Return to Play During a Pandemic

Original Editor - Wanda van Niekerk

Top Contributors - Wanda van Niekerk, Kim Jackson, Vidya Acharya and Lucinda hampton  

Introduction[edit | edit source]

The COVID-19 pandemic has affected the lifestyle of people around the world. Athletes of all levels, be it at school, recreational or elite level, have all been affected by lockdowns and various restrictive measures used to curb the spread of COVID-19. In many cases this may be the longest period away from structured training within the various sporting disciplines.

Although athletes of all levels have been able to train at home, these training activities and different exercise regimes are vastly different from the norm and it is highly unlikely that these methods of training are able to replicate match or competition demands. When considering return to play during a pandemic it is important to factor in the limitations of training from home and to identify the risks involved in returning to training and competitions. It is therefore important to develop appropriate athlete and sport specific return to play strategies.[1]

A safe progressive return to play strategy should consider[1]:

  • The duration of lockdown/ isolation/ quarantine
  • The health status of the athlete (for example is the athlete affected by Covid-19 or not?)
  • The complexity of the sport
  • The overall content and training load of training activities/exercise regimes during home isolation/lockdown

Generic return to play principles may be applied across sports to develop return to play strategies, but keep in mind that there are specific considerations needed for different sports. These are determined by the performance demands and training content.[1]

One of the strategies that countries around the world have adopted to safeguard public health, is the prolonged period of reduced or no access to sporting facilities. This led to a reduction in regular training sessions and competitions. Therefore, considerable care should be given on how to facilitate return to play, taking into consideration the athlete’s optimal performance levels, while still reducing the risk of injury and illness during these unprecedented times.[1]

Absence from regular sports training may cause detraining of several physiological, psychological and technical/tactical aspects which influences sports performance.[1] Detraining can be defined as “the partial or complete loss of training-induced adaptations in response to cessation of training or a substantial decrease in training load."[2]

Factors that may influence the condition in which an athlete return to training activities are[1]:

  • Level of activity that athlete was able to maintain
  • The volume, intensity and type of training performed
  • Nutritional habits during lockdown
  • If the athlete had contracted COVID-19 and the severity of symptoms

A framework for return to training has been designed and published in the Aspetar Guidelines: Returning to Sport during the Covid-19 pandemic.[1] This framework follows an admission process of gathering information needed to develop an individualised return to play strategy.

Aspetar Guidelines for Returning to Sport during the COVID-19 Pandemic[3]

Impact of COVID-19 on Athletes[edit | edit source]

The COVID 19 pandemic has significant effects on athletes. These include[4]:

  • Physical deconditioning
  • Altered sleep patterns
  • Worsening nutrition
  • Uncertainty on Return to Sport
  • Feelings of depression

It appears that athletes are well informed about the disease, but they still need to be provided with reliable, evidence-based resources. Recent research highlights the importance of closer medical, nutritional and psychological support to athletes during and after lockdown.[4]

Practical and Medical Recommendations on Resumption of Sport[edit | edit source]

Lollgen et al(2020)[7] recently published practical and medical recommendations for return to sport during the pandemic.[7] The following groups are distinguished (and these can refer to both leisure time and professional athletes) and the recommendations for the resumption of sport:[7]

Group Identification and Recommendations[edit | edit source]

