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The COVID-19 pandemic has caused mandatory lockdowns leading to disruptions in sports training programs. This study aimed to determine the effects of a 16-week COVID-19 lockdown on body composition as well as kinetic and kinematic parameters of the countermovement jump (CMJ) for professional martial artists. Thirteen (n=13) professional martial artists participated in this retrospective cohort study. Subjects were tested on the CMJ at four timepoints: 1) pre-lockdown (pre), 2) immediately post-lockdown (post), 3) two weeks post-lockdown (post+2), and 4) four weeks post-lockdown (post+4). Body composition was measured via bioelectrical impedance and jump data were collected using a force platform sampling at 1,000 Hz. Individual repeated-measures ANOVAs were conducted with pairwise post-hoc analyzes. Differences were observed in vertical jump height (VJH) of 10.33%, peak velocity (PV) of 3.10%, reactive strength index modified (RSImod) of 13.8%, and peak propulsive power (PPP) of 6.00% (p

Movement behaviours have been found to be important correlates of health for children and may be particularly important for children with Developmental Coordination Disorder (DCD) who often experience greater mental health problems. To date, however, little research has investigated the daily movement composition of preschool children with Developmental Coordination Disorder (DCD) and/or its association with mental health. The purpose of the current study was to: 1) examine whether differences in movement compositions (i.e., sedentary time, light physical activity, moderate-to-vigorous activity) exist between typically developing (TD) preschool-age children and those at risk for DCD (rDCD); and 2) investigate associations between movement compositions and mental health indicators. This cross-sectional study used the baseline cohort data from the Coordination and Activity Tracking in CHildren (CATCH) study. A total of 589 preschool-age children (Mage = 4.94 ± 0.59 years; 57.4% boys) were included in this analysis, of which 288 were classified as rDCD. Wake time movement behaviours were measured using accelerometers and parents completed the Child Behavior Checklist to assess their child’s mental health (i.e., internalizing and externalizing problems). Compositional data analysis techniques were used. After adjusting for potential confounders, the results demonstrated similar movement compositions between TD and rDCD children. Among the full sample, findings revealed a significant association between sedentary time and externalizing problems, however, each of the other associations did not reach statistical significance. These results are consistent with emerging evidence demonstrating similar patterns of physical activity and sedentary time among TD children and those classified as rDCD during the preschool years. Although movement behaviours explained little variance in mental health during this period, future research should investigate when movement compositions diverge, and how these changes may impact the mental health of TD children and those classified as rDCD later in childhood.

Periodizing rehearsal and performance schedules in professional ballet is difficult given a lack of published longitudinal data. We aimed to describe the structure of a professional ballet season, and identify factors associated with inter-dancer and inter-production variation in dance hours. Scheduling data were collected from 123 dancers over five seasons at The Royal Ballet. Linear mixed effects models were used to evaluate differences in weekly dance hours and performance counts across sexes, company ranks, and months. Random forest regressions were used to investigate factors associated with the variation in rehearsal hours across different productions. Performance congestion was observed in December, whereas total dance hours peaked between January and April. Differences in weekly dance hours were observed between company ranks (p < .001, range in means: 19.1–27.5 h·week-1). Seasonal performance counts varied across company ranks (p < .001), ranging from 28, 95% CI [22, 35] in principals, to 113, 95% CI [108, 118] in artists. Rehearsal durations were greatest in preparation for newly choreographed and longer ballets. Dancers creating roles in new ballets completed considerably more rehearsal hours than for existing ballet. These results provide a basis for the implementation of rehearsal and repertoireperiodization in professional ballet.

Background: The role of cheering in home advantage in sports performance is the subject of much debate. No definitive scientific evidence has so far been found capable of highlighting or denying its relevance. As pandemic restrictive measures (COVID-19) have prevented crowds from entering stadiums, analysis of the past two football seasons may reveal important new details. Objective: This paper aims to compare the statistics of the last two football seasons in Italy with the previous six, trying to highlight any pronounced and statistically significant changes due to the absence of cheering in the stadiums. Methods: We compared the average percentages of points obtained in home matches from 2013 to 2019 with those in the timelapse 2019-2021. The same operation was performed with referee statistics, such as fouls, penalties, and cards awarded against home teams. To do this, we used measures such as Welch's t-test and percentage increases. The distributive normality of the datasets was evaluated with the Shapiro-Wilk test and a graphical control. The lack of trend in the series was assessed with the Mann-Kendall test and Sen's Slope. Finally, Pearson and Spearman's correlations were searched between the percentages of points collected in home matches and total points, year by year, from 2013 to 2021.Results: The average percentage of points collected by teams in home matches dropped by almost 8% (Welch’s t-test = -4.3). Moreover, the negative correlations between home collected points and total points in 2013-2019 timelapse have drastically diminished during the last two seasons (average Welch’s t-test = 6.0, 95% CI: 5.4 – 6.4), approaching zero. Finally, penalties against home teams have increased by 30% (Welch’s t-test = 2.6), reaching figures closer to 50%.Conclusions: This research provides statistical evidence in favor of the relevance of home advantage in the top football league in Italy, such as Serie A. During the anti-COVID-19 restrictive measures - which prevented public access to the stadiums - a net reduction in the points collected by the teams in home matches was detected. In addition, the number of penalties awarded against home teams has increased significantly, approaching the ideal 50%. Since there are valid psychological reasons in the literature to support the crowd’s impact on sports and refereeing performance, it is plausible that our findings are causally related to the absence of cheering. Finally, as the averages of points collected at home remained far from 50%, our results suggest that a not negligible part of the home advantage in Serie A is linked to factors independent of the audience. Future research can deepen the above phenomena from a theoretical-psychological point of view.

Eating disorders (ED) are serious mental disorders, which can have serious health consequences and high mortality rates. Due to facing unique risk factors female athletes have increased susceptibility for ED. Female athletes are also at risk for subclinical conditions such as the Female Athlete Triad. There is a dearth of studies on preventing and identifying ED in female athletes and the role and responsibility of the sports coach is unclear. This study aimed to address the questions of whether female athletes are at increased risk for ED, what interventions currently show promise and what is the role of the sports coach in the intervention process. The study was based on a systematic review of relevant literature retrieved through PubMed and Sports Discus databases. Despite heterogeneity in prevalence studies, findings suggest that female athletes are at higher risk than male athletes and non-athletes and those in elite level sports or sports categorised as lean, aesthetic, endurance and weight-class are at increased risk for clinical and subclinical ED. Risk-factors unique to the sports environment such as weight pressures, competitive thinness and revealing uniforms, may lead to increased risk in female athletes. Despite a dearth of studies on interventions for ED in sport, findings suggest that primary prevention programs based on educating athletes such as ATHENA show most promise in prevention. Secondary prevention should focus on early identification using athlete-specific screening tools. Symptom checklists and pre-participation examinations can also assist coaches in early identification. Psychotherapy interventions such as CBT have had the best results for treatment. Sports coaches’ play a critical role in, early identification, referral, management and prevention of ED in female athletes. However, current findings suggest that many coaches lack knowledge about ED and require education to be able to intervene successfully in female athletes with ED. Inappropriate coaching behaviours have also been found to act as an additional risk-factor for ED. Recommendations for sports coaches in N.I. are provided to assist them in successful intervention, management and return to play of female athletes with ED.

This review highlights the importance of leadership within modern healthcare settings and provided an overview of common healthcare leadership approaches, including transactional and transformational leadership. Research has identified leader characters and specific competencies which are required by leaders in healthcare in order to achieve optimal outcomes. Although both transactional and transformational leadership approaches have their strengths and weaknesses, the evidence presented suggests a transformational leadership approach better suits the specific competencies required within a healthcare leadership context. Interventional, survey and qualitative studies have found a plethora of benefits associated with a transformational leadership approach in healthcare, including better patient outcomes and higher staff satisfaction and motivation compared to other approaches to leadership. Studies conducted with nursing and physiotherapy staff have consistently shown better outcomes with a transformational leadership approach, which is significant as they represent the second and third largest healthcare professions by numbers employed, respectively. Transformational leadership therefore appears to be the most evidence-based approach available within healthcare, at a time when evidence-based practice is considered mandatory within the NHS. Effective leadership within the NHS has never been more critical than at present, due to reduced government spending in healthcare and the increased pressures on the system during the Covid-19 pandemic. Although a transactional leadership approach in isolation has several weaknesses in modern healthcare and may be considered outdated, some of its components still possess merit and may have an additive effect if implemented alongside an overall transformational leadership approach in order to achieve optimal outcomes for patients and staff in healthcare settings.

