Sleep: More important than you think!
An average person spends about one third of their life sleeping. On top of that sleep plays an even more crucial role in athletic populations, especially in those that are still at growing ages. With all the scientific data today it is safe to say that the importance of sleep regarding the recovery and health of a person is undeniable. It is proven to support healthy cognition, mood, tissue repair, immune function as well as many other important metabolic processes in the brain and body.
Unfortunately sleep deprivation due to various reasons has become a very common phenomenon in today’s high pace society. The effects of sleep restriction and sleep deprivation can be observed in three contributors of overall performance – mood, cognitive performance, and motor performance. Findings of an earlier study done by VanHelder and Radomski (1989) suggested that a sleep deprivation up to 72 hours would have a significant impact on the time to exhaustion which in simple terms means getting tired quicker, and in addition to that Reilly and Piercy (1994) found that sleep deprivation negatively affected sub-maximal weight-lifting performance.
Previous literature on sleep has also shown that when an athlete/person has irregular sleep, the release of growth hormone and cortisol secretion are affected, which then has a detrimental effect on recovery from both stress and exercise. Lack of sleep has been shown to also elevate pro-inflammatory cytokines, which have been recognized as facilitators of pain and can lead to effects on the immune system, decreased muscle recovery and disparity of the autonomic nervous system.
Cohen et al., (2009) completed a study which supports this claim. Within this study, participants were asked to track their sleeping pattern and were then given the active cold virus. It was discovered that those who had less than 7 hours sleep before receiving the virus, had an increased chance of developing a cold after being administered the cold virus when compared to those participants who were sleeping 8 hours a night or more.
Substance use is another very common sleep disruptor in both athletic and general populations. The most commonly used substances in this category can be listed as caffeine (stimulant) and alcohol (depressant). While it could be strategically used to enhance athletic performance during both training and competition, it is recommended to avoid the use of caffeine after lunchtime, and that is due to its considerably long half-life of 3-7 hours which then may interfere with the onset of sleep.
Since alcohol is not considered to be an ergogenic aid unlike caffeine it is suggested that athletes should either completely avoid alcohol use or stop its consumption 3-4 hours before sleep time. And that is because contrary to common perception of alcohol as a sleep aid, literature in this field claims alcohol to have a noticeable negative impact on sleep.
Light exposure is another variable that has an effect on both sleep quality and quantity. While daytime exposure to light has a sleep promoting effect later at night, exposure to bright lights in the evening can have a negative impact on circadian rhythm, and can worsen sleep quality through repressing the secretion of the ‘sleep hormone’ melatonin . Therefore it is recommended for athletes, and for anyone in that matter, to avoid environments with bright lights towards the end of the day.
At times when an individual faces challenges to achieve a full night sleep, day-time naps can be implemented in order to obtain the full amount of daily sleep the individual requires. While this does not necessarily mean that one can or should replace as much of night sleep with day-time naps, it should be seen as a strategy to supplement total sleep time. On the other hand naps come with their own benefits such as a short term boost in overall performance in case of a lack of sleep (Brooks and Lack, 2006).