Better Sleep: How Better Sleep Helps With Fitness, Weight Loss, and More Benefits

Geschatte leestijd: 19 minutenGetting better sleep for more muscle mass, less body fat, and better athletic performance. Here you can read about the importance of sufficient sleep and why sleeping better can improve your athletic performance.

Table of Contents

• The importance of good sleep
• Rest and recovery
• Poor sleep affects several processes
• Poor sleep and its influence on weight and fat percentage
• Hunger and satiety
• Risk of obesity
• Variations in sleep duration undesirable
• Oxygen intake
• Fatigue
• Anabolic hormones during sleep
• Testosterone
• Growth hormone (HGH)
• Insulin-like growth factor (IGF-1)
• Cortisol during sleep
• Better sleep and the metabolic syndrome
• “Do not sleep less than 6 hours, not more than 10 hours”
• Metabolic syndrome
• Sleep, hormones, and overweight
• Poor sleep = 3 cm more on your waist
• No difference in diet
• “Poor sleep leads to more eating the next day”
• “Poor sleep leads to 385 kcal more eating”
• Short sleep, more appetite
• How much sleep deprivation?
• Not sleeping too long
• Later sleep is less healthy eating
• Circadian rhythm and eating behavior
• ‘Evening people eat less healthy’
• Difficult to steer towards better sleep
• Tip 1: Better sleep? Set goals
• Research: Goals for sleeping
• A goal gives you wings
• Tip 2: Better sleep? Make a to-do list
• To-do list for sleeping
• Faster asleep by writing things off your mind

The Importance of Good Sleep

Good sleep is very important for humans in general, but even more so when you are actively involved in fitness with muscle growth as a goal.

An active man or woman with developed muscles needs eight hours of sleep. This is because the muscles need rest to recover and grow. There are also processes in the body that are particularly active during sleep.

Processes that contribute to muscle growth and overall health.

There are many factors surrounding sleep to discuss, and we will cover as many as possible here. These include:

• The influence of sleep on hormones. Muscle-building (anabolic) hormones and muscle-breaking (catabolic) hormones, fat-burning hormones, as well as hormones that affect appetite.
• The effect on athletic performance
• The relationship between sleep and body weight, including the role in obesity and the risk of metabolic diseases such as diabetes.
• How to improve sleep quality. How do you, for example, ensure that you fall asleep faster?
• Where does the recommendation of 8 hours come from? And what happens if you sleep longer?

We have collected the articles we have written on these topics over the past years and compiled them into one comprehensive explanation.

Rest and Recovery

The recovery in your sleep works as follows:

At night, when you lie down to sleep, your heart rate and breathing decrease. Your whole body and even your brain relax.

Once you fall asleep, for the first fifteen minutes, you are in a very relaxed state, and your body barely moves. The next fifteen minutes, you enter a deeper sleep, after which you start dreaming. This can last for about an hour.

Then you return to light sleep, that relaxed state where the body hardly moves, and this process repeats until morning. It is during the deep sleep phase, which is between light sleep and dreaming, that your body repairs itself.

In fact, 5 to 6 hours of sleep is not enough to recover optimally. Research has shown that 8 hours and 15 minutes of sleep achieves the right amount of recovery for your body and mind, especially for the muscles.

Poor Sleep Affects Several Processes

Sleep is necessary for numerous processes. We are already aware of some disadvantages of poor sleep. Think of increased hunger and reduced satiety, a higher risk of obesity, poorer oxygen uptake, fewer anabolic hormones, more catabolic hormones, and quicker fatigue during activity.

Some time ago, I had a discussion with someone about the necessity as a personal trainer to inquire about the sleep habits of your client.

I didn’t really see the point. Sleeping better is an important factor when it comes to muscle mass and fat burning, and almost everyone has heard that eight hours of sleep is advisable for multiple reasons. However, I wondered if this information about your client is useful if you cannot then guide them to improve it. For example, if I look at myself, I know very well that I should sleep for eight hours, but in practice, it just never happens.

The day simply has too few hours (or I have too many activities).

Poor Sleep and Its Influence on Weight and Body Fat Percentage

How long you sleep can affect your body fat percentage and weight in various ways. In 2003, researchers from the University of Bristol looked at the average sleep duration of 30 Greek women aged 30-60 [1]. For every hour the women slept longer (limited to 8 hours), their body fat percentage decreased by an average of 2.8 percent.

