Comprehensive periodic health evaluations of 454 Norwegian Paralympic and Olympic athletes over 8 years: what did we learn?

OBJECTIVE: A periodic health evaluation (PHE) is a comprehensive and multidisciplinary investigation of athlete health widely used in elite sport, but its contents and benefits can be questioned. This study aimed to determine the prevalence of conditions identified by a PHE among Paralympic and Olympic athletes over four consecutive Games cycles from Rio de Janeiro 2016 to Beijing 2022 and to assess the benefits and potential pitfalls of a comprehensive PHE programme in detecting existing injuries, illnesses and other health issues. METHODS: We collected extensive health history and clinical examination data on elite athletes: medical history, ECG, blood pressure, blood samples, spirometry, musculoskeletal health, cognitive function, mental health and compliance with public health programmes. RESULTS: The final cohort included 87 Paralympic and 367 Olympic athletes, representing 565 PHE cycles. Musculoskeletal problems and unspecified pain, infections and allergies were the most frequent health issues. High blood pressure was the most prevalent cardiovascular finding, and vitamin D deficiency the most common laboratory abnormality. Most athletes complied with the public childhood vaccination programmes, but fewer with recommended cancer screening. Follow-up of health issues was variable. CONCLUSION: Our PHE programme identified musculoskeletal problems, infections, allergies, elevated blood pressure and vitamin D deficiency as common health conditions. Longitudinal follow-up of health conditions identified during screening and improved compliance with public health and cancer screening programmes is needed to determine the true benefits of athlete care prompted by the PHE.

A new statistical approach to training load and injury risk: separating the acute from the chronic load.

The relationship between recent (acute) training load relative to long-term (chronic) training load may be associated with sports injury risk. We explored the potential for modelling acute and chronic loads separately to address current statistical methodology limitations. We also determined whether there was any evidence of an interaction in the association between acute and chronic training loads and injury risk in football. A men's Qatar Stars League football cohort (1 465 players, 1 977 injuries), where training load was defined as the number of minutes of activity, and a Norwegian elite U-19 football cohort (81 players, 60 injuries), where training load was defined as the session rating of perceived exertion (sRPE). Mixed logistic regression was run with training load on the current day (acute load) and cumulative past training load estimated by distributed lag non-linear models (chronic load) as independent variables. Injury was the outcome. An interaction between acute and chronic training load was modelled. In both football populations, we observed that the risk of injury on the current day for different values of acute training load was highest for players with low chronic load, followed by high and then medium chronic load. The slopes varied substantially between different levels of chronic training load, indicating an interaction. Modelling acute and chronic loads separately in regression models is a suitable statistical approach for analysing the association between relative training load and injury risk in injury prevention research. Sports scientists should also consider the potential for interactions between acute and chronic load.

Injury and illness among Norwegian Olympic athletes during preparation for five consecutive Summer and Winter Games.

OBJECTIVE: To describe the patterns of health problems among Norwegian Olympic candidates during their preparations for five consecutive Olympic Games (London 2012, Sochi 2014, Rio de Janeiro 2016, PyeongChang 2018 and Tokyo 2020). METHODS: This was a descriptive epidemiological study using the Oslo Sports Trauma Research Center Questionnaire on Health Problems to collect data on all self-reported health problems from Norwegian Olympic candidate athletes for 12-18 months prior to each Olympic Games. Team physicians and physiotherapists followed up the athlete reports, providing clinical care and classifying reported problems according to the International Olympic Committee 2020 consensus statement on methods for recording and reporting of epidemiological data on injury and illness in sport. RESULTS: Between 2011 and 2020, 533 athletes were included in the Norwegian Olympic team monitoring programme, with a 78% response to the weekly questionnaire. During this time, athletes reported 2922 health problems, including 1409 illnesses (48%), 886 overuse injuries (repetitive mechanism, 30%) and 627 acute injuries (traumatic mechanism, 21%). Diagnostic codes were recorded for 2829 (97%) of health problems. Athletes reported, on average, 5.9 new health problems per year (95% CI: 5.6 to 6.1), including 1.3 acute injuries (CI: 1.2 to 1.4), 1.7 overuse injuries (CI: 1.6 to 1.9) and 2.9 illnesses (CI: 2.7 to 3.0). Each year, female and male athletes lost an average of 40 and 26 days of training and competition due to health problems, respectively. The diagnoses with the highest health burden were anterior cruciate ligament rupture, respiratory infection, lumbar pain and patellar tendinopathy. CONCLUSION: The injury burden was particularly high among female athletes and in team sports, whereas endurance sports had the greatest burden of illness. Our data provide a compelling argument for prioritising medical care and investing in prevention programmes not just during the Olympic Games, but also the preparation period.

