12):1161–9.
18. Cinar V, Nizamlioglu M, Mogulkoc R, Baltaci AK. Effects of magnesium supplementation on blood parameters of athletes at rest and after exercise. Biol Trace Elem Res. 2007;115(3):205–12.
19. Basso LE, Ubbink JB, Delport R. Erythrocyte magnesium concentration as an index of magnesium status: a perspective from a magnesium supplementation study. Clin Chim Acta. 2000;291(1):1–8.
20. Newhouse I, Finstad E. The Effects of Magnesium Supplementation on Exercise Performance. Clin J Sport Med. 2000;10(3):195–200.
21. Jahnen-Dechent W, Ketteler M. Magnesium basics. CKJ Clin Kidney J. 2012;5(SUPPL. 1).
22. Golf SW, Bender S, Grüttner J. On the Significance of Magnesium in Extreme Physical Stress. Cardiovasc Drugs Ther. 1998;12(2):197–202.
23. Cinar V, Mogulkoc R, Baltaci AK, Polat Y. Adrenocorticotropic Hormone and Cortisol Levels in Athletes and Sedentary Subjects at Rest and Exhaustion: Effects of Magnesium Supplementation. Biol Trace Elem Res. 2008;121(3):215–20.
24. Santos DA, Matias CN, Monteiro CP, Silva AM, Rocha PM, Minderico CS, et al. Magnesium intake is associated with strength performance in elite basketball, handball and volleyball players. Magnes Res. 2011;24(4):215–9.
25. Ismail Y, Ismail AA, Ismail AAA. The underestimated problem of using serum magnesium measurements to exclude magnesium deficiency in adults; A health warning is needed for ‘normal’ results. Clin Chem Lab Med. 2010;48(3):323–7.
26. Rude RK. Magnesium metabolism and deficiency. Endocrinol Metab Clin North Am. 1993;22(2):377–95.
27. Terblanche S, Noakes TD, Dennis SC, Marais D, Eckert M. Failure of magnesium supplementation to influence marathon running performance or recovery in magnesium-replete subjects. Int J Sport Nutr. 1992;2(2):154–64.
28. Cinar V, Polat Y, Baltaci A, Mogulkoc R. Effects of Magnesium Supplementation on Testosterone Levels of Athletes and Sedentary Subjects at Rest and after Exhaustion. Biol Trace Elem Res. 2011;140(1):18–23.
29. Clarkson PM, Haymes EM. Exercise and mineral status of athletes: calcium, magnesium, phosphorus, and iron. Med Sci Sports Exerc. 1995;27(6):831–43.
30. Escames G, Acuna-Castroviejo D, Leon J, Vives F. Melatonin interaction with magnesium and zinc in the response of the striatum to  sensorimotor cortical stimulation in the rat. J Pineal Res. 1998 Mar;24(2):123–9.
31. Claustrat B, Brun J, Chazot G. The basic physiology and pathophysiology of melatonin. Sleep Med Rev. 2005 Feb;9(1):11–24.
32. Treatment E. HHS Public Access. 2015;4(1):1–10.
33. Dawson D, Encel N. Melatonin and sleep in humans. J Pineal Res. 1993 Aug;15(1):1–12.
34. Srinivasan V, Pandi-Perumal SR, Trahkt I, Spence DW, Poeggeler B, Hardeland R, et al. Melatonin and melatonergic drugs on sleep: possible mechanisms of action. Int J Neurosci. 2009;119(6):821–46.
35. Dubocovich ML. Melatonin receptors: role on sleep and circadian rhythm regulation. Sleep Med. 2007 Dec;8 Suppl 3:34–42.
36. Sack RL, Hughes RJ, Edgar DM, Lewy AJ. Sleep-promoting effects of melatonin: at what dose, in whom, under what conditions, and by what mechanisms? Sleep. 1997;20(10):908–15.
37. Peuhkuri K, Sihvola N, Korpela R. Dietary factors and fluctuating levels of melatonin. Food Nutr Res. 2012;56(0):1–9.
38. Borges L da S, Dermargos A, Junior EP da S, Weimann E, Lambertucci RH, Hatanaka E. Melatonin decreases muscular oxidative stress and inflammation induced by strenuous exercise and stimulates growth factor synthesis. J Pineal Res. 2015;58(2):166–72.
39. Zeng Y, Yang J, Du J, Pu X, Yang X, Yang S, et al. Strategies of Functional Foods Promote Sleep in Human Being. Curr Signal Transduct Ther. 2015;9(3):148–55.