Hunger and Satiety

One reason for this can (among other things) be found in the effect of sleep duration on your feeling of hunger. Researchers from Stanford University compared the habits of 1024 participants in the Wisconsin Sleep Cohort, a study on the effects of sleep problems [2]. They compared sleep habits with other variables such as BMI, leptin, and ghrelin.

Leptin and ghrelin play a role in your feeling of hunger. Leptin provides a feeling of satiety, while ghrelin increases hunger. The Stanford researchers found that when only five hours of sleep were obtained instead of eight, the leptin levels were 15.5% lower. The ghrelin levels were 14.9% higher. This means more hunger and less satiety. It is then not surprising that they found that people who slept less than eight hours (almost 3/4 of the participants) had a higher BMI (weight relative to height).

Risk of Obesity

In other studies, a connection has also been made between lack of sleep and the risk of overweight.

Such as the study by Sanjay Patel in 2006, who concluded from data from the Nurses’ Health Study that women who sleep five hours or less gain more weight than women who sleep between seven and eight hours per night (graph on the right) [3]. For this study, the women themselves reported how much they had slept, so there may be some inaccuracy here.

Undesirable Variations in Sleep Duration

Last year, Patel conducted research again on the relationship between sleep and overweight [4]. This time, however, the duration of sleep was determined using a wrist activity monitor, and variations in sleep duration and the number of naps during the day were also considered. Apart from the total duration of sleep, large differences in sleep duration and a greater number of naps during the day were found to contribute to overweight.

Thinking that you can make up for missed sleep during the week on the weekend is therefore not wise. On average, you may reach the right duration, but the lack of regularity then increases the risk of overweight.

Oxygen Uptake

What happens when you wake up well-trained endurance athletes in the middle of the night at three o’clock? Research by French researchers shows that oxygen uptake deteriorates when training the next day. Despite the fact that the heart rate is increased (a sign that the heart has to work harder to supply the body with oxygen) [5].

Fatigue

This reduced oxygen uptake applied, by the way, during maximum effort. In a Turkish study involving runners and volleyball players, a night of sleep deprivation (yes, the whole night) had no effect on resting heart rate [6

]. However, it did cause the players to become fatigued more quickly during training. Now, I’m always in favor of demonstrating things in research rather than making assumptions. However, the statement: “After a night without sleep, you become fatigued more quickly” can only elicit one response: “Duhhh!!”

The Influence of Sleep on Anabolic Hormones

Looking at the influence on hormone levels, it is significant in several respects. The anabolic hormones responsible for tissue building such as muscle mass, such as testosterone, growth hormone, and IGF-1, are all negatively affected by sleep deprivation.

Testosterone

Researchers from the National University Hospital in Singapore examined the sleep habits and sexual activity of 531 Asian men aged 29 to 72 years. Sleep duration was found to have a positive effect on both total testosterone and free testosterone levels. Men who slept less than four hours per night had 35% lower levels than those who slept longer than 8 hours. Men who slept between four and six hours per night had 14% lower levels compared to those who slept more than 8 hours.

Growth Hormone (HGH)

The production of (human) growth hormone is known to be influenced by sleep. It was discovered in the sixties that the nightly peak of growth hormone does not occur when there is no sleep. This peak occurs in the first 90 minutes of sleep in the sleep phase called Slow Wave Sleep.

In a study conducted by researchers from the Toronto Hospital in Canada, it was observed that reduced growth hormone levels due to sleep deprivation could possibly be compensated for the next night. They found that when sleep was deprived, the growth hormone peak was indeed absent, but when sleep occurred, there was a longer-lasting peak and in some cases even two peaks in growth hormone. However, it is still necessary to have sleep to achieve the growth hormone peak, so the extent to which one bad night actually has an effect when it is compensated for at the next sleep remains questionable.

However, it is important to remember that irregular sleep may lead to faster accumulation of body fat, so it is advisable to keep sleep patterns stable.

Insulin-like Growth Factor (IGF-1)

Insulin-like growth factor (IGF-1) has muscle-strengthening and muscle-building effects. As a performance-enhancing substance, it is popular among athletes and bodybuilders, similar to testosterone and growth hormone. It can increase fat burning and limit muscle breakdown. In a study where rat sleep was disrupted, this also had a negative effect on the amount of IGF-1.

Cortisol During Sleep

The catabolic hormone cortisol, which is responsible for muscle breakdown, may be increased with sleep deprivation.

Researchers from the University of Chicago compared two extremes: six days of four hours of sleep per night or twelve hours of sleep per night. They found that four hours of sleep resulted in higher cortisol concentrations in the evening. Similarly, Australian researchers observed an increase in cortisol when no sleep occurred at all, which is unsurprising as it would not be beneficial for one’s physique.