During the COVID-19 pandemic, the necessity of using face masks during sports is likely balanced by coaches and athletes between the risk of infection and their impact on exercise performance. To inform this decision, we aimed to test the effects of wearing a cloth face mask on exercise performance and subjective responses during training of track and field athletes. Participants (n=10) performed two training sessions with and without a 3-layered cloth mask in a randomized, counterbalanced, crossover design. The training session was designed to simulate the specific demands of the sport that the athletes practiced. The sprint protocol consisted of performing five maximal 30 m sprints, with a passive 4-min interval between runs. Performance variables (sprint time, acceleration) were calculated using the sprint time data. Jump performance was assessed pre- and post-sprints using a countermovement vertical jump. Throughout the training session, ratings of perceived exertion (RPE) and affect were collected. There was no evidence of condition x time interactions for sprint time (P=0.21) or acceleration (P=0.47). There was weak evidence of an effect of condition (P=0.05) on RPE, though no evidence of a condition x time interaction (P=0.35). There was moderate evidence of a condition x time interaction (P=0.02) for affect, with lower ratings following sprints 3, 4 and 5 when using the mask. These findings suggest that wearing a mask may negatively impact subjective feelings of training without necessarily harming sprint performance. During an unmitigated epidemic such as in Brazil, the protection against SARS-CoV-2 infection associated with wearing a face mask appears to outweigh the increased discomfort and perception of effort related to this safety tool.

Objectives: To conduct a systematic review and multilevel meta-analysis of the current literature as to the effects of interval training (IT) vs moderate intensity continuous training (MICT) on measures of body composition, both on a whole-body and regional level. Design: Systematic review and meta-analysis. Data sources: English-language searches of PubMed/MEDLINE, Scopus, and CINAHL conducted in accordance with PRISMA guidelines. Eligibility criteria for selecting studies: a) randomized controlled trials that directly compared IT vs MICT body composition using a validated measure in healthy children and adults; b) training was carried out a minimum of once per week for at least four weeks; c) published in a peer-reviewed English language journal or on a pre-print server. Results: The main model for fat mass effects revealed a trivial standardized point estimate with high precision for the interval estimate, with negligible heterogeneity. The main model for lean mass effects revealed a trivial standardized point estimate with high precision for the interval estimate, with negligible heterogeneity. The GRADE summary of findings suggested high certainty for both main model effects. In comparison to non-intervention control groups, the IT conditions resulted in small reductions in fat mass and trivial increases in lean mass. The MICT conditions also produced small reductions in fat mass, and trivial increases in lean mass. Analysis of regional fat loss revealed trivial between group comparative treatment effects for upper body, lower body and trunk regions with minimal differences between regions. Conclusion: Our findings provide compelling evidence that the intensity of effort during endurance exercise has minimal influence on longitudinal changes in fat mass and lean mass.

While research has identified several practice variables that purportedly enhance motor learning, recent replication failures highlight the importance of conducting high-powered, pre-registered replications. The “expecting to teach” phenomenon was first reported in the motor learning literature by Daou and colleagues and suggested learners benefit from practicing with the understanding they will later need to teach the skill. The extant data have been mixed but generally positive. While expecting to teach has been shown to enhance motor learning of a golf putt, the mechanisms linked with this benefit are yet to be determined. As such, this study sought to replicate the expecting to teach effect and to extend those findings by exploring participants’ thought processes. Participants (N = 76) were randomly assigned to one of two groups in which they were told that they were learning a golf putt in order to 1) be tested on the skill or 2) to teach the skill to another individual. On Day 1, participants completed pre-test putts, a pre-acquisition intrinsic motivation inventory (IMI), a 2-minute study of an instructional booklet, 50 practice putts and a post-acquisition IMI. During practice, participants were also afforded opportunities to continue studying the booklet and to complete additional putts. Participants returned 24-hours later to complete a retention, a transfer (50 cm longer golf-putt), and a free recall test, as well as a post-study survey to reveal thoughts they engaged in after practice but before (or during) the retention test. Similar to Daou et al., no significant differences were found with study time, number of acquisition putts, or motivation. However, golf-putting performance during retention resulted in no differences for radial error, g = −.13 (95%CI [−.55, .29]), between the two groups and no differences were shown for the recall test. The present study fails to replicate the benefits reported in the original experiments.

Background: The level of effort seems to play a key role in determining neuromuscular adaptations; however, less is known regarding the optimal dose-response for intra-set levels of effort on chronic resistance training (RT) adaptations. Objective: We aimed to synthesize the current literature on chronic RT adaptations in response to different intra-set velocity loss (VL) thresholds in the back squat exercise. We investigated changes in muscle strength, muscular endurance, sports-related physical performance, and muscle hypertrophy outcomes during resistance exercise to establish optimal dose-response relationships in physically active individuals.Methods: We conducted a literature search using PubMed (Medline), Web of Science™, Scopus, and Cochrane up to April 2021, with no restriction on year of publication. The inclusion criteria were based on the PICO strategy. A random-effect meta-analysis was performed to determine the standardized mean differences (SMD ± 95% confidence intervals) for different intra-set VL thresholds (low VL [< 15%], moderate VL [≥ 15% and < 30%], and high VL [≥ 30%]) in RT on maximum muscular strength, bar velocity against submaximal loads, endurance against a given load, countermovement jump height, running sprint time, and muscle hypertrophy. Results: A total of 4,031 articles were found and 11 studies met our eligibility criteria. Pooled results revealed improvements between pre- and post-training intervention in 1RM strength (SMD = 0.78; p < 0.001); bar velocity outputs (light-loads [SMD = 0.79; p < 0.001] and heavy-loads [SMD = 2.08; p < 0.001]); endurance against a given load (SMD = 1.21; p < 0.001); countermovement jump height (SMD = 0.50; p < 0.001); running sprint time (SMD = - 0.28; p = 0.001); and muscle hypertrophy (SMD = 0.31; p = 0.05), with no significant difference between VL thresholds (p > 0.05). However, low VL elicited greater within-group SMD for 1RM strength than moderate and high VL thresholds (SMD = 0.93; 0.72; and 0.75; for low, moderate, and high VL thresholds, respectively). Low and moderate VL thresholds resulted in greater within-group SMD than high VL thresholds for velocity against light loads (SMD for low VL = 0.89; moderate VL = 0.90; high VL = 0.59); countermovement jump height (SMD for low VL = 0.51; moderate VL = 0.58; high VL = 0.36); and running sprint time (SMD for low VL = -0.49; moderate VL = -0.32; high VL = -0.09). Moderate and high VL thresholds induced higher within-group SMD for muscle hypertrophy than low VL (SMD for low VL = 0.14; moderate VL = 0.40; high VL = 0.44). Conclusions: Low to moderate VL thresholds may provide more effective and efficient training stimuli for improving performance in strength-power tasks, due to the similar or even greater chronic adaptations achieved compared with high VL, despite the lower number of repetitions performed during the RT program. Conversely, moderate to high VL may provide more favorable training stimuli for inducing muscle hypertrophy. Strength coaches may apply these dose-response trends to design optimal RT stimuli based on their specific training goals. Protocol registration: The study protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42020189321).