#ReadyToPlay: health problems in women's football-a two-season prospective cohort study in the Norwegian premier league.

OBJECTIVES: To describe the prevalence, incidence and burden of all health problems in the Norwegian women's premier league. METHODS: During the 2020 and 2021 seasons, players in the Norwegian women's premier league reported all health problems (sudden-onset injuries, gradual-onset injuries and illnesses) weekly, using the Oslo Sports Trauma Research Centre Questionnaire on Health Problems. Team medical staff diagnosed reported problems using the Sport Medicine Diagnostic Coding System. We calculated average weekly prevalence, incidence and burden of all health problems reported. RESULTS: We included 294 players (age: 22±4 years) from 11 teams. Response rate to the weekly questionnaire was 79%. On average, 32% (95% CI: 31% to 33%) of the players reported at least one health problem at any time and 22% (95% CI: 21% to 23%) reported a substantial health problem negatively affecting their training volume or performance. The overall incidence was 10.7 health problems per 1000 hours of football exposure. Sudden-onset injuries were most severe (68% of the total time loss), followed by gradual-onset injuries (25%) and illnesses (8%). Thigh was the most common injury location (26%), while knee injuries were most severe, causing 42% of the total injury time loss. Anterior cruciate ligament (ACL) injuries alone caused 30% of the total injury time loss. CONCLUSION: One in five players had a health problem negatively affecting their training volume or performance at any time. Sudden-onset injuries represented the most burdensome health problem. Thigh injuries were most frequent, while knee injuries, ACL injuries especially, were most severe.

A cross-sectional study of the relationship between injuries and quality of life, psychological distress, sleeping problems, and global subjective health in adults from three Norwegian counties.

BACKGROUND: Studies examining associations between injuries and outcomes like quality of life and psychological distress are important to understand a broader range of possible consequences of injuries for population health. AIMS: The aim of this study was to examine associations between self-reported injury and quality of life, psychological distress, sleeping problems, and global subjective health. METHODS: The sample was drawn from the Norwegian National Population Register. Data were collected among the general adult populations in three Norwegian counties in 2019-2020 (response rate 45.3%, n = 74,030). Exposure variables were being injured during the last 12 months, cause of injury (if more than one, the most serious one), and functional impairment due to injuries. Outcome variables included measures of total quality of life, global quality of life, positive affect, negative affect, positive social relations, social capital (trust, belongingness, feeling safe), psychological distress, sleep problems, loneliness, and global subjective health. Data were analysed with General Linear Modelling in SPSS Complex. RESULTS: Reporting to have been injured once during the last 12 months was associated with slightly elevated levels of psychological distress, sleeping problems, and loneliness, and lower mean scores on quality-of-life indicators and global subjective health. Reporting being injured twice or more showed more pronounced contrasts to the reference group on the same outcomes, with Cohen's d-values (absolute numbers) ranging from 0.17 to 0.54. For having been victim to violence, d-values ranged from 0.30 to 1.01. Moderate functional impairment due to injuries was associated with less favourable scores on all outcomes (d ranging from 0.15 to 0.71). For strong functional impairment d-values ranged from 0.35 to 1.17. CONCLUSIONS: Elevated levels of distress and reduced levels of quality of life are particularly associated with multiple injuries, being victim to violence, and functional impairment due to injuries. Prospective, longitudinal studies with high quality instruments and large samples, allowing adjustment for baseline values of outcome variables, and utilization of state-of-the-art statistical techniques, would bring this research closer to examining causality.

