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Background: Male youth soccer players competing at a high level will typically engage in large volumes of soccer training from a young age. However, it is not known whether the high levels of habitual training that these high-performing players are exposed to limit their ability to respond to strength, plyometric or combined training interventions. Objective: The primary aim of our systematic review and meta-analysis was to compare the specific effects of strength, plyometric and combined training with active controls (standard soccer training) on the strength, power and speed characteristics of high-level, highly trained young male soccer players. Methods: We performed a literature search across PubMed, Scopus, CINAHL, Web of Science and SPORTDiscus to identify controlled studies that implemented strength, plyometric or combined training in high-level male youth soccer players. Participants were defined as high level or highly trained based on established guidelines related to either competition level or age-related weekly hours spent in soccer training. Studies needed to report at least one outcome of lower body strength, squat jump, countermovement jump, horizontal power, acceleration (0–10 m), speed (15–40 m) or change of direction speed. A meta-analysis was then performed using a random-effects model to determine the magnitude (Hedge's g) of training responses and whether effects differed across modes of training. Results: From an initial return of 5464 papers, n = 34 studies met the inclusion criteria and provided a total sample of n = 1396 high-level male youth soccer players. Strength, plyometric and combined training resulted in improvements in strength, squat and countermovement jump, horizontal power, acceleration, change of direction speed (all p < 0.05; g = 0.73–1.08, moderate) and speed (p < 0.05; g = 0.40–0.59, small). Lower body strength was the only outcome where training mode had a significant effect (p < 0.05), with plyometric training producing small effects (g = 0.27, p < 0.05) compared with moderate effects for strength (g = 1.07, p < 0.05) and combined (g = 0.75, p < 0.05) training. Prediction intervals for overall effects (all training modes combined) showed that the greatest confidence that future training will lead to positive effects was in the squat and countermovement jump, horizontal power and acceleration (prediction intervals = 0.03–1.81). Conclusions: High-level, highly trained male youth soccer players can experience positive gains in indices of strength, power and speed from strength, plyometric and combined training, and the magnitude of gains are mostly similar across modes of training. Based on prediction intervals, there is a good level of certainty that future strength, plyometric and combined training in this population would lead to positive improvements in vertical and horizontal power and sprint acceleration. [ABSTRACT FROM AUTHOR]

Background: Team ball sports such as soccer, basketball and volleyball have high participation levels worldwide. Musculoskeletal injuries are common in team ball sports and are associated with significant treatment costs, participation loss and long-term negative side effects. The results of recent randomized controlled trials provide support for the protective effect of injury-prevention exercise programmes (IPEPs) in team ball sports, but also highlight that achieving adequate compliance can be challenging. A key process in enhancing the ultimate impact of team ball sport IPEPs is identifying the specific implementation components that influence the adoption, execution and maintenance of these interventions. Despite this, no systematic review focussing on the specific implementation components of team ball sport IPEPs has been conducted. Objectives: Our objective was to assess the reporting of specific implementation components in the published literature on team ball sport IPEPs using the Reach Efficacy Adoption Implementation Maintenance (RE-AIM) framework. Methods: Six electronic databases were systematically searched from inception to December 2012 for papers reporting team ball sport IPEP trials. All eligible papers were independently evaluated by two raters before reaching consensus on the reporting of individual RE-AIM items, using the RE-AIM Model Dimension Items Checklist (RE-AIM MDIC). Results: A total of 60 papers, reporting 52 unique intervention trials, met eligibility criteria. Before consensus, the level of agreement across all trials between reviewers using the RE-AIM MDIC ranged from 81 to 91 %. The RE-AIM MDIC dimension of 'efficacy' had the highest level of reporting, with the five individual items in this dimension reported in 19-100 % of eligible trials (mean 58 %). The RE-AIM MDIC dimension 'maintenance-setting level' had the lowest level of reporting, with none of the four individual items in this dimension reported. For other dimensions, the mean level of reporting and range across items were 'reach' 34 % (12-60 %); 'adoption-setting level' 1 % (0-2 %); 'adoption-delivery agent level' 7 % (4-10 %); 'implementation' 36 % (13-63 %) and 'maintenance individual level' 1 % (0-4 %). Conclusion: Information on the specific implementation components of team ball sport IPEPs in published studies is scarce. In particular, major reporting gaps exist regarding the adoption and maintenance of these programmes. The RE-AIM MDIC can be successfully applied to reviewing literature in this context. [ABSTRACT FROM AUTHOR]

Background: In recent years, there has been a large expansion in literature pertaining to the game of Australian football (AF). Furthermore, there have been a number of rule changes that are likely to have changed the demands of the game. Based on these advances and changes, it seemed important to conduct a review assessing the scientific literature surrounding the sport.Objective: The review evaluates the match demands of AF, the qualities required for success, and the impact training and competition have on adaptation, injury and fatigue.Methods: A systematic search of PubMed, CINAHL, SPORTDiscus, Web of Science and Scopus for AF literature was conducted; studies investigating match demands, physical qualities, training practices and injury were included. Weighted means and standard deviations were calculated for match demands and physical and anthropometric profiles across playing standards.Results: A total of 1830 articles were retrieved in the initial search, with 888 removed as duplicates, 626 removed for being non-relevant and a further 152 removed for being AF papers but not relevant to the review. As such, 164 AF papers were included in the review. Due to the intermittent high-intensity nature of match-play, players need a wide range of physical and technical qualities to excel, with speed, aerobic fitness, reactive agility and well-developed lean mass being central to success. Training for AF at the elite level is associated with high workloads, with players engaging in numerous training modalities; even altitude and heat training camps have been utilised by Australian Football League (AFL) teams to further augment fitness improvements. While high chronic workloads can be tolerated and are needed for improving physical qualities, careful planning and monitoring of internal and external workloads is required to minimise sharp spikes in load that are associated with injury.Conclusions: There is a complex interaction between numerous contextual factors that influence the match demands that are discussed in this review. Whilst players must have the physical capacities to cope with the intense physical demands of AF matches, the successful execution of technical skills during match-play is central to success. To develop these skills and attributes, specific and carefully planned and monitored training must be performed over a number of years. [ABSTRACT FROM AUTHOR]

Background: The high prevalence of injury amongst cricket fast bowlers exposes a great need for research into the risk factors associated with injury. Both extrinsic (environment-related) and intrinsic (person-related) risk factors are likely to be implicated within the high prevalence of non-contact injury amongst fast bowlers in cricket. Identifying and defining the relative importance of these risk factors is necessary in order to optimize injury prevention efforts. Objective: The objective of this review was to assess and summarize the scientific literature related to the extrinsic and intrinsic factors associated with non-contact injury inherent to adult cricket fast bowlers. Method: A systematic review was performed in compliance with the PRISMA guidelines. This review considered both experimental and epidemiological study designs. Studies that included male cricket fast bowlers aged 18 years or above, from all levels of play, evaluating the association between extrinsic/intrinsic factors and injury in fast bowlers were considered for inclusion. The three-step search strategy aimed at finding both published and unpublished studies from all languages. The searched databases included MEDLINE via PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Cochrane Controlled Trials Register in the Cochrane Library, Physiotherapy Evidence Database (PEDro), ProQuest 5000 International, ProQuest Health and Medical Complete, EBSCO MegaFile Premier, Science Direct, SPORTDiscus with Full Text and SCOPUS (prior to 28 April 2015). Initial keywords used were 'cricket', 'pace', 'fast', 'bowler', and 'injury'. Papers which fitted the inclusion criteria were assessed by two independent reviewers for methodological validity prior to inclusion in the review using standardized critical appraisal instruments from the Joanna Briggs Institute Meta Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI). Results: A total of 16 studies were determined to be suitable for inclusion in this systematic review. The mean critical appraisal score of the papers included in this study was 6.88 (SD 1.15) out of a maximum of 9. The following factors were found to be associated with injury: bowling shoulder internal rotation strength deficit, compromised dynamic balance and lumbar proprioception (joint position sense), the appearance of lumbar posterior element bone stress, degeneration of the lumbar disc on magnetic resonance imaging (MRI), and previous injury. Conflicting results were found for the association of quadratus lumborum (QL) muscle asymmetry with injury. Technique-related factors associated with injury included shoulder-pelvis flexion-extension angle, shoulder counter-rotation, knee angle, and the proportion of side-flexion during bowling. Bowling workload was the only extrinsic factor associated with injury in adult cricket fast bowlers. A high bowling workload (particularly if it represented a sudden upgrade from a lower workload) increased the subsequent risk to sustaining an injury 1, 3 or 4 weeks later. Conclusion: Identifying the factors associated with injury is a crucial step which should precede the development of, and research into, the effectiveness of injury prevention programs. Once identified, risk factors may be included in pre-participation screening tools and injury prevention programs, and may also be incorporated in future research projects. Overall, the current review highlights the clear lack of research on factors associated with non-contact injury, specifically in adult cricket fast bowlers. Systematic review registration number Johanna Briggs Institute Database of Systematic Reviews and Implementation Reports 1387 (Olivier et al., JBI Database Syst Rev Implement Rep 13(1):3-13. doi:, ). [ABSTRACT FROM AUTHOR]

