Written by Chris Dohrmann, DPT
Sleep is such an integral part of our lives. It’s inevitable, and shouldn’t be looked at as a nuisance. We’ll spend approximately a third of our lives sleeping, so understanding why it’s important is crucial. More specifically, I’d like to convey to the readers of this post why it’s important if you are in pain, trying to prevent pain, or trying to improve performance would be the true end goal of this post. First to understand that, we need to know what sleep is.
Sleep is defined as “a reversible, recurrent behavioral state of perceptual disengagement from and unresponsiveness to the environment.” Sleep health is further defined as:
“Sleep health is a multidimensional pattern of sleep-wakefulness, adapted to individual, social, and environmental demands, that promotes physical and mental well-being. Good sleep health is characterized by subjective satisfaction, appropriate timing, adequate duration, high efficiency, and sustained alertness during waking hours.”
The second part of that definition that defines what, “good” sleep health is, is what truly matters here. There are far too many individuals that are not getting the age recommended amount of sleep per night, and that’s not even discussing the quality of sleep yet. Refer to this recent instagram post for some data on sleep quantity in adolescent athletes, where according to national data from the CDC appear to be chronically sleep deprived. To understand why this is a problem, you first have to understand the two main subphases of sleep and what their roles are.
The first phase is non rapid eye movement sleep, or NREM. In this phase there’s a few main things that happen, but pertinent to recovery and performance, growth hormone is released. With the release of growth hormone, this stimulates protein synthesis, bone remodeling and growth, muscle repair and growth, and fat catabolism. Studies have shown that following repeated bouts of exercise, athletes who were deprived of NREM sleep had lower levels of growth hormone the following morning. The second stage of sleep in REM sleep, and may play a role in memory consolidation and learning. This is important for folks in regard to motor skill development.
Acute and chronic sleep deprivation have shown to have effects on cognitive function. This makes sense right? Have you had a night of two hours of sleep, and basically go through your day slinging back coffee, almost on autopilot. This happens after just one night! There’s similar effects when this is chronic (> 5 days in a row), however the problem is that these effects may persist for a longer period of time after that period of deprivation.
Athletic performance is also impaired. Studies have shown that athletes have lower mood, increased fatigue, and increased soreness amongst other self report measures with sleep deprivation. Our body will also choose protein over fats as a source of energy when we’re sleep deprived, so we’re also breaking down the tissue that makes us strong!
According to a study by Von Rosen at el, studying sleep, diet, and injury in adolescent athletes, the authors found a significant reduction in injuries for athletes sleeping greater than 8 hours of sleep per night. The authors had a population of 340 adolescent athletes and found that those that slept great than 8 hours of sleep per night had a reduction of injury risk of 60%. Conversely, a study by Milewski et al found that adolescents athletes in their study had a > 60% chance of injury over a 21 month period when chronically sleeping 7 hours or less of sleep per night. This risk of injury increased to over 70% for 6 hours or less!
The evidence is insurmountable folks. While we use exercise, manual therapy, and conversations on how to self manage symptoms everyday in our clinic, we’d be foolish to overlook such an important factor. Now intervening and improving this can be a tall task and in some cases requires further evaluation from a sleep specialist. However, many of us can do little things to improve our sleep hygiene and stay tuned for future posts on how we can take little steps to improve our sleep and hopefully our wellbeing.
Carskadon MA, Dement WC. Normal human sleep : an overview. In: Kryger MH, Roth T, Dement WC, editors. Principles and practice of sleep medicine. 5th ed. St. Louis: Elsevier Saunders; 2010. p 16-26.
Dwivedi, Shashank; Boduch, Abigail; Gao, Burke; Milewski, Matthew D.; Cruz, Aristides I. (2019). Sleep and Injury in the Young Athlete. JBJS Reviews, 7(9), e1–. doi:10.2106/jbjs.rvw.18.00197
Von Rosen P, Frohm A, Kottorp A, Friden C, ´ Heijne A. Too little sleep and an unhealthy diet could increase the risk of sustaining a new injury in adolescent elite athletes. Scand J Med Sci Sports. 2017 Nov;27(11):1364-71. Epub 2016 Aug 19.
Milewski, Matthew D.; Skaggs, David L.; Bishop, Gregory A.; Pace, J. Lee; Ibrahim, David A.; Wren, Tishya A.L.; Barzdukas, Audrius (2014). Chronic Lack of Sleep is Associated With Increased Sports Injuries in Adolescent Athletes. Journal of Pediatric Orthopaedics, 34(2), 129–133.