The influence of good sleep hygiene on the physical and mental health of the general population has been scientifically studied for decades. Sleep management is an essential element and increasingly the subject of research for sports practitioners, and even more so for professional athletes.
The sleep cycle
The sleep cycle lasts 90-120 minutes, occurs 4-5 times during the night, and has two phases: sleep without rapid eye movements (NREM) and sleep with rapid eye movements (REM). During the REM phase, the body recovers the substrates necessary for the generation of action potentials, and there is a restructuring of all physiological functions.
Sleep disorders are among the clinical conditions with the most significant impact on public health, causing severe economic damage to their populations.
Sleep is considered restorative, and exercise is related to several changes in sleep patterns. Sleep deprivation is the removal or partial suppression of sleep, and this condition can cause several alterations: endocrine, metabolic, physical, cognitive, neuronal, and sleep pattern changes, which together compromise the health and quality of life of the subject under these conditions.
On the other hand, regular physical exercise promotes benefits such as improvements in the cardiovascular, respiratory, endocrine, muscular, and humoral systems and improves the quality of sleep.
Since sleep deprivation is a factor that can accelerate the deterioration of human abilities, sleep should be more restful and of longer duration for those who engage in systematized physical activity, such as professional athletes.
Sleep deprivation negatively influences the performance of a top athlete on several levels. First, the physiological effects of sleep deprivation on athletic performance are profound. They include decreased motor skills, which substantially increases the likelihood of injury. In addition, reaction time is reduced, which can slow an athlete down, for example, in a 100-meter race where the reaction to the starting shot is critical to the final result.
Glucose levels are altered in the athlete suffering from sleep deprivation, which negatively influences performance, especially in endurance races where energy reserves must be restored.
In psychological terms, the effects of sleep deprivation can be profound. Changes in mood, feelings of tiredness, anxiety are often the result of a poor night's sleep and completely change the pre-disposition for competition, with results usually falling short of expectations. Another effect of sleep deprivation, although indirectly, are "overuse" injuries, which usually occur due to an excessive training load for some time. When an athlete is sleep-deprived, the exercise tolerance decreases, and these injuries can occur with a much lower training load.
When sleep deprivation affects an athlete's performance, the solution is not just one or two days of sleep, although this is already a good start. Instead, the athlete, or the group working with the athlete, should include rest in their training program, like any other component of physical preparation. Sleep deprivation can be treated in just a few weeks with proper care.
What is currently unquestionable is that sleep has therapeutic potential and restores the athlete's capacities, and therefore has a significant influence on performance in high competition.
Barcelona: a case study in soccer
In collaboration with UEFA and the AdSalutem Sleep Medicine Institute, Barcelona conducts several studies on 644 youngsters at its academy, La Masia. The club wants to prove that athletes tend to sleep less and worse than those who are not athletes; that lack of sleep is directly related to loss of speed and endurance but also to increased heart rate, oxygen consumption, and fatigue; that sleeping poorly affects neurocognitive performance, reducing concentration, problem-solving ability, and accuracy; and that sleep-related problem can increase the risk of injury and delay physical recovery, as well as cause changes in the metabolism of athletes, making it challenging to maintain a certain weight.
Thus, the youngsters of Barcelona's academy sleep with electronic jerseys (Hexoskin Smart), which monitors their sleep. A report made by the Spanish newspaper 'El Mundo' clarifies that this data is crossed with that collected from the GPS vests (Wimu Pro) that convert all physical activity into data.
Eduard Estivill, a sleep specialist doctor who works with several elite sportsmen, explained to 'El Mundo' that it is vital to know the circadian rhythm, the biological clock of each athlete, to study it.
The Spanish doctor recommends that athletes sleep between nine to ten hours a day they stop using mobile devices such as smartphones and tablets two hours before bedtime. If they choose to watch television, they should do so three or four meters away from the television set, with the light dimmed.
The case of Cristiano Ronaldo
Cristiano Ronaldo is one example of an athlete who places great importance on sleep. Nick Littlehales, a renowned sleep specialist, told the website 'Football Whispers' that he "taught Cristiano Ronaldo how to sleep". As a result, the Portuguese player has already assumed several times that he doesn't give up his sleep after lunch and always sleeps well. And this, in addition to a good diet, explains his longevity and the fact that he is still in top shape at 37.
Littlehales further explained that the Portuguese star does five or six 90-minute sleep cycles a day. "It's not a nap. It's a way to sleep less, but to improve recovery," the expert explained. "Before artificial lights, people slept for short periods," he recalled.
"Football players have private lives. The sport they play has very demanding schedules, and that will continue to be so... Many young athletes I work with suffering from insomnia, anxiety, stress, and all those things that end up being part of the world of sports", he explained, stressing that in such a competitive world, details make all the difference and that athletes must make decisions based on expert information to maintain optimal physical and mental fitness.