Explore the vast range of titles available.

Football is a global game which is constantly evolving, showing substantial increases in physical and technical demands. Nutrition plays a valuable integrated role in optimising performance of elite players during training and match-play, and maintaining their overall health throughout the season. An evidence-based approach to nutrition emphasising, a ‘food first’ philosophy (ie, food over supplements), is fundamental to ensure effective player support. This requires relevant scientific evidence to be applied according to the constraints of what is practical and feasible in the football setting. The science underpinning sports nutrition is evolving fast, and practitioners must be alert to new developments. In response to these developments, the Union of European Football Associations (UEFA) has gathered experts in applied sports nutrition research as well as practitioners working with elite football clubs and national associations/federations to issue an expert statement on a range of topics relevant to elite football nutrition: (1) match day nutrition, (2) training day nutrition, (3) body composition, (4) stressful environments and travel, (5) cultural diversity and dietary considerations, (6) dietary supplements, (7) rehabilitation, (8) referees and (9) junior high-level players. The expert group provide a narrative synthesis of the scientific background relating to these topics based on their knowledge and experience of the scientific research literature, as well as practical experience of applying knowledge within an elite sports setting. Our intention is to provide readers with content to help drive their own practical recommendations. In addition, to provide guidance to applied researchers where to focus future efforts.

Mental health symptoms and disorders are common among elite athletes, may have sport related manifestations within this population and impair performance. Mental health cannot be separated from physical health, as evidenced by mental health symptoms and disorders increasing the risk of physical injury and delaying subsequent recovery. There are no evidence or consensus based guidelines for diagnosis and management of mental health symptoms and disorders in elite athletes. Diagnosis must differentiate character traits particular to elite athletes from psychosocial maladaptations.Management strategies should address all contributors to mental health symptoms and consider biopsychosocial factors relevant to athletes to maximise benefit and minimise harm. Management must involve both treatment of affected individual athletes and optimising environments in which all elite athletes train and compete. To advance a more standardised, evidence based approach to mental health symptoms and disorders in elite athletes, an International Olympic Committee Consensus Work Group critically evaluated the current state of science and provided recommendations.

BackgroundThe UEFA Elite Club Injury Study is the largest and longest running injury surveillance programme in football.ObjectiveTo analyse the 18-season time trends in injury rates among male professional football players.Methods3302 players comprising 49 teams (19 countries) were followed from 2000–2001 through 2018–2019. Team medical staff recorded individual player exposure and time-loss injuries.ResultsA total of 11 820 time-loss injuries were recorded during 1 784 281 hours of exposure. Injury incidence fell gradually during the 18-year study period, 3% per season for both training injuries (95% CI 1% to 4% decrease, p=0.002) and match injuries (95% CI 2% to 3% decrease, p<0.001). Ligament injury incidence decreased 5% per season during training (95% CI 3% to 7% decrease, p<0.001) and 4% per season during match play (95% CI 3% to 6% decrease, p<0.001), while the rate of muscle injuries remained constant. The incidence of reinjuries decreased by 5% per season during both training (95% CI 2% to 8% decrease, p=0.001) and matches (95% CI 3% to 7% decrease, p<0.001). Squad availability increased by 0.7% per season for training sessions (95% CI 0.5% to 0.8% increase, p<0.001) and 0.2% per season for matches (95% CI 0.1% to 0.3% increase, p=0.001).ConclusionsOver 18 years: (1) injury incidence decreased in training and matches, (2) reinjury rates decreased, and (3) player availability for training and match play increased.

Correspondence to Dr Benno M Nigg, Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB T2L 1N4, Canada; nigg@ucalgary.ca The effect of shoe mid-sole construction on running performance was discussed with reference to the Nike Vaporfly 4%.1 Drs Burns and Tam described the mid-sole thickness as the major running shoe characteristic that contributes to changes in performance. [...]the results of the leg model (representative of average-level runners) correlated with the results of the field tests. [...]it appears inappropriate to regulate one specific footwear feature before understanding where these performance advantages originated from.7 However, our current knowledge suggests that, compared with the teeter-totter effect, all other shoe characteristic contributions to performance are small and negligible.

ObjectivesWe investigated medical staff interpretations and descriptions of internal communication quality in elite football teams to determine whether internal communication was correlated with injuries and/or player availability at training and matches.MethodsMedical staff from 36 elite football clubs across 17 European countries produced 77 reports at four postseason meetings to provide their perceptions of internal communications in their teams. They also recorded data on individual players’ exposure to football and time-loss injuries.ResultsThe injury burden and incidence of severe injuries were significantly higher in teams with low quality of communication between the head coach/manager and the medical team (scores of 1–2 on a 5-point Likert scale) compared with teams with moderate or high-quality scores (scores of 3–5; p=0.008 for both). Teams with low scores had 4%–5% lower training attendance (76% vs 83%, p=0.001) and less availability at matches (82% vs 88%, p=0.004) compared with teams with moderate or high communication quality scores.ConclusionsThe quality of internal communication within a team was correlated with injury rates, training attendance and match availability.

