Dr Lucy Chesson

Illness in athletes can cause time-loss and performance restriction from training and competition, as well as negatively affect physiological functioning. Team sport athletes, and in particular rugby players, may be at increased risk of illness due to close-proximity to teammates and competitors, as well the high-intensity exercise and collisions involved in the sport itself. Despite a growing wealth of literature assessing illness epidemiology in rugby, little is known about the incidence of illness in male academy rugby players, and no studies have assessed the lived experience of illness through qualitative inquiry. Therefore, the aim of this thesis was to investigate the presence and experiences of illness in rugby using a mixed methods approach. This programme of research includes three study chapters which 1) investigate and summarise the incidence, prevalence, and count of illnesses across full-contact football-code team sports through a systematic review 2) assess the incidence, prevalence, and consequences of illness in male academy rugby league players and 3) explore the barriers and enablers to the uptake of illness prevention guidelines in rugby. Chapter 3 highlighted that full-contact football-code team sport athletes are most commonly affected by respiratory system illnesses; however consistent methods of reporting were lacking, and future research should utilise International Olympic Committee (IOC) recommended definitions and monitoring tools. Chapter 5 identified that consequences of illness, such as loss of body mass and sleep disruptions, may negatively impact a male academy rugby league player’s development. Chapter 7 highlighted that tackling inequalities in resources between men’s and women’s cohorts is critical to effectively implement illness prevention guidelines. Education of coaches and players is essential, and emphasis must be placed on continuing preventative behaviours adopted due to COVID-19. In summary, the findings from this thesis suggest that illnesses pose less epidemiological burden than injury, however the consequences of illness may be detrimental to athlete development and future progression. This thesis offers new behavioural science driven practical recommendations to effectively implement illness prevention guidelines in the rugby context.

Rule changes within football-code team sports aim to improve performance, enhance player welfare, increase competitiveness, and provide player development opportunities. This manuscript aimed to review research investigating the effects of rule changes in football-code team sports. A systematic search of electronic databases (PubMed, ScienceDirect, CINAHL, MEDLINE, and SPORTDiscus) was performed to August 2023; keywords related to rule changes, football-code team sports, and activity type. Studies were excluded if they failed to investigate a football-code team sport, did not quantify the change of rule, or were review articles. Forty-six studies met the eligibility criteria. Four different football codes were reported: Australian rules football (n = 4), rugby league (n = 6), rugby union (n = 16), soccer (n = 20). The most common category was physical performance and match-play characteristics (n = 22). Evidence appears at a high risk of bias partly due to the quasi-experimental nature of included studies, which are inherently non-randomised, but also due to the lack of control for confounding factors within most studies included. Rule changes can result in unintended consequences to performance (e.g., longer breaks in play) and effect player behaviour (i.e., reduce tackler height in rugby) but might not achieve desired outcome (i.e., unchanged concussion incidence). Coaches and governing bodies should regularly and systematically investigate the effects of rule changes to understand their influence on performance and injury risk. It is imperative that future studies analysing rule changes within football codes account for confounding factors by implementing suitable study designs and statistical analysis techniques.

Illness prevention is essential for athlete health management, but little is known about its uptake in sport. Prior to the pandemic, the International Olympic Committee (IOC) published a consensus statement recommending illness prevention guidelines are implemented in sports. Yet, little is known about guideline uptake. Therefore, this study aimed to explore the (1) illness experiences of rugby players and athlete support personnel and (2) barriers and enablers to illness prevention guideline uptake in rugby, using the lens of behaviour change theory. In a bid to inform and enhance athlete welfare, we sought to amplify the voices of participants through qualitative inquiry. Between August 2020 and May 2021, 16 semi-structured interviews were undertaken with players and athlete support personnel working across rugby. Analysis was conducted using Braun and Clarke’s reflexive thematic analysis. Prior to COVID-19, participants deemed illness to be of little concern, with experience of illnesses and the global pandemic critical enablers to guideline uptake. The rugby environment was a barrier to illness prevention, particularly in women’s and academy teams where resource deficiency was highlighted. ‘Rugby identity’ acted as both a barrier and enabler with participants’ passion for rugby driving both guideline adherence and non-adherence. Tackling resource inequalities between men’s and women’s cohorts is critical to effectively implement guidelines. Coach and player education is essential, and emphasis must be placed on continuing preventative behaviours adopted due to COVID-19. Our findings offer new insight into illness prevention, moving away from prevailing quantitative research, and instead voicing players’ experiences.