Background: Soccer is the most popular sport worldwide, with a long history and currently more than 500 million active participants, of whom 300 million are registered football club members. On the basis of scientific findings showing positive fitness and health effects of recreational soccer, FIFA (Fédération Internationale de Football Association) introduced the slogan 'Playing football for 45 min twice a week-best prevention of non-communicable diseases' in 2010. Objective: The objective of this paper was to perform a systematic review and meta-analysis of the literature to determine the effects of recreational soccer on maximal oxygen uptake ( $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ ). Methods: Six electronic databases (MEDLINE, PubMed, SPORTDiscus, Web of Science, CINAHL and Google Scholar) were searched for original research articles. A manual search was performed to cover the areas of recreational soccer, recreational physical activity, recreational small-sided games and $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ using the following key terms, either singly or in combination: recreational small-sided games, recreational football, recreational soccer, street football, street soccer, effect, maximal oxygen uptake, peak oxygen uptake, cardiorespiratory fitness, $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ . The inclusion criteria were divided into four sections: type of study, type of participants, type of interventions and type of outcome measures. Probabilistic magnitude-based inferences for meta-analysed effects were based on standardised thresholds for small, moderate and large changes (0.2, 0.6 and 1.2, respectively) derived from between-subject standard deviations for baseline fitness. Results: Seventeen studies met the inclusion criteria and were included in the systematic review and meta-analysis. Mean differences showed that $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ increased by 3.51 mL/kg/min (95 % CI 3.07-4.15) over a recreational soccer training programme in comparison with other training models. The meta-analysed effects of recreational soccer on $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ compared with the controls of no exercise, continuous running and strength training were most likely largely beneficial [effect size (ES) = 1.46; 95 % confidence interval (CI) 0.91, 2.01; I = 88.35 %], most likely moderately beneficial (ES = 0.68; 95 % CI 0.06, 1.29; I = 69.13 %) and most likely moderately beneficial (ES = 1.08; 95 % CI −0.25, 2.42; I = 71.06 %), respectively. In men and women, the meta-analysed effect was most likely largely beneficial for men (ES = 1.22) and most likely moderately beneficial for women (ES = 0.96) compared with the controls. After 12 weeks of recreational soccer with an intensity of 78-84 % maximal heart rate (HR), healthy untrained men improved their $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ by 8-13 %, while untrained elderly participants improved their $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ by 15-18 %. Soccer training for 12-70 weeks in healthy women resulted in an improvement in $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ of 5-16 %. Significant improvements in $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ have been observed in patients with diabetes mellitus, hypertension and prostate cancer. Conclusion: Recreational soccer produces large improvements in $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ compared to strength training and no exercise, regardless of the age, sex and health status of the participants. Furthermore, recreational soccer is better than continuous endurance running, albeit the additional effect is moderate. This kind of physical activity has great potential for enhancing aerobic fitness, and for preventing and treating non-communicable diseases, and is ideal for addressing lack of motivation, a key component in physical (in)activity. [ABSTRACT FROM AUTHOR]

Exergaming is a combination of exercise and gaming. Evidence shows an association between exercise and cognition in older people. However, previous studies showed inconsistent results on the cognitive benefits of exergaming in people with cognitive impairment. Therefore, this study aims to examine the effect of exergaming intervention on cognitive functions in people with MCI or dementia. A systematic literature search was conducted via OVID databases. Randomized controlled trials (RCTs) examined the effect of an exergaming intervention on cognitive functions in people with MCI or dementia were included. Subgroup analyses were conducted according to the type of intervention and training duration. Twenty RCTs with 1152 participants were identified, including 14 trials for MCI and 6 trials for dementia. In people with MCI, 13 studies used virtual-reality (VR)-based exergaming. Those who received VR-based exergaming showed significantly better global cognitive function [SMD (95%CI) = 0.67 (0.23–1.11)], learning and memory [immediate recall test: 0.79 (0.31–1.27); delayed recall test: 0.75 (0.20–1.31)], working memory [5.83 (2.27–9.39)], verbal fluency [0.58 (0.12–1.03)], and faster in executive function than the controls. For people with dementia, all studies used video-based exergaming intervention. Participants with exergaming intervention showed significantly better global cognitive function than the controls [0.38 (0.10–0.67)]. Subgroup analyses showed that longer training duration generated larger effects. The findings suggest that exergaming impacts cognitive functions in people with MCI and dementia. Cognitive benefits are demonstrated for those with a longer training duration. With technological advancement, VR-based exergaming attracts the attention of people with MCI and performs well in improving cognitive functions. [ABSTRACT FROM AUTHOR]

Background: The adolescent 'growth spurt' results in rapid growth of the skeletal system. It has been theorised that absence of a concomitant increase in muscular adaptations in female athletes may predispose them to an increased risk of anterior cruciate ligament injuries. Objectives: To determine if sex differences exist in landing biomechanics and postural stability of adolescent athletes; with a further objective of determining if such differences are propagated during adolescence. Data sources: The following databases were searched: MEDLINE, EMBASE, CINAHL, PEDro, PubMed, SPORTDiscus and Web of Science. Research papers were identified by including search terms for neuromuscular control, lower limb and pubertal development. Inclusion Criteria: Studies were required to be written in English; report on biomechanical analyses; include landing or postural control tasks; be cross-sectional or longitudinal; and include healthy adolescent/pubertal subjects. Study Appraisal and Synthesis Methods: A modified version of the Strengthening the Reporting of Observational studies in Epidemiology checklist was used to rate methodological quality. Meta-analyses were performed when more than one study reported on an outcome measure. Results: Sixteen articles were included. The overall methodological quality of evaluated studies was low (mean score = 5.75/10 points). Adolescent females exhibited increased knee valgus with increasing maturity. There was no consensus on sex differences in postural stability. Conclusions: With increasing maturation, females are characterized by increased knee valgus during landing tasks. To date, no research has longitudinally investigated postural stability development during adolescence in females, despite the importance of postural control training in injury prevention programmes. Therefore, further research on this topic is warranted. [ABSTRACT FROM AUTHOR]

Background: Well programmed strength and conditioning training is an indispensable part of the long-term training process for athletes in individual and team sports to improve performance and prevent injuries. Yet, there is a limited number of studies available that examine the effects of resistance training (RT) on muscular fitness and physiological adaptations in elite female athletes. Objectives: This systematic review aimed to summarize recent evidence on the long-term effects of RT or combinations of RT with other strength-dominated exercise types on muscular fitness, muscle morphology, and body composition in female elite athletes. Materials and Methods: A systematic literature search was conducted in nine electronic databases (Academic Search Elite, CINAHL, ERIC, Open Access Theses and Dissertations, Open Dissertations, PsycINFO, PubMed/MEDLINE, Scopus, and SPORTDiscus) from inception until March 2022. Key search terms from the MeSH database such as RT and strength training were included and combined using the operators "AND," "OR," and "NOT". The search syntax initially identified 181 records. After screening for titles, abstracts, and full texts, 33 studies remained that examined the long-term effects of RT or combinations of RT with other strength-dominated exercise types on muscular fitness, muscle morphology, and body composition in female elite athletes. Results: Twenty-four studies used single-mode RT or plyometric training and nine studies investigated the effects of combined training programs such as resistance with plyometric or agility training, resistance and speed training, and resistance and power training. The training duration lasted at least 4 weeks, but most studies used ~ 12 weeks. Studies were generally classified as 'high-quality' with a mean PEDro score of 6.8 (median 7). Irrespective of the type or combination of RT with other strength-dominated exercise regimens (type of exercise, exercise duration, or intensity), 24 out of 33 studies reported increases in muscle power (e.g., maximal and mean power; effect size [ES]: 0.23 < Cohen's d < 1.83, small to large), strength (e.g., one-repetition-maximum [1RM]; ES: 0.15 < d < 6.80, small to very large), speed (e.g., sprint times; ES: 0.01 < d < 1.26, small to large), and jump performance (e.g., countermovement/squat jump; ES: 0.02 < d < 1.04, small to large). The nine studies that examined the effects of combined training showed significant increases on maximal strength (ES: 0.08 < d < 2.41, small to very large), muscle power (ES: 0.08 < d < 2.41, small to very large), jump and sprint performance (ES: 0.08 < d < 2.41, small to very large). Four out of six studies observed no changes in body mass or percentage of body fat after resistance or plyometric training or combined training (ES: 0.026 < d < 0.492, small to medium). Five out of six studies observed significant changes in muscle morphology (e.g., muscle thickness, muscle fiber cross-sectional area; ES: 0.23 < d < 3.21, small to very large). However, one study did not find any changes in muscle morphology (i.e., muscle thickness, pennation angle; ES: 0.1 < d < 0.19, small). Conclusion: Findings from this systematic review suggest that RT or combined RT with other strength-dominated exercise types leads to significant increases in measures of muscle power, strength, speed, and jump performance in elite female athletes. However, the optimal dosage of programming parameters such as training intensity and duration necessary to induce large effects in measures of muscular fitness and their physiological adaptations remain to be resolved in female elite athletes. [ABSTRACT FROM AUTHOR]

