The Relationship Between Sleep and Injury Risk

Relationship Between Sleep and Injuries

Sleep. It’s a tricky topic! We all know we should get more of it – but often don’t prioritize it. In fact, one study found that average Americans prioritize Fitness/Nutrition, Work, Hobbies/Interests, and then Sleep! Have you ever considered how sleep might be contributing to your running injuries? While you might just associate lack of sleep with grogginess and lack of focus, there are a number of ways that it can increase your risk of injury.

First, how much sleep should you get? As you know, it depends on your age group. Here’s a general guide from the National Sleep Foundation:

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As you can see, adults aged 26-64 should aim for 7-9 hours of sleep per night. What happens if you don’t make it to that minimum?

There are a number of negative impacts it can have on your athletic performance, including:

  1. Reaction times

  2. Injury rates

  3. Duration of playing career

  4. Accuracy, speed

  5. Mental errors

  6. Memory

  7. Recovery

Physiologically, poor sleep has these effects as well:

  • Decrease glycogen storage

  • Reduce testosterone

  • Lower HGH

  • Change metabolism

  • Reduce muscle memory

  • Increase inflammation

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Studies Addressing Sleep and Injury Risk

In a 2014 study, researchers looked at 112 middle/high school athletes with a mean age of 15.

Of those studied, the athletes who slept less than 8 hours per night were more likely to have injury compared to the athletes who slept for 8 or more hours. Here is a breakdown of what they found:

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Why Does Lack of Sleep Contribute To Injuries?

Researchers suspect that lack of sleep and can cause worsened reaction times, which leads to injury. Additionally, poor sleep can cause Impaired cognitive function and increased fatigue (Clin J Sport Med 2011;21:307–314). One particular study found that fatigue-related injuries were associated with an athlete getting ≤6 hours of sleep per night

Another theory is that sleep loss causes reduced bone mineral density. The reduced bone mineral density causes an increased risk of runner’s stress fractures.

The impact of sleep on muscle tension and repair is another contributing factor to injury risk. During Non-REM stage 3 sleep, blood flow to muscles increases, which cause a number of other positive events including:

  • Tissue growth and repair occurs

  • Growth hormone released during stage 3 sleep

  • Energy expenditure lower during sleep – more energy can be directed to musculoskeletal repair

During REM sleep, muscles relax, which may reduce muscle tension.

If the body doesn’t get enough sleep, it doesn’t have enough time to repair tissue and relax the muscles deeply. this is why sleep deprivation slows wound healing and may leave you injured for longer.

What Does This Mean?

So lack of sleep can lead to an injury, and continued lack of sleep can make it harder for your body to heal. Your body needs sleep! Always aim to hit 7-9 hours per night as an adult, and 8-10 hours per night as a teen. This will help you to run faster, run longer, and run injury-free.

Contact us for a consultation today if you have more questions.

Sources:

Science Translational Medicine 08 Nov 2017: Vol. 9, Issue 415, eaal2774

Endocrine. 2015;49:538–48.

Journal of the American Geriatrics Society. 2015;63:1401–6

Journal of Pediatric Orthopaedics34(2):129-133, March 2014.

Charlotte Spangler