Relationships Between Dry-land Resistance Training and Swim Start Performance and Effects of Such Training on the Swim Start: A Systematic Review No sources of funding were used in the preparation of this article.

Correction to: Injury Incidence, Prevalence and Severity in High-Level Male Youth Football: A Systematic Review First Key Point, sentence 2, which previously read:

Sex Dimorphism of VO 2max Trainability: A Systematic Review and Meta-analysis Abstract Background Increases in maximal oxygen uptake (VO2max) are strongly associated with improved cardiovascular health. Objective The aim was to perform a systematic review and meta-analysis to determine whether VO2max responses to endurance training (ET), the most effective intervention to improve VO2max, are influenced by sex. Methods We conducted a systematic search of MEDLINE and Web of Science since their inceptions until February 2019 for articles assessing the VO2max response to a given sex-matched dose of ET in healthy age-matched men and women. Meta-analyses were performed to determine the mean difference between VO2max responses in men versus women. Subgroup and meta-regression analyses were used to assess potential moderating factors. Results After systematic review, eight studies met the inclusion criteria. All studies implemented common modalities of ET in healthy untrained individuals, comprising a total of 175 men and women (90 ♂, 85 ♀). ET duration and intensity were sex-matched in all studies. After data pooling, ET induced substantially larger increases in absolute VO2max in men compared with women (mean difference = + 191 ml·min−1, 95% CI 99, 283; P < 0.001). A greater effect of ET on relative VO2max was also observed in men versus women (mean difference = + 1.95 ml·min−1·kg−1, 95% CI 0.76, 3.15; P = 0.001). No heterogeneity was detected among studies (I2 = 0%, P ≥ 0.59); the meta-analytical results were robust to potential moderating factors. Conclusion Pooled evidence demonstrates greater improvements in VO2max in healthy men compared with women in response to a given dose of ET, suggesting the presence of sexual dimorphism in the trainability of aerobic capacity.

The Effect of Training Interventions on Change of Direction Biomechanics Associated with Increased Anterior Cruciate Ligament Loading: A Scoping Review Abstract Change of direction (COD) manoeuvres are associated with anterior cruciate ligament (ACL) injury risk due to the propensity to generate large multiplanar knee joint loads. Given the short- and long-term consequences of ACL injury, practitioners are interested in methods that reduce knee joint loads and subsequent ACL loading. An effective strategy to reduce ACL loading is modifying an athlete’s movement mechanics to reduce knee joint loading. The purpose of this scoping review was to critically appraise and comprehensively synthesise the existing literature related to the effects of training interventions on COD biomechanics associated with increased knee joint loads and subsequent ACL loading, and identify gaps and recommend areas for future research. A review of the literature was conducted using Medline and Sport DISCUS databases. Inclusion criteria consisted of pre-post analysis of a COD task, a minimum 4-week training intervention, and assessments of biomechanical characteristics associated with increased ACL loading. Of the 1,027 articles identified, 22 were included in the scoping review. Based on current literature, balance training and COD technique modification are the most effective training modalities for reducing knee joint loading (small to moderate effect sizes). One study reported dynamic core stability training was effective in reducing knee joint loads, but further research is needed to definitively confirm the efficacy of this method. Perturbation-enhanced plyometric training, the F-MARC 11 + soccer specific warm-up, Oslo Neuromuscular warm-up, and resistance training are ineffective training modalities to reduce COD knee joint loads. Conflicting findings have been observed for the Core-Pac and mixed training programme. Consequently, practitioners should consider incorporating balance and COD technique modification drills into their athletes’ training programmes to reduce potentially hazardous knee joint loads when changing direction. However, training intervention studies can be improved by investigating larger sample sizes (> 20), including a control group, acknowledging measurement error when interpreting their findings, and considering performance implications, to confirm the effectiveness of training interventions and improve adherence.