Background: Preserving physiological functional capacity (PFC), the ability to perform the activities of daily life, and the ease with which they can be performed, in older adults, defined for this study as ≥ 50 years of age, is an important consideration for maintaining health and independence through the ageing process. Physical activity, and exercise training in particular, has been positively associated with improvement in PFC. In addition to improving aerobic and anaerobic capacity, promoting and preserving functional movement as a component of PFC is an important goal of physical activity, especially for older adults. High-intensity interval training (HIIT), an exercise protocol where repeated bouts of increased intensity are interspersed with active or passive recovery periods, has often been studied as an alternative to traditional moderate-intensity continuous training (MICT) exercise, where a continuous intensity is maintained throughout the exercise session. A large body of research has determined that both types of exercise programme are effective in improving measures of aerobic and anaerobic fitness in older adults. However, the effect of the two exercise modalities on functional movement has most often been a secondary outcome, with a range of observational techniques applied for measurement. Objectives: The primary objective of this research is to systematically review and meta-analyse published studies of HIIT interventions that measured functional movement in older adults to conclude if HIIT is effective for improving functional movement. A secondary objective is to determine if there are significant differences between HIIT and MICT effect on functional movement. Methods: A search strategy of terms locating studies of HIIT interventions, functional movement outcome measures, and older adult population samples was executed on seven digital databases. Randomized and pair-matched trials of > 2 weeks were considered for inclusion. Studies of participants with neurological impairment or studies using combined exercise modality were rejected. Standardized mean difference for functional movement outcome measures was calculated. A meta-analysis of the included studies and subgroups was performed along with study quality (risk of bias and publication bias) evaluation. Results: A total of 18 studies were included in random effects model pooled analysis. Subgroup analysis of HIIT versus MICT on functional movement showed a trivial effect in favour of HIIT (ES 0.13, 95% CI [−0.06, 0.33] p = 0.18) and did not achieve statistical significance. However, HIIT showed a medium, statistically significant favourable effect on functional movement versus non-intervention control (ES = 0.60 95% CI [0.24, 0.95] p = 0.001). Further subgroups analysis using singular and multiple functional movement outcome measures showed similar results. Conclusion: This meta-analysis indicates that HIIT interventions in older adults may be effective at promoting improvements in functional movement, though it is unclear whether HIIT is superior to MICT. [ABSTRACT FROM AUTHOR]

Background: The relationship between exercise-induced muscle damage (EIMD) indicators and acute training loads (TL) is yet to be reviewed extensively in semi-elite and elite athlete populations. Objectives: The objectives of this systematic review and meta-analysis were threefold: (1) to evaluate studies of EIMD following the initial period of the preseason in semi-elite and elite athletes: (2) to examine acute physiological and performance responses across two periods of the season with similar TL; and (3) to examine acute physiological and performance responses to acute changes in TL during the season. Methods: The CINAHL, PubMed, Scopus, SPORTDiscus and Web of Science databases were systematically searched for studies that investigated: (1) semi-elite or elite athletes in team or individual sports following a periodised training programme; and (2) measured acute responses to training. Studies were excluded if: (1) conducted in animals; (2) non-English language; or (3) a conference abstract, review or case report. The Kmet Quality Scoring of Quantitative Studies tool was used for study appraisal. Synthesis Methods: Data were quantitatively analysed by generating forest plots to report test statistics for statistical significance and inter-trial heterogeneity. Results: Of the included studies (n = 32), athletes experienced greater creatine kinase (CK) concentrations (Z = 4.99, p < 0.00001, I2 = 74%), inflammatory factors and other indirect measures of muscle damage in the initial phase of the preseason period compared to the off-season; there were no changes in CK (Z = 1.43, p = 0.15, I2 = 74%) across two time points of similar TL; and there were concurrent increases in CK with increases in TL (Z = 4.26, p < 0.0001, I2 = 36%) and vice versa (Z = 4.33, p < 0.0001, I2 = 79%).The qualitative analysis identified that the response of inflammatory factors and other indirect measures of muscle damage to changes in load were inconclusive. Limitations: This review included varying age, sex, sports and competition levels. The group level meta-analysis failed to identify within-athlete or position-specific differences across time. Conclusion: Blood biomarkers of EIMD may not differ across periods of similar TL, however can be considered a sensitive monitoring tool for assessing responses following acute TL changes in semi-elite and elite athletes. [ABSTRACT FROM AUTHOR]

Background: Short-sprint (≤ 20 m) performance is an important quality for success in the football codes. Therefore, developing an evidence base for understanding training methods to enhance short-sprint performance is key for practitioners. However, current systematic reviews are limited by (1) a lack of focus on football code athletes, (2) a lack of consideration of all training modalities and (3) a failure to account for the normal training practices undertaken by intervention groups within their analysis. Therefore, this review aimed to (1) conduct a systematic review of the scientific literature evaluating training interventions upon short-sprint performance within football code athletes, (2) undertake a meta-analysis to assess the magnitude of change of sport-sprint performance following training interventions and (3) identify how moderator variables affect the training response. Methods: A systematic search of electronic databases was conducted. A random-effects meta-analysis was performed to establish standardised mean difference with 95% confidence intervals. This identified the magnitude and direction of the individual training effects of intervention subgroups (primary, secondary, combined-specific, tertiary and combined training methods) on short-sprint performance while considering moderator variables (i.e., football code, sex, age, playing standard, phase of season). Results: 121 studies met the inclusion criteria, totalling 3419 athletes. Significant improvements (small-large) were found between pre- and post-training in short-sprint performance for the combined, secondary, tertiary and combined-specific training methods. No significant effect was found for primary or sport only training. No individual mode was found to be the most effective. Between-subgroup analysis identified that football code, age, playing standard and phase of season all moderated the overall magnitude of training effects. Conclusions: This review provides the largest systematic review and meta-analysis of short-sprint performance development methods and the only one to assess football code athletes exclusively. Practitioners can apply combined, secondary and tertiary training methods to improve short-sprint performance within football code athletes. The application of sport only and primary methods does not appear to improve short-sprint performance. Regardless of the population characteristics, short-sprint performance can be enhanced by increasing either or both the magnitude and the orientation of force an athlete can generate in the sprinting action. Trial Registration: OSF registration https://osf.io/kshqn/. [ABSTRACT FROM AUTHOR]

