The Effects of Sleep on Athletic Performance, Health and Body Composition.
Struggling with your weight? Feeling bummed out? Sluggish during workouts? Or just
sluggish in general? – Poor diet isn’t always to blame.
We all know someone who brags about how they only need a few hours sleep at night and they feel fine, but every time you look at them they’ve got an extra large coffee from starbucks.. A Trenta I believe its called (1.) Or you know someone who’s tired and sluggish all day but complain they can’t get to sleep at night because they are ‘wired’. You know someone who’s complaining about how they can’t lose weight despite the fact they eat healthy and exercise frequently.
Perhaps maybe one of the above is you.
//. Side note – In this article I use the word Athlete a lot but I don’t just mean a professional athlete I am also referring to the everyday person like You and Me who like to hit a new Personal Best in the gym or perhaps play 5 a side football or enjoy the odd marathon (I don’t personally.)
What happens during sleep?
Sleep is prompted by natural cycles of activity in the brain and consists of two basic states: rapid eye movement (REM) sleep and non-rapid eye movement (NREM) sleep (14.)
There are five stages that occur during sleep. Light sleep occurs during stages one and two, while stages three and four are deep sleep. It’s in stages three and four that GH secretion (Growth Hormone) occurs. Rapid-eye movement sleep, generally when dreaming occurs, takes place during stage five. A full cycle through these five stages occurs about every 90 minutes. If numerous full cycles of sleep aren’t attained most nights, GH secretion can diminish and influence physical and mental restoration. Before stage one occurs the body needs to be in a relaxed state for 5-20 minutes so avoiding any stimulating activity before bed is highly recommended (watching tv, mobile phones random push ups ect) (4,14, 19 & 20.)
5 Signs That You’re Sleep Patterns aren’t Working for You (2.)
Your mind is Foggy.
Everything we learn and experience gets integrated into our brains whilst we sleep, interference with this process causes, Reduced alertness and concentration, Confusion, Impaired Judgement and Forgetfulness.
Fresh Neurotransmitters and Hormone Production is regulated whilst we sleep Interference in this process causes, Possible increases of Depression, Low Mood, Impaired Regulation of Emotions and Heightened Stress
You’re getting Sick a lot.
When we don’t get enough sleep T-cells go down and inflammation goes up causing, Increased risk of Heart Disease and other inflammation-related diseases, Acute increased risk of getting sick and Increased Vulnerability to Viruses and Bacteria.
You’re Struggling with your Weight.
Poor Sleep has been linked to excess body fat and excess body fat can also reduce sleep quality as it can, Disrupts appetite regulation, Cause you to feel hungrier and Lead to Increased Calorie Intake.
Your Workouts feel too Hard
Our body uses sleep to refresh neurotransmitter levels and remove energy-draining metabolites therefore lack of sleep causes, Decreased Central Nervous System (CNS) Activity, Slower Reaction time, Low energy and endurance capacity, Depressed Mood and a reduced desire to exercise.
Why Can’t you Sleep,
One of the main reason people ‘can’t sleep’ or lose sleep is actually voluntary (4.) You probably don’t realise it but your voluntary delaying your bedtime. Think about it how many nights do you sit in bed watching Netflix (someone say Netflix and chill?.. No ok back to writing) browsing the internet or just sit on our phones browsing Facebook.
Another reason you’re not sleeping or waking up in the middle of the night could be due to Stress.
Stress and Sleep.
Yes, stress surrounds us daily we can’t avoid it, Let’s have a quick look at how stress affects our sleep (3.)
Every time you do something your body perceives as a challenge, it activates the sympathetic nervous system (SNS), which causes an accelerated heart rate, sweat, adrenaline increases, cortisol, etc.
In the short term, this is all great and important like when we exercise, but the issue in today’s society is, it’s too widespread and frequent (stress and SNS activation) – It happens from the first minute we wake up to when we try and get to sleep,
Not by choice, of course, but as a product of the difficult situations and stresses we’re increasingly facing today.
Over-training,Chronic dieting, Malnourishment, Lack of sleep, Too much caffeine or sugar, Emotional trauma (e.g. unhappiness, fear, anxiety), Many infections and illnesses, Occupational troubles. There’s just a few. Other factors include your alarm clock & getting stuck behind Brake Light Betty who can’t seem to find her accelerator – If that’s you sorry but your burning my adrenals out.