French Translation and Validation of the OSTRC-H2 Questionnaire on Overuse Injuries and Health Problems in Elite Athletes.

Background: To evaluate the burden of overuse injuries, the Oslo Sports Trauma Research Centre (OSTRC) questionnaire on health problems (OSTRC-H2) was developed in English in 2013. Purpose: To translate and culturally adapt the OSTRC-H2 into French and investigate the reliability and validity of this new version. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: The OSTRC-H2 was translated from English to French according to international guidelines. A total of 80 elite athletes were then invited to complete the OSTRC-H2 weekly for 3 months. Potential ceiling effects, construct validity, and reliability were investigated. Convergent validity was measured using Pearson correlations for continuous items and kappa coefficients for binary items; internal consistency was measured using the Cronbach alpha coefficient; and test-retest reliability was measured using the intraclass correlation coefficient (ICC). Separate analyses were performed on the entire cohort of athletes (population 1 [P1]) and on athletes who reported a health problem during the follow-up (P2). Results: A total of 80 elite athletes took part in this study. The response rate was very high, with 909 of 960 questionnaires returned (95%). The mean weekly prevalence of health problems was 19.6% during the follow-up period. Nineteen participants reported a health problem during the follow-up (P2). The OSTRC-H2 showed very good test-retest reliability for both populations (ICC, 0.85 [95% CI, 0.77-0.90] for P1; ICC, 0.90 [95% CI, 0.68-0.98] for P2). Internal consistency was very good for P2 (Cronbach α = .94). The OSTRC-H2 demonstrated high concordance with the visual analog scale of symptom intensity (r = 0.52; P < .05), and low concordance with the overtraining questions from the Questionnaire de la Société Française de Médecine du Sport (κ from -0.01 to 0.12; P > .05). Conclusion: The French version of the OSTRC-H2 was found to be valid and reliable when applied to French-speaking elite athletes.

Female athlete health domains: a supplement to the International Olympic Committee consensus statement on methods for recording and reporting epidemiological data on injury and illness in sport.

The IOC made recommendations for recording and reporting epidemiological data on injuries and illness in sports in 2020, but with little, if any, focus on female athletes. Therefore, the aims of this supplement to the IOC consensus statement are to (i) propose a taxonomy for categorisation of female athlete health problems across the lifespan; (ii) make recommendations for data capture to inform consistent recording and reporting of symptoms, injuries, illnesses and other health outcomes in sports injury epidemiology and (iii) make recommendations for specifications when applying the Strengthening the Reporting of Observational Studies in Epidemiology-Sport Injury and Illness Surveillance (STROBE-SIIS) to female athlete health data.In May 2021, five researchers and clinicians with expertise in sports medicine, epidemiology and female athlete health convened to form a consensus working group, which identified key themes. Twenty additional experts were invited and an iterative process involving all authors was then used to extend the IOC consensus statement, to include issues which affect female athletes.Ten domains of female health for categorising health problems according to biological, life stage or environmental factors that affect females in sport were identified: menstrual and gynaecological health; preconception and assisted reproduction; pregnancy; postpartum; menopause; breast health; pelvic floor health; breast feeding, parenting and caregiving; mental health and sport environments.This paper extends the IOC consensus statement to include 10 domains of female health, which may affect female athletes across the lifespan, from adolescence through young adulthood, to mid-age and older age. Our recommendations for data capture relating to female athlete population characteristics, and injuries, illnesses and other health consequences, will improve the quality of epidemiological studies, to inform better injury and illness prevention strategies.