Objectives To assess the incidence, prevalence and consequences of illness in one professional academy rugby league club during an in-season period. Design Observational prospective cohort study. Method Seventeen male rugby league players (age 17.7 ± 0.7 years, stature 178.8 ± 5.1 cm, body mass 87.2 ± 9.6 kg) completed a weekly self-report illness questionnaire using an amended version of the Oslo Sports Trauma Research Centre (OSTRC) questionnaire on health problems. Results A total of 24 new illnesses were reported over the 25-week study period. 65% of players experienced at least one illness during the study. The incidence of illness in this cohort was 14.3 per 1000-player days, with the respiratory system being most commonly affected (n = 15; 62.5%). The average weekly illness prevalence was 10.3%. Time-loss illness incidence was 1.4 per 1000-player days. Loss of body mass and sleep disruptions were the most commonly reported consequences of illness episodes. Mean body mass loss during a period of illness was 2.2 ± 0.6 kg. Conclusions Academy rugby league players are most commonly affected by respiratory illness with a total of nineteen training and competition days lost to illness. Associated consequences of illness, such as loss of body mass and sleep disruptions may present a challenge and negatively impact a rugby league player’s development. Appropriate medical provisions should be provided for Academy rugby league players to support them during periods of illness to limit the impact of these consequences.

Abstract

Introduction: Physical and nutritional behaviours among female cricketers have yet to be explored. Therefore, the purpose of the present study was to estimate energy intake (EI), total energy expenditure (TEE), macronutrient and fluid intake in elite and highly trained female cricketers over 24-hour periods across 50-over home fixtures. Methods: Ten elite and highly trained female cricketers (age 24.1 ± 4.9 years; body mass 73.8 ± 7.8 kg; stature 171.3 ± 3.2 cm) were observed over three 50-over home matches. Body composition was measured using dual X-ray absorptiometry. EI was assessed through a combination of food photography and weighing of food intake. Resting metabolic rate was measured using indirect calorimetry, physical activity was monitored using accelerometry, and thermic effect of food was estimated; therefore, TEE was inferred. Results: The mean daily EI, TEE and resulting energy balance (EB) were 2558 ± 622 kcal·day

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Limited data exist describing how professional footballers meet their energy requirements during pre-season, a phase characterised by increased training volume and a progressive shift from general conditioning to football-specific preparation. This study quantified total, resting, and activity energy expenditure (AEE), diet-induced thermogenesis, water turnover, and dietary intake in six professional male soccer players (age: 25 ± 1 year; height: 182.5 ± 10.1 cm; body mass: 77.8 ± 8.2 kg). Players were studied across 14 consecutive days, representing training-only and training-plus-match microcycles. Total energy expenditure (TEE) was measured using doubly labelled water, resting energy expenditure (REE) by indirect calorimetry and dietary intake using the remote food photography method. Fourteen-day mean TEE, REE, AEE and water turnover were 13.25 ± 1.31 MJ⋅day−1, 7.96 ± 0.89 MJ⋅day−1, 4.20 ± 1.03 MJ⋅day−1, 5.16 ± 0.66 L⋅day−1, respectively. Physical activity level was 1.67 ± 0.16 AU. Energy, carbohydrate, protein, and fat intakes were 10.95 ± 1.52 MJ⋅day−1, 2.8 ± 0.6 g⋅kg−1⋅day−1, 2.2 ± 0.4 g⋅kg−1⋅day−1, and 1.5 ± 0.4 g⋅kg−1⋅day−1, respectively. Total energy expenditure was not significantly different between training-only and training-plus-match microcycles (+1.89 ± 1.98 MJ⋅day−1; ES = 0.95 ± 1.08; p = 0.100). No significant differences were observed in energy or macronutrient intake across weekly microcycles (p > 0.068) or between days (p > 0.144). Players did not achieve energy balance or align dietary intake with day-to-day training demands, suggesting limited nutrition periodisation during pre-season. These findings highlight the need for practitioners to implement strategies supporting fuelling, recovery and adaptation during this critical phase.

