Adolescents Lack of Sleep & Injury | Delayed Phase Shift

Have you noticed on those nights of poor sleep, you are less likely to put in a good effort at training or at work the next day. Just can't seem to find top gear or put it all together?

You may recall a couple of months ago I drew your attention to a couple of articles examining the relationships between poor sleep and migraine and poor sleep and LBP. If not you can catch it here.

Today's article titled 'Chronic Lack of Sleep is Associated With Increased Sports Injuries in Adolescent Athletes' examines another aspect of short sleeping, that is, increased injury rates. As health professionals, we are familiar with considerations of overall training loads, rates of increased training loads and specific mechanics of movement, and how they can all contribute to injury. Do you also consider quality and quality of sleep contributing to your young athletes in jury rates? Are you aware that young athletes are particularly prone to a sleep disorder called delayed phase shift? More on this later.

Milewski and co-authors studied 112 athletes in grades 7 - 12 (middle/high school) by collecting injury records and comparing them with an online sleep survey. The key findings were that hours of sleep per night and the grade the students were in at school were the best independent predictors of injury. Athletes who slept on average <8 hours per night were 1.7 times (95%Cl 1.0-3.0; p = 0.04) more likely to have had an injury compared with athletes who slept for 8 or more hours. For each additional grade in school, the athletes were 1.4 times more likely to have an injury (95% CI 1.2-1.6; p < 0.001).

It is important to note that while Milewski and colleagues used less that 8 hours as their cut point, the National Sleep Foundation (USA) in 2015, recommended teenagers 14-17 years of age achieve 8-10 hours of quality sleep per night. In addition to traumatic injuries, other effects of lack of sleep for adolescents include increased rates of acute illness and the development of chronic illnesses (Ref.)

And to my final point about this particular group of young adults. Quite commonly their circadian clocks are set late. That is biologically (read, not deliberately trying to tick of Mum & Dad) their melatonin buildup doesn't peak till around midnight, whereas most adults will peak around 10.00pm. Put another way, it is like the average adult trying to go to bed at 8.00pm and not their regular 10.00pm. This phenomenon is called delayed phase shift disorder and wouldn't be a problem if they could also sleep late into the morning, to achieve their necessary 8 - 10 hours of sleep. However, alarm clocks, parents, bus and school schedules don't allow this 5 days of the week. Throw in screens, parties, training and homework, and you can see how easy a train wreck can occur.

As health professionals, it is important that we educate young adults and their parents about the importance of sleep for optimal mental and physical health. You can learn more about managing phase shift disorders and other sleep conditions in the clinician-specific Sleep Mastery course here.

Here's to a great night of sleep tonight!