Here’s what happens when our SNS is activated.
Your brain signals your adrenal glands to secrete the hormones cortisol & adrenaline. This happens because of our ancestors way back in day 1, when they faced a daily stressor it was literally a matter of life or death so their SNS was activated so they could fight (a T-Rex or something along those lines) or Run. Another example would be Malnutrition or Chronic dieting, Day 1 man when Malnutritioned meant food was scarce, modern day man still thinks it’s going to die when you decide to cut calories ( I talk more about this in The Benefits and Drawbacks of Calorie Counting) Remember your body does not care about your vanity or weight it cares for one thing, survival.
However modern day man still can not distinguish the difference between an alarm clock or a T-Rex’s Raw, causing adrenal overuse. The issue of adrenal “overuse” referred to as adrenal fatigue comes from numerous daily stressors that accumulate over time and burden the glands (see the list above.) Under too much demand especially chronic demand the adrenals crank out too much cortisol and then “burn out.”
Are you one of those people who wake up between 2-4 AM? One of the telltale signs of adrenal fatigue is the inability to stay asleep. Well the adrenal glands release adrenaline (which keep you alert and focused) instead of slowly releasing cortisol, this is why you wake up in the middle of the night. Cortisol levels normally escalate slowly whilst you sleep and peak in the morning. Since the adrenal cortex has been burnt out throughout the day/week/month it doesn’t have much ‘drive’ this is why adrenaline is released from the adrenal medulla waking you up in the middle of the night despite the fact you have that big meeting in the morning.
Do you ever feel sluggish upon waking up in the morning with the stubbornness to find coffee? Well similar to the above, adrenaline is the reason. Due to adrenal fatigue and lack of cortisol production when we need it most we end up with a cortisol flat line when it should be at it’s highest for the day.
So naturally you search ravenously for caffeine fix to squeeze that little bit extra out of your adrenals in order to wake up and get to work.
As discussed above stress impacts our ability to fall and stay asleep in a study evaluating the effects of stress hormones after 24hours of Sleep Deprivation (SD) in six healthy volunteers (all men, age 23-27 years). All were good sleepers, had no history of medical or neuropsychiatric diseases, and were not taking any kind of medication.
The study shows that mean serum concentrations of all stress hormones such as cortisol, epinephrine, and norepinephrine were significantly elevated in the morning after SD (6.)
Stress does not just affect our ability to fall asleep and wake up again, it affects much more from our, Immune system to our thyroid and sex hormone production. On top of that, you might experience symptoms of –
An inability to lose weight, Physical fatigue, Sugar cravings, Brain fog, Loss of sex drive, Depression and Irritability, In one study, researchers found that women who reported feeling stressed or depressed had slower metabolisms and burned an average of 104 fewer calories following a meal than those who felt more mellow (5.)
Sleep and the Effects on Health & Body Composition
Health effects and sleep
Getting less than 7.5 hours of sleep each night means that you’re at greater risk of heart attack, stroke, and sudden cardiac death than your pals who get plenty of snooze time. Also, with the weight gain that could come with minimal sleep, you’d likely see insulin resistance (IR), glucose intolerance, type 2 diabetes (4) and Cancer. A study involving 5,968 women in Maryland found that people who do regular physical activity are less likely to develop cancer. However they found that sleep appeared to play an important role in cancer risk. Those who slept less than seven hours nightly had a 47 percent higher risk of cancer than those who got more sleep among the physically active women (8.)
A 1999 study took Eleven healthy men in their 20s, The study only allowed 4 hours of sleep for six straight nights. The study assessed carbohydrate metabolism, thyrotropic function, activity of the hypothalamo-pituitary-adrenal axis, and sympathovagal balance after the 4 hours of sleep and compared the sleep-debt condition with measurements taken at the end of a sleep-recovery period when participants were allowed 12 h in bed per night for 6 nights.
Glucose tolerance and thyrotropin concentrations was lower in the sleep-debt condition than in the fully rested condition. Evening cortisol concentrations were raised and activity of the sympathetic nervous system was increased in the sleep-debt condition At the end of this study, the young men had the insulin sensitivity of a 70 year old pre-diabetic (ouch.)