  1. Individuals without COVID-19 symptoms and signs and who have never tested positive for COVID-19[7]
    • Assess risk stratification for safe return to sport through questionnaires.
    • Compile data on: personal and medical history
    • Close contact with individuals with positive COVID-19 tests
    • Contact with individuals at high risk of being infected (hotspots)
    • Document that individual confirms that he/she is free of any symptoms
    • Exercise testing may be necessary in certain sports due to the expected detraining after lockdown
    • Perform exercise testing in line with the latest COVID 19 health and safety regulations as stipulated by country and/or sporting organisation
  2. Individuals who tested positive for COVID-19, without any symptoms, but who are isolating at home(quarantine) and who are under medical observation (telehealth)[7]
    • May resume return to sport after 14 days of quarantine
    • Medical examinations should include:
      • Medical history
      • Physical examination
      • ECG – 12 channel
      • Lung function assessment with typical respiratory signs and symptoms
      • ECG stress test
      • Echocardiography if clinically indicated
  3. Individuals with COVID-19 with mild symptoms, received only outpatient treatment and are isolating at home (quarantine) for 14 days[7]
    • Resume return to sport after 14 days quarantine and strict social distancing for another 2 weeks
    • Should be medically examined by sport and exercise medicine physician
    • Examination should include:
      • Medical history
      • Physical examination
      • Blood tests (focus on critical markers such as C-reactive protein, high sensitivity troponin-I, natriuretic peptides)
      • Resting ECG
      • In cases where symptoms involved respiratory or cardiac impairment additional tests should include:
        • lung function assessment
        • Stress test with ECG
        • Blood gas analysis
        • Spiroergometry
        • Echocardiography
    • Return to regular sport possible 3-4 weeks after start of symptoms under medical surveillance
    • Medical surveillance should continue for 6 months after return to sport if any symptoms are present but not limiting the athlete’s return to sport
  4. Individuals with COVID-19 with moderate symptoms, received inpatient treatment due to an increased risk as a result of pre-existing conditions such as asthma or diabetes[7]
    • Similar to group 3, but medical examination should include compulsory ergometry with blood gas analysis and/or spiroergometry
    • Chest X-ray in hospital
    • High resolution CT of the thorax  in severe cases with consultation with a lung specialist
    • Cardiac examinations will depend on medical history, signs and symptoms
    • Return to sport vary from 2 to 6 months depending on the severity of respiratory and cardiac involvement
  5. Individuals with COVID-19 with severe symptoms, received inpatient treatment, including intensive care without artificial respiration[7]
    • Rehabilitation is recommended following discharge from ICU or hospital
    • Important to perform complete pulmonary and cardiac examination
    • Return to sport after several months depending on the severity and completeness of recovery
  6. Individuals with COVID-19 with severe symptoms, received inpatient treatment in intensive care and on artificial respiration[7]
    • Rehabilitation is recommended following discharge from ICU or hospital
    • Important to perform complete pulmonary and cardiac examination
    • Return to sport after several months depending on the severity and completeness of recovery

The resumption of sporting activities should be evaluated on a case by case scenario and be individualised for the athlete. Considerations should include: pre-existing conditions, the type of sport and the risk of infection from other athletes. Training should gradually be increased and the athlete should be monitored for any signs and symptoms of possible health issues.[7]

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Effects of Detraining on Physiological Systems[edit | edit source]

Detraining affects many physiological systems and muscle and tendon tissues in the human body. Some of these effects include[1]:

Neuromuscular Effects of Detraining[edit | edit source]

Cardiorespiratory Effects of Detraining[edit | edit source]

  • Reduced maximal oxygen uptake
  • Increased mean blood pressure
  • Increased maximal heart rate
  • Increased submaximal heart rate
  • Decreased maximal cardiac output
  • Decreased lactate threshold
  • Decreased endurance performance

Musculoskeletal Effects of Detraining[edit | edit source]

  • Reduced bone mineral density
  • Reduced oxidative enzyme activity
  • Reduced glycogen synthase activity
  • Reduced mitochondrial ATP Production
  • Reduction in tendon quality

Healthcare professionals and coaches need to consider the training history of athletes during periods of lockdown or isolation as this will guide the appropriate training loads and activities to be performed for the level of conditioning of the athlete, as well as the progression of training load and activities. It is evident that physiological systems that improve with training will also decline when the training stimulus is removed.[1] Factors that may influence the level of decline are[1]:

  • Pre-existing fitness levels
  • Training history
  • Genetics
  • Age
  • Specificity and characteristics of training during lockdown/isolation

Athletes who have had COVID-19 might have a greater reduction in physical conditioning. This will be related to the severity and duration of COVID-19 symptoms. It is recommended and advised that athletes who had COVID-19 should undergo a complete medical and physical assessment before return to play and that the return to play guidelines should be based on the outcomes of the medical and physical assessment and adapted as needed. Athletes should also be monitored regularly.[1]

Evidence for the Effects of Detraining[edit | edit source]