Purpose: Elite swimmers (SW) have reduced diastolic function compared to elite runners, possibly as an adaptation to the aquatic training environment. Water polo players (WP) and artistic swimmers (AS) are exposed to the same hydrostatic pressures as SW, but are subject to different training intensities, postures, and hemodynamic stressors. Our purpose was to compare resting and exercising cardiac function in elite SW, WP, and AS, to characterize the influence of training for aquatic-sport on left ventricular (LV) adaptation.Methods: Ninety athletes (SW:20M/17F; WP:21M/9F; AS:23F) at the 2019 FINA World Championships volunteered for resting and stress (3min 30% maximal isometric handgrip) echocardiographic assessment of LV global function and mechanics. Results: Male SW displayed improved resting systolic and diastolic function compared to WP; however, both groups maintained stroke volume under high-pressure handgrip stress (SW:∆-4±12%; WP:∆-1±13%, P=0.11). There were no differences between female SW and WP resting LV function, but SW demonstrated improved function over AS. During isometric handgrip, all female sport athletes maintained stroke volume (SW:∆3±16%; WP:∆-10±11%; AS:∆-2±14%, P=0.46), but WP had improved apical rotation (∆1.7±4.5°), which was reduced in AS (∆-3.1±4.5°) and maintained in SW (∆-0.5±3.8°, P=0.04). Unlike SW and WP, AS displayed a unique maintenance of early filling velocity during handgrip exercise (SW:∆-3.5±14.7cm/s; WP:∆-15.1±10.8cm/s; AS:∆1.5±15.3cm/s, P=0.02).Conclusion: Among male athletes, SW display primarily volume-based functional adaptations distinct from the mixed volume-pressure adaptations of WP; however, both groups can maintain stroke volume with increased afterload. Female SW and WP do not demonstrate sport-specific differences like males, perhaps owing to sex-differences in adaptation, but have greater volume-based adaptations than AS. Lastly, AS display unique functional adaptations, that may be driven by elevated pressures under low-volume conditions.

Research investigating coaching effectiveness is of great importance to ensure the sporting experience and development of athletes is optimised. Coaches are significant figures for the athletes they coach, especially for youth athletes within sporting programmes. Therefore, understanding what makes an ‘effective coach’ in terms of leadership and coaching behaviours will only aid positive youth development and help ensure youth athletes are afforded optimal opportunities to enhance their skills and attributes. This systematic review aims to present a comprehensive review of the coaching effectiveness literature. A systematic search was conducted of four electronic databases: PsycArticles, PsycINFO, SPORTDiscus, and Web of Science. Scholarly peer-reviewed studies published in English were included in this review. The initial search yielded 137 papers, with 45 papers retained and referenced within the review following screening. Studies either developed a measurement tool to assess coaching behaviour, evaluated a measurement tool, or employed such tools in studies assessing sources, dimensions or outcomes of coaching behaviour. Overall, the review offers support for the importance of athletes’ perceptions of coaching behaviours in shaping an athletes’ psychological development and well-being. Understanding athlete perceptions of effective coaching behaviours and how they impact specific outcomes may help to improve positive development in youth athletes.

Objectives: The COVID-19 crisis also affected elite sport severely, as elite athletes either stopped or drastically reduced their training regimen due to the lack of competitions and the mandatory lockdown. The aim of this study was to test whether heart rate variability was a reliable index of training load, which was dramatically altered due to the mandatory lockdown that occurred as a consequence of the COVID-19. Equipment and methods: Training (volume and intensity) and heart rate variability of sixteen professional male (n=8; body mass index = 22.2±2.0) and female cyclists (n=8; body mass index = 20.3±1.1) before (4 weeks), during (7 weeks), and after (4 weeks) the mandatory lockdown in Spain were monitored. Results: Individual analyses showed that the mandatory lockdown caused reliable reductions in training volume in 13 subjects (-96 to -7 % reductions in minutes), that were followed by an increase after the lockdown in all subjects (5 to 270%). In contrast, changes in training load were not homogenous across individuals. Moreover, such changes were not matched by comparable variations in heart rate variability. A mixed model of the heart rate variability as a function of training volume and intensity revealed no significant modulation by these two variables, and subject specific effects on the slope. In this study, we did not find evidence of association between heart rate variability and training load and/or intensity as many previous reports have suggested, even if training conditions changed dramatically overnight.

Mental fatigue can impart negative effects on subsequent physical performance, although the mechanisms underlying these effects are not well understood. This study examined whether mental fatigue confers negative carryover effects on the performance of a set of biceps curls, while also investigating physiological and psychological mechanisms proposed to explain the predicted effect. A randomized, cross-over design was employed. On visit 1, participants (N = 10) performed a barbell biceps curl one-repetition maximum (1RM) test. On visits 2–3, participants performed 20 biceps curls at 50% of their 1RM, followed by their respective 10 min experimental manipulation (high vs. low cognitive exertion) and then a second set of biceps curls to exhaustion. Ratings of perceived exertion and electromyography of the biceps brachii, triceps brachii, upper trapezius, thoracic erector spinae and lumbar erector spinae were recorded during the physical task. The total number of repetitions completed was similar across the conditions. Results also failed to show between-condition differences for muscle activation and perceptions of exertion. Future research is needed to build an adequate knowledge base to determine whether there is an effect of mental fatigue on dynamic resistance-based task performance and, if so, identify the mechanisms explaining how and why.

The present study examined the associations of physical fitness and motor competence with P3 and alpha desynchronization (ERD), two neuroelectric indices of brain development underlying controlled attention, in 4-6 year-old preschool children. All participants completed physical fitness and motor competence test batteries and an auditory oddball task while electroencephalogram (EEG) was recorded. Results revealed that increased muscular power, muscular endurance, physical fitness, and motor competence were associated better attentional task performance. Analysis on neuroelectric indices showed that muscular endurance was related to increased P3 amplitude, while the increases in physical fitness and motor competence were associated with greater upper alpha (10-12 Hz) ERD following the stimulus evaluation and response selection. Further, the negative associations of physical fitness and motor competence with task response time were mediated by the upper alpha ERD. These findings highlight the importance of early childhood motor competence and physical fitness, especially muscular endurance, to neurocognitive function.

Purpose: To investigate whether mild dehydration, as a weight reduction strategy for lightweight rowers, compromises rowing performance despite a two-hour rehydration window. Both 2000m time trial and visuomotor performance were assessed for impairment. Methods: Experienced rowers (N=14) twice performed a 2000 m rowing ergometer time trial and visuomotor battery: once euhydrated and once after mild dehydration (-1.68 ± .23% body mass reduction). Weight loss was achieved through a combination of 12-hour (overnight) fluid restriction and sauna exposure. Results: Participants were significantly slower on the 2000 m rowing trial in the dehydration condition than in the euhydration condition (2.44 ± 4.5 s, p

The purpose of the present systematic review and network meta-analysis is to compare the effectiveness of different treatment classes across a range of tendinopathies and outcomes to better establish a treatment hierarchy. Where sufficient data are obtained, the potential for covariates including patient demographics and condition specifics (e.g. symptom severity) to explain statistical heterogeneity will be explored.

Physical activity reduces cancer risk but the underlying mechanisms remain unclear. We meta-analysed the effects of acute exercise and exercise training on serum-stimulated cancer cell behaviours in vitro. Systematic searches of PubMed, Scopus and SPORTDiscus up to February 2021 revealed 8 studies reporting 61 effect sizes eligible for meta-analysis. Standardised mean differences (SMDs) between exercise-conditioned serum and resting serum were pooled using random-effects models. Acute exercise-conditioned serum significantly reduced cancer cell growth (SMD -1.31, 95% CI -1.77 to -0.86, p

Fitting an FFM via NLS in practice assumes that a unique optimal solution exists and can be found by the algorithm applied. However, this idealistic scenario may not hold for two reasons: 1) the absolute minimum may not be unique; and 2) local minima, saddle points, and/or plateau features may exist that cause problems for certain algorithms. If there exist different parameter sets in the domain that share the same global minimum under standard NLS, then there is a situation where parameters aren’t uniquely identified without additional constraints or regularisation terms. However, more likely is that problems with the typical FFM fitting process will stem from the existence of local minima, saddles, or plateau features that cause the algorithm to converge to a solution not equal to the global minimum. Local optima can provoke sensitivities in the fitting process for first and second-order algorithms that are by definition local optimisers. This manifests as sensitivity to initial parameter estimates (i.e., the starting point the algorithm initialises the search from). The extent of starting point sensitivity is largely unknown in the context of FFMs for common algorithms adopted and has not been studied directly. Given this concern, research reporting a single model solution derived from ‘one shot’ minimisation of NLS via typical first and second-order algorithms is fundamentally limited by possible uncertainty as to the suitability of fitted estimates as global minimisers. Therefore, the primary aim of this study was to investigate the sensitivity of a classical first-order search algorithm to selection of initial estimates when fitting a fitness-fatigue model (FFM) via nonlinear least-squares (NLS), and to subsequently assess the existence of local optima. A secondary aim of this study was to examine the implications of any findings in relation to previous research and provide considerations for future experimentation. The aims of the study were addressed through a computer experiment (in silico) approach that adopted a deterministic assumption the FFM completely specified athlete response. Under this assumption, two FFMs (standard, and fitness-delay) were simulated under a set of hypothetical model inputs and manually selected ‘true’ parameter values (for each FFM), generating a set of synthetic performance data. The two FFMs were refitted to the synthetic performance data without noise (and under the same model inputs) by the quasi-Newton L-BFGS-B algorithm in a repetitive fashion initiated from multiple starting points in the parameter space, attempting to at each search recover the true parameter values. Estimates obtained from this process were then further transformed into prediction errors quantifying in-sample model fit across the iterations and non-true solutions. Within the standard model scenarios, 69.1-70.3% of solutions found were the true parameters. In contrast, within the fitness-delay model scenarios, 17.6-17.9% of solutions found were the true parameters. A large number of unique non-true solutions were found for both the standard model (N=275-353) and the fitness-delay model (N=383-550) in this idealistic environment. Many of the non-true extrema found by the algorithm were local minima or saddles. Strong in-sample model fit was also observed across non-true solutions for both models. Collectively, these results indicate the typical NLS approach to fitting FFMs is harder for a hill-climbing algorithm to solve than previously recognised in the literature, particularly for models of higher complexity. The findings of this study add weight to the hypothesis that there exists substantial doubt in reported estimates across prior literature where local optimisers have been used or models more complex than the standard FFM applied, particularly when optimisation procedures reported have lacked the relevant detail to indicate that these issues have been considered. Future research should consider the use of global optimisation algorithms, hybrid approaches, or different perspectives (e.g., Bayesian optimisation).