Background: Effects of resistance training on muscle strength and hypertrophy are well established in adults and younger elderly. However, less is currently known about these effects in the very elderly (i.e., 75 years of age and older). Objective: To examine the effects of resistance training on muscle size and strength in very elderly individuals. Methods: Randomized controlled studies that explored the effects of resistance training in very elderly on muscle strength, handgrip strength, whole-muscle hypertrophy, and/or muscle fiber hypertrophy were included in the review. Meta-analyses of effect sizes (ESs) were used to analyze the data. Results: Twenty-two studies were included in the review. The meta-analysis found a significant effect of resistance training on muscle strength in the very elderly [difference in ES = 0.97; 95% confidence interval (CI) 0.50, 1.44; p = 0.001]. In a subgroup analysis that included only the oldest-old participants (80 + years of age), there was a significant effect of resistance training on muscle strength (difference in ES = 1.28; 95% CI 0.28, 2.29; p = 0.020). For handgrip strength, we found no significant difference between resistance training and control groups (difference in ES = 0.26; 95% CI − 0.02, 0.54; p = 0.064). For whole-muscle hypertrophy, there was a significant effect of resistance training in the very elderly (difference in ES = 0 30; 95% CI 0.10, 0.50; p = 0.013). We found no significant difference in muscle fiber hypertrophy between resistance training and control groups (difference in ES = 0.33; 95% CI − 0.67, 1.33; p = 0.266). There were minimal reports of adverse events associated with the training programs in the included studies. Conclusions: We found that very elderly can increase muscle strength and muscle size by participating in resistance training programs. Resistance training was found to be an effective way to improve muscle strength even among the oldest-old. [ABSTRACT FROM AUTHOR]

Background: Resistance-training causes changes in the central nervous system (CNS); however, the sites of these adaptations remain unclear. Objective: To determine sites of neural adaptation to resistance-training by conducting a systematic review and meta-analysis on the cortical and subcortical responses to resistance-training. Methods: Evidence from randomized controlled trials (RCTs) that focused on neural adaptations to resistance-training was pooled to assess effect estimates for changes in strength, cortical, and subcortical adaptations. Results: The magnitude of strength gain in 30 RCTs (n = 623) reported a standardised mean difference (SMD) of 0.67 (95% CI 0.41, 0.94; P < 0.001) that measured at least one cortical/subcortical neural adaptation which included: motor-evoked potentials (MEP; 19 studies); silent period (SP; 7 studies); short-interval intracortical inhibition (SICI; 7 studies); cervicomedullary evoked potentials (CMEP; 1 study); transcranial magnetic stimulation voluntary activation (VATMS; 2 studies); H-reflex (10 studies); and V-wave amplitudes (5 studies). The MEP amplitude during voluntary contraction was greater following resistance-training (SMD 0.55; 95% CI 0.27, 0.84; P < 0.001, n = 271), but remained unchanged during rest (SMD 0.49; 95% CI -0.68, 1.66; P = 0.41, n = 114). Both SP (SMD 0.65; 95% CI 0.29, 1.01; P < 0.001, n = 184) and active SICI (SMD 0.68; 95% CI 0.14, 1.23; P = 0.01, n = 102) decreased, but resting SICI remained unchanged (SMD 0.26; 95% CI − 0.29, 0.81; P = 0.35, n = 52). Resistance-training improved neural drive as measured by V-wave amplitude (SMD 0.62; 95% CI 0.14, 1.10; P = 0.01, n = 101), but H-reflex at rest (SMD 0.16; 95% CI − 0.36, 0.68; P = 0.56; n = 57), during contraction (SMD 0.15; 95% CI − 0.18, 0.48; P = 0.38, n = 142) and VATMS (MD 1.41; 95% CI − 4.37, 7.20; P = 0.63, n = 44) remained unchanged. Conclusion: There are subtle neural adaptations following resistance-training involving both cortical and subcortical adaptations that act to increase motoneurone activation and likely contribute to the training-related increase in muscle strength. [ABSTRACT FROM AUTHOR]

Background: Evidence for the efficacy of low-volume high-intensity interval training (HIIT) for the modulation of body composition is unclear. Objectives: We examined the effect of low-volume HIIT versus a non-exercising control and moderate-intensity continuous training (MICT) on body composition and cardiorespiratory fitness in normal weight, overweight and obese adults. We evaluated the impact of low-volume HIIT (HIIT interventions where the total amount of exercise performed during training was ≤ 500 metabolic equivalent minutes per week [MET-min/week]) compared to a non-exercising control and MICT. Methods: A database search was conducted in PubMed (MEDLINE), EMBASE, CINAHL, Web of Science, SPORTDiscus and Scopus from the earliest record to June 2019 for studies (randomised controlled trials and non-randomised controlled trials) with exercise training interventions with a minimum 4-week duration. Meta-analyses were conducted for between-group (low-volume HIIT vs. non-exercising control and low-volume HIIT vs. MICT) comparisons for change in total body fat mass (kg), body fat percentage (%), lean body mass (kg) and cardiorespiratory fitness. Results: From 11,485 relevant records, 47 studies were included. No difference was found between low-volume HIIT and a non-exercising control on total body fat mass (kg) (effect size [ES]: − 0.129, 95% confidence interval [CI] − 0.468 to 0.210; p = 0.455), body fat (%) (ES: − 0.063, 95% CI − 0.383 to 0.257; p = 0.700) and lean body mass (kg) (ES: 0.050, 95% CI − 0.250 to 0.351; p = 0.744), or between low-volume HIIT and MICT on total body fat mass (kg) (ES: − 0.021, 95% CI − 0.272 to 0.231; p = 0.872), body fat (%) (ES: 0.005, 95% CI − 0.294 to 0.304; p = 0.974) and lean body mass (kg) (ES: 0.030, 95% CI − 0.167 to 0.266; p = 0.768). However, low-volume HIIT significantly improved cardiorespiratory fitness compared with a non-exercising control (p < 0.001) and MICT (p = 0.017). Conclusion: These data suggest that low-volume HIIT is inefficient for the modulation of total body fat mass or total body fat percentage in comparison with a non-exercise control and MICT. A novel finding of our meta-analysis was that there appears to be no significant effect of low-volume HIIT on lean body mass when compared with a non-exercising control, and while most studies tended to favour improvement in lean body mass with low-volume HIIT versus MICT, this was not significant. However, despite its lower training volume, low-volume HIIT induces greater improvements in cardiorespiratory fitness than a non-exercising control and MICT in normal weight, overweight and obese adults. Low-volume HIIT, therefore, appears to be a time-efficient treatment for increasing fitness, but not for the improvement of body composition. [ABSTRACT FROM AUTHOR]

Background: Type two diabetes mellitus (T2DM) is caused and progressed by an individual's lifestyle and, therefore, its optimal day-to-day management may involve the patient taking responsibility for this, including fulfilling a planned and prescribed exercise regime used as part of the treatment. A prescription of exercise designed to meet a patient's individual needs with minimal supervision from healthcare practitioners would facilitate this. However, the optimal prescription of exercise in the population remains unclear. Objective: This review examines the effects planned self-directed exercise has on glycosylated haemoglobin and other outcomes in individuals with T2DM and aims to identify the most suitable forms of planned self-directed exercise for individuals with T2DM that can be carried out independently. Methods: A search of the electronic databases PubMed, SPORTDiscus, CINAHL, EMBASE, Cochrane (Trials) and ClinicalTrials.gov was conducted along with reference lists of previous reviews. Randomised controlled trials published in English between January 1990 and February 2015 examining participants diagnosed with T2DM only were included. Studies were critically appraised using the PEDro (Physiotherapy Evidence Database) scale and data were presented on standardised tables. Results: Twenty-eight articles that used five element gymnastics, a games console exercise intervention (Wii fit plus) or aerobic, resistance or combined training were included. Conclusion: This review comprehensively summarised the effects planned self-directed exercise interventions had on individuals with T2DM. The review found that self-directed exercise was found to be beneficial for individuals with T2DM for improving glycosylated haemoglobin, physical characteristics, cardiorespiratory fitness, functional measures and other metabolic outcomes. [ABSTRACT FROM AUTHOR]