A decline of between 2% to 4% in cardiovascular, metabolic and neuromuscular performance has been reported in elite athletes as a result of detraining or lack of activity. Maintaining some form of training may be enough to alleviate these losses and it has been reported that retraining may recover performance parameters within 2-6 weeks. In the musculoskeletal system extreme situations of inactivity may affect bone mineral density.[1]

Insufficient training may lead to a reduction in aerobic capacity in highly trained athletes. This will cause an increase in heart rate for any given workload, compared to when the athlete is fully trained.[2]

Periods of inactivity/deconditioning leads to a reduction in endurance capacity and repeated sprint ability after just two weeks, as seen in semi-professional soccer players. The extent of the aerobic capacity decline is dependent on initial performance levels and the extent of the detraining or inactivity period.[11]

In well-trained cyclists a reduction in aerobic capacity and power output has been reported after four weeks of detraining. Furthermore, endurance capacity declines with detraining in endurance athletes, but at least one short 35-minute high intensity bout of exercise per week may help to maintain VO2 max in well-trained endurance athletes.[12]

Studies have reported a loss of force and power-generating capacity between 2% and 60% after periods of detraining.[2]

Planning Graded Return to Training and Competition[edit | edit source]

In this unique situation of a pandemic, the length and degree of detraining/deconditioning/inactivity are key considerations in the planning of return to play strategies. Athletic populations do show a quick return to original performance levels.[13]

High intensity training, such as plyometric and fast eccentric loading activities should be carefully introduced, especially if the athlete has not been able to maintain this during lockdown/isolation. There may be an increased risk of injury if these activities are introduced without caution.[1]

Assessing and Monitoring Fitness Levels[edit | edit source]

Some factors to consider with the assessment and monitoring of fitness levels to individualise training are[1]:

  • Assess training status of athlete when training resumes
  • In the first phase of return to play, avoid maximal testing activities to reduce injury risk and perform physical assessments at submaximal performance
  • Sports-specific testing, observations and assessments may be performed and gradually introduced as part of the warm-up and/or training activities – approach this like a pre-season training resumption
  • Use the data from the sport-specific testing to develop an individualised training programme
  • Assess training history, details of detraining/deconditioning/inactivity
  • Regular monitor training activities and athlete feedback and adjust the training regime where necessary
  • Monitor internal and external load
  • Evaluate cardiorespiratory responses to training, especially in athletes who had COVID-19
  • Assess the cognitive, technical and tactical skills relevant to the sport of the athlete

Injury Prevention[edit | edit source]

Athletes may be more at risk of injury after prolonged periods of lockdown/isolation. During the National Football League (NFL) lockout in 2011 in the United States, there was a prolonged off-season (more than 3 months) with no access to training facilities. A higher rate of Achilles tendon injuries, occurring during the first period of training camp and the season was reported after this lockout period. It is important to monitor the physical status of athletes to determine the readiness of the athlete to safely return to play.[14]

Monitor the athlete’s training load and ensure that the training load is not too high for the athlete’s fitness level or even too different in movement patterns and intensity.[15] Athletes may also have developed poor sleeping and eating habits during the lockdown period and this may also affect their readiness to return to play. Assess the athlete’s wellbeing regularly. One way of doing this is to routinely assess pain perception with body maps as this may help the medical staff identify potential issues.[16]

Psychological Support[edit | edit source]

The suspension and cancellation of competitions may and have caused grief, frustration, stress, anxiety, sadness and depression for athletes. However, return to play may also cause significant stress and anxiety to athletes as they are concerned about their health, the fear of contagion and concerns about falling ill with COVID-19, as the risk is always present.[17]

Many athletes will be able to cope with these unique circumstances, but there are athletes that might struggle with this and not have the coping resources. These athletes will be at an increased risk of mental health issues, injuries and a drop in performance levels.[17][18] Healthcare professionals working with these athletes should anticipate this and be aware that some athletes may need additional mental health support.[19]

Practical Recommendations for Healthcare Professionals Working with Athletes[edit | edit source]