Acute Sport Concussion Assessment Optimization: A Prospective Assessment from the CARE Consortium Abstract Background Numerous medical organizations recommend a multifaceted approach to the assessment of concussion occurring during sporting events. A number of tools are available to clinicians, with a wide breadth of sensitivity and specificity; however, little work has been done to evaluate the combined efficiency of these tools in concussed male and female athletes from a broad array of collegiate sports and with variable time from the pre-season baseline evaluation. Objective The aim of this study was to optimize the concussion assessment battery for application within the first 72 h of injury, and to identify the necessary baseline retesting frequency. Methods Between 2014 and 2017, a total of 1458 National Collegiate Athletic Association (NCAA) athletes sustaining 1640 diagnosed concussions completed a baseline assessment each year of the investigation and were evaluated up to three times within the first 72 h of injury using a standardized assessment protocol. Classification and regression tree analyses were implemented to identify the most efficient multifaceted assessment pathway to quantify concussion-related outcomes. Results were optimized for assessments occurring within 1 h post-injury, 1–24 h post-injury, and 24–72 h post-injury when using the raw post-injury assessment performance, difference scores from baseline evaluations occurring in the same year, and difference scores from baseline evaluations occurring the year prior. Results At each of the assessment time points, the analyses indicated that alone or in combination, a symptom evaluation, Balance Error Scoring System (BESS) scores collected on the firm surface, and Standardized Assessment of Concussion (SAC) total score offered the best overall performance when compared with pre-morbid performance captured in the same season. Optimized sensitivity of the multifaceted approach was 61% within 1 h of injury, 67% at the 1–24 h interval, and 55% at the 24–72 h interval when difference scores from the same-season baseline were available. Conclusions This investigation identified key concussion assessments in quantifying post-concussion performance among student athletes, that were maximized when same-season pre-morbid evaluations were available. Consistent with clinical recommendations, medical professionals should continue to focus on symptom reporting, postural control, and neurocognitive screening to support the clinical examination when making a concussion diagnosis.

Injury Incidence, Prevalence and Severity in High-Level Male Youth Football: A Systematic Review Abstract Background At a young age, high-level youth footballers enter structured practice where they engage in regular training and matches. The academy system is considered fundamental to a young footballer’s tactical, technical and physical development. Yet, with regular training and matches, high-level youth footballers may be exposed to the risk of injury. Objective This systematic review analyses and summarises published scientific information on high-level youth football injury characteristics and calculates the risk of them sustaining an injury over the course of a typical season. Methods The search was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Of the 1346 studies found, 23 fulfilled the inclusion criteria. Results Quality assurance scores for the selected research articles ranged between two and five out of eight. A high degree of heterogeneity between studies was observed. The probability of sustaining a time-loss injury during a high-level youth season ranged between < 1% and 96% for under 9- to under 16-year age groups and 50% and 91% for under 18- to under 21-year age groups. Pooled estimates for total (training and match) incidence per 1000 h was 5.8 for youth players aged under 9 to under 21 years, 7.9 for older players (under 17–under 21 years) and 3.7 for younger aged players (under 9–under 16 years). Training injury incidence rate ranged from 0.69 to 7.9 per 1000 h for all age groups in youth football. Match injury incidence rate for high-level youth players ranged from 0.4 to 80.0 per 1000 h. Close to one-fifth (18%) of all high-level youth football injuries were classified as severe and required > 28 days recovery time. Muscle strain injury accounted for 37% of all injuries reported in youth football. High probabilities (> 90%) of sustaining a time-loss injury over one typical high-level football season were found. Conclusion High-level youth players lose large portions of the seasonal development to injury, with players seemingly suffering long absences from training and matches, consequently affecting health and well-being and possibly burdening club/parental finances and healthcare systems.

The Translation of Sport Science Research to the Field: A Current Opinion and Overview on the Perceptions of Practitioners, Researchers and Coaches Abstract Evidence-based practice (EBP) is the collated integration of practitioner expertise, athlete values and research evidence aimed to optimise the decision-making process surrounding sport performance. Despite the academic interest afforded to sport science research, our knowledge of how this research is applied in elite sport settings is limited. This current opinion examines the existing evidence of the translation of sport science research into the field, with a tailored focus on the current perceptions of practitioners, researchers and coaches. Recent studies show that practitioners and researchers report they ascertain sport science knowledge differently, with coaches preferring personal interactions compared with coaching courses or scientific journals. The limited peer-reviewed research shows that coaches perceive their knowledge is greater in fields such as tactical/technical areas, rather than physical fitness or general conditioning. This likely explains coaches’ greater perceived value in research dedicated to technical and tactical expertise, as well as mental training and skill acquisition. Practitioners place a large emphasis on the need for research in physical fitness areas, which is likely due to their occupational focus. There are many perceived barriers of sport science research application, including funding, time, coach/player/staff ‘buy in’ and research questions that may not apply to the setting. We contend that researchers and practitioners may benefit in producing research, ascertaining knowledge and disseminating findings in alternative methods that better align with coaches’ needs. In addition, educational strategies that focus on real-world context and promote social interaction between coaches, practitioners, organisational personnel and researchers would likely benefit all stakeholders.