40. Fullagar HHK, Duffield R, Skorski S, Coutts AJ, Julian R, Meyer T. Sleep and recovery in team sport: Current sleep-related issues facing professional team-sport athletes. Vol. 10, International Journal of Sports Physiology and Performance. 2015.
41. Dennis J, Dawson B, Heasman J, Rogalski B, Robey E. Sleep patterns and injury occurrence in elite Australian footballers. J Sci Med Sport. 2016;19(2).
42. Samuels C, James L, Lawson D, Meeuwisse W. The Athlete Sleep Screening Questionnaire: a new tool for assessing and managing sleep in elite athletes. Br J Sport Med . 2015 May 22;
43. Fullagar HK, Skorski S, Duffield R, Hammes D, Coutts A, Meyer T. Sleep and Athletic Performance: The Effects of Sleep Loss on Exercise Performance, and Physiological and Cognitive Responses to Exercise. Sport Med. 2015;45(2):161–86.
44. Journal I, Sports OF, Universit HF, Universit SS, Universit TM. Sleep , Travel and Recovery Responses of National Footballers During and Following Long-Haul International Air Travel. 2015;(MAY).
45. Ghaly M, Teplitz D. The biologic effects of grounding the human body during sleep as measured by cortisol levels and subjective reporting of sleep, pain, and stress. J Altern Complement Med. 2004 Oct;10(5):767–76.
46. Roehrs T, Burduvali E, Bonahoom A, Drake C, Roth T. Ethanol and sleep loss: a ‘dose’ comparison of impairing effects. Sleep. 2003;26(8):981–5.
47. TAKEUCHI L, DAVIS GM, PLYLEY M, GOODE R, SHEPHARD ROYJ. Sleep deprivation, chronic exercise and muscular performance. Ergonomics. 1985 Mar 1;28(3):591–601.
48. Fallon KE. Blood tests in tired elite athletes: expectations of athletes, coaches and sport science/sports medicine staff. Br J Sports Med. 2007;41(1):41–4.
49. Kishi T, Sunagawa K. Experimental ‘jet lag’ causes sympathoexcitation via oxidative stress through AT1 receptor in the brainstem. Conf Proc  . Annu Int Conf IEEE Eng Med Biol Soc IEEE Eng Med Biol Soc Annu Conf. 2011;2011:1969–72.
50. Samuels C. Sleep, Recovery, and Performance: The New Frontier in High-Performance Athletics. Neurol Clin. 2008;26(1):169–80.
51. Van Cauter E, Plat L. Physiology of growth hormone secretion during sleep. J Pediatr. 2015 May 14;128(5):S32–7.
52. Waterhouse J, Atkinson G, Edwards B, Reilly T. The role of a short post-lunch nap in improving cognitive, motor, and sprint performance in participants with partial sleep deprivation. J Sports Sci. 2007 Dec;25(14):1557–66.
53. Smith RS, Guilleminault C, Efron B. Circadian rhythms and enhanced athletic performance in the National Football League. Vol. 20, Sleep. 1997. p. 362–5.
54. REILLY T, PIERCY M. The effect of partial sleep deprivation on weight-lifting performance. Ergonomics. 1994 Jan 1;37(1):107–15.
55. Sassin JF, Parker DC, Mace JW, Gotlin RW, Johnson LC, Rossman LG. Human growth hormone release: relation to slow-wave sleep and sleep-walking cycles. Science. 1969 Aug;165(3892):513–5.
56. Blumert PA, Crum AJ, Ernsting M, Volek JS, Hollander DB, Haff EE, et al. The acute effects of twenty-four hours of sleep loss on the performance of national-caliber male collegiate weightlifters. J strength Cond Res / Natl Strength Cond  Assoc. 2007 Nov;21(4):1146–54.
57. Souissi N, Sesboüé B, Gauthier A, Larue J, Davenne D. Effects of one night’s sleep deprivation on anaerobic performance the following day. Eur J Appl Physiol. 2003;89(3–4):359–66.
58. Bulbulian R, Heaney JH, Leake CN, Sucec AA, Sjoholm NT. The effect of sleep deprivation and exercise load on isokinetic leg strength and  endurance. Eur J Appl Physiol Occup Physiol. 1996;73(3–4):273–7.
59. Reilly T, Edwards B. Altered sleep-wake cycles and physical performance in athletes. Physiol Behav. 2007;90(2–3):274–84.