Background: In professional senior soccer, training load monitoring is used to ensure an optimal workload to maximize physical fitness and prevent injury or illness. However, to date, different training load indicators are used without a clear link to training outcomes. Objective: The aim of this systematic review was to identify the state of knowledge with respect to the relationship between training load indicators and training outcomes in terms of physical fitness, injury, and illness. Methods: A systematic search was conducted in four electronic databases (CINAHL, PubMed, SPORTDiscus, and Web of Science). Training load was defined as the amount of stress over a minimum of two training sessions or matches, quantified in either external (e.g., duration, distance covered) or internal load (e.g., heart rate [HR]), to obtain a training outcome over time. Results: A total of 6492 records were retrieved, of which 3304 were duplicates. After screening the titles, abstracts and full texts, we identified 12 full-text articles that matched our inclusion criteria. One of these articles was identified through additional sources. All of these articles used correlations to examine the relationship between load indicators and training outcomes. For pre-season, training time spent at high intensity (i.e., >90 % of maximal HR) was linked to positive changes in aerobic fitness. Exposure time in terms of accumulated training, match or combined training, and match time showed both positive and negative relationships with changes in fitness over a season. Muscular perceived exertion may indicate negative changes in physical fitness. Additionally, it appeared that training at high intensity may involve a higher injury risk. Detailed external load indicators, using electronic performance and tracking systems, are relatively unexamined. In addition, most research focused on the relationship between training load indicators and changes in physical fitness, but less on injury and illness. Conclusion: HR indicators showed relationships with positive changes in physical fitness during pre-season. In addition, exposure time appeared to be related to positive and negative changes in physical fitness. Despite the availability of more detailed training load indicators nowadays, the evidence about the usefulness in relation to training outcomes is rare. Future research should implement continuous monitoring of training load, combined with the individual characteristics, to further examine their relationship with physical fitness, injury, and illness. [ABSTRACT FROM AUTHOR]

Background: Cardiorespiratory fitness (CRF) among people with severe mental illness (SMI) (i.e., schizophrenia, bipolar disorder, and major depressive disorder) is a critical clinical risk factor given its relationship to cardiovascular disease and premature mortality. Objectives: This study aimed to: (1) investigate the mean CRF in people with SMI versus healthy controls; (2) explore moderators of CRF; and (3) investigate whether CRF improved with exercise interventions and establish if fitness improves more than body mass index following exercise interventions. Methods: Major electronic databases were searched systematically. A meta-analysis calculating Hedges' g statistic was undertaken. Results: Across 23 eligible studies, pooled mean CRF was 28.7 mL/kg/min [95 % confidence interval (CI) 27.3 to 30.0 mL/kg/min, p < 0.001, n = 980]. People with SMI had significantly lower CRF compared with controls ( n = 310) (Hedges' g = −1.01, 95 % CI −1.18 to −0.85, p < 0.001). There were no differences between diagnostic subgroups. In a multivariate regression, first-episode ( β = 6.6, 95 % CI 0.6-12.6) and inpatient ( β = 5.3, 95 % CI 1.6-9.0) status were significant predictors of higher CRF. Exercise improved CRF (Hedges' g = 0.33, 95 % CI = 0.21-0.45, p = 0.001), but did not reduce body mass index. Higher CRF improvements were observed following interventions at high intensity, with higher frequency (at least three times per week) and supervised by qualified personnel (i.e., physiotherapists and exercise physiologists). Conclusion: The multidisciplinary treatment of people with SMI should include a focus on improving fitness to reduce all-cause mortality. Qualified healthcare professionals supporting people with SMI in maintaining an active lifestyle should be included as part of multidisciplinary teams in mental health treatment. [ABSTRACT FROM AUTHOR]

Background: Overuse injuries are multifactorial resulting from cumulative loading. Therefore, clear differences between normal and at-risk individuals may not be present for individual risk factors. Using a holistic measure that incorporates many of the identified risk factors, focusing on multiple joint movement patterns may give better insight into overuse injuries. Lower body stiffness may provide such a measure. Objective: To identify how risk factors for Achilles tendon injuries influence measures of lower body stiffness. Methods: SPORTDiscus, Web of Science, CINAHL and PubMed were searched for Achilles tendon injury risk factors related to vertical, leg and joint stiffness in running athletes. Results: Increased braking force and low surface stiffness, which were clearly associated with increased risk of Achilles tendon injuries, were also found to be associated with increased lower body stiffness. High arches and increased vertical and propulsive forces were protective for Achilles tendon injuries and were also associated with increased lower body stiffness. Risk factors for Achilles tendon injuries that had unclear associations were also investigated with the evidence trending towards an increase in leg stiffness and a decrease in ankle stiffness being detrimental to Achilles tendon health. Conclusion: Few studies have investigated the link between lower body stiffness and Achilles injury. High stiffness is potentially associated with risk factors for Achilles tendon injuries although some of the evidence is controversial. Prospective injury studies are needed to confirm this relationship. Large amounts of high-intensity or high-speed work or running on soft surfaces such as sand may increase Achilles injury risk. Coaches and clinicians working with athletes with new or reoccurring injuries should consider training practices of the athlete and recommend reducing speed or sand running if loading is deemed to be excessive. [ABSTRACT FROM AUTHOR]

Background: A number of resistance training (RT) program variables can be manipulated to maximize muscular hypertrophy. One variable of primary interest in this regard is RT frequency. Frequency can refer to the number of resistance training sessions performed in a given period of time, as well as to the number of times a specific muscle group is trained over a given period of time. Objective: We conducted a systematic review and meta-analysis to determine the effects of resistance training frequency on hypertrophic outcomes. Methods: Studies were deemed eligible for inclusion if they met the following criteria: (1) were an experimental trial published in an English-language refereed journal; (2) directly compared different weekly resistance training frequencies in traditional dynamic exercise using coupled concentric and eccentric actions; (3) measured morphologic changes via biopsy, imaging, circumference, and/or densitometry; (4) had a minimum duration of 4 weeks; and (5) used human participants without chronic disease or injury. A total of ten studies were identified that investigated RT frequency in accordance with the criteria outlined. Results: Analysis using binary frequency as a predictor variable revealed a significant impact of training frequency on hypertrophy effect size ( P = 0.002), with higher frequency being associated with a greater effect size than lower frequency (0.49 ± 0.08 vs. 0.30 ± 0.07, respectively). Statistical analyses of studies investigating training session frequency when groups are matched for frequency of training per muscle group could not be carried out and reliable estimates could not be generated due to inadequate sample size. Conclusions: When comparing studies that investigated training muscle groups between 1 to 3 days per week on a volume-equated basis, the current body of evidence indicates that frequencies of training twice a week promote superior hypertrophic outcomes to once a week. It can therefore be inferred that the major muscle groups should be trained at least twice a week to maximize muscle growth; whether training a muscle group three times per week is superior to a twice-per-week protocol remains to be determined. [ABSTRACT FROM AUTHOR]

Background: The FIFA Medical and Research Centre (F-MARC) has designed a comprehensive warm-up program targeting muscular strength, body kinaesthetic awareness, and neuromuscular control during static and dynamic movements to decrease injury risk for soccer players. Prior studies have investigated the effectiveness of the F-MARC programs, but have not consistently reported a statistically significant reduction in injury and reduction in time loss due to injury from utilizing the program. Objective: The purpose of this study was to conduct a systematic review and meta-analysis of randomized controlled trials and interventional studies that evaluated the efficacy of the F-MARC injury prevention programs in soccer. Methods: Two independent researchers searched the relevant article databases. The keyword domains used during the search were 'F-MARC', 'FIFA 11+', 'the 11+', 'injury prevention programs', 'soccer', and variations of these keywords. The initial search resulted in 4299 articles which were filtered to nine articles that met the inclusion criteria. Main inclusion criteria were randomized controlled trials or interventional studies, use of F-MARC injury prevention programs, and the primary outcome measuring overall and lower extremity injuries. Extracted data were entered and analyzed using Comprehensive Meta-Analysis software, version 2 (CMA.V2). Results: The pooled results based on total injuries per 1000 h of exposure showed that F-MARC injury prevention programs had a statistically significant reduction in the overall injury risk ratio of 0.771 (95 % CI 0.647-0.918, p = 0.003) and the lower extremity injury risk ratio of 0.762 (95 % CI 0.621-0.935, p = 0.009). Moreover, FIFA '11+' had a statistically significant reduction in the overall injury risk ratio to 0.654 (95 % CI 0.537-0.798, p < 0.001) and the lower extremity injury risk ratio of 0.612 (95 % CI 0.475-0.788, p < 0.001). However, FIFA '11' did not reach significance for the lower extremity and overall injury reduction. It can be suggested that teams involved in the FIFA '11+' warm-up program will reduce injury rates by between 20 and 50 % in the long term compared with the teams that do not engage in F-MARC programs. Conclusions: This systematic review and meta-analysis indicated that use of F-MARC injury prevention programs, particularly the '11+' program, decreases the risk of injuries among soccer players. These data also support the case for the development and introduction of sport-specific programs. [ABSTRACT FROM AUTHOR]