Handling and reporting missing data in training load and injury risk research.

PURPOSE: To map the current practice of handling missing data in the field of training load and injury risk and to determine how missing data in training load should be handled. METHODS: A systematic review of the training load and injury risk literature was performed to determine how missing data are reported and handled. We ran simulations to compare the accuracy of modelling a predetermined relationship between training load and injury risk following handling missing data with different methods. The simulations were based on a Norwegian Premier League men's football dataset (n = 39). Internal training load was measured with the session Rating of Perceived Exertion (sRPE). External training load was the total distance covered measured by a global positioning systems (GPS) device. RESULTS: Only 37 (34%) of 108 studies reported whether training load had any missing observations. Multiple Imputation using Predicted Mean Matching was the best method of handling missing data across multiple scenarios. CONCLUSION: Studies of training load and injury risk should report the extent of missing data, and how they are handled. Multiple Imputation with Predicted Mean Matching should be used when imputing sRPE and GPS variables.

Injury characteristics in Norwegian male professional football: A comparison between a regular season and a season in the pandemic.

The Coronavirus Disease-19 (COVID-19) pandemic forced the Norwegian male premier league football season to reschedule, reducing the fixture calendar substantially. Previous research has shown that a congested match schedule can affect injury rates in professional football. Therefore, we aimed to investigate whether the Norwegian premier league teams suffered more injuries in the more match congested 2020 season than in the regular 2019-season. We invited all teams having participated in both seasons to export their injury data. Only teams that used the same medical staff to register injuries in both seasons were included, and to maximize data comparability between seasons, we applied a time-loss injury definition only. Seven of 13 teams agreed to participate and exported their injury data. Both seasons had 30 game weeks, but the 2020 season was 57 days shorter than the 2019 season. The match injury incidence did not differ significantly [incidence rate ratio 0.76 (0.48-1.20; p = 0.24) in the 2020 season compared to the 2019 season. Furthermore, we found no differences in the number of injuries, days lost to injury, matches missed to injury, or injury severity. We could not detect any differences between the two seasons, suggesting the congested match calendar combined with the safety measures in the 2020 season can be a safe alternative in future seasons.

Methodological considerations in injury burden of disease studies across Europe: a systematic literature review.

BACKGROUND: Calculating the disease burden due to injury is complex, as it requires many methodological choices. Until now, an overview of the methodological design choices that have been made in burden of disease (BoD) studies in injury populations is not available. The aim of this systematic literature review was to identify existing injury BoD studies undertaken across Europe and to comprehensively review the methodological design choices and assumption parameters that have been made to calculate years of life lost (YLL) and years lived with disability (YLD) in these studies. METHODS: We searched EMBASE, MEDLINE, Cochrane Central, Google Scholar, and Web of Science, and the grey literature supplemented by handsearching, for BoD studies. We included injury BoD studies that quantified the BoD expressed in YLL, YLD, and disability-adjusted life years (DALY) in countries within the European Region between early-1990 and mid-2021. RESULTS: We retrieved 2,914 results of which 48 performed an injury-specific BoD assessment. Single-country independent and Global Burden of Disease (GBD)-linked injury BoD studies were performed in 11 European countries. Approximately 79% of injury BoD studies reported the BoD by external cause-of-injury. Most independent studies used the incidence-based approach to calculate YLDs. About half of the injury disease burden studies applied disability weights (DWs) developed by the GBD study. Almost all independent injury studies have determined YLL using national life tables. CONCLUSIONS: Considerable methodological variation across independent injury BoD assessments was observed; differences were mainly apparent in the design choices and assumption parameters towards injury YLD calculations, implementation of DWs, and the choice of life table for YLL calculations. Development and use of guidelines for performing and reporting of injury BoD studies is crucial to enhance transparency and comparability of injury BoD estimates across Europe and beyond.

