Log in to BOXROX Pro

How Sleep Affects Recovery, Performance and Health for CrossFit Athletes

Sleep is a natural process with remarkable benefits for the human body, which recovers the muscles from effort, consolidates learning and memorizing, and also helps manage stress and emotions better than any medication or supplements available on the market.

In the daily rush of today’s modern lifestyle defined by speed, a need for efficiency and a constant state of stress, numerous elements of man’s primary set-up, from nutrition to social interaction, suffer significant changes. One of these features which are heavily affected by our hectic routines is sleep. Despite (or, perhaps, due to) being a basic human necessity, little research had been conducted on sleep until the second half of the 20th century. Given its key connection to the complex, sometimes mysterious mechanism of the brain, it is admittedly a difficult subject to study.

improve your movement bar muscle upSource: WODSHOTS
Sleep well and improve your performances

However, what we do know about it today suffices to reveal numerous extraordinary benefits for the human body. The purpose of the present article is to provide an overview of these effects particularly in the context of sport, and hence to raise awareness of sleep’s importance as a factor which greatly influences recovery and performance.


The human body is a complicated machine run by specialized systems of organs. Just like nutrition, sleep is a comprehensive, multi-purpose feature, providing a framework for a number of different processes. Following intense activity throughout the day, the body partially ‘switches off’ during sleep by slowing down or even interrupting some of its functions. By doing so, it conserves its resources for the day to come, as energy consumption is reduced.

However, this process is more of a means of achieving something we shall now turn our attention to, rather than the purpose of sleep. After a day of moving around, thinking, exercising and learning, the human body needs to recover. The more such activities we undertake and the more intense they are, the more profound the recovery must be. Therefore, whether we talk about high levels of physical or intellectual activity, the fact that sleep is especially important when the body is subjected to higher amounts of stress than normal is self-explanatory.

crossfit recovery posesSource: RX'd Photography
That was horrible…What time tomorrow?

Nevertheless, when one wishes to look beyond the indisputable truth of the claim that sleep is paramount in post-exercise or post-studying recovery, it will become apparent that little is known about the complex processes behind these miraculous, literally overnight transformations.

Keeping the references to the two aforementioned types of intense daytime activity – physical and intellectual – let’s see what happens during sleep that helps us recover from them. The processes which occur while we are sleeping can roughly be divided into two categories: although this classification is very broad and does not encompass specific physiological criteria, it will be used here to facilitate the explaining and understanding of the effects that sleep has on the human body.


During infancy, childhood and adolescence, sleep plays an essential role in development, as it is the time of day when the largest amount of growth hormones is secreted. Similarly, although their quantity decreases significantly, these hormones continue to be secreted in adulthood, boosting protein synthesis. This process plays an important part in the recovery from physical effort, as it helps consolidate the worn-out cells in the muscles of the athlete, as well as forming new ones. Therefore, this is how (and when) most muscle is built. Moreover, these changes at the level of the fibers are also part of the process which eliminates the tiredness you feel in your body after a workout.

sleep crossfitter muscle upSource: WODSHOTS
Train hard and recover properly.

As you start to recover after exercise, the food you are digesting is broken down into the components needed for ‘feeding’ the cells in your body, the wider process to which the reparation of damaged muscle belongs. During sleep, physiological functions such as the increase in the parasympathetic activity of the nervous system determine a boost in digestion and further assistance in the muscular recovery.

Furthermore, the immune system also benefits from the processes associated with sleep, thus regaining much of its potential to fight pathogens when the body’s ‘active’ state resumes.


Our brains process a tremendous amount of data every day. Recalling a piece of information, memorizing somebody’s name or new vocabulary in a foreign language you are learning, making decisions and reminiscing about your last holiday – all these activities place a heavy burden on your brain cells, the neurons. Therefore, just as your body feels tired at the end of a workout, so does your brain following intense intellectual activity. The brain does not completely shut down during sleep, but stays active, particularly in the REM (rapid eye movement) stage, when dreams and sleepwalking or talking occur, alongside with other processes which will be explored in a further section of this article. However, of the five stages of a sleep cycle, two allow the brain to considerably reduce its activity and recover from the mental effort that was made throughout the day. They are collectively and adequately called “deep sleep”, and take place just before the final, hectic REM stage of the cycle.