The findings show that Sleep debt has a harmful impact on carbohydrate metabolism and endocrine function. The effects of lack of sleep are similar to those seen in normal ageing and, therefore, sleep debt may increase the severity of age-related chronic disorders.
Chronic sleep loss, whether behavioural or sleep disorder related, may represent a novel risk factor for weight gain, insulin resistance, and Type 2 diabetes. (7, 10)
Ok so we now know that sleep loss whether behavioural or a disorder can decrease our ability to metabolise carbohydrates and increase the chance of insulin resistance, but can lack of sleep affect our food choices, when and how much we eat?
Imagine you’ve had a sleepless night night and have a busy day ahead, are you going to make a healthy egg omelette or just opt for the toast and O.J (Orange juice) or pop to McD’s for a double sausage and egg Mcmuffin (Actually that does sound good). The point is you’re probably going to opt for the unhealthy fast option,and probably not just for breakfast all your food choices throughout the day will most probably be like this as well. Why?
Well a study to see whether lack of sleep could alter appetite regulation shows
The study took 12 healthy men and put them on 2 days of sleep restriction and 2 days of sleep extension under controlled conditions of caloric intake and physical activity and measured their Daytime profiles of plasma leptin and ghrelin levels and subjective ratings of hunger and appetite.
The results show that Sleep restriction was associated with average reductions in the hormone leptin (decrease, 18%), elevations in ghrelin (increase, 28%), and increased hunger (increased, 24%) and appetite (increase, 23%), especially for calorie-dense foods with high carbohydrate content (increase, 33% to 45%) (11.) The men reported higher overall hunger ratings, especially cravings for energy dense, processed foods like sweets, baked goods and bread. This is because low leptin and high ghrelin both stimulate hunger and appetite, Thus, scientists speculate that deregulation of appetite hormones could be another reason that sleep deprivation results in body fat gains.
A similar study compared brain activity in response to food when either sleep deprived or rested, participants were of a healthy weight and results showed that the participants MRI scan showed that brain activity was higher when showed higher calorie foods in the sleep deprived state than lower calorie foods, also participants reported a greater deal of hunger whilst sleep deprived (12, 13.)
On top of all that lack of sleep can also make our daily life function suffer as well, including moods, cognition, and memory. Going 24 hours without sleep is similar to performing with a blood alcohol level of 0.10%. Good luck navigating the road and/or the treadmill while “intoxicated” from minimal sleep.) (9)
The Hormone of Darkness – Melatonin
Melatonin is a natural hormone made by your body’s pineal gland located just above the middle of the brain. Melatonin levels vary in 24 hour cycles and plays a critical role in the regulation of the sleeping and waking cycle and other circadian rhythms (14,15,16,17,18).
The Pineal gland produce Melatonin in response to light and darkness. During the day Melatonin levels are very low or not present. This is due to the fact that light suppresses Melatonin production (14,15.) Melatonin levels rise as the sun goes down and darkness occurs. (This is why it is sometime referred to as the hormone of darkness.) As a result, melatonin levels in the blood rise sharply and you begin to feel less alert. Sleep becomes more inviting. Melatonin levels in the can blood stay elevated for about 12 hours, all through the night, before the light of a new day when they fall back to low daytime levels by about 9 am. Daytime levels of melatonin are barely detectable (16,17,18).
The production of Melatonin can be suppressed by artificial light from your T.V, Mobile Phones, Laptops and any other form of light, This is why you struggle to sleep when you have the tv on.
Melatonin is also found in foods, including tomatoes, walnuts, flaxseeds, tart cherries, almonds, raspberries, and milk (23.) Interestingly, studies have shown that milk that is collected at night can improve sleep and reduce anxiety more than anti-anxiety medication Called “night milk,” it contains ten times as much melatonin and 25 percent more tryptophan than milk collected from cows during the day (21 & 22) However I don’t think you can pick this up from your local Asda.
Sleep & Athletic Performance
As we now know that sleep is essential to avoid cardiac diseases, weight gain and to reset your adrenal glands – just to name a few, Sleep is also a very important factor for your training program as well.
How does Sleep affect your training program?
Sleep deprivation leads to poor performance through reduced motivation and reduced cognitive processes leading to poor attention and concentration and heightened levels of perceived exertion and pain perception (32). You can see how Sleep deprivation affects your performance. Common indicators of Sleep deprivation include reductions in reaction times, increases in unstable emotional states and exercise performance as well as increased risk of injury (19).
