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 (1). Furthermore, another study reports 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 to say that we should be asking our patients and sub-elite athletes about their sleeping habits and educating 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 for adults, 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, although not limited to, 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, 4).
In elite and sub-elite athletes late night training or late night games are common, and this has been shown to negatively affect sleep duration and quality in professional soccer players, when compared to training days and day matches (5, 6). Reasons for this have been postulated (5):
- 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 during games, but physiologically, caffeine inhibits melatonin secretion thus effecting sleep behaviour (7).
In regards to sporting performance, sleep behaviours have discovered some interesting results (4):
- 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%.
- Tennis players were encouraged to increase sleep duration by 2 hours per night, which improved their serving accuracy by 5% over the trial period.
In summing up this blog, sleep behaviours have 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 behaviours, 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 optimise their sleep patterns (4):
1) Encourage 7-9 hours per night and consider naps during the day if less than 7 hours sleep per night.
2) Sleep in cool (but not cold), dark room.
3) Avoid using electronics or personal devices in bedroom.
4) Limit technology use 1 hour before bed.
5) Reduce caffeine after lunch, and minimise alcohol at night.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.