  • Check in regularly with athletes
  • Help athletes develop resilience, learn from life experiences, rely on past successes to give them confidence
  • Facilitate consultations with psychologist where needed

Specific Athlete Populations[edit | edit source]

School Children, Adolescents, Young athletes and School Sports[edit | edit source]

Many young athletes have had to deal with the disappointment of not being able to take part in any sports or school sports activities during the pandemic. For many of these young athletes, their final year of school and school sports is a stepping stone to a career in professional sport, or access to university or college on sport scholarships. These young athletes will have to deal with a great deal of uncertainty and disappointment during the pandemic and that may have an affect on their mental health and performance.[20]

Young people all over the world also have to deal with a sudden change in lifestyle and being a lot more inactive than what they are used to. For many the lockdown periods in many countries lead to children spending a lot more time indoors, spending more time on digital devices and being sedentary. They also had to cope with minimal social interaction with their peers and many also developed poor eating habits. Now with schools reopening and young people starting to get more involved in organised sports within the relevant COVID-19 regulations, they do seem a bit more sluggish and some are carrying a bit more weight or showing a change in body composition compared to before lockdown periods.[20]

Furthermore, many young athletes have had growth spurts in the past couple of months and are now presenting with many growth-related injuries such as:

As a result of a more sedentary lifestyle during lockdown, young athletes may have developed certain musculoskeletal issues. For example[20]:

  • Tightness or shortening of the hip flexors
  • Tightness or shortening of the hamstrings
  • Atrophy of gluteal muscles
  • Weakness of core muscles

With the return to school and some sporting activities being allowed, coaches may be overzealous to increase the level of fitness of these young athletes. This may lead to overuse injuries, such as medial tibial stress syndrome (MTSS). Many young athletes may also not have done any proprioceptive training during lockdown and there is the risk of ankle injuries.[20]

With the return to sport in young athletes during a pandemic, physiotherapists will most likely see quite a few growth-related injuries as well as inactivity-related injuries. Young athletes will also probably show signs of a loss in strength and stability as well.[20]

Return to Play Tips for School Children[edit | edit source]

  • Advise coaches on gradual return to play principles
  • Building blocks to concentrate on may include:
    • Core muscle strength
    • Stabilising muscles
    • Balancing muscles
    • Proprioception
  • Slow and gradual progression of cardiorespiratory fitness
  • Provide psychological support to young athletes, reassurance of future opportunities, etc

Weekend Warriors[edit | edit source]

Weekend warriors are individuals who “engage in [physically] demanding recreational sporting activities on weekends despite minimal physical activity during the [work] week.[21] One of the most common reason that they provide for this type of behaviour is time constraints.

Many weekend warriors are executives or office workers who have suddenly been forced to work remotely from home during the pandemic. Along with working remotely comes a few issues, such as[20]:

  • Inadequate home offices with no ergonomically correct set-up
  • Loss of sense of time – no end to the workday
  • Increased levels of stress

Many of these weekend warrior athletes may present with issues such as back and neck pain as well as headaches. Also, many countries had extremely strict lockdown regulations and people were not allowed to leave their homes to exercise. This resulted in many people taking up challenges such as running various distances around their house or in their backyard.[20]

Weekend Warrior Runner[edit | edit source]

As a result of sitting and being sedentary many of these weekend warriors present with shortened hip flexors, hamstrings and deactivated gluteal and core muscles. As lockdown restrictions ease, these athletes tend to want to start running and often end up injured as a result of increasing their training load too soon.[20]

Return to Play Tips for Runners[edit | edit source]

  • Physiotherapists should advice these athletes on a slow return to fitness
  • Provide guidance on strength building at home – include exercises such as gluteus maximus strengthening and hip extension exercises[20]
  • Running analysis where needed and teach athletes the proper running technique
  • Assess shoe wear
  • Watch out for over-striding as this is a risk for injury, especially in the hamstring complex[20]

Weekend Warrior Cyclists[edit | edit source]

  • Provide guidance on proper bike-set up
  • Ensure that athletes are sitting correctly on bicycle with the correct posture

Weekend Warrior Squash[edit | edit source]