Sleep deprivation has been shown to reduce reaction times significantly. Even a single all-nighter can reduce reaction times by more than 50%, not to mention recovering takes several days. Studies have shown even a surprisingly low level of fatigue can impair reaction times as much, if not more, than being legally drunk (25 & 26.)
In the study from The effect of partial sleep deprivation on weight-lifting performance, After just 3 hours of sleep each day for 4 days performance showed signiﬁcant reductions. Reductions in Maximal Bench Press and in the Deadlift were shown. A reduction of 9 kg for the MBP & 30kg for the DL (33.)
The effects of sleep reduction have also been considered for both aerobic and anaerobic performances. Sleep deprivation over 2 consecutive nights resulted in slower sprint times (34). Similarly for endurance-based performances, 24 hours of reduced sleep resulted in decreased aerobic performance over a 30-minute period (35.)
A study from the University of California concluded that injury rates in youth athletes increased during games that followed a night of sleep fewer than 6 hours (27.) Another study looking at injury rates in high school athletes found that sleep hours was the strongest predictor of injuries, even more so than the hours of practice.(28) Interesting and this could be due to numerous reasons. As explained earlier fatigue affects reaction time, A tired athlete is slower to react to a potentially fatal tackle on the field, or a haymaker in the ring that could’ve been avoided if the athlete was fully rested. Secondly, fatigue affects the body’s immune system, making players more susceptible to illness. Thirdly, shorter sleep periods don’t provide the body with sufficient time to regenerate cells and repair from the abuse of workouts, games, and daily activities. Over time, game-earned injuries, health issues, and the inability to fully recover can wear on an athlete and contribute to more time spent on the bench or in rehab (25, 26 & 29.)
Recovery and Sleep
General recommendations suggest that 7–9 hours of sleep is adequate for psychological and physiological recovery (36). However it has been suggested that athletes require more to recover effectively. This is because the greater the frequency and duration of REM (Rapid Eye Movement) experienced during total sleep is suggested to enhance the recovery processes and lead to a more optimal wakefulness (37 & 19.)
During sleep, recovery is promoted largely through activity from growth hormones and androgen’s which are released within deep sleep (stages 3 and 4.) They are both essential for muscle repair, muscle building, bone growth and promoting fat oxidation (38). Sleep promotes the restoration of the immune and endocrine systems, recovery of the nervous system and the metabolic expenditure of the previous training day, whilst stimulating memory and learning potential for the subsequent training day (39.) Melatonin is also active during the recovery process working as an antioxidant activating other pro-inflammatory enzymes to neutralise oxidative radicals which harm cells and promote tissue inﬂammation (40).
A study on extended sleep time in athlete showed that performance can be increased compared to Habitual sleep. The study compared a 4-week baseline habitual sleep period to a 7-week sleep extension period involving at least 10 hours sleep each night, The results showed that basketball performance measures were enhanced , sprint times were faster (15.5 – 0.54 seconds versus 16.2 – 0.61), and shooting accuracy improved by 9% coupled with decreased reaction times, reported “sleepiness” and improved proﬁle of mood states (POMSs) (31).
A similar study took five healthy students on the Stanford University men’s and women’s swimming teams. During the first two weeks of the study, the students maintained their usual sleep-wake pattern (Habitual Sleep). The athletes then extended their sleep to 10 hours per day for six to seven weeks. Athletic performance was assessed after each regularly scheduled swim practice. After obtaining extra sleep results showed that athletes swam a 15-meter sprint 0.51 seconds faster, reacted 0.15 seconds quicker off the blocks, improved turn time by 0.10 seconds and increased kick strokes by 5.0 kicks (30)
Obviously In comparison to non athletes, athletes require a greater volume of sleep in order for sufﬁcient recovery to occur as a result of high volumes of training modalities (41).In light of this, the athlete should sleep for at least 7 hours minimum and more when training demands are high to ensure optimal recovery and stay on top of their game. To facilitate these adequate sleeping hours, routines must be reached where sleeping and waking times are consistent, stimulating the quality of sleep. Improving sleep quality reduces sleep latency and enhances transition through the sleep stages, promoting volume of REM sleep and therefore optimising recovery and wakefulness (19).