In strength training, personalised strength training (autoregulation) approaches have been used to individualise exercise programs with monitoring for dynamic adjustment based on the individual response to training. While this transition from tradition-based training to evidence-based training framework has been an improvement in training practices, we argue that the future of strength training will also incorporate deep learning models powered by data. We refer to this data-driven framework as precision strength training inspired by the similar modeling frameworks used in precision medicine. In contrast to current personalised training in which the acquired athlete data is often subject to human expert decision-making, we are anticipating the rise of human-in-the-loop systems with an augmented coach who will be doing decisions collaboratively with the machine. Similar to other precision frameworks, such as precision health, we envision such a future to take decades to be realised and we focus here on practical short-term targets on a way to long-term realisation. In this chapter, we will review the measurement technology needed for continuous data acquisition from an individual during training/physical activity, how to acquire these datasets for the development of such systems and, how a proof-of-concept system could be developed for powerlifting training with applicability to general strength and conditioning (S&C) and physical rehabilitation purposes. Additionally, we will evaluate how the user experience (UX) of the system feedback and visualisation could be designed.

The aim of this multi-experiment paper was to explore the concept of the minimum effective training dose (METD) required to increase 1-repetition-maximum (1RM) strength in powerlifting (PL) athletes. The METD refers to the least amount of training required to elicit meaningful increases in 1RM strength. A series of 5 studies utilising mixed methods, were conducted using PL athletes & coaches of all levels in an attempt to better understand the METD for 1RM strength. The studies of this multi-experiment paper are: an interview study with elite PL athletes & highly experienced PL coaches (n=28), an interview & survey study with PL coaches and PL athletes of all levels (n=137), 2 training intervention studies with intermediate-advanced PL athletes (n=25) & a survey study with competitive PL athletes of different levels (n=57). PL athletes looking to train with a METD approach can do so by performing approximately 3-6 working sets of 1-5 repetitions each week, with these sets spread across 1-3 sessions per week per powerlift, using loads above 80% 1RM at a Rate of Perceived Exertion (RPE) of 7.5 to 9.5 for 6-12 weeks and expect to gain strength. PL athletes who wish to further minimize their time spent training can perform autoregulated single repetition sets at an RPE of 9-9.5 though they should expect that strength gains will be less likely to be meaningful. However, the addition of 2-3 back-off sets at approximately 80% of the single repetitions load, may produce greater gains over six weeks while following a 2-3-1 squat-bench press-deadlift weekly training frequency. When utilizing accessory exercises in the context of METD, PL athletes typically utilize 1-3 accessory exercises per powerlift, at an RPE in the range of 7-9 and utilize a repetition range of approximately 6-10 repetitions.

Purpose: compare linear and curvilinear models to describe the force-velocity relationship, especially on the velocity end, in lower limb acyclic extensions. Methods: nine athletes performed horizontal lower limb extensions on a leg press ergometer allowing to set from very high to very low (i.e. horizontal assisted extensions) resistive and inertial conditions. Lower limb force and velocity were continuously measured over the push-off in six resistive conditions to determine individual force-velocity relationships. Goodness of fit (GoF) of the linear model on force and velocity data (using the basic first order polynomial function), was compared to that of curvilinear models (using the basic second order polynomial function, Fenn and Marsh’s, and Hill’s equations) based on the Akaike Information Criterion (AIC). Results: When expressed relative to the theoretical maximal force (F0-L) and velocity (v0) obtained from the linear model, force and velocity data ranged from 26.6±6.6 to 96.0±3.6%F0-L and from 8.3±1.9 to 76.6±7.0%v0-L (range of individual values=5-86%v0-L and 16-99%F0-L). Curvilinear and linear models showed very high GoF (r2=0.951-0.999; SEE=17-159N). Despite higher GoF for curvilinear models, AIC showed that the linear model presented ~99-100 % chance to be the best one to describe the force-velocity relationship. Conclusion: the force-velocity relationship in acyclic lower limb extensions can be considered as linear from its force (from 5%v0-L) to its velocity end (up to 86%v0-L). Assisted horizontal acyclic lower limb extensions allowed achievement of movement velocities very close to v0, representing an interesting modality for training or testing force production capabilities at high velocities, notably for weaker populations.

Athlete external load is typically quantified as volumes or discretised threshold values using distance, speed and time. A framework that accounts for the movement sequences of athletes has previously been proposed using radio frequency data. This study developed a framework to identify sequential movement sequences using GPS-derived spatiotemporal data in team-sports and establish it’s stability. 13 rugby league players during one match were analysed to demonstrate the application of the framework. The framework (Sequential Movement Pattern-mining [SMP]) applies analysis techniques to handle i) geospatial data (i.e., decimal degree latitude and longitude), ii) determined players turning angles, iii) improved movement descriptor assignment thus, improving movement unit formation and iv) improved the classification and identification of players frequent SMP. The SMP framework allows for sub-sequences of movement units to be condensed, removing repeated elements, which offers a novel technique for the quantification of similarities or dissimilarities between players and playing positions. The SMP framework provides a robust and stable method which allows, for the first time the analysis of GPS-derived data and identifies the frequent SMP of field-based team-sport athletes. The application of the SMP framework in practice could optimise the outcomes of training of field-based team-sport athletes by improving training specificity.

Background: Research has established beneficial associations between 24-hour movement guideline adherence and several health outcomes in typically developing (TD) children, but these relationships are poorly understood in children with neurodevelopmental disorders (NDD). Purpose: To examine: (1) 24-hour movement guideline adherence; (2) the influence of disability severity; and (3) associations between guideline adherence and health outcomes in children with NDD and TD children. Methods: This cross-sectional study used data from the 2018-2019 cycles of the US National Survey of Children's Health. Parental/caregiver reports of movement behaviors (physical activity, screen time, and sleep), disability severity (limitations to daily activities) and health outcomes (general health status, anxiety, and depression) were provided for 8,554 children with NDD and 19,669 TD children aged 6-17 years. Results: Children with NDD had significantly lower odds of meeting each movement behavior guideline compared to TD children and these effects were most pronounced for those who experienced consistent limitations to daily activities. Meeting at least two guidelines significantly lowered the odds for anxiety and depression, and increased the odds for better general health for children with NDD. Conclusions: These findings suggest degree of disability severity has a strong influence on adherence to 24-hour movement guidelines among children with NDD. Funding: N/A., The Health & Fitness Journal of Canada, Vol. 14 No. 3 (2021): Proceedings from the 8th International Society for Physical Activity and Health Congress

When sampling electromyograms (EMGs) with one pair of electrodes, it seems implicitly assumed the detected signal reflects the net muscle excitation. However, this assumption is discredited by observations of local muscle excitation. Therefore, we hypothesize that the accurate assessment of muscle excitation requires multiple EMG detection and consideration of electrode-fiber alignment. We advise prudence when drawing inferences from individually collected EMGs

Introduction Low back pain is a major health issue in elite rowers. High training volume, frequent flexion movements of the lower spine and rotational movement in sweep rowing contribute to increased spinal strain and neuropathological patterns. Perturbation-based trunk stabilization training (PTT) may be effective to treat neuromuscular deficits and low back pain. Methods All boat classes (8+, 4+/-, 2-) of the male German national sweep rowing team participated in this non-randomized parallel group study. We included 26 athletes (PTT: n = 12, control group: n = 14) in our analysis. Physical and Sports therapists conducted 16 individualized PTT sessions á 30–40 minutes in 10 weeks, while the control group kept the usual routines. We collected data before and after intervention on back pain intensity and disability, maximum isometric trunk extension and flexion, jump height and postural sway of single-leg stance. Results We found less disability (5.3 points, 95% CI [0.4, 10.1], g = 0.42) for PTT compared to control. Pain intensity decreased similar in both groups (-14.4 and -15.4 points), yielding an inconclusive between-group effect (95% CI [-16.3, 14.3]). Postural sway, strength and jump height tend to have no between- and within-group effects. Conclusion Perturbation-based trunk stabilization training is possibly effective to improve the physical function of the lower back in elite rowers.

