Sports Physio: Sleep and its Effects on Injury and Performance in Athletes

For elite athletes, sleep is a crucial part of their preparation for sport and an even more crucial part of their recovery from matches and injury. For amateur and community level athletes however, it is a frequently over-looked strategy to improve performance and assist in recovery from injury. I often ask my patients how they recover from training and games, and they will rattle of “stretch, foam roll, hydrate (+/- a couple of post-games beers), eat well, etc”…but rarely do I hear “I try to get at least 8 hours or more sleep per night”.

I posted earlier this week to on my website, the link to a paper that concluded that teenage athletes who get less than 8 hours of sleep each night, increase their injury risk by 1.7x, compared to those who get 8 or more hours sleep per night.1 Another study I found claimed that sleeping less than 6 hours or less per night was associated with fatigued-related injuries among young soccer basketball, football, soccer and running athletes.2 As a result, I looked deeper into the research about sleep, recovery and performance and found further evidence that suggest we ask patients and sub-elite athletes about their sleeping habits and educate them on the power of sleep, to assist them with their injury prevention/rehab and training goals.

The American National Sleep Foundation recommends that the optimal sleep duration is 7-9 hours per night, but sleep quantity is not the only important factor. Sleep quality and timing of sleep are key components to sleep, and any disturbance to 1 of these 3 factors can negatively affect the post-exercise recovery process.3 Physiologically, sleep loss impairs the following:

  • Growth hormone release and muscle protein synthesis: This means the ability for skeletal muscle to adapt and repair, which also has a direct impact on training adaptations such as speed, endurance, strength and power.3,5
  • The learning of new skills and memory: Sleep is crucial for memory consolidation and motor learning.2 Sport is a constantly evolving process, where not only do you need highly developed physical attributes, but sport also requires high levels of motor learning, skill acquisition, strategy, decision-making, cognition and memory to carry out tasks which ultimately influence performance.3

Compared with non-athletes, elite athletes tend to sleep less (6.5 – 6.7hrs per night) and the quality of sleep is lower.5 Athletes also face a unique set of constraints that also effect sleep – busy training schedules, lengthy travel to games/competitions, jet-lag, pre-comp anxiety – which all effect sleep behaviors.4 Furthermore, late night training or late night games have been shown to negatively affect sleep duration and quality in Australian and European soccer players, when compared to training days and day matches.5,6 Reasons for this have been postulated:

  • Bright lights: Light has an inverse relationship with the sleep hormone melatonin; therefore light/artificial light may suppress melatonin and negatively affect sleep.
  • 79% of professional soccer players also reported using smartphones, watching TV, using laptops prior to sleep which all have artificial lighting that reinforces the above point.

Furthermore, technology use prior to sleep may not allow the athlete to “switch-off” prior to bed, with frequent users of social media reporting almost 1 hour per night less sleep.

  • Caffeine is frequently used by athletes to enhance stamina, mental acuity and performance, but physiologically, caffeine inhibits melatonin secretion thus effecting sleep behavior.

In addition, team-sports that are played late at night often involve post-match conferences, recovery and social functions (often including alcohol) that extend their sleep time out significantly compared to their normal sleep time during the week. Early morning recovery sessions the day after the game will also compound poor sleep duration and quality.7

In regards to sporting performance, sleep behaviors have discovered some interesting results:

  • A group of basketball players were encouraged to increase their sleeping habits from an average of 6.5hrs per night to 8.5hours per night. At the end of the 7 week trial; speed tests increased by 5%, free throw accuracy increased by 9% and 3-point accuracy improved by 9%.4
  • Tennis players were encouraged to increase sleep duration by 2 hours per night, which improved their serving accuracy by 5% over the trial period.4

Finally, the effect of sleep quality prior to a concussion and its effect on post-concussion symptoms is something that we should all be aware of:

  • Adolescent and young athletes (mean age 17yrs) with poor sleep behavior (difficulty falling to sleep, sleeping less than usual) prior to sustaining a concussion were compared against those who had good sleep behavior prior to concussion.8
  • The poor sleep group performed significantly worse on visual memory, verbal memory and reaction time compared to the controls, in particularly within the first 2-5 days post-concussion, with reaction time being significantly slower up to 14 days after the concussion.8
  • In regards to concussive and sleep-related symptoms, the poor sleep group consistently showed increased symptoms during the first 14 days post-concussion.8

Conclusion: Athletes with pre-injury sleep difficulties performed worse on neuro-cognitive tests and had worse concussive symptoms after the injury, compared to those athletes that did not have poor sleep difficulties, especially reaction time tests up to 14 days post-concussion.