Acknowledgement to Referees

Relationships Between Dry-land Resistance Training and Swim Start Performance and Effects of Such Training on the Swim Start: A Systematic Review Abstract Background The swim start requires an explosive muscular response of the lower body musculature to effectively initiate movement off the starting blocks. There are currently key gaps in the literature evaluating the relationship between dry-land resistance training and swim start performance and the effects of this training on swim start performance, as assessed by the time to 5, 10 or 15 m. Objectives The aims of this systematic review were to critically appraise the current literature on (1) the acute relationship between dry-land resistance training and swim start performance and (2) the acute and chronic effects of dry-land resistance training on swim start performance. Methods An electronic search using AusportMed, Embase, Medline (Ovid), SPORTDiscus and Web of Science was performed. The methodological quality of the studies was evaluated using the Newcastle–Ottawa quality assessment scale (NOS) (cross-sectional studies) and the Physiotherapy Evidence Database (PEDro) scale (intervention studies). Results Sixteen studies met the eligibility criteria, although the majority did not utilise the starting blocks or technique currently used in elite swimming. Swim start performance was near perfectly related (r > 0.90) to vertical bodyweight jumps and jump height. Post-activation potentiation and plyometrics were found to produce significant improvements in acute and chronic swim start performance, respectively. Conclusion While there appears to be strong evidence supporting the use of plyometric exercises such as vertical jumps for monitoring and improving swim start performance, future studies need to replicate these findings using current starting blocks and techniques and compare the chronic effects of a variety of resistance training programmes.

Effects of Physical Exercise Training in the Workplace on Physical Fitness: A Systematic Review and Meta-analysis Abstract Background There is evidence that physical exercise training (PET) conducted at the workplace is effective in improving physical fitness and thus health. However, there is no current systematic review available that provides high-level evidence regarding the effects of PET on physical fitness in the workforce. Objectives To quantify sex-, age-, and occupation type-specific effects of PET on physical fitness and to characterize dose–response relationships of PET modalities that could maximize gains in physical fitness in the working population. Data Sources A computerized systematic literature search was conducted in the databases PubMed and Cochrane Library (2000–2019) to identify articles related to PET in workers. Study Eligibility Criteria Only randomized controlled trials with a passive control group were included if they investigated the effects of PET programs in workers and tested at least one fitness measure. Study Appraisal and Synthesis Methods Weighted mean standardised mean differences (SMDwm) were calculated using random effects models. A multivariate random effects meta-regression was computed to explain the influence of key training modalities (e.g., training frequency, session duration, intensity) on the effectiveness of PET on measures of physical fitness. Further, subgroup univariate analyses were computed for each training modality. Additionally, methodological quality of the included studies was rated with the help of the Physiotherapy Evidence Database (PEDro) Scale. Results Overall, 3423 workers aged 30–56 years participated in 17 studies (19 articles) that were eligible for inclusion. Methodological quality of the included studies was moderate with a median PEDro score of 6. Our analyses revealed significant, small-sized effects of PET on cardiorespiratory fitness (CRF), muscular endurance, and muscle power (0.29 ≤ SMDwm ≤ 0.48). Medium effects were found for CRF and muscular endurance in younger workers (≤ 45 years) (SMDwm = 0.71) and white-collar workers (SMDwm = 0.60), respectively. Multivariate random effects meta-regression for CRF revealed that none of the examined training modalities predicted the effects of PET on CRF (R2 = 0). Independently computed subgroup analyses showed significant PET effects on CRF when conducted for 9–12 weeks (SMDwm = 0.31) and for 17–20 weeks (SMDwm = 0.74). Conclusions PET effects on physical fitness in healthy workers are moderated by age (CRF) and occupation type (muscular endurance). Further, independently computed subgroup analyses indicated that the training period of the PET programs may play an important role in improving CRF in workers.