Background: In order to implement running to promote physical activity, it is essential to quantify the extent to which running improves health. Objective: The aim was to summarise the literature on the effects of endurance running on biomedical indices of health in physically inactive adults. Data Sources: Electronic searches were conducted in October 2014 on PubMed, Embase, CINAHL, SPORTDiscus, PEDro, the Cochrane Library and LILACS, with no limits of date and language of publication. Study Selection: Randomised controlled trials (with a minimum of 8 weeks of running training) that included physically inactive but healthy adults (18-65 years) were selected. The studies needed to compare intervention (i.e. endurance running) and control (i.e. no intervention) groups. Study Appraisal and Synthesis Methods: Two authors evaluated study eligibility, extracted data, and assessed risk of bias; a third author resolved any uncertainties. Random-effects meta-analyses were performed to summarise the estimates for length of training and sex. A dose-response analysis was performed with random-effects meta-regression in order to investigate the relationship between running characteristics and effect sizes. Results: After screening 22,380 records, 49 articles were included, of which 35 were used to combine data on ten biomedical indices of health. On average the running programs were composed of 3.7 ± 0.9 sessions/week, 2.3 ± 1.0 h/week, 14.4 ± 5.4 km/week, at 60-90 % of the maximum heart rate, and lasted 21.5 ± 16.8 weeks. After 1 year of training, running was effective in reducing body mass by 3.3 kg [95 % confidence interval (CI) 4.1-2.5], body fat by 2.7 % (95 % CI 5.1-0.2), resting heart rate by 6.7 min (95 % CI 10.3-3.0) and triglycerides by 16.9 mg dl (95 % CI 28.1-5.6). Also, running significantly increased maximal oxygen uptake ( VO) by 7.1 ml min kg (95 % CI 5.0-9.1) and high-density lipoprotein (HDL) cholesterol by 3.3 mg dl (95 % CI 1.2-5.4). No significant effect was found for lean body mass, body mass index, total cholesterol and low-density lipoprotein cholesterol after 1 year of training. In the dose-response analysis, larger effect sizes were found for longer length of training. Limitations: It was only possible to combine the data of ten out the 161 outcome measures identified. Lack of information on training characteristics precluded a multivariate model in the dose-response analysis. Conclusions: Endurance running was effective in providing substantial beneficial effects on body mass, body fat, resting heart rate, VO, triglycerides and HDL cholesterol in physically inactive adults. The longer the length of training, the larger the achieved health benefits. Clinicians and health authorities can use this information to advise individuals to run, and to support policies towards investing in running programs. [ABSTRACT FROM AUTHOR]

Background: The vertical jump (VJ) is considered a key indicator of lower limb explosive strength. Previous research has established that rate of force development and time to peak force are linked closely to athletic ability and hence the ability to extract these accurately is of significance. Objectives: The objectives of this study were to (1) review the literature to ascertain what methods are currently used to extract jump phases from the force platform data and (2) compare identified methods on neutral data. Methods: In Part 1, an electronic search was conducted using PubMed, Central, and EBSCO host (January 1965 to April 2014). Articles were included if they (1) detailed how VJ phases from the force platform data were identified and (2) used only force platform data in the analysis. Additionally, study design and quality was independently examined. In Part 2, the three common methodologies identified were used to analyze a neutral pool of data to determine if any variance existed. Results: For Part 1, a total of 19 studies met the inclusion criteria. Meta-analysis determined three methods of phase identification used in the literature from which to extract force-time variables. In Part 2, a one-way analysis of variance and Scheffe's post-hoc tests showed significant differences ( p < 0.01) for force-time variables (eccentric phase time, concentric phase time, time to peak force, rate of force development) between methods. Conclusion: The results demonstrate that three common methods exist for determination of the VJ phases from force platform data. Consequently, each produce different values for force-time variables when used on a neutral data pool. There is a clear need for a robust agreed method for VJ analysis. [ABSTRACT FROM AUTHOR]

Background: Knee injuries are prevalent among a variety of competitive sports and can impact an athlete's ability to continue to participate in their sport or, in the worst case, end an athlete's career. Objective: The aim was to evaluate biomechanics associated with both patellofemoral pain syndrome (PFPS) and anterior cruciate ligament (ACL) injuries (in sports involving landing, change in direction, or rapid deceleration) across the three time points frequently reported in the literature: pre-injury, at the time of injury, and following injury. Methods: A search of the literature was conducted for research evaluating biomechanics associated with ACL injury and PFPS. The Web of Science, SPORTDiscus, EBSCO, PubMed, and CINAHL databases, to March 2015, were searched, and journal articles focused on ACL injuries and PFPS in sports that met the inclusion criteria were reviewed. The search methodology was created with the intent of extracting case-control, case, and cohort studies of knee injury in athletic populations. The search strategy was restricted to only full-text articles published in English. These articles were included in the review if they met all of the required selection criteria. The following inclusion criteria were used: (1) The study must report lower extremity biomechanics in one of the following settings: (a) a comparison of currently injured and uninjured participants, (b) a prospective study evaluating risk factors for injury, or (c) a study reporting on the injury event itself. (2) The study must include only currently active participants who were similar at baseline (i.e. healthy, high school level basketball players currently in-season) and include biomechanical analysis of either landing, change in direction, or rapid deceleration. (3) The study must include currently injured participants. The studies were graded on the basis of quality, which served as an indication of risk of bias. An adapted version of the 'Strengthening the Reporting of Observational Studies in Epidemiology' (STROBE) guidelines was used to rate observational research. Results: Fifteen journal articles focusing on ACL injuries and PFPS in sports met the inclusion criteria. These included three associated with both ACL injuries and PFPS across multiple time points. There was limited evidence for an association between ankle biomechanics and knee injury, with only one ACL injury study identifying decreased plantar flexion in association with injury. Limitations: Only prospective studies can determine biomechanical risk factors associated with ACL injuries and PFPS. Case studies and case-control studies do not allow for the determination of risk factors associated with both ACL injuries and PFPS as there is no certainty regarding the presence of the observed biomechanics prior to the onset of injury. Further, each study design has its own set of limitations. Lastly, the majority of the studies included in this review had adult female participants. Conclusion: By evaluating several different study designs looking at knee injuries during high-risk manoeuvres, we were able to obtain a holistic perspective of biomechanics associated with PFPS and ACL injuries. Looking at different biomechanical research approaches allowed us to assess not only the mechanism of injury, but also to look for commonalities in biomechanics (in particular, altered frontal plane mechanics at the knee and altered sagittal plane mechanics at the knee and hip) between injured and uninjured participants pre-injury, at the time of injury, and following injury, to better understand potential causes of PFPS and ACL injury. Development of injury prevention programmes should focus on correcting these mechanics observed across the three time points during high-risk manoeuvres as this may help decrease the prevalence of ACL injury and PFPS. Programmes focusing not only on neuromuscular training, but also skill-specific training focused on correcting mechanics during these high-risk manoeuvres may be of greatest benefit regarding prevention. Future research should consider the impact of cumulative loading on knee injury risk. Additionally, better techniques for assessing mechanics in-game are needed in order to facilitate injury prevention and screening strategies. [ABSTRACT FROM AUTHOR]

Speed skating is an intriguing sport to study from different perspectives due to the peculiar way of motion and the multiple determinants for performance. This review aimed to identify what is known on (long-track) speed skating, and which individual characteristics determine speed skating performance. A total of 49 studies were included. Based on a multidimensional performance model, person-related performance characteristics were categorized in anthropometrical, technical, physiological, tactical, and psychological characteristics. Literature was found on anthropometry, technique, physiology, and tactics. However, psychological studies were clearly under-represented. In particular, the role of self-regulation might deserve more attention to further understand mechanisms relevant for optimal performance and for instance pacing. Another remarkable finding was that the technically/biomechanically favourable crouched skating technique (i.e. small knee and trunk angle) leads to a physiological disadvantage: a smaller knee angle may increase the deoxygenation of the working muscles. This is an important underlying aspect for the pacing tactics in speed skating. Elite speed skaters need to find the optimal balance between obtaining a fast start and preventing negative technical adaptations later on in the race by distributing their available energy over the race in an optimal way. More research is required to gain more insight into how this impacts on the processes of fatigue and coordination during speed skating races. This can lead to a better understanding on how elite speed skaters can maintain the optimal technical characteristics throughout the entire race, and how they can adapt their pacing to optimize all identified aspects that determine performance. [ABSTRACT FROM AUTHOR]