Across the world, young people do not have the same opportunities to develop their potential and become well-rounded adults. The world's population is approximately 1.8 billion young people aged 10 to 24, and about 90% of them live in developing countries within extreme development context. Optimal development of those generations depends on the resources for support, education and health and the means implemented to sustain this development. However, the imbalance of these resources is clearly observable throughout the world. Sport has been use in many developing countries to contribute to health and education for youth following Sustainable Development Goals (SDG) of the United Nations. More especially, sport is use as a leisure to generate resilience, the capacity of a person or group to develop well, to continue to project itself into the future despite destabilizing events, difficult living conditions, and severe trauma. Several authors emphasize the role of recreational activities such as physical activity and sport in the resilience process or for academic perseverance. The chapter explores the perspective and the potential of using sport for the sustainable development for health and education of youth as targeted in the SDG. More especially, we aim to understand how sport can contribute to health and education of youth through cases studies from various developing countries.

Introduction: To maintain optimal glycemic levels and prevent long-term complications, adolescents with type 1 diabetes (T1DM) should engage in regular moderate to vigorous activity (MVPA) in addition to other diabetes self-care behaviors. Though interventions to prepare adolescents safely increase MVPA have been developed and tested, barriers continue to limit dissemination and engagement in clinical and community settings. Objective: To examine youth and parent perspectives on the acceptability of a group physical activity and coping intervention for adolescents with T1DM.Subjects: 18 adolescents (11-19 years) with T1DM who completed the intervention and at least one of their parents.Methods: Adolescents completed an exit survey measuring satisfaction with the intervention (program components, comfort, and instructors) on a 5-point scale. Semi-structured interviews were conducted with adolescents and at least one parent. Qualitative description was used to develop themes that summarize participant experiences during the intervention. Results: The intervention was rated highly: program components (M=4.5), comfort (M=4.4), and instructors (M=4.3). Themes included: (1) Adolescents and parents valued being around others with T1DM and their families; (2) The intervention helped adolescents gain knowledge and reinforce diabetes self-management behaviors; (3) Challenges included convenience and sustaining participant engagement; and (4) Adolescents intended to sustain physical activity and diabetes self-management behaviors after the intervention.Conclusions: Adolescents with T1DM and their parents viewed a group physical activity and discussion intervention as a positive experience. Because participants highly valued the group aspect of the intervention, future MVPA interventions would likely benefit from integrating social interactions with others with T1DM.

Background: Large-scale health surveys often consider sociodemographic characteristics and several health indicators influencing physical activity that often vary across units (regions or states). Data in a survey for some small units are often not representative of the larger population. This study developed a relatively simple multilevel regression and poststratification (MRP) model to estimate the proportion of leisure-time physical activity across Brazilian state capitals, based on the Brazilian cross-sectional national survey VIGITEL (2018). Methods: We used various approaches to evaluate whether the MRP approach outperforms single-level aggregated estimates, with various subsample proportions tested. Results: The mean absolute errors were consistently smaller for the MRP estimates than single-level regression estimates, particularly with smaller sample sizes. MRP consistently had predictions closer to the estimation target than single-level aggregated estimations. MRP presented substantially smaller uncertainty estimates compared to aggregated estimates. Conclusions: Our results confirm that MRP is a promising strategy to derive disaggregated data for health-related outcomes and, in particular, physical activity indicators from aggregated-level surveys. Overall, the MRP is superior to single-level aggregated estimates and disaggregation, yielding smaller errors and more accurate estimates. MRP significantly expands the scope of issues for which researchers can better address participation bias and interpret interactions to estimate descriptive population quantities. The observations present in this study highlight the need for further research, potentially incorporating more information in the models to better interpret interactions and types of activities across target populations.

Objective: Evaluate feasibility, safety, acceptability, and estimate efficacy of an exercise promotion intervention for adults with type 1 diabetes (T1D) and sub-optimal baseline exercise patterns.Design: Single-group, 2-week baseline observation then 10-week intervention with follow-up observation.Setting: Community-based sample participating remotely with physician oversightParticipants: Volunteers 18-65 years old with T1D screened for medical readiness for exercise intervention offerings. N=20 enrolled, N=17 completing all outcomes with 88%-91% biosensor adherence. Intervention: Feedback on big data from continuous glucose monitoring (CGM), its intersection with other ecological datasets (exercise, mood, sleep), and other informational and motivational elements (exercise videos, text-based exercise coach, self-monitoring diary). Main Outcome Measures: Feasibility (use metrics, assessment completion), safety (mild and severe hypoglycemia, diabetic ketoacidosis), acceptability (system usability scale, single items, interview themes), standard clinical and psychosocial assessments.Results: Participants increased exercise from a median of 0 (IQR 0, 21) to 64 (20, 129) minutes per week (p=.004, d=0.71) with no severe hypoglycemia or ketoacidosis. Body mass index increased (29.5±5.1 to 29.8±5.4 kg/m2, p= .02, d= 0.57). Highest satisfaction ratings were for CGM use (89%) and data on exercise and its intersection with CGM and sleep (94%). Satisfaction was primarily due to improved exercise management behavioral skills, although derived motivation was transient.Conclusions: The use of personalized big data from biosensors to substantiate human-delivered, client-centered exercise support for T1D is feasible and acceptable for interventions involving big data collection. However, there is a need for more intensive, sustained support. The big data could support informatics-based, automated motivational tools.

Background. Autism Spectrum Disorder (ASD) is a common neurodevelopmental condition characterised by social-communication deficits and is often accompanied by an array of symptoms, including cognitive and motor differences. Research has begun to investigate the utility of exergames (virtual exercise games) for combating some of the functionally impairing facets of ASD. However, no review to date has investigated the positive effects of exergaming for young individuals diagnosed with ASD, exclusive of their effects on fitness-related/health-related outcomes. Methods. We systematically reviewed the literature for articles published between 1990 – 2020, which aimed to examine the effectiveness of exergames for targeting some of the symptoms observed in children diagnosed with ASD, exclusive of physical fitness-related outcomes. Results. Out of 193 relevant articles, 10 met the inclusion criteria. All studies showed beneficial effects of exergaming for executive function and motor skills, however more work is needed to examine the beneficial effects of exergaming for social development in young autistic individuals. Conclusion. The present review supports the use of exergaming to improve some functions in ASD and suggests future research is needed to expand on this for the enhancement of social-communication skills.