60. Basta M, Chrousos GP, Vela-Bueno A, Vgontzas AN. Chronic Insomnia and the Stress System. Sleep Med Clin. 2007;2(2):279–91.
61. Penev PD. Association between sleep and morning testosterone levels in older men. Sleep. 2007;30(4):427–32.
62. Reimund E. The free radical flux theory of sleep. Med Hypotheses. 1994 Oct;43(4):231–3.
63. Meier-Ewert HK, Ridker PM, Rifai N, Regan MM, Price NJ, Dinges DF, et al. Effect of sleep loss on C-Reactive protein, an inflammatory marker of cardiovascular risk. J Am Coll Cardiol. 2004;43(4):678–83.
64. Liu R, Liu X, Zee PC, Hou L, Zheng Z, Wei Y, et al. Association between sleep quality and C-reactive protein: Results from national health and nutrition examination survey, 2005-2008. PLoS One. 2014;9(3):2005–8.
65. Ogilvie RD, Hunt HT, Tyson PD, Lucescu ML, Jeakins DB. Lucid dreaming and alpha activity: a preliminary report. Percept Mot Skills. 1982 Dec;55(3 Pt 1):795–808.
66. Sokal K, Sokal P. Earthing the human body influences physiologic processes. J Altern Complement Med. 2011 Apr;17(4):301–8.
67. Walker M, Brakefield T, Seidman J, Morgan a, Hobson J, Stickgold R. Sleep and the time course of motor skill learning. Learn Mem. 2003;10(4):275–84.
68. Walker MP, Brakefield T, Morgan A, Hobson JA, Stickgold R. Practice with sleep makes perfect: Sleep-dependent motor skill learning. Neuron. 2002;35(1):205–11.
69. Milewski MD, Skaggs DL, Bishop GA, Pace JL, Ibrahim DA, Wren TAL, et al. Chronic Lack of Sleep is Associated With Increased Sports Injuries in Adolescent Athletes. J Pediatr Orthop. 2014;34(2).
70. Mah CD, Mah KE, Kezirian EJ, Dement WC. The effects of sleep extension on the athletic performance of collegiate basketball players. Sleep. 2011;34(7):943–50.
71. Leproult R, E VC. EFfect of 1 week of sleep restriction on testosterone levels in young healthy men. JAMA. 2011 Jun 1;305(21):2173–4.
72. Yoo S, Gujar N, Hu P, Jolesz FA, Walker MP. The human emotional brain without sleep — a prefrontal amygdala disconnect. :877–8.
73. Viola AU, Archer SN, James LM, Groeger JA, Lo JCY, Skene DJ, et al. Report PER3 Polymorphism Predicts Sleep Structure and Waking Performance. 2007;613–8.
74. Facer-Childs E, Brandstaetter R. The Impact of Circadian Phenotype and Time since Awakening on Diurnal Performance in Athletes. Curr Biol. 2015 Feb 16;25(4):518–22.
75. Thun E, Bjorvatn B, Flo E, Harris A, Pallesen S. Sleep, circadian rhythms, and athletic performance. Sleep Med Rev. 2015 Oct;23(0):1–9.
76. Abedelmalek S, Boussetta N, Chtourou H, Souissi N, Tabka Z. Effect of partial sleep deprivation and racial variation on short-term maximal performance. Biol Rhythm Res. 2014 Mar 17;45(5):699–708.
77. Chennaoui M, Arnal PJ, Sauvet F, Léger D. Sleep and exercise: A reciprocal issue? Sleep Med Rev. 2015 Apr;20(0):59–72.
78. Romyn G, Robey E, Dimmock JA, Halson SL, Peeling P. Sleep, anxiety and electronic device use by athletes in the training and competition environments. Eur J Sport Sci. 2015 Mar 20;1–8.
79. Rattray B, Argus C, Martin K, Northey J, Driller M. Is it time to turn our attention toward central mechanisms for post-exertional recovery strategies and performance? Front Physiol. 2015 Mar 17;6(March).
80. Ekstedt M, Söderström M, Åkerstedt T. Sleep physiology in recovery from burnout. Biol Psychol. 2009 Dec;82(3):267–73.
81. Reviews C, Lebedeva NN, Sulimov A V, Sulimova OP, Korotkovskaya TI, Gailus T. Investigation of Brain Potentials in Sleeping Humans Exposed to the Electromagnetic Field of Mobile Phones. (7):61–9.