  • There is a high risk for Achilles tendon and meniscus injuries in squash players
  • Focus on flexibility and strength of gastrocnemius and soleus muscles and hamstring complex
  • Strengthening of the gluteal muscles
    • concentrate on changing direction exercises
    • proprioceptive training
    • dynamic and explosive (jumping) exercises
  • Advise athletes on proper warm-up techniques
  • Ergonomics at home office

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Elite Athletes[edit | edit source]

The Covid-19 pandemic has significantly impacted elite athletes. A recent study on the impact of the pandemic on elite and semi-elite athletes in South Africa highlights the many issues that this specific population of athletes must cope with.[4] Some aspects that came out of this study are[4]:

  • Most athletes continued with daily training, alone and at moderate intensity for about 30 to 60 minutes
  • Athletes preferred sedentary above active behaviour during leisure time
  • Athletes’ sleep patterns changed significantly
  • Athletes had changes in nutritional behaviour with a significant number of athletes consuming excessive carbohydrates
  • Athletes felt depressed and required motivation to keep active

Olympic athletes have been significantly affected as the Olympic Games were postponed. Athletes were well-trained and in their final phases of training preparation for the Olympic Games when the games were postponed. Athletes had to deal with the disappointment of this, but also had to deal with sudden changes in their training schedules and instead of focusing on peak performance at the right time, they suddenly had to focus on deconditioning and restructuring their training regimes in order to prevent burn-out or overuse injuries.[20]

Worldwide many sports have started opening again, such as rugby, cricket, football, tennis, golf etc under strict COVID-19 regulations. But for many athletes the cancellation of sporting events also meant a loss of income. This may significantly affect the mental health of the athlete and cause increased levels of stress and anxiety.[20] Psychological support for athletes is essential and athletes will need as much support as possible during this pandemic. For many of them, their identity is grounded in their sports career and with them being unable to compete they will need inspiration and motivation.

Elite athletes, just as the general population, also underwent drastic lifestyle changes during lockdown measures with the majority choosing sedentary behaviour, especially watching television. The negative effects of a sedentary lifestyle are well documented. Some issues that physiotherapists may see are weakness of the gluteal muscles, tightness of the hip flexors and hamstrings and low back pain and/or neck pain from ongoing stress.[20]

A positive that may come out of this is that physiotherapists may now be able to spend more time on prehabilitation and injury prevention with athletes, instead of only focusing on rehabilitation after injury.[20]

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Athletes with Disabilities[edit | edit source]

Athletes with disabilities are also significantly impacted by the pandemic and with the Paralympic Games of 2020 also postponed many athletes are dealing with disappointment and uncertainty. For many athletes with disabilities the Paralympics is the global stage where they can showcase their talents and abilities. There are not as many competition opportunities for athletes with disabilities as there are for athletes with no disabilities.[20]

Training is very different for athletes with disabilities and they must cope with various challenges, such as severe muscle imbalances, spasticity, muscle weakness, balance and proprioception challenges.[20]

With lockdown and restrictive measures around the world, many athletes with disabilities found it challenging training and exercising at home without the right equipment and training facilities. The “forced” sedentary lifestyle also created challenges, with athletes being inactive and experiencing poor circulation and poor breathing patterns.[20]

Healthcare professionals working with athletes with disabilities need to be sensitive to the unique challenges that an athlete may be facing. With return to play it is recommended to progress slowly with a gradual increase. Work on muscle imbalances and focus on basic foundational rehabilitation, strengthening, prehabilitation, mobility and stability. Aim to keep athletes motivated by setting small and specific goals.[20]

Telehealth and Social Media Platforms[edit | edit source]

The COVID-19 pandemic has caused many healthcare professionals to consider and implement Telehealth in their practices and patient care. Telehealth can provide physiotherapists ways to connect with athletes and still provide ongoing care, advice and rehabilitation where necessary.[20]

It is also important to be aware of the effect of social media on athletes. Unfortunately, there are many irresponsible fitness challenges available online and athletes often try these out because of boredom or just testing their limits. with some negative effects such as injuries.[20]

Collision Sports[edit | edit source]