Changes in life expectancy and disease burden in Norway, 1990-2019: an analysis of the Global Burden of Disease Study 2019.

BACKGROUND: Geographical differences in health outcomes are reported in many countries. Norway has led an active policy aiming for regional balance since the 1970s. Using data from the Global Burden of Disease Study (GBD) 2019, we examined regional differences in development and current state of health across Norwegian counties. METHODS: Data for life expectancy, healthy life expectancy (HALE), years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) in Norway and its 11 counties from 1990 to 2019 were extracted from GBD 2019. County-specific contributors to changes in life expectancy were compared. Inequality in disease burden was examined by use of the Gini coefficient. FINDINGS: Life expectancy and HALE improved in all Norwegian counties from 1990 to 2019. Improvements in life expectancy and HALE were greatest in the two counties with the lowest values in 1990: Oslo, in which life expectancy and HALE increased from 71·9 years (95% uncertainty interval 71·4-72·4) and 63·0 years (60·5-65·4) in 1990 to 81·3 years (80·0-82·7) and 70·6 years (67·4-73·6) in 2019, respectively; and Troms og Finnmark, in which life expectancy and HALE increased from 71·9 years (71·5-72·4) and 63·5 years (60·9-65·6) in 1990 to 80·3 years (79·4-81·2) and 70·0 years (66·8-72·2) in 2019, respectively. Increased life expectancy was mainly due to reductions in cardiovascular disease, neoplasms, and respiratory infections. No significant differences between the national YLD or DALY rates and the corresponding age-standardised rates were reported in any of the counties in 2019; however, Troms og Finnmark had a higher age-standardised YLL rate than the national rate (8394 per 100 000 [95% UI 7801-8944] vs 7536 per 100 000 [7391-7691]). Low inequality between counties was shown for life expectancy, HALE, all level-1 causes of DALYs, and exposure to level-1 risk factors. INTERPRETATION: Over the past 30 years, Norway has reduced inequality in disease burden between counties. However, inequalities still exist at a within-county level and along other sociodemographic gradients. Because of insufficient Norwegian primary data, there remains substantial uncertainty associated with regional estimates for non-fatal disease burden and exposure to risk factors. FUNDING: Bill & Melinda Gates Foundation, Research Council of Norway, and Norwegian Institute of Public Health.

Assessing the cumulative effect of long-term training load on the risk of injury in team sports.

Objectives: Determine how to assess the cumulative effect of training load on the risk of injury or health problems in team sports. Methods: First, we performed a simulation based on a Norwegian Premier League male football dataset (n players=36). Training load was sampled from daily session rating of perceived exertion (sRPE). Different scenarios of the effect of sRPE on injury risk and the effect of relative sRPE on injury risk were simulated. These scenarios assumed that the probability of injury was the result of training load exposures over the previous 4 weeks. We compared seven different methods of modelling training load in their ability to model the simulated relationship. We then used the most accurate method, the distributed lag non-linear model (DLNM), to analyse data from Norwegian youth elite handball players (no. of players=205, no. of health problems=471) to illustrate how assessing the cumulative effect of training load can be done in practice. Results: DLNM was the only method that accurately modelled the simulated relationships between training load and injury risk. In the handball example, DLNM could show the cumulative effect of training load and how much training load affected health problem risk depending on the distance in time since the training load exposure. Conclusion: DLNM can be used to assess the cumulative effect of training load on injury risk.

Mental Health in Elite Student Athletes: Exploring the Link Between Training Volume and Mental Health Problems in Norwegian College and University Students.