Background: The promotion of sport and physical activity (PA) for children is widely recommended to support a healthy lifestyle, but being engaged in sport bears the risk of sustaining injuries. Injuries, in turn, can lead to a reduction in current and future involvement in PA and, therefore, may negatively affect future health as well as quality of life. Thus, sports injury prevention is of particular importance in youth. Objective: The aim of this systematic review was to quantify the effectiveness of exercise-based injury prevention programs in child and adolescent sport in general, and with respect to different characteristics of the target group, injury prevention program, and outcome variables. Data Sources: An Internet-based literature search was conducted in six databases (CINAHL, Cochrane, EMBASE, ISI Web of Science, PubMed, SPORTDiscus) using the following search terms with Boolean conjunction: (sport injur* OR athletic injur* OR sport accident*) AND (prevent* OR prophylaxis OR avoidance) AND (child* OR adolescent OR youth). Study Selection: Randomized controlled trials and controlled intervention studies in organized sport, published in English in a peer-reviewed journal, analyzing the effects of an exercise-based injury prevention program in athletes younger than 19 years of age. Data Extraction: Two reviewers evaluated eligibility and methodological quality. Main outcome extracted was the rate ratio (RR). Statistical analyses were conducted using the inverse-variance random effects model. Results: Twenty-one trials, conducted on a total of 27,561 athletes (median age 16.7 years [range 10.7-17.8]), were included. The overall RR was 0.54 (95 % CI 0.45-0.67) [ p < 0.001]. Girls profited more from injury prevention than boys ( p = 0.05). Both prevention programs with a focus on specific injuries (RR 0.48 [95 % CI 0.37-0.63]) and those aiming at all injuries (RR 0.62 [95 % CI 0.48-0.81]) showed significant reduction effects. Pre-season and in-season interventions were similarly beneficial ( p = 0.93). Studies on programs that include jumping/plyometric exercises showed a significant better ( p = 0.002) injury preventive effect (RR 0.45 [95 % CI 0.35-0.57], Z = 6.35, p < 0.001) than studies without such exercises (RR 0.74 [95 % CI 0.61-0.90], Z = 3.03, p = 0.002). Conclusions: The results provide good evidence and clearly demonstrate beneficial effects of exercise-based injury prevention programs in youth sports as they can result in statistically significant and practically relevant injury reduction. In particular, multimodal programs including jumping/plyometric exercises can be recommended. However, there is a considerable lack of data for children (under 14 years of age) and for individual sports in general. Future research should include these groups and focus on the effect of specific exercises and compliance. [ABSTRACT FROM AUTHOR]

Background: Knee joint mechanics during sidestepping are associated with anterior cruciate ligament injury. Unplanned sidestepping more closely emulates game scenarios when compared with planned sidestepping by limiting decision time, increasing knee loading and challenging the integrity of soft-tissue structures in the knee. It is important to quantify the loads that may challenge the integrity of the knee during planned and unplanned sidestepping. Objective: Our objective was to review literature on knee mechanics during planned and unplanned phases of sidestepping. Data sources: PubMed, CINAHL, MEDLINE (EBSCO), SPORTDiscus and Web of Science were searched using the terms knee mechanics OR knee kine*, AND plan*, unplan*, anticipat*, unanticipat*, side*, cut* or chang*. Study selection: A systematic approach was used to evaluate 4,629 records. Records were excluded when not available in English, only available in abstract of conference proceedings, not involving a change-of-direction sidestep, not comparing planned and unplanned or maintaining a running velocity greater than 2 m s. Data extraction: Included studies were evaluated independently by two authors using a custom-designed methodological quality assessment derived from the Physiotherapy Evidence Database (PEDro) scale and then confirmed by a third author. Data synthesis: Only six studies met the inclusion criteria and were retained for meta-analysis. Magnitude-based inferences were used to assess the standardised effect of the differences between planned and unplanned sidestepping. Knee angles and knee moments were extracted and reported for flexion/extension, abduction/adduction and internal/external rotation for initial contact, weight acceptance, peak push-off and final push-off phases of sidestepping. Results: For kinematic variables, unplanned sidestepping produced a wide range of small to large increases in knee extension angles, small and moderate increases in knee abduction angles and a small increase in internal rotation angle relative to planned sidestepping during the sidestepping manoeuvre. For kinetic variables, unplanned sidestepping produced mostly small (small to large) increases in knee flexor moments, small to moderate increases in knee abductor moments and mostly moderate (small to large) increases in internal rotator moments relative to planned sidestepping. Limitations: Approach velocity constraints during the sidestepping manoeuvre were lifted due to the low number of eligible studies. The varying approach velocities included (ranging from 3.0 to 5.5 m s) may impact the kinematic and kinetic variables examined in this review. Conclusions: Differences in knee mechanics between planned and unplanned sidestepping exist. The most substantial effects occurred during the weight acceptance phase of sidestepping. It seems that biomechanical factors commonly associated with anterior cruciate ligament injury risk are affected the most during the loading phase compared with peak push-off; made evident in the coronal (abductor) and transverse (internal rotator) knee kinetic data presented in this review. The authors of this review propose a rationale for the incorporation of unplanned sport tasks in the development of anterior cruciate ligament injury screening and in prophylactic training programmes. [ABSTRACT FROM AUTHOR]

Background: Skeletal muscle plays an important role in maintaining the stability of the lumbar region. However, there is conflicting evidence regarding the effects of exercise on trunk muscle morphology. Objective: To systematically review the literature on the effects of exercise training on lower trunk muscle morphology to determine the comparative effectiveness of different exercise interventions. Data Source and Study Selection: A systematic search strategy was conducted in the following databases: PubMed, SportDiscus, CINAHL, the Cochrane Library and PEDro. We included full, peer-reviewed, prospective longitudinal studies, including randomized controlled trials and single-group designs, such as pre- to post-intervention and crossover studies, reporting on the effect of exercise training on trunk muscle morphology. Study Appraisal and Synthesis: Study quality was assessed with the Cochrane risk-of-bias tool. We classified each exercise intervention into four categories, based on the primary exercise approach: motor control, machine-based resistance, non-machine-based resistance or cardiovascular. Treatment effects were estimated using within-group standardized mean differences (SMDs). Results: The systematic search identified 1,911 studies; of which 29 met our selection criteria: motor control ( n = 12), machine-based resistance ( n = 10), non-machine-based resistance ( n = 5) and cardiovascular ( n = 2). Fourteen studies (48 %) reported an increase in trunk muscle size following exercise training. Among positive trials, the largest effects were reported by studies testing combined motor control and non-machine-based resistance exercise (SMD [95 % CI] = 0.66 [0.06 to 1.27] to 3.39 [2.80 to 3.98]) and machine-based resistance exercise programmes (SMD [95 % CI] = 0.52 [0.01 to 1.03] to 1.79 [0.87 to 2.72]). Most studies investigating the effects of non-machine-based resistance exercise reported no change in trunk muscle morphology, with one study reporting a medium effect on trunk muscle size (SMD [95 % CI] = 0.60 [0.03 to 1.16]). Cardiovascular exercise interventions demonstrated no effect on trunk muscle morphology (SMD [95 % CI] = −0.16 [−1.14 to 0.81] to 0.09 [−0.83 to 1.01]). Limitations: We excluded studies published in languages other than English, and therefore it is possible that the results of relevant studies are not represented in this review. There was large clinical heterogeneity between the included studies, which prevented data synthesis. Among the studies included in this review, common sources of potential bias were random sequence generation, allocation concealment and blinding. Finally, the details of the exercise parameters were poorly reported in most studies. Conclusion: Approximately half of the included studies reported an increase in lower trunk muscle size following participation in an exercise programme. Among positive trials, studies involving motor control exercises combined with non-machine-based resistance exercise, as well as machine-based resistance exercises, demonstrated medium to large effects on trunk muscle size. Most studies examining the effect of non-machine-based resistance exercise and all studies investigating cardiovascular exercise reported no effect on trunk muscle morphology. However, these results should be interpreted with caution because of the substantial risk of bias and suboptimal reporting of exercise details in the included studies. Additional research, using methods ensuring a low risk of bias, are required to further elucidate the effects of exercise on trunk muscle morphology. [ABSTRACT FROM AUTHOR]

