Updated: Jun 7
“A night of sleep is as much preparation for the subsequent day’s activity as it is recovery from that of the previous day” John Allan Hobson
In today’s modern society, sleep is an afterthought. With a culture that praises working hard above all else, sleep is very low on the priority list of most individuals. I blame it on the lack of education to the youth and to the general public. We cannot fix or alleviate what we do not know is broken.
This is probably the reason I get looked at as if I’m speaking a lost language when I mention to my athletes that an average person should get around 7-8 hours of sleep and that athletes typically need more. Many athletes rely on caffeine to get through the day, without realizing the athlete is perpetuating their poor sleep cycle.
Getting a full night of sleep may seem like a dream to many so in this article I will attempt to break down what sleep is, why it’s important and how to improve the quality of our sleep.
While I am primarily focusing on how sleep affects athletic performance in this article, please realize that lack of sleep has much more devastating and long lasting effects on the body than just running fast or not getting a new personal record.
WHAT IS SLEEP?
Many people think that sleep is just a time when your mind gets to rest but this could be further from the truth. Sleep is a state where awareness to environmental stimuli is reduced.1 It is distinguished from wakefulness by a decreased ability to react to stimuli, but more reactive than a coma or disorders of consciousness, with sleep displaying different, active brain patterns.3 Sleep serves an essential function that allows your body and mind to recharge, leaving you refreshed and alert when you wake up.3 Healthy sleep helps the body remain healthy and stave off diseases. Without enough sleep, the brain cannot function properly. This can impair your abilities to concentrate, think clearly, and process memories.2 This can explain why a lack of sleep or quality sleep can make you feel lethargic or unable to optimally perform.
WHY DO WE SLEEP?
There are four different major theories as to why we sleep.
Main function of sleep is to reduce a person's energy demand during part of the day and night when it is least efficient to hunt for food.5 Body has decreased metabolism during sleep.4 This concept is backed by the way our metabolic rate drops during sleep.4 Research suggests that 8 hours of sleep for human beings can produce a daily energy savings of 35 percent.4
This could be a result of not having readily available food in the early development of humans so our bodies had to rest during the night so we could have energy during the day until the next meal.
The inactivity theory is based on the concept that humans were less active at night because we might die from predation of injury in the dark, thus creating an evolutionary and reproductive benefit of sleeping at night.5
Restoration theory is based on the fact that sleep allows for the body to repair and replete cellular components necessary for biological functions that become depleted the longer we stay awake and deprive ourselves of sleep.5 This is backed by the findings that many functions in the body such as muscle repair, tissue growth, protein synthesis, and release of many of the important hormones for growth occur primarily during sleep.5
Brain plasticity theory
Brain plasticity theory states that sleep is necessary for neural reorganization and growth of the brain’s structure and function.5 It is clear that sleep plays a role in the development of the brain in infants and children and explains why infants must sleep upwards of 14 hours per day.5
The brain has trouble processing what we have learned during the day or trouble recalling information in the future if it does not receive a healthy amount of sleep.6
I believe that it is not one but a combination of these theories as to why we need sleep. This not only applies to us humans but to all animals. All animals need sleep.
WHY IS SLEEP IMPORTANT?
Sleep is the primary factor in athletic performance.7 This is not to say that sleep will alter your genetic code and make you faster but that proper sleep will help you reach the optimal athletic performance capacity. Athletes always want to know what supplements they can take to get better while ignoring the fact that sleep is the best legal performance enhancing drug.8
Usain Bolt slept around 9.5-10 hours a day during his time competing as an elite athlete. Sleep after performance is just as important as sleep is after performance.8 An athlete's speed of recovery is markedly improved as sleep helps to fight against chronic inflammation.8
EFFECTS ON THE BODY WITH 6 HOURS OR LESS OF SLEEP 9
Time to physical exhaustion is dropped by 30%
Peak muscle strength decreases
Exhalation carbon dioxide decreases
Inhalation of oxygen decreases
Risk of injury increases
Age at a much faster rate
If you are an athlete or a coach, the bullet points above should be very alarming. No matter how we want to look at it or attempt to justify it, there are no benefits for lack of sleep or shortcuts to getting the sleep back. Lack of sleep produces a lower quality of life.
HOW SLEEP HELPS ATHLETIC PERFORMANCE
A study conducted on the Stanford University men's varsity basketball team, showed that players that had 10 hours of sleep for 5 to 7 weeks had a significant improvement in all measures after habitual sleep extension.10 Players that slept more demonstrated faster sprint times and greater shooting accuracy.10 Players also reported improved alertness and mood and less sleepiness and fatigue.10
Although this study was conducted with basketball players, there is a good possibility that some of the improvement experienced by the players would also apply to track and field athletes . For example, this study shows that the players increased their sprint times by 4.5% with sleep extension.10 All power athletes should take this information to heart. If a bit of sleep extension can help an athlete perform at an optimal level then why wouldn’t an athlete take full advantage of the benefits?
Napping can be beneficial to athletes suffering from some degree of sleep deprivation.12 A 30 minute nap has shown to increase 20 meter sprint performance, alertness and decrease sleepiness.11 Although athletes should be getting 8 plus hours of sleep a night, a quick nap may be quite beneficial to athletes before a big competition or tough practice. Especially, when time constraints just will not allow an athlete to get adequate sleep. It is said that Usain Bolt woke up from a nap 35 minutes before he broke the world record.
A study of middle and high school athletes found that teens who slept less than 8 hours per night were 70% more likely to report an injury than those who slept more than 8 hours.16 Athletes that slept 6 hours or less per night were 80% more likely to report an injury compared to athletes that slept 9 hours or more per night that only reported a 15-20% chance of injury.16 Decreased sleep has been shown to be immunosuppressive and increases susceptibility to upper respiratory infections in particular. 17
Sleep helps to prevent injury. Athletes and coaches have to be very conscious of sleep and rest. When an athlete has finals or has to stay up late studying for an exam, it would be wise for the athletes and coaches to reduce the training volume so that the athlete can recover. The highest risk for injury occurs when the training load increases and sleep duration decreases.
Sleep is a typically overlooked part of recovery by athletes. Sleep is the body’s natural way to repair itself. Imagine that each night your body needs 8 hours of sleep to completely repair itself but yet an athlete is only getting 6 hours of sleep. Eventually the body starts to break down if this repetitive cycle continues to repeat.
Lack of sleep is one of the main causes of fatigue and tiredness among athletes.13 During sleep, recovery is largely promoted through hormone activity.14 Melatonin helps to neutralize oxidative radicals which harm cells and promote tissue inflammation.15 Melatonin also regulates the circadian rhythm in response to light with low and high levels of secretion.15
Sleep promotes the restoration of the immune and endocrine systems, recovery of the nervous system and the metabolic expenditure of the previous training day, and stimulating memory and learning potential for the subsequent training day.13