OBJECTIVES: To examine mental health problems among elite athletes in a student population, compared to the general student population, and to explore the association between weekly hours of training across mental health indicators. METHODS: Data are from a national study from 2018 of all college and university students in Norway. Participants indicated if they considered themselves to be an elite athlete, and how many hours per week they trained. Mental health problems were assessed using several well-validated questionnaires. RESULTS: Among 50,054 students, 1.3% identified themselves as elite athletes. Both male and female elite athletes had generally better mental health across most health outcomes, reporting fewer mental health problems, less loneliness, higher satisfaction with life, more positive affect, and fewer alcohol problems. Elite athletes in team sports had slightly better mental health compared to athletes of individual sports. Increased hours of weekly exercise was associated with better mental health. However, there was generally little to be gained from increasing the amount of training from 7-10 hours/week to 14+ hours per week. Female athletes who trained 14 or more hours per week reported poorer mental health across most outcome measures. CONCLUSION: This study showed that both male and female elite athletes generally had better mental health across a range of health outcomes, when compared to the general student population. The study also found a positive dose-response relationship between weekly hours of training and mental health, but also a worsening of mental health for females at the extreme end of exercise continuum. The self-report nature of this student sample means that care should be taken when generalizing to other studies of elite athletes.

Incidence, Prevalence, and Severity of and Risk Factors for Hip and Groin Problems in Swedish Male Ice Hockey Players: A 1-Season Prospective Cohort Study.

CONTEXT: The epidemiologic focus on time loss may underestimate the true magnitude of hip and groin problems in male ice hockey players. OBJECTIVE: To describe the prevalence, incidence, and severity of hip and groin problems (time loss and non-time loss) in Swedish ice hockey players over the course of a season and explore potential preseason risk factors for these conditions. DESIGN: Prospective 1-season cohort study. SETTING: Professional and semiprofessional Swedish ice hockey players. PATIENTS OR OTHER PARTICIPANTS: A total of 12 professional and semiprofessional male ice hockey teams were invited to participate. Of those, 9 teams agreed, and 163 players were included in the analyses. MAIN OUTCOME MEASURE(S): Hip and groin problems in the previous season (time loss, non-time loss), isometric adduction and abduction strength, and 5-second squeeze test results were recorded before the season and served as independent variables in the risk factor analysis. Main outcome measures were cumulative incidence of hip and groin problems, average prevalence, and odds ratios (ORs) for groin problems in season. RESULTS: Cumulative incidence was 45.4% (95% CI = 37.6%, 53.4%) for all problems and 19% (95% CI = 13.3%, 25.9%) for substantial problems. Average prevalence was 14.1% (95% CI = 10.8%, 17.5%) for all and 5.7% (95% CI = 4.3%, 7.2%) for substantial problems. Among reported problems, 69.2% had a gradual onset, and only 17% led to time loss. Players with non-time-loss problems in the previous season had higher odds for new problems (all: OR = 3.3 [95% CI = 1.7, 6.3]; substantial: OR = 3.6 [95% CI = 1.8, 8.4]). Preseason strength was not significantly associated with the odds for subsequent problems. CONCLUSION: Hip and groin problems are common in ice hockey players and may lead to substantial impairments in performance. Only 1 in 5 problems led to time loss, and 7 in 10 had a gradual onset. Non-time-loss problems in the previous season were a significant risk factor for new problems, whereas decreased preseason hip-adduction and -abduction strength was not.

Illness and injury among Norwegian Para athletes over five consecutive Paralympic Summer and Winter Games cycles: prevailing high illness burden on the road from 2012 to 2020.