The researchers from Toronto who kept 10 young men awake for 40 hours did not observe a difference in the average cortisol levels measured over 24 hours during sleep deprivation or after sleeping. They only observed that the peak in cortisol could occur at a different time due to sleep deprivation.

Looking at studies in rats, different outcomes are observed, leaving the effect of sleep deprivation on cortisol (in animals corticosterone) unclear.

Better Sleep and Metabolic Syndrome

Sleeping less than six hours a day and more than ten hours is associated with metabolic syndrome and its symptoms such as a wider waist and higher blood sugar levels.

The influence of sleep on fat mass was also part of a new study. This study not only looks at the effects of sleep deprivation but also those of oversleeping. South Korean researchers wanted to know what the influence of this is on the risk of metabolic syndrome, a collection of metabolic problems.

“Not Sleeping Less Than 6 Hours, Not More Than 10 Hours”

According to the research by the Koreans, sleeping less than six hours a day is associated with various characteristics of metabolic syndrome. For the study by the Seoul National University College of Medicine, data from more than 133,000 Korean men and women aged between 40 and 69 years old were used.

Women who slept less than six hours had a larger waist circumference. Women who slept longer than ten hours had a larger waist circumference, higher blood sugar levels, and lower HDL (the ‘good’ cholesterol).

Men who slept less than six hours had a larger waist circumference. Men who slept longer than ten hours had higher levels of triglycerides in the blood.

Almost 11 percent of men and 13 percent of women slept less than six hours. Sleeping longer than ten hours was much less common, with 1.5% and 1.7% for men and women, respectively.

This is the largest study examining a dose-response association between sleep duration and metabolic syndrome and its components separately for men and women. Because we were able to expand the sample of our previous study, we were able to detect associations between sleep and metabolic syndrome that were unnoticed before. We observed a potential gender difference between sleep duration and metabolic syndrome, with an association between metabolic syndrome and long sleep in women and metabolic syndrome and short sleep in men. – Claire E. Kim, Seoul National University College of Medicine

Metabolic Syndrome

In all cases, the risk of metabolic syndrome was increased. According to the definition used, this means that three of the following symptoms were found:

• Increased waist circumference
• High levels of triglycerides inthe blood
• Low levels of HDL cholesterol
• High blood pressure
• High blood sugar

29% of men and 24.5% of women met this criterion. The researchers therefore point out that it is important to be able to identify risk factors such as sleep, especially because this is a factor that you can influence yourself.

Sleep, Hormones, and Overweight

The researchers refer to possible mechanisms that could explain the link between sleep duration and metabolic syndrome. Think of increased levels of hormones that increase appetite and/or decrease energy expenditure. However, we extensively covered this in the previously mentioned article about sleep deprivation (though not about the relationship with oversleeping).

Poor Sleep = 3 cm More on Your Waist

Three hours less sleep would add 3 cm to (the circumference of) your waist. This is the outcome of research by the University of Leeds.

Researchers from the University of Leeds concluded that sleeping 6 hours per night instead of 9 hours adds 3 cm to your waist. For this, they looked at the sleep and eating habits of 1615 adults to see the effect of sleeping less on indicators of metabolic health such as blood pressure, cholesterol, thyroid function, and waist circumference.

People who slept an average of 6 hours or less per night had a waist circumference that was 3 cm larger than that of participants who slept an average of 9 hours.

There was also a link between less sleep and (‘good’) HDL cholesterol, which normally protects against certain heart and vascular diseases.

No Difference in Diet

The researchers refer to previous studies that showed a link between less sleep and greater food intake. Interestingly, this effect of sleep on waist circumference and weight did not seem to be caused by differences in diet. The researchers found no link between less sleep and a poorer diet as seen in previous studies.

Earlier research showed a link between less sleep and increased levels of the ‘hunger hormone’ ghrelin. Increased levels of ghrelin due to sleep deprivation led to increased food intake in a study from last year.

It is therefore unclear to what extent the effect of sleep reduction on total weight is caused by increased eating. In this latest study, this was not the case. However, the researchers take into account that people with overweight may be more inclined to not be completely honest in answering questions about healthy eating.

Other possible factors were also examined, such as the effect on thyroid hormones like T4. There was a significant link between reduced sleep and lower T4 levels. This confirms findings from previous research on the link between sleep and T4 levels. T4 increases basal metabolism, causing you to burn more energy at rest.

