Sleep deprivation – it’s more harmful than you think
Although the objectiveness of how much sleep and effectiveness of sleep is yet to be officially determined, in this context of athletes and sport, sleep deprivation can be described as the lack of sleep quantity and quality required to recover from sport and perform at a high level.
Now that we understand how sleep aids in the recovery process, it’s easy to see how sleep deprivation can be detrimental to physiological growth and repair. However, it is important to note there is a difference between acute (one night) and chronic (5+ days) sleep deprivation. Acute sleep deprivation yields consequences related to mood, cognition, performance, emotions, and behaviour, while chronic sleep deprivation can lead to long-term health problems such as cardiovascular disease, weight-related issues, cancer, and risk of mortality.
Sleep problems can include: long sleep latency (taking too long to fall asleep), waking up during sleep, short sleep duration, and lack of sleep quality. These issues can arise from the increased time demands of athletes pushing other responsibilities to later in the day, which reduces sleep duration. For example, morning training sessions which limit the opportunity for sleep and lead to increased pre-training fatigue levels. Additionally, the stress (both physical and psychological) and pressure to achieve high performance may cause sleep problems. This doesn’t mean athletes should not train in the morning, neglect outside responsibilities, or have lower expectations, it just means these factors need to be considered when planning out training and daily life.
These lifestyle factors can turn into a vicious cycle of not receiving enough sleep due to an early practice, a midday nap affecting later sleep latency, bedtime being pushed back due to increased time demands of practice/games, the inability to stay asleep because of the pressure to perform, all combining to alter the athlete’s circadian rhythm and biological systems required for sleep. When this is accumulated over the course of a month, a semester, a school year, and so on, athletes can experience decreased performance and an increased risk of injury.
One of the biggest issues surrounding sleep deprivation is injury risk. Although injury risk is hard to predict and we need to keep in mind correlation is not causation, some studies have started to describe this relationship. It has been shown that both acute stress and coping ability contribute to injury risk. A risk factor for adolescents includes the amount of sleep they get per night, and adolescents with chronic lack of sleep are more likely to suffer sports injuries than those who sleep well; however, the acute effects of poor sleep are not yet determined. Lastly, logically, it can be deduced that when sleep-deprived athletes are in a poorer physical condition and possess less neuromuscular coordination when performing the skills of a sport, they could be more prone to injury.
Not only can early identification of fatigue-related performance decrements aid injury reduction efforts, but these can also be addressed firsthand by sleep-related issue identification. Valid and reliable questionnaires exist that identify athletes who could benefit from sleep-related interventions.