Recognising and removing players with suspected sport-related concussions is crucial for community sports. Objectives Quantify rates and factors associated with non-reporting of concussion symptoms in community rugby league. Methods Overall, 484 community rugby league players aged ≥18 years and 965 parents of rugby league players aged <18 years completed an online survey, regarding concussion history, knowledge, prevalence and reasons for non-reporting of concussion, long-term implications and perceptions of concussion. Results Thirty-five percent of players aged ≥18 years and 22% of parents of players aged <18 years reported at least one concussion in the last two seasons. Forty-three percent of players aged ≥18 years and 5% of parents of players aged<18 years surveyed stated they did not report concussion-related symptoms sustained during 2020 and 2021 seasons. The two most common reasons for non-reporting of concussion symptoms were‘didn’t want to be ruled out of a match’and‘didn’t want to let down the team’. Players aged ≥18 years who received external coaching pressures around concussion were more likely to not report concussion symptoms. Over 40% of parents and players were concerned about the potential long-term implications. Ten percent of players aged ≥18 years and 7% of parents of players aged <18 years would encourage their family members/children to not play rugby league. Conclusions Non-reporting rates of suspected concussion symptoms in adult community players were twice as high as in professional rugby league, with similar reasons (wanting to play and not letting the team down). Engaging coaches to prioritise brain health and providing broader and appropriate education on concussion should be focused on, given the concerns reported by community players and parents.

OBJECTIVES: Full-contact football-code team sports offer a unique environment for illness risk. During training and match-play, players are exposed to high-intensity collisions which may result in skin-on-skin abrasions and transfer of bodily fluids. Understanding the incidence of all illnesses and infections and what impact they cause to time-loss from training and competition is important to improve athlete care within these sports. This review aimed to systematically report, quantify and compare the type, incidence, prevalence and count of illnesses across full-contact football-code team sports. DESIGN/METHODS: A systematic search of Cochrane Library, MEDLINE, SPORTDiscus, PsycINFO and CINAHL electronic databases was performed from inception to October 2019; keywords relating to illness, athletes and epidemiology were used. Studies were excluded if they did not quantify illness or infection, involve elite athletes, investigate full-contact football-code sports or were review articles. RESULTS: Twenty-eight studies met the eligibility criteria. Five different football-codes were reported: American football (n=10), Australian rules football (n=3), rugby league (n=2), rugby sevens (n=3) and rugby union (n=9). One multi-sport study included both American football and rugby union. Full-contact football-code athletes are most commonly affected by respiratory system illnesses. There is a distinct lack of consensus of illness monitoring methodology. CONCLUSIONS: Full-contact football-code team sport athletes are most commonly affected by respiratory system illnesses. Due to various monitoring methodologies, illness incidence could only be compared between studies that used matching incidence exposure measures. High-quality illness surveillance data collection is an essential component to undertake effective and targeted illness prevention in athletes.