Poor Sleep Leads to Eating More the Next Day

Too little sleep leads to eating more the next day. According to recent research, too little sleep can lead to eating more the next day. This can make the difference between losing weight, maintaining weight, or gaining weight.

Poor Sleep Leads to 385 kcal More Eating

Dr. Gerda Pot, senior author of the Diabetes & Nutritional Sciences Division at King’s College London and the Vrije Universiteit Amsterdam, and her colleagues conducted a meta-analysis. Their findings were published earlier this month in the European Journal of Clinical Nutrition.

They compared the results of multiple smaller studies on the effects of sleep deprivation on food intake the next day. In total, 11 studies were compared, involving 172 participants.

From this analysis, it followed that people with sleep deprivation ate an average of 385 kcal more the next day. Furthermore, it was found that sleep deprivation did not cause people to burn more energy, resulting in a net intake of 385 kcal more.

Short Sleep, More Appetite

The researchers refer to previous studies to indicate possible causes. For example, a study involving 26 adults in which sleep deprivation led to greater activation of areas in the brain associated with a “reward impulse when exposed to food”.

Another possible cause, according to them, is the mentioned altered regulation of hormones such as leptin and ghrelin by disrupting the day-night rhythm. These hormones are involved in providing a feeling of satiety (leptin) and hunger (ghrelin).

How Much Sleep Deprivation?

We have discussed the importance of sufficient sleep on the site before. The crucial question here is, of course, how significant the sleep deprivation/interruptions were in the compared studies. The sleep-deprived groups slept between 3.5 and 5.5 hours per night. The control groups slept between 7 and 12 hours per night.

Additionally, the long-term effect is interesting. These studies lasted 1 or 2 days. The authors of the meta-analysis would therefore like to see more research conducted on the long-term effects to see how this affects weight and obesity.

Eating 385 kcal more due to less sleep is significant. If I calculate a nutritional requirement for someone (in the Fitsociety Online Coaching app) and it comes out to be 2500 kcal per day, then 385 kcal less or more could be a normal amount to ensure weight loss or gain.

Not Sleeping Too Long

It is striking that only the benefits of longer sleep are discussed here. Other studies have also shown risks of sleeping too long. Sleeping longer than 8 hours would actually increase the risk of obesity, diabetes, and cardiovascular diseases. Although the above graphs might suggest that longer sleep is always better, other studies have shown that you should aim for between 7 and 8 hours.

Sleeping Later Means Less Healthy Eating

Late Sleepers Eat Less Healthy Than Early Birds

Late sleepers eat less protein and more sugars and saturated fats than people who go to bed earlier.

Circadian Rhythm and Eating Behavior

Finnish researchers wanted to know the influence of the circadian rhythm (sleep-wake cycle) on eating behavior. They compared the data of 2,000 randomly chosen people from the FINRISK 2007 study to see how their (chrono)type circadian rhythm influenced their diet. They compared “morning types” with “evening types”: what, how much, and when they eat. They published their findings in the scientific journal of The Obesity Society.

‘Evening People Eat Less Healthy’

Early birds may have an extra advantage over night owls when it comes to fighting obesity as they are instinctively choosing to eat healthier foods earlier in the day. Previous studies have shown that eating earlier in the day may help with weight loss and lower the risk of developing diabetes and heart disease. What this new study shows is that our biological clocks not only affect our metabolism but also what we choose to eat.

Courtney Peterson, The Obesity Society

Evening types ate less protein throughout the day and more sugars in the morning. In the evenings, evening types also ate more sugars and saturated fats. The differences were even greater on weekends. Evening types ate less regularly but twice as often. Additionally, they slept worse and were less active.

Difficult to Control for Better Sleep

With a standard 9 to 5 job, you’re home for 6 hours, done eating by 7 p.m., back from the gym by 9:30 p.m., and should go to bed by 11 p.m. to wake up at 7 a.m. For 9 hours of sleep, you should already be in bed by 10 p.m., leaving you with only half an hour for yourself. Sleep is then the largest block of time in the day where you can still squeeze in something for yourself.

This type of research can help you find the right motivation to give sleep sufficient attention. In certain cases, these findings could also provide insight into why people with overweight make certain food choices.

Perhaps this latest research is an extra motivation to take a closer look at your day-night rhythm, as far as you have room for it.

Tip 1: Better Sleep? Set Goals

People who have a purpose in life sleep better. That’s the outcome of research from Northwestern University.

Research from Northwestern University in Illinois recently showed that having a purpose in life actually improves sleep. Especially in people with sleep problems such as apnea and insomnia. A drive for life could thus be a good alternative to sleep medication.