Yoke carrySource: Wodshots
Make time for sleep and your performances and health will thank you for it.

Furthermore, scientists believe that sleep works wonders in keeping mood under control, as it is said to basically reset your perception of recent events. You may have noticed that the anxiety or anger you had experienced before going to sleep one night had a significantly lower emotional impact the following morning. This happens without you being aware of it, while during REM sleep your brain is reliving and categorizing the events which had been causing distress. Consequently, you start seeing them in a new, more balanced light, in this way becoming less likely to overreact or allow them to cause any illnesses such as depression. In fact, research has shown that mental health issues of this kind are closely linked to the amount and quality of sleep one enjoys.


It is only natural that a well-rested body will show a higher level of alertness while undertaking daily activities, be they physical or intellectual.

This is reflected in attention, concentration and reaction times, as these depend on the capacity of the neurons to fire. Besides these areas in which the consequences of the quality and duration of sleep are more easily observed, the learning and memorizing capacities are two crucial fields to consider when discussing the effects of sleep on performance. All types of information and experiences are acquired during the day as a consequence of the person coming into contact with them for the first time. However, the actual learning process, which makes the brain ‘save’ them like a computer does, happens during REM sleep. Although it is not exactly known how this occurs, neuroscientists believe that the process is a result of the brain’s neurons repeatedly firing in certain patterns associated with new pieces of information, which leads to these pathways being strengthened. This in turn makes the information more readily available when the person needs to access it. Furthermore, it is also during sleep that the less significant details acquired throughout the day are deleted from the brain, thus clearing space for more important information.

But what about athletic performance: how is it influenced by proper sleep? First of all, the previously described recovery process is essential for allowing the body to perform at its highest level once again, as well as for preventing injuries. These can be caused by fatigued muscles, which have a lower capacity to protect their connective tissues, tendons, ligaments and bones, as well as by low levels of attention and concentration, which increase the risk of executing an exercise in a wrong way.

Furthermore, like other types of information, muscle memory is also coordinated by the brain primarily during sleep. Therefore, a good night’s sleep could lead to better accuracy and to an improved overall athletic performance.


Let’s keep it simple. It all comes down to three basic elements which determine the quality of your life: nutrition, sleep and exercise. They work together, permanently influencing one another to create the ideal conditions for you to physically and mentally thrive. As we have seen, there is a significant link between sleep and digestion, therefore, an incorrect nutrition could have a detrimental impact on your rest. For instance, eating just before your bedtime and consuming caffeinated drinks and foods will negatively affect the quality of your sleep by overloading the digestion process and by raising energy levels at a time when they are supposed to drop, respectively. Furthermore, studies have indicated that improper sleep can lead to an increased consumption of food and to changes in one’s eating habits.

Sarah Loogman at the californian regionalsSource: CrossFit Inc
Good quality rest will help you become a happier, healthier athlete

This article has shown how proper sleep carries out the recovery of the body and mind while positively affecting athletic performance. In addition to this, it is also important to note the impact of exercise on sleep, with physical activity undertaken anytime during the day up to a few hours before going to bed having a positive impact on the quality of the nightly rest.

However, the world we live in has added a fourth element to the equation, which often governs the three aforementioned areas. That is stress, an intruder which is increasingly difficult to avoid given the demands of our society. Stress can be alleviated by exercise and proper sleep, but it may also wreak havoc in the other areas, as it can destabilize one’s diet and greatly decrease the quality of sleep by keeping the body in a constant state of tension. This situation is created as a result of stress hormones being secreted, which keep the organism alert in the face of an imaginary imminent danger.

To conclude, sleep is a natural process with remarkable benefits for the human body, which recovers the muscles from effort, consolidates learning and memorizing, and also helps manage stress and emotions better than any medication or supplements available on the market. Consequently, for the optimal functioning of your organism, as well as for a number of added bonuses in your athletic, academic or professional performance, make good-quality sleep a priority in your busy daily schedule. All else can, and should wait.

4 Steps to Efficient Recovery After Crossfit Training

Image Sources

Related news