How do we choose sleep well It all starts with your choices. You have to ask yourself what is more important; do you want to burn fat, fully recover for your next workout produce as much GH as possible or watch your favourite late night TV show, check to see if anyones updated their FB status at 01:00am or just do a bit of online shopping?
Don’t get the wrong idea, I realise the demands of modern life. I know you are busy, work hard, exercise, and try to find time to do the things you enjoy. I know because i’m human too and sometimes stay up till stupid ‘o’clock playing on the Playstation, Watching Rick & Morty or checking to see if someone’s updated their status I also find i’m more creative at night as a matter of fact as I edit this it’s 4am.
However that being said you need to be aware that you have the choice and you can choose to be strategic with your choices to. When work and training demands are high (Normally throughout the week) turn the tv off a little earlier and get those extra hours of sleep in. Weekend yeah stay up a little later watch love island on catch up and have a lie in.
‘But I can’t sleep early I just don’t feel tired at night’ — I’ve got you covered.
To promote general sleep quality and quantity, it is important to ﬁrst adhere to strategies that will enhance the processes of falling asleep.These measures are simple and effective when performed routinely.
When preparing for sleep, a dark room is vital, within a cool environment and absence of noise (42). The use of eye masks and earplugs may prove beneﬁcial to further enhance the ability to fall asleep. As discussed earlier The release of Melatonin is subject to light and dark sensitivity, so its transmission is promoted within a dark environment which is important because of its sleep promoting effects and enhancing the speed at which sleep begins (20 & 32). It’s also strongly recommended to avoid the use of TV’s, Mobile phones and Laptops for a minimum of 1 hour before bed to avoid the suppression of Melatonin activation. This reduces the potential of disturbed sleep, most notably for the initial stage which is the lightest of the sleep stages, and therefore is at the greatest risk of disrupting the onset of sleep.
A further consideration when trying to speed up the onset of sleep is the temperature of the environment (your bedroom), The right temperature will inﬂuence the onset of sleep and the efﬁciency of the sleep stages. When attempting to sleep heat exposure leads to greater wakefulness and reduces time spent experiencing REM (42), Therefore it’s best to keep the environment at room temperature.
To avoid temperatures getting too hot throughout the night take consideration of the type of bedding you have and also your PJ’s our sleep is disturbed more by temperatures getting too hot more so they do for temperatures being too cold. This is due to the fact that our Core temperature decreases with the onset of sleep while the peripheral temperature increases with greater blood ﬂow to the skin , accelerating the onset of sleep and strongly associated with melatonin secretion (43,44,45 & 46.)
Ok so they were simple practices and habits that you can implement into your everyday life or at least throughout the week when you work/social & gym life is hectic so you can recover and perform properly. However being human who tends to overthink or get carried away with the latest Marvel Netflix series, I know it’s not always possible.
So how can we recover from poor sleep if our sleep is disturbed. Well let me introduce you to my favourite hobby.
The use of napping can be implemented to recover sleep debt, when athletes have had poor nighttime sleep duration and quality. A 30-minute nap between 13.00 and 13.30, after a night of just 4 hours sleep showed improvements in alertness and both mental and physical performance . Reported sleepiness reduced after napping and short-term memory improved, coupled with enhancements in reaction time and greater performance for 20 m sprints (47).
** The time of day in which napping occurs should be a major consideration It’s recommended to avoid naps in the late afternoon and evening because this will induce negative repercussions on nighttime sleep routine (47). I can personally vouch that it does cause repercussions when trying to sleep at night.
There are many factors that can affect our sleep patterns like stress and artificial lighting. Lack of sleep can cause us to gain weight through increased Ghrelin production and reduced leptin production making us crave anything sweet and fatty. you’d also increase the risks of insulin resistance (IR), glucose intolerance, type 2 diabetes Cancer and other cardiovascular diseases. Athletic performance is also affected through increased risk of injury, reduced reaction time as well as reduced speed and power performance. Periods of extended sleep has been shown to improve performance, due to greater recovery whilst sleeping. Sleeping in cool, Dark environments help production of Melatonin and REM helping get to sleep quicker and less chance of being disturbed whilst sleeping. Sleep debt can be recovered through napping during the day however later on in the afternoon isn’t recommended. To conclude – Get some sleep.
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