OBJECTIVE: To describe the illness and injury pattern of Norwegian Para athletes over five consecutive Paralympic Summer and Winter Games cycles and to identify which health problems should be targeted in risk management plans with respect to impairment types. METHODS: We monitored athletes from 12 to 18 months prior to each Game using a weekly online questionnaire (Oslo Sports Trauma Research Center-H2 (OSTRC-H2)). We asked them to report all health problems they had experienced in the preceding 7 days, irrespective of their consequences on their sports participation or performance and whether they had sought medical attention. RESULTS: Between 2011 and 2020, 94 candidate athletes were included in this monitoring programme and prepared to represent Norway; of these, 66 (71%) were finally selected for multiple Paralympic Games. The overall response rate to the weekly questionnaires was 87%. At any given time during the five observation cycles, 37% of the athletes (95% CI 36% to 38%) reported having at least one health problem. Athletes with neurological impairments (n=51) lost 10 days per year due to respiratory problems (95% CI 9 to 11) compared with 9 days (8-10) among those with musculoskeletal impairments (n=37). Gastrointestinal problems caused a time loss of on average 4 days per year in athletes with neurological impairments versus 1 day in athletes with musculoskeletal impairments (mean difference 2.7 days, 2.1-3.3). Musculoskeletal injuries generated a high burden for both athlete groups, in particular, to the elbow, shoulder and lumbosacral regions. CONCLUSION: At any given time, nearly two out of five elite Norwegian Para athletes reported at least one health problem. Respiratory tract and other infections; gastrointestinal problems, injuries to the shoulder, elbow and lumbosacral regions represented the greatest health burden. Our findings can help guide the allocation of clinical resources, which should include a broad network of medical specialists, together with dieticians and physiotherapists, to meet the health challenges in Para athletes.

Hip and groin function and strength in male ice hockey players with and without hip and groin problems in the previous season- a prospective cohort study.

OBJECTIVE: To describe and compare hip and groin strength and function of male ice hockey players over one season in players with and without hip and groin problems in the previous season. DESIGN: Prospective cohort study. SETTING: Swedish male ice hockey. PARTICIPANTS: We followed 193 players from 10 teams during the 2017/2018 season. MAIN OUTCOME MEASURES: Hip adduction and abduction strength, 5 s squeeze test (5SST), and self-reported hip and groin function (Hip and Groin Outcome Score). Changes over the season and differences between players with and without problems in the previous season were analyzed by linear mixed models. RESULTS: Adduction strength decreased slightly from pre-to mid-season and abduction strength increased slightly over the full season. However, self-reported function or pain did not change. Players with hip and groin problems in the previous season had significantly worse self-reported function, and more groin pain during the 5SST compared to players without. Strength measurments did not differ between groups. CONCLUSIONS: Hip muscle strength, groin pain, and self-reported function appear to remain stable throughout the season in male ice hockey players. Remaining impairments in players with problems in the previous season suggest that function does not recover by ice hockey participation alone.

Not straightforward: modelling non-linearity in training load and injury research.

OBJECTIVES: To determine whether the relationship between training load and injury risk is non-linear and investigate ways of handling non-linearity. METHODS: We analysed daily training load and injury data from three cohorts: Norwegian elite U-19 football (n=81, 55% male, mean age 17 years (SD 1)), Norwegian Premier League football (n=36, 100% male, mean age 26 years (SD 4)) and elite youth handball (n=205, 36% male, mean age 17 years (SD 1)). The relationship between session rating of perceived exertion (sRPE) and probability of injury was estimated with restricted cubic splines in mixed-effects logistic regression models. Simulations were carried out to compare the ability of seven methods to model non-linear relationships, using visualisations, root-mean-squared error and coverage of prediction intervals as performance metrics. RESULTS: No relationships were identified in the football cohorts; however, a J-shaped relationship was found between sRPE and the probability of injury on the same day for elite youth handball players (p<0.001). In the simulations, the only methods capable of non-linear modelling relationships were the quadratic model, fractional polynomials and restricted cubic splines. CONCLUSION: The relationship between training load and injury risk should be assumed to be non-linear. Future research should apply appropriate methods to account for non-linearity, such as fractional polynomials or restricted cubic splines. We propose a guide for which method(s) to use in a range of different situations.

Facilitators and barriers for implementation of a load management intervention in football.