Background. Stress fractures are injuries caused by repetitive loading during activities such as running. The application of advanced analytical methods such as machine learning to data from multiple wearable sensors has allowed for predictions of biomechanical variables associated with running-related injuries like stress fractures. However, it is unclear if data from a single wearable sensor can accurately estimate variables that characterize external loading during running such as peak vertical ground reaction force (vGRF), vertical impulse, and ground contact time. Predicting these biomechanical variables with a single wearable sensor could allow researchers, clinicians, and coaches to longitudinally monitor biomechanical running-related injury risk factors without expensive force-measuring equipment.Purpose. We quantified the accuracy of applying quantile regression forest (QRF) and linear regression (LR) models to sacral-mounted accelerometer data to predict peak vGRF, vertical impulse, and ground contact time across a range of running speeds.Methods. Thirty-seven collegiate cross country runners (24 females, 13 males) ran on a force-measuring treadmill at 3.8 – 5.4 m/s while wearing an accelerometer clipped posteriorly to the waistband of their running shorts. We cross-validated QRF and LR models by training them on acceleration data, running speed, step frequency, and body mass as predictor variables. Trained models were then used to predict peak vGRF, vertical impulse, and contact time. We compared predicted values to those calculated from a force-measuring treadmill on a subset of data (n = 9) withheld during model training. We quantified prediction accuracy by calculating the root mean square error (RMSE) and mean absolute percentage error (MAPE).Results. The QRF model predicted peak vGRF with a RMSE of 0.150 body weights (BW) and MAPE ± SD of 4.27 ± 2.85%, predicted vertical impulse with a RMSE of 0.004 BW*s and MAPE of 0.80 ± 0.91%, and predicted contact time with a RMSE of 0.011 s and MAPE of 4.68 ± 3.00%. The LR model predicted peak vGRF with a RMSE of 0.139 BW and MAPE of 4.04 ± 2.57%, predicted vertical impulse with a RMSE of 0.002 BW*s and MAPE of 0.50 ± 0.42%, and predicted contact time with a RMSE of 0.008 s and MAPE of 3.50 ± 2.27%. There were no statistically significant differences between QRF and LR model prediction MAPE for peak vGRF (p = 0.549) or vertical impulse (p = 0.073), but the LR model’s MAPE for contact time was significantly lower than the QRF model’s MAPE (p = 0.0497).Conclusions. Our findings indicate that the QRF and LR models can accurately predict peak vGRF, vertical impulse, and contact time (MAPE < 5%) from a single sacral-mounted accelerometer across a range of running speeds. These findings may be beneficial for researchers, clinicians, or coaches seeking to monitor running-related injury risk factors without force-measuring equipment.

Tools for reliable assessment of socially sensitive or transgressive behavior warrant constant development. Among them, the Crosswise Model (CM) has gained considerable attention. We systematically reviewed and meta-analyzed empirical applications of CM and addressed a gap for quality assessment of indirect estimation models. Guided by the PRISMA protocol, we identified 45 empirical studies from electronic database and reference searches. Thirty of these were comparative validation studies (CVS) comparing CM and direct question (DQ) estimates. Six prevalence studies exclusively used CM. One was a qualitative study. Behavior investigated were substance use and misuse (k= 13), academic misconduct (k= 8), and corruption, tax evasion, and theft (k= 7) among others. Majority of studies (k= 39) applied the “more is better” hypothesis. Thirty-five studies relied on birthday distribution and 22 of these usedP= 0.25 for the non-sensitive item. Overall, 11 studies were assessed as high-, 31 as moderate-, and two as low quality (excluding the qualitative study). The effect of non-compliance was assessed in eight studies. From mixed CVS results, the meta-analysis indicates that CM outperforms DQ on the “more is better” validation criterion, and increasingly so with higher behavior sensitivity. However, little difference was observed between DQ and CM estimates for items with DQ prevalence estimate around 50%. Based on empirical evidence available to date, our study provides support for the superiority of CM to DQ in assessing sensitive/transgressive behavior. Despite some limitations, CM is a valuable and promising tool for population level investigation.

Recent work has demonstrated the collective impact of daily movement behaviours on mental health outcomes, however, positive aspects of mental health have received much less attention. The purpose of this study was to identify unique adolescent movement behaviour profiles and determine whether profile membership is associated with differences in mental wellbeing. This study used data from the baseline assessment of the ADAPT study. A total of 1166 Canadian adolescents enrolled in grade 11 classes (Mage = 15.91 ± 0.48; 54% female) self-reported their movement behaviours – moderate-to-vigorous physical activity (MVPA), recreational screen time (ST) and sleep – and completed three measures of mental wellbeing: flourishing, self-esteem and resiliency. Latent profile analysis with distal outcomes comparisons were conducted. Four distinct profiles were identified: one healthy profile (high MVPA/low ST), two mixed behavioural profiles (low MVPA/low ST and high MVPA/high ST), and one profile considered to be the least healthy (low MVPA and high ST). Sleep patterns were similar across the profiles. The healthiest profile was consistently associated with better mental wellbeing, followed by the mixed behaviour profiles, and the least healthy profile had the poorest scores for mental wellbeing. These findings highlight the additive benefits of engaging in a full complement of healthy movement behaviours. Moving forward, behavioural interventionists should consider adopting an integrated approach to promoting mental wellbeing through targeting each of the movement behaviours concurrently.

The theory of effort minimization in physical activity (TEMPA) argues that individuals have an automatic attraction toward effort minimization. To engage in a physically active behavior, this automatic attraction needs to be overridden by controlled processes. However, direct evidence showing that inhibitory control is required to avoid effort minimization is lacking. Here, we used go/no-go tasks and electroencephalography (EEG) to assess the neural correlates of inhibitory control associated with visual stimuli depicting physical inactivity, physical activity, or that were neutral in 50 healthy young adults. The N2 event-related potential (ERP) component amplitude was used as a physiological index of inhibitory control. Results showed significant two-way interactions between the type of trials (i.e., go vs. no-go trials) and the type of stimuli on N2, revealing a significantly more pronounced no-go effect (i.e., higher N2 in no-go relative to go trials) for neutral and physical inactivity stimuli compared with physical activity stimuli. Simple tests further revealed that N2 amplitude was more negative in no-go than go trials for neutral stimuli (b=-.91 µV, 95%CI=-1.42 to -.40 µV, p

Authentic leadership is a form of leadership which has received a relatively limited amount of research in sport despite the suggestion that it may be related to numerous positive outcomes in athletes. We conducted a study in sport in order to investigate proposed relationships between authentic leadership and athlete outcomes. Specifically, we investigated whether coaches’ authentic leadership is related to athletes’ achievement and moral outcomes via trust and the culture of the team. Data were collected via questionnaires. The design was a cross-sectional study with 366 (240 females, Mage = 21.07) team sport athletes. Authentic leadership was positively related to athletes’ trust and team culture. Authentic leadership was also positively related to athletes’ commitment, positive affect and perceptions of their teammates’ prosocial behaviours, via trust and team culture. Our findings enhance our understanding of authentic leadership in sport and highlight its importance in predicting crucial positive athlete outcomes.

Introduction: The issue of integrating transgender athletes into sport is becoming more prominent with the rising numbers of those identifying as transgender in society. Whether it is fair for transgender athletes to be included in their affirmed gender category across all levels of sport from grassroots to elite is the crux of the debate. Previous studies have shown muscle mass loss in transwomen and muscle mass and strength gain in transmen after 1 year of gender-affirming treatment (GAT). Wiik et al., 2020 found that transmen retain a strength disadvantage over cisgender men and transwomen retain muscle mass and strength advantages over cisgender women after 1 year of GAT. Roberts et al., 2020 also found that running performance in transwomen was maintained but not baseline muscular strength. However, very little data on sports performance measures outside muscular strength and running times exist, nor has any of the previous data been compared with a comparative control group. Aim: To investigate the effect of “muscle memory” in transgender athletes and investigate changes in physiology after 2 years of GAT such as bone mineral density, lean muscle mass, and fat mass, coupled with sports performance measures in transwomen and transmen athletes and compare them with a cisgender female athletic cohort. This will elucidate what advantages/disadvantages transgender athletes gain/retain after 2 years of GAT over their cisgender counterparts and this will better inform policymakers who control their integration into their affirmed gender category in sport.

Purpose: To examine the influence of hip abductor strength, neuromuscular activation, and pelvis & femur morphology in contributing to sex differences in hip adduction during running.Methods: Fifteen female and 14 male runners underwent strength testing, instrumented overground running (e.g., kinematics and muscle activation), and computed tomography scanning of pelvis and femur. Morphologic measurements included bilateral hip width to femur length ratio, acetabulum abduction, acetabulum anteversion, femoral anteversion, and femoral neck-shaft angles. Sex differences for all variables were examined using independent t-tests. Linear regression was used to assess the ability of each independent variable of interest to predict peak hip adduction during the late swing and stance phase of running. Results: Compared to males, females exhibited significantly greater peak hip adduction during both late swing (8.5 ± 2.6° vs 6.2 ± 2.8°, p = 0.04) and stance phases of running (13.4 ± 4.2° vs 10.0 ± 3.2°, p = 0.02). In addition, females exhibited significantly lower hip abductor strength (1.8 ± 0.3 vs 2.0 ± 0.3 Nm/kg, p=0.04), greater femoral neck-shaft angles (134.1 ± 5.0° vs 129.9 ± 4.1°, p=0.01), and greater hip width to femur length ratios than males (0.44 ± 0.02 vs 0.42 ± 0.03, p=0.03). Femoral anteversion was the only significant predictor of peak hip adduction during late swing (r=0.36, p=0.05) and stance (r=0.41, p=0.03).Conclusion: Our findings highlight the contribution of femur morphology as opposed to hip abductor strength and activation in contributing to hip adduction during running.

