How Important Is Sleep for Preventing Injury and Recovering From One?

When you're recovering from an injury, you think about exercises, appointments and how much you can load it. Sleep rarely makes the list. It should. Not because it's a magic fix, but because poor sleep quietly works against almost every part of recovery, and fixing it costs nothing.

Does poor sleep make you more likely to get injured?

For young athletes, probably yes. In a study of 112 high school athletes, those who averaged less than 8 hours a night were 1.7 times more likely to have been injured than those sleeping 8 hours or more.¹ In 340 elite adolescent athletes, sleeping more than 8 hours on weeknights was linked to 61% lower odds of a new injury.² Pooling the available studies, teenagers who chronically slept poorly had about 58% higher odds of injury than those who slept well.³

For adults, the evidence is surprisingly thin. A 2021 systematic review of 12 prospective studies in adult athletes concluded that poor sleep hasn't yet been shown to be an independent risk factor for injury.⁴ That doesn't mean sleep is irrelevant for adults. The studies are small, measure sleep in different ways, and injury has many causes: training load, strength, previous injury, and more. Sleep is likely one piece of that picture rather than the whole story.

One honest caveat: all of these are observational studies. They show an association, not proof that short sleep causes injury. Teenagers who sleep less may also be training more or under more stress.

Where sleep clearly matters: healing

Once you're injured, the case for sleep gets stronger, because we can measure what sleep loss does to the healing process directly.

It slows rebuilding. In a controlled trial, one night without sleep reduced muscle protein synthesis (the process your body uses to rebuild muscle) by 18% in healthy young adults. Cortisol, a stress hormone that breaks tissue down, rose by 21%, and testosterone, which supports rebuilding, fell by 24%.⁵ A full night without sleep is more extreme than most people's week, but it shows clearly which direction sleep loss pushes you.

It slows healing. Researchers made small, controlled skin wounds in healthy adults. After a few nights restricted to 2 hours of sleep, the wounds took about 5 days to heal, compared with about 4.2 days after normal sleep. Giving people extra protein and nutrients didn't close that gap.⁶ Skin isn't a tendon or a ligament, but it's a clean look at the same repair machinery.

The practical takeaway: you can't out-supplement poor sleep. Nutrition matters, but it doesn't replace what sleep does.

Sleep turns the volume on pain up or down

This is the part most people notice first. After one night without sleep, people's pain thresholds dropped: things that weren't painful before became painful, and the brain areas that detect pain became more reactive. Just as importantly, outside the lab, ordinary night-to-night changes in sleep quality predicted how much pain people felt the next day.⁷

Over the longer term, a review of 16 studies following more than 61,000 people found that when sleep got worse, the risk of developing a pain condition rose two- to three-fold. When sleep improved, physical function improved too.⁸

Pain and sleep feed each other. Pain disrupts sleep, and poor sleep amplifies pain. If you're stuck in that loop, working on the sleep side is often easier than people expect, and it makes every other part of rehab feel more manageable. It's a similar trap to the one we describe in breaking the boom–bust cycle.

Does improving sleep actually help?

Yes, with some limits worth being upfront about. When university basketball players extended their sleep by almost 2 hours a night for several weeks, their sprint times got faster, their shooting accuracy improved by around 9%, and their reaction times sharpened.⁹ For people with chronic pain and insomnia, a review of 12 randomised trials found that cognitive behavioural therapy for insomnia (CBT-I) produced large improvements in sleep and small improvements in pain.¹⁰

What we don't have yet is a trial showing that sleeping more directly cuts injury rates. So treat sleep as a powerful recovery tool, not a guarantee against injury.

How to make your sleep work for your recovery

1. Protect the hours. Adults should aim for at least 7 hours a night,¹¹ and teenagers 8–10.¹² Needs vary between people,¹³ so a better test than any number is whether you usually wake up feeling rested.
2. Keep a steady wake-up time, including weekends. It anchors your body clock and makes falling asleep at night easier.
3. Stop caffeine 6 hours before bed. Caffeine taken even 6 hours before bedtime measurably disrupted sleep.¹⁴ For a 10pm bedtime, that means your last coffee by 4pm.
4. Go easy on alcohol. It can help you fall asleep, but it fragments sleep later in the night.
5. Set your injury up for the night. A pillow between the knees for back or hip pain, a pillow supporting the arm for shoulder pain, a swollen ankle raised on a pillow. Ask your physio what position suits your injury.
6. Plan your pain relief. If pain keeps waking you, talk to your GP or pharmacist about pain relief and timing that suits you.
7. Keep the room cool, dark and quiet, and give yourself a wind-down period before bed rather than going straight from a screen to sleep.
8. Use naps as a top-up, not a replacement. A short early-afternoon nap can help after a bad night, but it doesn't replace night-time sleep.

When to get help

• Trouble sleeping most nights for three months or more: see your GP. CBT-I is an effective treatment for insomnia, including when pain is involved.¹⁰
• Loud snoring, gasping at night, or feeling sleepy during the day despite enough time in bed: see your GP to rule out sleep apnoea.
• Pain that wakes you every night and doesn't ease with changing position, especially with fever, unexplained weight loss or feeling unwell: see your GP promptly.

How we factor sleep into rehab at Move

We ask about sleep in every assessment, because it changes how we plan your rehab. A week of poor sleep is a reason to hold your program steady rather than push it harder. We'll give you practical positioning advice for your specific injury, and if sleep looks like a bigger problem, we'll point you to your GP.

Sleep won't replace good rehab. But good rehab works a lot better when sleep is on your side.

Daniel Ryan

Senior Physiotherapist · Founder, Move Physiotherapy & Fitness

Masters of Physiotherapy, University of South Australia. Founded Move Physiotherapy in 2018. Provides match day services to sporting clubs across Perth, with a focus on evidence-based rehabilitation and objective return-to-sport testing.