We all know how important sleep can be and a fair share of us don’t fulfill our needs consistently (according to the CDC, only one third of adults actually do). You may hear high performers proud to skip sleep to be more productive but sleep allows us to make the most of our time while awake. Our sleep plays a vital role in recovery and physical wellbeing. Here are a few reasons why your physical therapist may ask about your sleep habits.

Sleep protects us from injury. One study tracked over a hundred student-athletes for about 20 months and found a direct relationship between sleep deprivation and increased risk of injury. Overall, athletes who slept less than 8 hours had a 1.7 times increased in injury risk and those who slept 6 hours a night had almost a 4.2 times higher risk than athletes who slept 9 hours (1).

Sleep reduces chronic pain

When we have a nagging shoulder injury or back pain, it makes sense that it may keep us from dozing peacefully. Finan et al (2013) examined available research of the opposite relationship and found that poor sleep lowered participants’ pain tolerance and they concluded “sleep disturbance is a stronger predictor of future pain than pain of sleep disturbance” (2).

Another study tried to replicate a busy work week with 5 nights of limited sleep followed by a weekend of full sleep to “catch up.” After only one week of their study, participants already had significantly reduced pain tolerance (3). It is understandable how being under slept for long periods could compound and contribute to developing chronic pain.

Sleep improves recovery

So sleep can help improve our pain tolerance, but there are other ways it helps to speed up recovery after injury. During sleep, the hormone prolactin is released to help combat inflammation while growth hormone is released to stimulate muscle repair. Increased sleep time also reduces cortisol (the stress hormone) which allows growth hormone to become more efficient in rebuilding damaged tissues. Sleep deprivation can cause an imbalance in these hormones leading to increased inflammation and delayed healing (4).

Sleep boosts performance

If you have ever tried to drag yourself out of bed to run before work or stayed up late to hit the gym, you know all too well how being sleepy can impact the effectiveness of our exercise. Cullen et al found that after only one night of poor sleep, athletes had reduced aerobic performance, jump height, reaction time, and grip strength. A full 8 hours of sleep leads to faster sprint times, faster skill development, and higher testosterone (which in turn can improve performance over time) (5). This performance trend continues across various sports. Basketball players improve their sprint speed and shooting accuracy (6), tennis players serve more precisely (7), weightlifters increased their maximal strength during compound movements (8), and soccer players had improved endurance, strength, reaction speed, and performed better during skill training (9). Sleep is one of the best performance enhancers athletes have at their disposal.

Recommendations for Better Rest

Quality sleep can reduce our risk of injury, prevent chronic pain, improve our recovery, and increase our performance. It is easy to tell someone to just “sleep better,” but hearing this can be frustrating. We all know we should sleep. Here are specific and actionable steps you can take to improve your sleep quantity and quality (10):

The Dos:

• Exercise during the day

• Expose yourself to natural light during the day to regulate circadian rhythm

• Have a consistent bedtime and wake time allowing at least 7 hours of sleep

• Relaxing bedtime routine

• Use bedroom for bedroom activities only

• Keep your bedroom dark, quiet, and cool (around 60 degrees and consider blackout curtains or sleep masks)

The Do Not’s:

• Limit daytime naps to 30 minutes

• No caffeine or nicotine 4+ hours before bed

• No stimulating activity within 3 hours of bed (HIIT, video games)

• No heavy meals or alcohol 3 hours before bed

• Minimal screen time w/ blue light filtering or no screen time

• No over the counter sleeping pills

Whether you are a collegiate athlete, weekend warrior, or enjoy a more sedentary lifestyle, quality sleep helps us feel our best and is one of the greatest things we can do for ourselves. Please talk to your doctor or healthcare professional if you are having difficulty sleeping.

Written by Benjamin Blakely PT, DPT, CSCS

References:

1. Milewski MD, Skaggs DL, Bishop GA, et al. Chronic lack of sleep is associated with increased sports injuries in adolescent athletes. J Pediatr Orthop. 2014;34(2):129-133. doi:10.1097/BPO.0000000000000151

2. Finan PH, Goodin BR, Smith MT. The association of sleep and pain: an update and a path forward. J Pain. 2013;14(12):1539-1552. doi:10.1016/j.jpain.2013.08.007

3. Simpson NS, Scott-Sutherland J, Gautam S, Sethna N, Haack M. Chronic exposure to insufficient sleep alters processes of pain habituation and sensitization. Pain. 2018;159(1):33-40. doi:10.1097/j.pain.0000000000001053

4. Chennaoui M, Vanneau T, Trignol A, et al. How does sleep help recovery from exercise-induced muscle injuries?. J Sci Med Sport. 2021;24(10):982-987. doi:10.1016/j.jsams.2021.05.007

5. Cullen T, Thomas G, Wadley AJ, Myers T. The effects of a single night of complete and partial sleep deprivation on physical and cognitive performance: A Bayesian analysis. J Sports Sci. 2019;37(23):2726-2734. doi:10.1080/02640414.2019.1662539

6. Mah CD, Mah KE, Kezirian EJ, Dement WC. The effects of sleep extension on the athletic performance of collegiate basketball players. Sleep. 2011;34(7):943-950. Published 2011 Jul 1. doi:10.5665/SLEEP.1132

7. Schwartz J, Simon RD Jr. Sleep extension improves serving accuracy: A study with college varsity tennis players. Physiol Behav. 2015;151:541-544. doi:10.1016/j.physbeh.2015.08.035

8. Knowles OE, Drinkwater EJ, Urwin CS, Lamon S, Aisbett B. Inadequate sleep and muscle strength: Implications for resistance training. J Sci Med Sport. 2018;21(9):959-968. doi:10.1016/j.jsams.2018.01.012

9. Clemente FM, Afonso J, Costa J, Oliveira R, Pino-Ortega J, Rico-González M. Relationships between Sleep, Athletic and Match Performance, Training Load, and Injuries: A Systematic Review of Soccer Players. Healthcare (Basel). 2021;9(7):808. Published 2021 Jun 26. doi:10.3390/healthcare9070808

10. Siengsukon CF, Al-Dughmi M, Stevens S. Sleep Health Promotion: Practical Information for Physical Therapists. Phys Ther. 2017;97(8):826-836. doi:10.1093/ptj/pzx057