BACKGROUND: In a recent randomised controlled trial, we found that a commonly used training load management approach was not effective in preventing injuries and illnesses in Norwegian elite youth footballers. AIM: To investigate players' and coaches' barriers and facilitators to a load management approach to prevent injuries and illnesses and their attitudes and beliefs of load management and injuries and illnesses in general. METHODS: We asked players and coaches about their views on injury risk in football, the benefits and limitations of load management in general and implementation of load management in football. The questionnaires used were based on similar studies using the Reach, Effectiveness, Adoption, Implementation and Maintenance framework. RESULTS: We recorded answers from 250 players and 17 coaches. Most players (88%) reported that scientific evidence showing improved performance from the intervention measures is a key facilitator to completing the intervention. Similarly, coaches reported that the most important facilitator was scientific evidence that the preventive measures were effective (100%). Players reported that the coach's attitude to preventive measures was important (86%), and similarly, 88% of coaches reported that the player's attitude was important. CONCLUSIONS: By having a mutual positive attitude towards the intervention, players and coaches can positively contribute to each other's motivation and compliance. Both players and coaches reported scientific evidence for load management having injury-preventive and performance-enhancing effect and being time efficient as important facilitators. TRIAL REGISTRATION NUMBER: Trial registration number.

Methods, challenges and benefits of a health monitoring programme for Norwegian Olympic and Paralympic athletes: the road from London 2012 to Tokyo 2020.

OBJECTIVE: To describe the implementation of a health monitoring programme for Norwegian Paralympic and Olympic candidates over five consecutive Olympic and Paralympic Games cycles (London 2012, Sochi 2014, Rio de Janeiro 2016, PyeongChang 2018 and Tokyo 2020). METHODS: Athletes were monitored for 12-18 months preparing for the games using a weekly online questionnaire (OSTRC-H2) with follow-up by physicians and physiotherapists, who provided clinical care and classified reported problems. RESULTS: Between 2011 and 2020, 533 Olympic and 95 Paralympic athletes were included in the monitoring programme, with an overall response of 79% to the weekly questionnaire and a total observation period of 30 826 athlete weeks. During this time, 3770 health problems were reported, with a diagnosis rate of 97%. The average prevalence of health problems at any given time was 32% among Olympic athletes and 37% among Paralympic athletes. Acute traumatic injuries represented the greatest burden for Olympic team sport athletes, and illnesses represented the greatest burden for Olympic endurance and Paralympic athletes. On average, Olympic athletes lost 27 days and Paralympic athletes lost 33 days of training per year due to health problems. CONCLUSION: Conducting long-term health monitoring of Olympic and Paralympic athletes is challenging, particularly because athletes travel frequently and often relate to many medical providers. This programme has been implemented and improved within Team Norway for five Olympic and Paralympic cycles and during this time we believe it has helped protect our athletes' health.

Methods for epidemiological studies in competitive cycling: an extension of the IOC consensus statement on methods for recording and reporting of epidemiological data on injury and illness in sport 2020.

In 2020, the IOC released a consensus statement that provides overall guidelines for the recording and reporting of epidemiological data on injury and illness in sport. Some aspects of this statement need to be further specified on a sport-by-sport basis. To extend the IOC consensus statement on methods for recording and reporting of epidemiological data on injury and illness in sports and to meet the sport-specific requirements of all cycling disciplines regulated by the Union Cycliste Internationale (UCI). A panel of 20 experts, all with experience in cycling or cycling medicine, participated in the drafting of this cycling-specific extension of the IOC consensus statement. In preparation, panel members were sent the IOC consensus statement, the first draft of this manuscript and a list of topics to be discussed. The expert panel met in July 2020 for a 1-day video conference to discuss the manuscript and specific topics. The final manuscript was developed in an iterative process involving all panel members. This paper extends the IOC consensus statement to provide cycling-specific recommendations on health problem definitions, mode of onset, injury mechanisms and circumstances, diagnosis classifications, exposure, study population characteristics and data collection methods. Recommendations apply to all UCI cycling disciplines, for both able-bodied cyclists and para-cyclists. The recommendations presented in this consensus statement will improve the consistency and accuracy of future epidemiological studies of injury and illness in cycling.