Aims In recent years there has been a significant rise in the popularity of muscle gun devices. However, the current research regarding handheld muscle gun devices is unclear. Therefore, this literature review will explore the current literature regarding the effect of muscle gun device on lower limb range of motion, muscle activation, force output and the possibility of reducing delayed onset muscle soreness. Methods Four databases were used along with two academic search engines to search for studies that satisfied the inclusion criteria. To fulfil the inclusion criteria studies had to be of a pre-post design with a focus on the use of percussion massage devices on lower limbs. Studies exploring range of motion and muscle force output were of particular interest. Results Thirty-nine included studies were used in this literature review. It was found that handheld percussive massage devices are the most effective method of increasing lower limb range of motion compared to foam rolling and other self-myofascial protocols. The use of handheld percussive massage devices directly after exercise reduces delayed onset muscle soreness. However, there was no reported significant increase in muscle activation or force output following the usage of a handheld percussive massage device. Conclusion The use of muscle gun devices is recommended as part of a structured warm-up pre-exercise due to an increase in range of motion, reduction in perceived muscle soreness whilst having no negative impact on muscle activation and force output. Muscle guns may also be implemented as part of a rehabilitation programme post injury due to their ability to increase range of motion and reduce perceived pain and muscle soreness.

Introduction Authentic leadership is a form of leadership which could result in positive outcomes in athletes, yet, it has received limited research attention in sport. Furthermore, previous research of authentic leadership in has been cross sectional and so it is not known how the relationships between authentic leadership and athlete outcomes change over time. The aim of the study was to investigate whether coaches’ changes in authentic leadership are related to changes in athlete outcomes directly and indirectly through changes in trust, team culture, and cohesion over time. MethodData were collected via questionnaires. The study had a longitudinal design with 421 (227 females, Mage = 20.32) team sport athletes at time 1 and 247 athletes at time 2 (5 months later). ResultsChanges over time in authentic leadership were related to changes in athletes’ perceptions of their teammates’ prosocial behaviours and enjoyment, both directly and indirectly via changes in trust and cohesion.ConclusionsOur findings enhance our understanding of authentic leadership in sport and highlight its importance in predicting crucial positive athlete outcomes.

Objectives Authentic leadership is a style of leadership which could be promising in sport. However, to date, very little research has examined this leadership style in coaches. The purpose of this research was to investigate the effects of an authentic leadership manipulation on athletes’ trust, achievement, and moral outcomes. Design Experiment using a 3 x 2 between-participant design.Methods 129 university athletes (Mage = 19.36; 76 females) were randomly assigned to either a high, low or neutral authentic leadership condition. Results A multivariate analysis of variance indicated that participants in the high authentic leadership condition reported higher trust, commitment, enjoyment, and anticipated guilt for aggression, and lower aggression compared to participants in the low authentic leadership and neutral conditions. Conclusions The findings suggest that high authentic leadership could be key to creating more positive environments in sport.

ObjectivesAuthentic leadership could produce promising outcomes in sport. However, no intervention designed to increase coaches’ authentic leadership exists. The aim of this study was to develop and evaluate such an intervention by examining its efficacy on a range of athlete outcomes.Design Mixed design with Group (Intervention, Control) as between and Time (pre, post) as within-participants factors.MethodA total of 18 coaches (Mage = 37.89; 83% male) who were coaching 153 athletes (Mage = 20.48; 50.3% females) were randomly allocated, via block randomisation, into either an intervention (n = 60) or a control group (n = 93). The coaches in the intervention group received a 2-hour-long workshop, had a midway-point meeting, and completed weekly coaching logs. The control group did not receive an intervention. Data were collected prior to the intervention and two months after the intervention had been completed. Results A manipulation check revealed the intervention group reported higher authentic leadership, compared to the control group. A repeated measures multivariate analysis of variance indicated that athletes in the intervention group reported significantly higher enjoyment and prosocial behaviours from pre to post-test compared to the control group. Conclusions The findings suggest that an authentic leadership intervention could be effective in improving coaches’ authentic behaviours and promoting positive athlete outcomes

Objectives: The primary purpose of this systematic review is to examine the literature on resistance training interventions for lower limb tendinopathy to evaluate the proportion of interventions that implemented key resistance training principles (specificity, progression, overload, individualisation) and reported relevant prescription components (frequency, intensity, sets, repetitions) and reported intervention adherence. Design: Two reviewers performed a qualitative systematic review after screening titles and abstracts based on eligibility criteria. Identified papers were obtained in full text, with data extracted regarding the implementation of resistance training principles. Included articles were evaluated by the Cochrane risk of bias tool, with a scoring tool out of 10 used for implementation and reporting of the 5 key principles. Scientific databases were searched in November 2020 and included Medline, CINAHL, AMED, and Sportsdiscus.Results: 52 randomised controlled trials investigating resistance training in five different lower limb tendinopathies were included. Although most studies considered the principles of progression (92%) and individualisation (88%), only 19 studies (37%) appropriately described how this progression in resistance was achieved, and only 18 studies (35%) reported specific instruction on how individualisation was applied. Adherence was considered in 27 studies (52%), with only 17 studies (33%) reporting the levels of adherence. In the scoring criteria, only 5 studies (10%) achieved a total maximum score of 10, with 17 studies (33%) achieving a maximum score of 8 for implementing and reporting the principles of specificity, overload, progression and individualisation.Conclusion: There is meaningful variability and methodological concerns regarding the application and reporting of resistance training principles, particularly progression and individualisation, along with intervention adherence throughout studies. Collectively, these findings have important implications for the prescription of current resistance training interventions, including the design and implementation of future interventions for populations with lower limb tendinopathies.

Background: The use of gamification to change behaviors and promote physical activity is a promising avenue to tackle the global physical inactivity pandemic and the current prevalence of chronic diseases. However, we do not have yet evidence of the effectiveness of gamified interventions with the existence of mixed results in the literature.Objective: This systematic review and meta-analysis aimed to evaluate the effectiveness of gamified interventions and their healthcare potential by testing the scalability and sustainability of their influence on physical activity (PA) and sedentary behaviors (SB).Methods:Five electronic databases (Pubmed, EMBASE, Scopus, Web of Science and CENTRAL) were searched for randomized controlled trials (RCTs) published since 2010. Eligibility criteria were based on components of PICO (participants, interventions, comparators, and outcomes). Studies were included when they used gamified interventions in daily life with an active or inactive control group, and when they assessed a PA or SB outcome. Studies were excluded when the intervention was based on an active video game using a gaming console. We conducted meta-analyses using a random effects model approach. Sensitivity analyses, influence analyses and publication bias analyses were performed to examine the robustness of our results.Results: The main meta-analysis performed on 16 studies and 2407 participants, revealed a small to medium summary effect of gamified interventions on PA behavior (g = 0.42 (95%CI [0.14, 0.69]). No statistical difference was found between different subgroups (adults vs adolescents, healthy participants vs adults with chronic diseases) and no interaction effects with moderators like age, gender or BMI, suggesting good scalability of gamified interventions. Moreover, the effect appears better on the step count (MD = +1609.56 steps per day (95%CI [372.39, 2846.73]) than on moderate-to-vigorous PA (g = 0.31 (95%CI [-0.19, 0.80]). The long-term effect (measured with follow-up averaging 14 weeks after the end of the intervention) is more volatile with a very small to small effect (g = 0.15, [0.07, 0.23]).Conclusions: This meta-analysis confirms that gamified interventions are promising to promote PA in various publics. However, if the effect persists after the end of the program, suggesting that it is not just a novelty effect due to the playful nature of gamification, it seems volatile with a small long-term effect. The integration of gamification in more global healthcare interventions could be a way to address this low sustainability. Future rigorous trials are needed to explore these perspectives.