What this information shows is that we need to be screening our athletes sleep habits regularly throughout the competitive season so that we are aware of the potential ramifications of concussion, and subsequent slower recovery time of their reaction time and verbal memory. Importantly, neuro-cognitive test results lagged behind symptom resolution, which highlights the need for more thorough neuro-cognitive testing of the concussed player, rather than allowing them to return to sport in the absence of symptoms.

Additionally, sleep has a significant effect on injury recovery, training adaptation, neuro-cognition and the ability to perform sport at an optimum level. In my opinion, not only should we be monitoring and educating our elite athletes on their sleep behaviors, but ALL of our patients from the semi-elite junior athlete, to the weekend warrior, to the sedentary office worker. Here are simple strategies recommended by Simpson et al (2016) for all of our patients and athletes to optimize their sleep patterns:

  • Encourage 7-9 hours per night and consider naps during the day if less than 7 hours sleep per night
  • Sleep in cool (but not cold), dark room
  • Avoid using electronics or personal devices in bedroom
  • Limit technology use 1 hour before bed
  • Reduce caffeine after lunch, and minimize alcohol at night

Injury prevention and improved sporting performance are huge passions of mine, particularly in the adolescent athlete, and the more doctors, physical therapists, exercise physiologists, S&C coaches, personal trainers, players, parents, coaches that get on board with this information and understand the benefits and power of sleep, the better performances we will see on the field, and the less injuries we will see in the clinic!

www.mickhughes.physio

Opinions expressed by physiogramworld contributors are their own.

References:

  1. Milewski MD, Skaggs DL, Bishop GA, Pace JL, Ibrahim DA, Wren TA, et al. Chronic lack of sleep is associated with increased sports injuries in adolescent athletes. Journal of pediatric orthopedics. 2014 Mar;34(2):129-33. PubMed PMID: 25028798. Epub 2014/07/17. eng.
  2. Luke A, Lazaro RM, Bergeron MF, Keyser L, Benjamin H, Brenner J, et al. Sports-related injuries in youth athletes: is overscheduling a risk factor? Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine. 2011 Jul;21(4):307-14. PubMed PMID: 21694586. Epub 2011/06/23. eng.
  3. Fullagar HH, Duffield R, Skorski S, Coutts AJ, Julian R, Meyer T. Sleep and Recovery in Team Sport: Current Sleep-Related Issues Facing Professional Team-Sport Athletes. International journal of sports physiology and performance. 2015 Nov;10(8):950-7. PubMed PMID: 25756787. Epub 2015/03/11. eng.
  4. Simpson NS, Gibbs EL, Matheson GO. Optimizing sleep to maximize performance: implications and recommendations for elite athletes. Scandinavian journal of medicine & science in sports. 2016 Jul 1. PubMed PMID: 27367265. Epub 2016/07/02. Eng.
  5. Nedelec M, Halson S, Abaidia AE, Ahmaidi S, Dupont G. Stress, Sleep and Recovery in Elite Soccer: A Critical Review of the Literature. Sports medicine (Auckland, NZ). 2015 Oct;45(10):1387-400. PubMed PMID: 26206724. Epub 2015/07/25. eng.
  6. Fullagar HH, Skorski S, Duffield R, Julian R, Bartlett J, Meyer T. Impaired sleep and recovery after night matches in elite football players. Journal of sports sciences. 2016 Jul;34(14):1333-9. PubMed PMID: 26750446. Epub 2016/01/12. eng.
  7. Fullagar HH, Skorski S, Duffield R, Hammes D, Coutts AJ, Meyer T. Sleep and athletic performance: the effects of sleep loss on exercise performance, and physiological and cognitive responses to exercise. Sports medicine (Auckland, NZ). 2015 Feb;45(2):161-86. PubMed PMID: 25315456. Epub 2014/10/16. eng.
  8. Sufrinko A, Pearce K, Elbin RJ, Covassin T, Johnson E, Collins M, et al. The effect of preinjury sleep difficulties on neurocognitive impairment and symptoms after sport-related concussion. The American journal of sports medicine. 2015 Apr;43(4):830-8. PubMed PMID: 25649087. Epub 2015/02/05. eng.

 

Mick Hughes

Leave a Reply

Your email address will not be published. Required fields are marked *