ObjectiveTo identify and quantify determinants of anxiety symptoms and disorders experienced by elite athletes.DesignSystematic review and meta-analysis.Data sourcesFive online databases (PubMed, SportDiscus, PsycINFO, Scopus and Cochrane) were searched up to November 2018 to identify eligible citations.Eligibility criteria for selecting studiesArticles were included if they were published in English, were quantitative studies and measured a symptom-level anxiety outcome in competing or retired athletes at the professional (including professional youth), Olympic or collegiate/university levels.Results and summaryWe screened 1163 articles; 61 studies were included in the systematic review and 27 of them were suitable for meta-analysis. Overall risk of bias for included studies was low. Athletes and non-athletes had no differences in anxiety profiles (d=−0.11, p=0.28). Pooled effect sizes, demonstrating moderate effects, were identified for (1) career dissatisfaction (d=0.45; higher anxiety in dissatisfied athletes), (2) gender (d=0.38; higher anxiety in female athletes), (3) age (d=−0.34; higher anxiety for younger athletes) and (4) musculoskeletal injury (d=0.31; higher anxiety for injured athletes). A small pooled effect was found for recent adverse life events (d=0.26)—higher anxiety in athletes who had experienced one or more recent adverse life events.ConclusionDeterminants of anxiety in elite populations broadly reflect those experienced by the general population. Clinicians should be aware of these general and athlete-specific determinants of anxiety among elite athletes.

ObjectivesTo explore how sports injury prevention takes place in elite sport practice and to describe the perspectives of athletes, coaches and physiotherapists regarding the most critical factors that help prevent injury in the elite sports context.MethodsQualitative study. Semistructured interviews with 19 international level athletes, coaches and physiotherapists, from different Olympic sports. Interviews were transcribed verbatim and analysed using comparative data analysis based on Grounded Theory.ResultsThe participants perceived injury risk as an inherent part of elite sports, because athletes try to enhance performance by pushing their limits. Participants described injury prevention as a learning process that changed over time, based on their sports experience and the injuries that they had sustained along their career. Communication among the athletes, coaches and physiotherapists was described as a key component of the injury prevention process. Study participants emphasised the relevance of teamwork and shared responsibility. Performance was presented as the core of the athlete’s daily practice, indicating that injury prevention can be a means to that end but is not a goal in itself for this community.ConclusionParticipants perceive injury prevention as part of elite sports and thus embrace the need for injury prevention. Injury prevention strategies in elite sports were described as a learning process, following the dynamic nature of training for maximal performance. Performance is the participants’ main goal.

Background The influence of injuries on team performance in football has only been scarcely investigated. Aim To study the association between injury rates and team performance in the domestic league play, and in European cups, in male professional football. Methods 24 football teams from nine European countries were followed prospectively for 11 seasons (2001–2012), including 155 team-seasons. Individual training and match exposure and time-loss injuries were registered. To analyse the effect of injury rates on performance, a Generalised Estimating Equation was used to fit a linear regression on team-level data. Each team's season injury rate and performance were evaluated using its own preceding season data for comparison in the analyses. Results 7792 injuries were reported during 1 026 104 exposure hours. The total injury incidence was 7.7 injuries/1000 h, injury burden 130 injury days lost/1000 h and player match availability 86%. Lower injury burden (p=0.011) and higher match availability (p=0.031) were associated with higher final league ranking. Similarly, lower injury incidence (p=0.035), lower injury burden (p<0.001) and higher match availability (p<0.001) were associated with increased points per league match. Finally, lower injury burden (p=0.043) and higher match availability (p=0.048) were associated with an increase in the Union of European Football Association (UEFA) Season Club Coefficient, reflecting success in the UEFA Champions League or Europa League. Conclusions Injuries had a significant influence on performance in the league play and in European cups in male professional football. The findings stress the importance of injury prevention to increase a team's chances of success.

ObjectiveTo characterise the core temperature response and power output profile of elite male and female cyclists during the 2016 UCI Road World Championships. This may contribute to formulating environmental heat stress policies.MethodsCore temperature was recorded via an ingestible capsule in 10, 15 and 15 cyclists during the team time trial (TTT), individual time trial (ITT) and road race (RR), respectively. Power output and heart rate were extracted from individual cycling computers. Ambient conditions in direct sunlight were hot (37°C±3°C) but dry (25%±16% relative humidity), corresponding to a wet-bulb globe temperature of 27°C±2°C.ResultsCore temperature increased during all races (p<0.001), reaching higher peak values in TTT (39.8°C±0.9°C) and ITT (39.8°C±0.4°C), relative to RR (39.2°C±0.4°C, p<0.001). The highest temperature recorded was 41.5°C (TTT). Power output was significantly higher during TTT (4.7±0.3 W/kg) and ITT (4.9±0.5 W/kg) than RR (2.7±0.4 W/kg, p<0.001). Heart rate increased during the TTs (p<0.001) while power output decreased (p<0.001).Conclusion85% of the cyclists participating in the study (ie, 34 of 40) reached a core temperature of at least 39°C with 25% (ie, 10 of 40) exceeding 40°C. Higher core temperatures were reached during the time trials than the RR.

When Nike compared its energetic cost (running economy) to contemporary elite racing shoes, the Vaporfly provided a 4% improvement in economy (hence the shoe’s moniker) and an estimated 3.4% increase in running speed.1 Subsequent independent laboratory testing2 and big-data performance analyses3 have corroborated the benefit. Schematic of the Nike Vaporfly 4% (images adapted from Nike.com) Carbon-fibre plate The full-length embedded carbon-fibre plate increases the longitudinal bending stiffness of the shoe, reducing running economy by 1%.5 While widely used in sprinting spikes, it was an uncommon addition to long-distance racing shoes. The Vaporfly has a 31 mm heel-height, and weighs 184 g, whereas the Streak has a 23 mm heel-height and weighs 181 g. This provides the energetic benefit of increased cushioning without incurring the energetic penalty of added weight.7 8 Moreover, the thicker midsole extends the effective leg length of the runner. [...]selecting parameters for shoe regulation would be troublesome up front and operationally burdensome over time for the IAAF. [...]a precedent exists: IAAF Rule 143.5 stipulates a sole and heel thickness for shoes used in high jump and long jump competitions.