Sleep and Injury Recovery
by: Caroline Cochrane, BScKin
Even while you’re asleep, your body is still working hard. During the night, your body is resting and recovering from the stress of your busy day. There are many reasons you should be getting a full eight hour sleep, especially if you have been recently injured. Sleep is the time for our bodies to recover, heal and grow. While you sleep, your brain is regulating different hormones that help your body with those processes. Not only are there benefits to a full night's sleep, there are serious decrements to sleep deprivation. Without a good night’s sleep, you are less alert and can experience muscle fatigue the next day. If you are someone who stays up late or wakes up early to exercise, you may benefit from a nap in the early afternoon. Having a short nap can help with muscle growth and make you more awake for the rest of your day. Keep reading to learn about why sleep should be your best friend, and for some tips on how to get a better night’s sleep!
There are two main hormones regulated while we sleep; human Growth Hormone (HGH) is increased and cortisol, the stress hormone, is lowered. About an hour after falling asleep, the pituitary gland becomes more active and releases HGH.1 As the name implies, HGH is responsible for bone and muscle growth, which would help regenerate damaged muscles. It’s doubly important that you are getting sleep as HGH is suppressed while you are awake.1 At the same time, our body suppresses it’s cortisol secretion, which is one of the body’s main “stress hormones”. The main action of cortisol is to suppress other unnecessary hormones during a stressful situation.2 The decrease of cortisol at night time allows our body’s other hormones, like HGH, to be increased, letting us relax and recover from the stress of the day.
Not only is getting sleep important, but studies show that sleep deprivation can increase your chances of injuring yourself. A study from the Journal of Pediatric Orthopaedics surveyed a group of high school athletes about their sleeping habits, their athletic schedules, and how many injuries they had sustained at or outside of school. They found that lack of sleep can negatively impact “motor function, mood, and cognitive functions, all of which could affect a young student athlete’s performance and injury risk.”3 Being tired throughout the day from lack of sleep is going to negatively affect athletic performance. The same study shows that “athletes sleeping less than 8 hours per night were 1.7 times more likely to have a sports injury.”3 Without a good night’s sleep, the students experienced decreased alertness and muscle fatigue, which are great risk factors for injury.
After a night of poor or interrupted sleep, you may benefit from a short nap. Many studies have proven that “daytime napping can improve performance of both athletic and cognitive tasks.”1 A nap has a positive impact on alertness during the day, as well as being able to counteract the results of sleep deprivation.4 One study from the Journal of Sports Sciences found a positive impact on sprinters who took a nap after a night of interrupted sleep. The sprinters self-reported a feeling of being more awake and alert, and even managed to shave off 0.1 seconds in a 20m sprint. It is important to note that performance is only improved after an hour of waking up from a nap. There are lingering effects of sleep, called sleep inertia, for about an hour after waking up.4 Scheduling a nap in your day can have a great benefit for someone who likes to get up early to work out or has multiple training sessions a day.
Now that we know all about how important sleep is, it’s important to learn how we can get the best sleep we can. We can do this by maintaining good sleep hygiene. Sleep hygiene is all about creating good habits and routines to benefit your sleep at night.5 The first component of sleep hygiene is creating a sleep schedule; going to bed and waking up at a similar time everyday. Once you’re adjusted to a routine, your brain will learn to use that time more efficiently and actually get a full and restful night of sleep.5 Another important routine to practice is your bedtime routine. It’s important to include a thirty minute “wind down” before bed.5 Dim the lights and unplug from electronics as harsh lights can suppress melatonin production. Doing things like brushing your teeth and putting on pyjamas lets your brain know that it's bedtime and to begin winding down as well.5 Maintaining sleep hygiene doesn’t just start at night, there are also habits to practice during the day. One being reserving the bed for sleep only, read your book or watch TV on the couch instead of in your bed. Limit coffee to the morning, as caffeine can keep you awake. Try not to snack or drink alcohol close to bedtime either, digestion and the effects of alcohol can disrupt your sleep.5 You can also practice nap hygiene, including limiting naps to the early afternoon, as your circadian rhythm brings you down around this time. Keep naps to no more than an hour, otherwise you may just wake up more sluggish than before.
It is very important to prioritize a good night’s sleep, especially during injury recovery. Ask us about how our health care professionals, including our physiotherapists, massage therapists, and dietitians are able to help with your sleep and injury recovery!
1. Growth Hormone and Cortisol Secretion in Relation to Sleep and Wakefulness, Davidson, Moldofsky & Lue (1991), Journal of Psychiatry and Neuroscience
2. Cortisol and Recovery, Dr. Jason Barker (2014), Natural Athlete’s Clinic https://www.naturalathleteclinic.com/blogs/natural-athlete-solutions/cortisol-and-recovery
3. Chronic lack of sleep associated with increased sports injuries in adolescent athletes, Milewski et al. (2014), J Pediatr Orthop
4. J. Waterhouse, G. Atkinson, B. Edwards & T. Reilly (2007) The role of a short post-lunch nap in improving cognitive, motor, and sprint performance in participants with partial sleep deprivation, Journal of Sports Sciences
5. What is Sleep Hygiene? Eric Suni (2020), Sleep Foundation https://www.sleepfoundation.org/sleep-hygiene