Background: Research into the nature of overuse Achilles tendon injuries is extensive, yet uncertainty remains around how to identify athletes susceptible to Achilles tendon injury. Objective: To identify the strength of evidence for biomechanical risk factors associated with Achilles tendon injuries. Research Methods: SPORTDiscus, CINAHL, Web of Science and PubMed were searched for Achilles tendon injury risk factors and biomechanical measures which are altered in runners with Achilles tendon injuries, excluding ruptures. Fifteen articles were included in the analysis. Results: Two variables, high vertical forces and high arch, showed strong evidence for reduced injury risk. High propulsive forces and running on stiffer surfaces may also be protective. Only one biomechanical variable, high braking force, showed clear evidence for increasing Achilles injury risk. Discussion: Gait retraining to direct the centre of mass further forward to reduce high braking force could be useful in decreasing the risk of Achilles injury. The majority of biomechanical risk factors examined showed unclear results, which is likely due to the multifactorial nature of Achilles overuse injuries. Many risk factors are related to how the athlete's body interacts with the environment during gait, including ground reaction forces, muscle activity both prior to landing and immediately post ground contact, and joint motion throughout stance. Conclusion: Multiple risk factors have been associated with the development of Achilles tendon injuries in running athletes but most effects remain unclear. Advice for athletes recovering from Achilles tendon injuries could include avoiding soft surfaces and reducing the pace of recovery runs. Orthotic intervention could assist athletes with low arches but modification of pronation should be viewed with caution. Strength training and gait retraining could be beneficial for reducing injury risk. [ABSTRACT FROM AUTHOR]

Background and Objective: Skeletal muscle wasting resulting in reduced muscular strength and health-related quality of life (HR-QOL) is common in chronic kidney disease (CKD) and may be reversed with progressive resistance training (PRT). Therefore, we systematically assessed the effect of PRT on measures of skeletal muscle hypertrophy, muscular strength and HR-QOL in this cohort to inform clinical practice and guidelines. Design: We performed a systematic review and meta-analysis. Inclusion Criteria: We included randomised controlled trials (RCTs) that investigated the independent effect of PRT (>6 weeks) on measures of skeletal muscle hypertrophy [muscle mass or cross-sectional area (CSA)], muscular strength and/or HR-QOL in adults with CKD. Data Extraction and Analysis: The standardised mean difference (SMD) from each study was pooled to produce an overall estimate of effect and associated 95 % confidence interval (95 % CI) between treatment and control groups on primary outcomes. Results: Seven RCTs in 271 patients with Stage 3-5 CKD yielded seven studies on muscular strength ( N = 249), six studies on total body muscle mass ( N = 200) and six studies on HR-QOL ( N = 223). PRT significantly improved standardised muscular strength [SMD 1.15 (95 % CI 0.80-1.49)] and HR-QOL [SMD 0.83 (95 % CI 0.51-1.16)], but not total body muscle mass [SMD 0.29 (95 % CI −0.27 to 0.86)] in our primary analysis. However, secondary analysis of six studies showed that PRT induced significant muscle hypertrophy of the lower extremities (leg mass, or mid-thigh or quadriceps CSA) [SMD 0.43 (95 % CI 0.11-0.76)], a pertinent analysis given that most studies implemented lower-body PRT only. Conclusions: Robust evidence from RCTs indicates that PRT can induce skeletal muscle hypertrophy and increase muscular strength and HR-QOL outcomes in men and women with CKD. Therefore, clinical practice guidelines should be updated to inform clinicians on the benefits of PRT in this cohort. [ABSTRACT FROM AUTHOR]

Background: Resistance and aerobic exercises are both recommended as effective treatments for people with type 2 diabetes. However, the optimum type of exercise for the disease remains to be determined to inform clinical decision-making and facilitate personalized exercise prescription. Objectives: Our objective was to investigate whether resistance exercise is comparable to aerobic exercise in terms of effectiveness and safety in people with type 2 diabetes. Data sources: PubMed, EMBASE, CENTRAL, CINAHL, and SPORTdiscus were systematically searched up to March 2013. The reference lists of eligible studies and relevant reviews were also checked. Study Selection: We used the following criteria to select studies for inclusion in the review: (i) the study was a randomized controlled trial; (ii) the participants were people with type 2 diabetes aged 18 years or more; (iii) the trial compared resistance exercise with aerobic exercise for a duration of at least 8 weeks, with pre-determined frequency, intensity, and duration; and (iv) the trial provided relevant data on at least one of the following: glycaemic control, blood lipids, anthropometric measures, blood pressure, fitness, health status, and adverse events. Study Appraisal and Synthesis Methods: The assessment of study quality was based on the Cochrane Risk of Bias tool. For effectiveness measures, differences (resistance group minus aerobic group) in the changes from baseline with the two exercises were combined, using a random-effects model wherever possible. For adverse events, the relative risks (resistance group vs. aerobic group) were combined. Results: Twelve trials ( n = 626) were included. Following the exercise interventions, there was a greater reduction of glycosylated hemoglobin with aerobic exercise than with resistance exercise (difference 0.18 % (1.97 mmol/mol), 95 % confidence interval (CI) 0.01, 0.36). This difference became non-significant with sensitivity analysis ( p = 0.14). The differences in changes from baseline were also statistically significant for body mass index (difference 0.22, 95 % CI 0.06, 0.39), peak oxygen consumption (difference −1.84 mL/kg/min, 95 % CI −3.07, −0.62), and maximum heart rate (difference 3.44 beats per minute, 95 % CI 2.49, 4.39). Relative risks for adverse events (all) and serious adverse events were 1.17 (95 % CI 0.77, 1.79) and 0.89 (95 % CI 0.18, 4.39), respectively. Limitations: Most included trials were short term (8 weeks to 6 months), and seven had important methodological limitations. Additionally, the meta-analyses for some of the secondary outcomes had a small number of participants or substantial statistical heterogeneity. Conclusions: Although differences in some diabetic control and physical fitness measures between resistance exercise and aerobic exercise groups reached statistical significance, there is no evidence that they are of clinical importance. There is also no evidence that resistance exercise differs from aerobic exercise in impact on cardiovascular risk markers or safety. Using one or the other type of exercise for type 2 diabetes may be less important than doing some form of physical activity. Future long-term studies focusing on patient-relevant outcomes are warranted. [ABSTRACT FROM AUTHOR]

Background: Although a series of meta-analyses demonstrated neuromuscular training (NMT) is an effective intervention to reduce anterior cruciate ligament (ACL) injury in female athletes, the potential existence of a dosage effect remains unknown. Objective: Our objective was to systematically review previously published clinical trials and evaluate potential dosage effects of NMT for ACL injury reduction in female athletes. Design: This study took the form of a meta- and sub-group analysis. Setting: The keywords 'knee', 'anterior cruciate ligament', 'ACL', 'prospective', 'neuromuscular', 'training', 'female', and 'prevention' were utilized in PubMed and EBSCO host for studies published between 1995 and May 2012. Participants: Inclusion criteria set for studies in the current analysis were (i) recruited female athletes as subjects, (ii) documented the number of ACL injuries, (iii) employed an NMT intervention aimed to reduce ACL injuries, (iv) had a control group, (v) used a prospective control trial design, and (vi) provided NMT session duration and frequency information. Main outcome measures: The number of ACL injuries and female athletes in each group (control and intervention) were compared based on duration, frequency, and volume of NMT via odds ratios (ORs). Results: A total of 14 studies were reviewed. Analyses that compared the number of ACL injuries with short versus long NMT duration showed greater ACL injury reduction in female athletes who were in the long NMT duration group (OR 0.35, 95 % CI 0.23-0.53, p = 0.001) than in those in the short NMT duration group (OR 0.61, 95 % CI 0.41-0.90, p = 0.013). Analyses that compared single versus multi NMT frequency indicated greater ACL injury reduction in multi NMT frequency (OR 0.35, 95 % CI 0.23-0.53, p = 0.001) compared with single NMT frequency (OR 0.62, 95 % CI 0.41-0.94, p = 0.024). Combining the duration and frequency of NMT programs, an inverse dose-response association emerged among low (OR 0.66, 95 % CI 0.43-0.99, p = 0.045), moderate (OR 0.46, 95 % CI 0.21-1.03, p = 0.059), and high (OR 0.32, 95 % CI 0.19-0.52, p = 0.001) NMT volume categories. Conclusions: The inverse dose-response association observed in the subgroup analysis suggests that the higher the NMT volume, the greater the prophylactic effectiveness of the NMT program and increased benefit in ACL injury reduction among female athletes. [ABSTRACT FROM AUTHOR]