Despite the positive health effect of physical activity, one third of the world’s population is estimated to be insufficiently active. Prior research has mainly investigated physical activity on an aggregate level over short period of time, e.g., during 3 to 7 days at baseline and few-month later, post intervention. To develop effective interventions, we need a better understanding of the temporal dynamics of physical activity. We proposed here an approach to studying walking behavior at “high-resolution” and by capturing the idiographic and day-to-day changes in that behavior. We analyzed daily step count among 151 young adults with overweight or obesity who had worn an accelerometer for an average of 226 days (~25,000 observations). We then used a recursive partitioning algorithm to characterize patterns of change, here sudden behavioral gains and losses, over the course of the study. These behavioral gains or losses were defined as a 30% increase or reduction in steps relative to each participants’ median level of steps lasting at least 7 days. After the identification of gains and losses, fluctuation intensity in steps from each participant’s individual time series was computed with a dynamic complexity algorithm to identify potential early warning signals of sudden gains or losses. Results revealed that walking behavior change exhibits non-linearities that can be described as sudden gains and losses. On average, participants experienced six sudden gains or losses over the study. We also observed a significant and positive association between critical fluctuations in walking behavior, a form of early warning signals, and the subsequent occurrence of sudden behavioral losses in the next days. Altogether, this study suggests that walking behavior could be well understood under a dynamic paradigm. Results also provide support for the development of “just-in-time” behavioral interventions based on the detection of early warning signals for sudden behavioral losses.

Background: Plantar heel pain (PHP) is a common musculoskeletal disorder, with both extracorporeal shockwave therapy (ESWT) and specific exercise such as plantar fascia specific stretching shown to be effective treatments. This review aimed to evaluate the effectiveness of combined ESWT and exercise interventions versus other interventions in treating PHP. Methods: A systematic review of effectiveness was conducted, adhering to the PRISMA guidelines. Five databases were searched for studies published between January 2000 and March 2020, with 12 studies meeting the inclusion criteria. The Grading of Recommendations Assessment Development and Evaluation (GRADE) framework was used to determine quality of recommendations. Results: The 12 included studies (n = 861) compared ESWT and stretching with various other treatments. Due to clinical and methodological heterogeneity, pooling of data was not possible, and a narrative synthesis of findings was provided. There was high quality evidence that combined ESWT and stretching interventions are more effective than those using either alone or botulinum toxin injections, and low-quality evidence of superiority versus ultrasound and stretching. There was moderate quality evidence that combined ESWT and stretching is no more effective than corticosteroid injection (CSI), and high quality evidence that the combination is no more effective than blood-derived injection therapies, custom orthotics or low-level laser therapy (LLLT) combined with stretching. There is high quality evidence that the use of topical corticosteroid or laser therapy in combination with ESWT and stretching increases effectiveness compared to ESWT and stretching alone, and moderate quality evidence for the additive effective of dry needling. Conclusions: Combined ESWT and stretching treatments are effective and may be recommended where they are available and practical to implement. Further high-quality studies with larger sample sizes and longer follow-up durations comparing combined interventions for PHP, including different exercise types such as resistance training are required.

Background: Plantar heel pain (PHP) is considered a tendinopathy and it affects up to 10% of the population. Both heavy slow resistance training (HSRT) and extracorporeal shockwave therapy (ESWT) have shown effectiveness for treating PHP in isolation. However more comprehensive exercise protocols and progression methods are needed due to poor long-term outcomes, and better standardization of ESWT protocols are required. Autoregulation of resistance training involves self-selecting exercise dosage based on individual factors. Although autoregulation has proven effective for strength gains in athletes, it has not been investigated in tendinopathy. It is recommended that PHP not be treated by one treatment in isolation, with there being a need to investigate feasibility and effectiveness of combined treatments in PHP. Currently, no studies have investigated autoregulated HSRT combined with ESWT, despite their individual efficacy. The optimal treatment protocol for PHP is unknown, and there is a need to ascertain whether the addition of ESWT to autoregulated HSRT leads to better outcomes compared to either alone. Methods: A three-arm randomised controlled trial (RCT) comparing these groups would be the ideal way to investigate this question, with a pilot RCT testing trial procedures and process evaluation required prior to a definitive RCT. Patients expectations, feasibility and acceptability of combined ESWT and exercise for PHP also remain unknown. Therefore, the addition of qualitative interviews in a mixed methods pilot RCT would help ascertain acceptability and help explain the intervention outcomes.

Background: Musculoskeletal disorders such as tendinopathy are having an increasing burden on society and health systems. Plantar heel pain (PHP) is considered a tendinopathy and it affects up to 10% of the population, having a high incidence in running athletes. Although resistance training has shown short-term effectiveness for treating PHP, more comprehensive exercise protocols and progression methods are needed due to poor long-term outcomes. Combining heavy slow resistance training with other types of exercise, such as plyometric exercise could lead to superior outcomes. It is recommended that PHP not be treated by one exercise type in isolation. However, studies often use only one type of exercise, with there being a need to investigate feasibility and effectiveness of comprehensive exercise programs in PHP. Resistance training programs in PHP are currently not achieving required intensity and dosage, leading to high recurrence rates. Therefore, better methods for progressing resistance training are required to improve outcomes. One potential method is autoregulation, which allows individuals to progress at their own rate, taking individual factors into account. Despite being found effective in increasing strength in healthy athletes, autoregulation methods have not been investigated in tendinopathy. Methods: A feasibility cohort study investigating a comprehensive exercise program for PHP could test feasibility and acceptability, prior to conducting a larger-scale study. A feasibility study would also help to determine if specific autoregulation progression methods for resistance training is feasible and acceptable for use with PHP patients. Patients expectations, and views on feasibility and acceptability of different types of exercise as well as autoregulation progression methods for PHP are unknown. Therefore, the addition of qualitative interviews in a mixed methods format would help ascertain acceptability of these methods and exercise interventions for the first time and help explain the intervention outcomes, allowing for design of a larger-scale study to determine effectiveness.

Introduction: Breast cancer and its treatments lead to several physical and psychological repercussions in the short and long term. Furthermore, breast cancer survivors (BCS) tend to present sedentary behavior, which worsens the aforementioned breast cancer treatment side effects. Physical exercise has been demonstrated to be effective for improving physical and psychological BCS aspects. Therefore, the purpose of this study is to investigate the effects of 24 weeks of supervised Mat Pilates on force production, flexibility, postural control, gait, body composition, pain, cancer related fatigue (CRF), body image, physical activity level, quality of life, and nutritional status in BCS undergoing hormone therapy. Methods and design: The HAPiMat Study is a randomized controlled clinical intervention trial comparing Mat Pilates with a control group. The primary outcomes are force production in different muscle groups, upper and lower limb flexibility, and gait and balance parameters. The secondary outcomes are quality of life, pain, cancer related fatigue, body image, sedentary behavior, functional capacity, physical activity level, nutritional intake, anthropometric measurements, and body composition. The safety of the Mat Pilates intervention and physical assessments are monitored throughout the intervention. Discussion: The strengths of this study are that the Pilates Method is mind-body training, which might ameliorate the side effects of breast cancer treatments, and that our intervention is systematized into sets, with the number of repetitions increased every eight weeks, enabling better results in the physical variables. Moreover, to date, no Pilates studies have focused on BCS undergoing hormone therapy only.

Review Objective: To synthesize the best available evidence on the effectiveness of interventions that have used autoregulated and individualised resistance training versus pre-determined and standardised resistance training in treating any tendinopathy. Introduction: Recent evidence suggests that individualised exercise may be more effective than standardised exercise for musculoskeletal disorders such as tendinopathy. However, no systematic reviews have been conducted on the topic and optimal treatment protocols and clinical recommendations are lacking.Inclusion criteria: Randomised controlled trials assessing the effectiveness of autoregulated and individualised resistance training versus pre-determined and standardised resistance training for tendinopathy in adults will be included. Methods: The authors will search for a wide range of sources to find both published and unpublished studies via EBSCOhost, including, but not limited to, MEDLINE, SPORTDiscus, CINAHL, Cochrane Central Register of Controlled Trials (CENTRAL), and Allied and Complementary Medicine Database (AMED). Studies published in a language other than English will only be considered if a translation is available. The JBI systematic review methodology will be followed when conducting the review. Data synthesis will be conducted using meta-analysis or narrative synthesis, where appropriate.