The COVID-19 pandemic has created an unusual period of training restriction for all athletes around the world. Return to play activities need to be carefully planned by all sporting bodies and governments. These methods will differ between countries and sports, considering the different levels of impact COVID-19 has had on training restriction and modification and the different stages of the season athletes were in.[24]

In collision sports, return to play will be more difficult to manage following a period of modified isolated training. Reasons for this are[24]:

  • High-risk nature of participation in collision sports
  • Importance of strength and power in collision sports (this may have been affected by restricted access to training equipment and space)
  • Executing skills in high-risk areas of the game, such as tackling in rugby, and the lack of opportunity available to train these skills
  • Training progressions will also be influenced by:
    • The limit on the number of players allowed to train together
    • The limit on the amount of time it is acceptable for players to be in close contact with other players

However, this unique period of non-contact training in collision sports, may not all be negative. It could create a positive period for physical and psychological rest and recovery for athletes.[24] This may improve an athletes’ performance and well-being, if appropriate and progressive return to play and reconditioning practices are in place.[24] Furthermore, athletes now have the chance to target and develop specific physical weaknesses without the pressure of being match-ready for weekly competitive matches.[24]

Practical Implications for Athletes[edit | edit source]

The COVID-19 pandemic and the measures to curb the spread of the disease has significantly affected athletes around the world. Some practical implications to consider are[4]:

  1. A culture of education for athletes and support staff needs to be created and implemented regarding hand hygiene, the wearing of face masks, social distancing and self-isolation. This may improve health literacy and promote the necessary required behavioural changes
  2. Athletes need health, nutritional and psychological support during lockdown periods
  3. Progression in training load and allowing maximal adaptation to training stimuli before competitions may reduce the risk of injury
  4. Athletes need to be educated on sleep hygiene and its effect on performance
  5. A thorough medical assessment, including nutrition assessment, is needed before athletes return to high intensity sporting activities
  6. The mental health of athletes is paramount and forms an integral part of athlete performance and any issues regarding this should be addressed
  7. Athletes need to be educated on financial planning for their future

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Resources[edit | edit source]

References[edit | edit source]