Background: Given the high injury rate of netball, injury prevention is a focus within the sport and for governing bodies. To support the development of appropriate injury mitigation strategies further consideration of the risk factors for injury is needed. Therefore, this study aimed to establish consensus on injury risk factors (RFs) in women’s netball via a combined systematic review and Delphi method approach. 6 Methodology: A systematic search of databases (PubMed, Scopus, MEDLINE, SPORTDiscus, CINAHL) was conducted from inception until June 2023. Twenty-four risk factors (RFs) were extracted from 17 studies and combined with a three-round Delphi approach to achieve consensus. In round-one, experts listed perceived RFs for injury in netball which were combined with the RFs identified via the systematic review. In rounds-two and round-three, experts rated their level of agreement with each risk factor on a 5-point Likert scale (1-strongly disagree to 5-strongly agree). Consensus was defined as >80% agreement (with <10% in disagreement). In round-three, experts also rated the priority for mitigating the risk factor (1- very low to 5-very high). Results: Nineteen experts participated in round-one and round-two, and sixteen participated in round- three (response rate 84%). One-hundred and nine RFs for injury were identified by the systematic review and experts combined. Sixty-one RFs reached consensus, categorised into five groups: ‘individual characteristics’ (n = 22), ‘lifestyle’ (n = 11), ‘training and competition’ (n = 14), ‘sport science and medical provision’ (n = 6) and ‘facilities and equipment’ (n = 8). ‘Poor landing technique/ mechanics’ had a median (interquartile range) mitigation priority rating of 5(1), while all others had median ratings of 3-4.5. Conclusion: This study identifies a range of RFs for injury, provides focus areas for injury prevention and highlights the importance of a multi-disciplinary approach to injury mitigation in netball. Future research is needed to investigate the priority and feasibility of the mitigation of the risk factors in specific environments to support tailored injury prevention strategies.

This study aimed to establish consensus on injury risk factors in netball via a combined systematic review and Delphi method approach. A systematic search of databases (PubMed, Scopus, MEDLINE, SPORTDiscus, CINAHL) was conducted from inception until June 2023. Twenty-four risk factors were extracted from 17 studies and combined with a three-round Delphi approach to achieve consensus. In round-one, experts listed perceived risk factors for injury in netball which were combined with the risk factors identified via the systematic review. In round-two and round-three, experts rated their level of agreement with each risk factor on a 5-point Likert scale (1-strongly disagree to 5-strongly agree). Consensus was defined as 80% agreement (with <10% in disagreement). In round-three, experts also rated the priority for mitigating the risk factor (1-very low to 5-very high). Nineteen experts participated in round-one and round-two, and sixteen participated in round-three (response rate 84%). One-hundred and nine risk factors for injury were identified by the systematic review and experts combined. Sixty-one risk factors reached consensus, categorised into five groups: ‘individual characteristics’ (n=22), ‘lifestyle’ (n=11), ‘training and competition’ (n=14), ‘sport science and medical provision’ (n=6) and ‘facilities and equipment’ (n=8). ‘Poor landing technique/mechanics’ had a median (interquartile range) mitigation priority rating of 5(1), while all others had median ratings of 3-4.5. This study identifies a range of risk factors for injury, provides focus areas for injury prevention, and highlights the importance of a multi-disciplinary approach to injury mitigation in netball.

Objective Within women’s rugby league (n=12 teams), we (1) identified modifiers for head-to-head contacts informed by sport partners (eg, players, coaches, match officials); (2) compared head-to-head contact and concussion rates to the previous two seasons following a one-season tackle technique coaching intervention and (3) explored barriers and enablers of the intervention. Methods A multi-method design was used. Part 1: Mitigation strategies were identified by sport partners reviewing footage of head-to-head contacts, informing the development of a coach-targeted tackle technique intervention. Part 2 evaluated the intervention, comparing head-to-head contact and concussion incidence rates (IRs). Interviews with coaches and players (n=6) explored barriers and enablers to effective implementation and compliance with the intervention. Results Sport partners reported tacklers were more responsible for head-to-head contacts and lowering the tackle height was the most frequently suggested mitigation strategy preintervention and postintervention. Head-to-head contact rates were significantly lower during the intervention than preintervention (IR 59; 95% CI 56 to 62 vs IR 28; 95% CI 25 to 30/1000 tackle events); however, concussion rates showed no difference. Perceived barriers to the intervention included underdeveloped physical and technical foundations of players, lack of knowledge and understanding of the intervention and its purpose, and the environmental context and lack of resources in women’s rugby league. Beliefs about the consequences of the tackle and concussion were perceived as barriers and enablers. Conclusions Head-to-head contact rates were significantly lower; however, concussion rates did not decrease following a tackle technique coaching intervention. Reduced head-to-head contacts are potentially due to an increased focus on head injury reduction and increased player/coach awareness and support.