Also, complaints caused by the so-called ‘restless leg syndrome’ would decrease. This is a condition of uncomfortable sensations in the legs leading to an urge to move them. This mainly occurs before bedtime and at rest.

Research: Goals for Sleeping

The research was conducted among the elderly (age 60 to 100 years), although the researchers state that the results can also be translated to younger people. They followed the sleep pattern of 823 people for two years.

People who felt they were ‘leading a meaningful life’ had a 63 percent lower risk of sleep apnea and 52 percent less chance of restless leg syndrome. Sleep quality was also better. To determine the extent to which people found their life meaningful, or had led, ten questions were asked, such as: “I feel good about what I have done in the past and hope to do in the future.”

A next step in researching this would be to study mindfulness techniques that should give more meaning to life.

A Purpose Gives You Wings

In practice, you may have already ended up in such a downward spiral. A daily routine that doesn’t give satisfaction, but is demanding and exhausting. Energy to explore a new direction, let alone pursue it, is often lacking.

I know myself that I would never have had the energy for the hours I now put in as a blogger and fitness photographer if I had to deal with work that is not my passion.

Tip 2: Better Sleep? Make a To-Do List

It may seem too simple, but a small-scale study shows that it works: Spending 5 minutes before bed on a to-do list helps you fall asleep faster.

Personally, it doesn’t really surprise me. I’m also someone who often lies in bed worrying about everything I still have to do. Sometimes I’m already formulating half articles for the next day or coming up with poses for a shoot in my head.

I assume that for many people, mentally planning for the next day makes it harder to fall asleep. You think about that difficult meeting the next day, actions that still need to be taken, people you need to write to, etc.

According to research from Baylor University’s Sleep Neuroscience and Cognition Laboratory, there is now a way to prevent these concerns from disrupting your sleep. By creating a to-do list before bed, you shift this responsibility of planning forward.

We live in a 24/7 culture in which our to-do lists seem to be constantly growing and causing us to worry about unfinished tasks at bedtime. Most people just cycle through their to-do lists in their heads, and so we wanted to explore whether the act of writing them down could counteract nighttime difficulties with falling asleep.

Michael Scullin, director of Baylor’s Sleep Neuroscience and Cognition Laboratory

Recognizable, in an article about stress and the zen of training, I wrote:

Everything that contributes to the fact that the mental to-do list just doesn’t want to get any shorter can contribute to stress.

To-Do List Before Bed

To test the theory that you can write away these worries before sleep, the researchers invited 57 men and women (between 18 and 30 years old) to spend a night in the sleep laboratory. The instructions were simple: Lights out at 10:30 p.m. and no technology, homework, or other distractions.

All participants were asked to perform a writing task five minutes before bedtime. The control group, half of the participants, was asked to write down tasks they had performed in recent days. The other participants, the test group, were asked to write down tasks that needed to be done in the coming days. This way, the effect of writing itself could be corrected, and the effect of writing down pending actions could really be looked at. After the writing task, the participants went to bed.

The researchers measured the brain activity of each participant throughout the night using a technique called ‘polysomnography’. This technique measures eye movements as well as muscle activity and other biological changes.

The researchers then observed that the participants who had written the to-do list fell

asleep an average of 9 minutes faster than those who had noted what they had done. Moreover, it turned out that the more specific the to-do list was, the faster they fell asleep. An opposite trend was seen when writing about completed tasks.

“Nine minutes? That’s not much,” I thought when I read the above. However, in an interview with Time Magazine, the researchers point out that this is as much as seen in some clinical trials for sleep medication. If it’s good enough to develop a drug for, you would think that these kinds of methods offer a useful, natural alternative. However, if you consider that making the list itself takes 5 minutes, you effectively have 4 minutes left.

The researchers point out that further research with a larger number of participants is needed to confirm these findings. In addition, more personal data from participants should be included. For example, the extent to which someone normally suffers from anxiety. Unfortunately, there is no good Dutch translation for this concept, but those who know Tweek from Southpark have a good idea. If you relatively often experience these feelings of ‘anxious excitement’, for example, it is possible that you also relatively have more difficulty falling asleep and benefit more from this method.

Falling Asleep Faster by Writing Away

There are studies showing that writing down and describing emotions and stress can improve the immune system of patients suffering from diseases such as asthma, HIV/AIDS, and arthritis. In other studies, keeping a journal, diary, emails, or a blog during times of stress or emotional times has been linked to reducing stress.

However, you can imagine that you don’t need a scary disease or traumatic experience to benefit from this.

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