The impact of sleep on sports performance: Factors that affect sleep in CrossFit athletes

In this series dedicated to sleep and its influence on sports performance, we have seen how rest plays a fundamental role and is essential for sports performance. During sleep, the body recovers, regenerates and strengthens, which helps avoid injuries and maintain excellent physical condition. Additionally, adequate sleep allows for deep memory consolidation and significantly improves concentration, contributing to outstanding mental and technical performance in any sport. Sleep also helps regulate hormonal imbalances and strengthen the immune system, which promotes good overall health and faster recovery after intense physical exertion.

After exploring in depth how sleep affects overall performance in sports, we now delve into the factors that impact our rest.

In this second article, we will focus on understanding the factors that affect our quality of sleep. Also, we will discuss how maximizing sleep can become a critical differentiator in the pursuit of success in this rigorous and exciting sport.

Training schedules

We know that not all of us can dedicate ourselves solely to training, we have a job, a family to take care of...that is why we often have to train at the end of the day, once our responsibilities are finished.

Carrying out intense training sessions in the afternoon/night can cause us to experience difficulties falling asleep due to the high physical and mental stimulation that these sessions imply. During training, the release of cortisol and the activation of the sympathetic nervous system occurs, which involves an increase in heart rate and blood pressure. This state of excitement can make it difficult for us to fall asleep, since our body remains in a state of alert.

On the other hand, if we train in the morning we must make sure to maintain an early bedtime to ensure a restful sleep and adequate recovery. In fact, multiple research has shown that exposure to natural light during the morning helps regulate the body's circadian rhythm, making it easier to fall asleep at night and promoting higher quality sleep.

In your job you may have to work shifts and that is why there will be days when you train in the morning and others in the afternoon and even at night... The variability in schedules can modify the natural circadian rhythm of our body, which can result in difficulties falling asleep and sleep interruptions.

That is, our training schedules can significantly influence our sleep quality due to their impact on physiological activation and circadian rhythm. Therefore, it is essential that, as much as possible, we establish consistent training schedules and schedule our sessions in a way that gives us enough time to relax and unwind before we go to bed. Thus, we will facilitate falling asleep, promoting better physical and mental recovery.

At Aether, we know that although we are not guilty of what happens to us, at this point we apply it to our external obligations, however, we are responsible for how we respond to it, that is why we will carefully analyze the impact of rest on our body and different tools that can help us optimize it.

You have power over your mind, not over events. Realize this and you will find strength. Marcus Aurelius.

Supplementation and consumption of stimulants

Next, we will look at the effects that supplementation and stimulants have on sleep, as many athletes turn to their use to optimize their performance. However, it is crucial to understand how these

(We won't get into the debate of which supplements are useful or not, we will simply talk about their impact on sleep and rest.)

The supplements are known to provide improved performance and speed recovery. However, some supplements can have a negative impact on sleep if taken at inappropriate times.


Caffeine is one of the most widely used stimulants in the world of sports, it can have both positive and negative effects on sleep and sports performance.

For one thing, caffeine can increase alertness, improve concentration, and reduce perceived effort during exercise , potentially leading to better training performance. However, consuming too much or too close to bedtime can interfere with sleep quality by making it difficult to fall asleep and reducing the duration of deep, restful sleep. Therefore, we must know our body and be aware of our individual sensitivity to caffeine and adjust our consumption accordingly to maximize the benefits without compromising the rest necessary for optimal recovery and performance.


Beta-Alanine is an amino acid known for its ability to improve muscle endurance and delay fatigue , however, it can impact our rest.

Although its ergogenic benefits are well known, some studies suggest that it may increase neuronal excitability , thus interfering with sleep quality if consumed in large quantities or close to bedtime. In addition, some people may experience tingling sensations on the skin, known as paresthesia, as a side effect of its consumption and this makes it difficult to fall asleep due to the discomfort.

Therefore, similar to what we saw for caffeine, if we consume supplements (such as some Pre-Workouts) that contain Beta-Alanine, or Beta-Alanine directly, we must be aware of these possible effects and consider the timing and the doses in which we consume them to minimize any negative impact and ensure optimal physical and mental recovery.

Fat Burners

Fat burners, also known as Fat Burners , can impact sleep and sports performance.

These supplements, which are designed to increase metabolism and fat burning , often contain stimulant ingredients such as Caffeine , Synephrine and Yohimbine , which can temporarily improve alertness and energy during training but excessive consumption or at inappropriate times, especially around bedtime, it can interfere with our rest.

Once again, we see that we must be aware of the possible stimulant effects, and if we use fat burners, adjust its consumption and intake schedule to minimize any negative impact.