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 Aspetar Clinical Guideline. Safe Return to Sport during the COVID-19 Pandemic. June 2020
  2. 2.0 2.1 2.2 Mujika I, Padilla S. Detraining: loss of training-induced physiological and performance adaptations. Part I. Sports Medicine. 2000 Aug 1;30(2):79-87.
  3. Aspetar Clinical Guideline. Safe Return to Sport during the COVID-19 Pandemic. June 2020
  4. 4.0 4.1 4.2 4.3 4.4 Pillay L, van Rensburg DC, van Rensburg AJ, Ramagole DA, Holtzhausen L, Dijkstra HP, Cronje T. Nowhere to hide: the significant impact of coronavirus disease 2019 (COVID-19) measures on elite and semi-elite South African athletes. Journal of Science and Medicine in Sport. 2020 May 19.
  5. Cleveland Clinic. COVID-19 and Athletes: Impact on Sports and Exercise. Available from https://www.youtube.com/watch?v=hnxSqe9N2lE (last accessed 3 November 2020)
  6. Olympic channel. How has COVID-19 affected athletes’ dreams of Tokyo 2020? Available from https://www.youtube.com/watch?v=PyybSCupXOY (last accessed 3 November 2020)
  7. 7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 Löllgen H, Bachl N, Papadopoulou T, Shafik A, Holloway G, Vonbank K, Jones NE, Bigard X, Niederseer D, Meyer J, Muniz-Pardos B. Recommendations for return to sport during the SARS-CoV-2 pandemic. BMJ Open Sport & Exercise Medicine. 2020 Jul 1;6(1):e000858.
  8. Cleveland Clinic.COVID-19 and Athletes: Return to Play Recommendations. Available from https://www.youtube.com/watch?v=BrRoBpbQAaM. (last accessed 3 November 2020)
  9. Soccer Physiologist. DETRAINING - What Happens When We Stop Exercising? Available from https://www.youtube.com/watch?v=-dT5CC3LaV0 (last accessed 3 November 2020)
  10. Ross Tucker. Detraining in lockdown part 2. Available from https://www.youtube.com/watch?v=ByD9HjJL554. (last accessed 3 November 2020)
  11. Joo CH. The effects of short term detraining and retraining on physical fitness in elite soccer players. PloS one. 2018 May 10;13(5):e0196212.
  12. Maldonado-Martín S, Cámara J, James DV, Fernández-López JR, Artetxe-Gezuraga X. Effects of long-term training cessation in young top-level road cyclists. Journal of sports sciences. 2017 Jul 18;35(14):1396-401.
  13. Staron RS, Leonardi MJ, Karapondo DL, Malicky ES, Falkel JE, Hagerman FC, Hikida RS. Strength and skeletal muscle adaptations in heavy-resistance-trained women after detraining and retraining. Journal of Applied Physiology. 1991 Feb 1;70(2):631-40.
  14. Myer GD, Faigenbaum AD, Cherny CE, Heidt RS, Hewett T. Did the NFL lockout expose the achilles heel of competitive sports. Journal of Orthopaedic and Sports Physical Therapy. 2011 Oct;41(10):702-5.
  15. Drew MK, Finch CF. The relationship between training load and injury, illness and soreness: a systematic and literature review. Sports medicine. 2016 Jun 1;46(6):861-83.
  16. Caseiro M, Woznowski‐Vu A, De Oliveira AS, Reis FJ, Wideman TH. From paper to digitalized body map: a reliability study of the pain area. Pain Practice. 2019 Jul;19(6):602-8.
  17. 17.0 17.1 Zhang J, Lu H, Zeng H, Zhang S, Du Q, Jiang T, Du B. The differential psychological distress of populations affected by the COVID-19 pandemic. Brain, behavior, and immunity. 2020 Apr 15.
  18. Reardon CL, Hainline B, Aron CM, Baron D, Baum AL, Bindra A, Budgett R, Campriani N, Castaldelli-Maia JM, Currie A, Derevensky JL. Mental health in elite athletes: International Olympic Committee consensus statement (2019). British Journal of Sports Medicine. 2019 Jun 1;53(11):667-99.
  19. Toresdahl BG, Asif IM. Coronavirus Disease 2019 (COVID-19): Considerations for the Competitive Athlete. Sports Health. 2020 Apr 6;12(3):221-4.
  20. 20.00 20.01 20.02 20.03 20.04 20.05 20.06 20.07 20.08 20.09 20.10 20.11 20.12 20.13 20.14 20.15 20.16 20.17 20.18 20.19 Brent Grimsley. Return to Play During a Pandemic. Plus Course. 2020
  21. Roberts DJ, Ouellet JF, McBeth PB, Kirkpatrick AW, Dixon E, Ball CG. The “weekend warrior”: Fact or fiction for major trauma?. Canadian journal of surgery. 2014 Jun;57(3):E62.
  22. Professional Seminars. Returning to Sports Post-COVID - Professional Athletes to the Weekend Warrior. Available from https://www.youtube.com/watch?v=LtzXnGEr15k&t=848s (last accessed 3 November 2020)
  23. SABC News. Coronavirus and sport | Effects of COVID-19 on elite athletes discussed. Available from https://www.youtube.com/watch?v=4zsHPAVtyq8&t=1s (last accessed 3 November 2020)
  24. 24.0 24.1 24.2 24.3 24.4 Stokes KA, Jones B, Bennett M, Close GL, Gill N, Hull JH, Kasper AM, Kemp SP, Mellalieu SD, Peirce N, Stewart B. Returning to play after prolonged training restrictions in professional collision sports. International journal of sports medicine. 2020 May 29.
  25. Netball Queensland. RHP Physio Return to Play. Available from https://www.youtube.com/watch?v=7Ov5xSHxMF4&t=10s (last accessed 3 November 2020)
  26. Memorial Health Care System. Return to Sport in a time of COVID-19. Available from https://www.youtube.com/watch?v=PJSKJS8chys (last accessed 29 October 2020)
  27. The Aspen Institute. Coronavirus and Youth Sports: How Should Youth Sports Return to Play? Available from https://www.youtube.com/watch?v=x8rnND2F9Pc (last accessed 29 October 2020)