Are there supplements to improve sleep?

Of course! There are a variety of supplements that have been shown to have positive effects on sleep quality. One of the best known is Melatonin , a natural hormone that regulates the sleep-wake cycle. Melatonin is especially useful in situations such as travel or changes in schedules that can disrupt our usual sleep patterns.

In addition to Melatonin, other supplements may also be beneficial. For example, L-tryptophan and 5-HTP are capable of increasing the production of Serotonin , a neurotransmitter associated with sleep and mood. These supplements can help promote a feeling of calm and relaxation, thus facilitating the process of falling asleep.

On the other hand, certain herbs and compounds have also been shown to have positive effects on sleep quality. L-Theanine , for example, commonly found in green tea, has relaxing properties that can help reduce stress and improve sleep quality. CBD (Cannabidiol) , Ashwagandha , Glycine , Saffron and Valerian have also been associated with improvements in sleep due to their relaxing and anti-anxiety effects.

In short, there are a variety of supplement options available for those looking to improve their sleep quality. However, it is important to remember that supplements can affect each person differently, so it is advisable to consult with a health professional before beginning any supplementation regimen.

On our journey toward physical and mental excellence, we cannot forget the wise words of Seneca:

'Virtue is the only good and is based on knowledge.' Lucius Anneus Seneca.

Although supplements can be powerful allies, it is crucial to know their effects and capabilities. Let us cultivate, then, the virtue of balance and wisdom in our decisions, since our true strength lies in them.

Stress and hormonal impact

Stress is an inevitable part of life and we are not exempt from its effects, but we can try to manage it in the best way possible.

Stress, whether physical or emotional, triggers the release of hormones such as Cortisol . Cortisol, also known as the stress hormone , plays a crucial role in the body's response to stress. During periods of high tension, Cortisol levels increase in order to mobilize the energy necessary to cope with the situation. However, when stress becomes chronic , its levels can remain elevated, leading to hormonal imbalances that interfere with sleep.

Cortisol has a diurnal rhythm , with higher levels in the morning to help wake up and lower levels at night to facilitate sleep. However, chronic stress can disrupt this natural rhythm, resulting in elevated levels of cortisol during the night that make it difficult to fall asleep and reduce sleep quality.

In addition to cortisol, stress can also affect other hormones important for sleep, such as the aforementioned Melatonin and Growth Hormone (HGH Somatotropin) . As we have mentioned, Melatonin, known as the sleep hormone , regulates the sleep-wake cycle and is produced in greater quantities when it gets dark to induce sleep. However, stress can inhibit the production of Melatonin, making it even more difficult to fall asleep.

Likewise, chronic stress can suppress the production of Growth Hormone, which is crucial for muscle recovery and regeneration during sleep. This suppression negatively affects the body's ability to recover from training and increases the risk of injury.

To mitigate the effects of stress on sleep, it is essential to implement stress management strategies; relaxation techniques such as meditation and deep breathing, as well as writing a diary, can be our great allies.

Additionally, we must prioritize self-care to improve our quality of life. Recognizing the importance of balance between effort and recovery is essential to maintaining optimal performance and overall health.

Prioritizing adequate rest and establishing consistent sleep routines helps restore natural hormonal rhythms and improve sleep quality. By reducing the stress load and restoring hormonal balance, we will optimize our recovery and sports performance.

It is essential to recognize that sleep plays a crucial role in performance. Training schedules, supplement consumption and stress can significantly impact the quality of sleep and, therefore, our ability to recover and improve physically and mentally.

Prioritizing adequate rest, establishing consistent sleep routines, and managing stress effectively are essential steps to optimizing athletic performance and promoting overall health. Below are some key points that summarize the most important aspects discussed in this article:

  • Training schedules: Maintaining consistency in training schedules and scheduling sessions that allow enough relaxation time before bed can improve sleep quality.
  • Supplementation and consumption of stimulants: Know the effects of Caffeine, Beta-Alanine and other supplements on sleep, and adjust your consumption accordingly to avoid interference with rest.
  • Stress management: Implement stress management strategies to reduce Cortisol levels and promote better sleep.
  • Prioritize self-care: Recognize the importance of balance between effort and recovery, and establish routines that promote adequate rest to optimize recovery and sports performance.
  • Consult with a health professional: Before beginning any supplementation regimen or implementing significant changes to our routines, it is advisable to seek guidance from a health professional to ensure a safe and effective practice.

Subscribe to our Newsletter to stay up to date with the latest Aether news!

Back to blog

Leave a comment

Please note, comments need to be approved before they are published.