Journal of Sports Sciences最新文献

It is not known whether aerobic capacity (fitness) or overweight/obesity (fatness) moderate the association between physical activity (PA) and lipoproteins/lipids in children. The aim of this study was to investigate moderation of the cross-sectional and longitudinal associations between PA and the lipoprotein subclass profile by fitness and fatness in children. Eight hundred and sixty-two (cross-sectional analysis) or 787 (longitudinal analysis) children (age 10.2 years; body mass index 18.0; 49% girls) provided data on PA (ActiGraph GT3X+), the Andersen aerobic fitness test, and waist-to-height ratio at baseline, and lipoprotein particle concentrations, sizes and lipids (nuclear magnetic resonance spectroscopy) at baseline and 7-month follow-up. Associations for the PA intensity spectrum with a lipoprotein score were analysed by quartiles of baseline fitness and fatness using multivariate pattern analysis. Explained variances for the associations between PA and the lipoprotein score were 2.32-6.99% for children having low fitness or high fatness, adjusted for covariates. In these subgroups, PA was associated with a less atherogenic lipoprotein profile and sedentary time with a more atherogenic lipoprotein profile. No associations were found in more favourable fitness or fatness subgroups. Our findings suggest that PA can mitigate the increased risk of cardiovascular disease among children with low fitness and/or high fatness levels.

Complying with prescribed training plans is an important challenge for swimmers, as deviations from intended intensity or duration can reduce gains in performance and fitness. This randomised controlled trial investigated whether real-time visual feedback enhances compliance with prescribed training protocols among recreational swimmers. Fifty-seven participants were randomised into feedback (FB) and non-feedback (NFB) groups and completed 35 workouts over 12 weeks across three training volumes (small, medium, large). The FB group used FORM Goggles to receive real-time visual feedback; the NFB group used printed instructions and standard timing tools. Metrics included workout length count, workout effort, incomplete workouts, interval effort, rest time, and stroke type. Compliance was analysed using generalised linear mixed-effects models. The FB group demonstrated significantly better compliance with workout length count than the NFB group in the small and large plans (p < 0.004), with large effect sizes. Interval effort compliance was also higher in the FB group for the large training plan (69% vs. 58%, p = 0.044). Other metrics showed no meaningful group differences. These findings suggest that real-time visual feedback improves adherence to prescribed workout length and, to a lesser extent, interval effort, supporting its potential value in recreational swim training programmes.

Europe stages highly competitive World Triathlon Youth and Junior competitions. Results from 46 sprint and super sprint European triathlon events between 2021 and 2023 included 2137 competition data entries of 494 males and 1576 entries of 351 females. The competition split-times were converted to average velocity to account for competition distance variability. Performance trajectories were estimated using linear mixed model regression and subdivided by sex, competition distance, and segment with age as the main factor of interest. Random effects included competition's external factors, intra-athlete variability, and country of origin. Estimated velocity was not statistically different between sprint and super sprint distances in female swim, and male and female cycle, run, and full-race. Males were faster than females in all segments and across all ages. The total estimated performance progression from 15 to 19 years-of-age was small for adolescent triathletes: males (swimming ~4.2%; cycling ~3.2%; running ~6.0%); females (swimming ~2.4%; cycling ~1.7%; running ~4.1%). Age explained <7.0% of performance progression. Performance variance explained by random effects differed by sex, distance and segment. Despite the small contribution of age, the most successful adolescent triathletes continually develop at rates determined by sex.

This study examined whether the performance characteristics of male university field hockey players were associated with undergraduate degree year of study. Fifty-two male university field hockey players (age 20.8 ± 2.4 years, stature 1.79 ± 0.06 m, body mass 75.8 ± 8.3 kg) were monitored over 85 matches played across four national league seasons in the UK (2018-2022) using 15 Hz Global Positioning System units and heart rate monitors. Total distance, high-speed running distance (≥15.5 km.h^-1), accelerations (≥2 m.s^-1), decelerations (≤ -2 m.s^-1), average heart rate and percentage of time spent at >85% of maximum heart rate were compared between 1st year, 2nd year and final year players across 1090 player-match files. Hierarchical linear modelling of performance characteristics (Match - level 1, Player - level 2), normalised to 70 min match time, found that the total and high-speed running distance covered by final year players was lower compared to 2nd year players (by 163 m and 127 m, respectively, both p < 0.05). With increased training experience in a high-performance programme, running performance required to perform optimally could be reduced in university players due to the high level of match performance achieved, development of game understanding and improved technical ability.

How the interaction between physiological and motivational responses to exercise contribute to explaining endurance performance is poorly understood. This study investigated whether within-person changes in blood lactate concentration, heart rate (HR), volume of oxygen uptake ($\stackrel{.}{V{O}_2}$) and body temperature underlie desire to reduce effort and performance goal value during incremental exercise. Furthermore, the role of core affect in explaining these relationships was explored. Fifty participants (28 males, 22 females, M_age = 23.52 years; SD = 6.95 years) completed an incremental cycling step test. Work rate increased 25 watts every 4 min until voluntary exhaustion. The three psychological and four physiological measurements were taken at every stage, then analysed using multilevel modelling. Within-person variation in blood lactate concentration predicted desire to reduce effort (b = 2.19, p < .001) and performance goal (b = -0.85, p = .002). $\stackrel{.}{V{O}_2}$ and HR predicted desire to reduce effort (b = 2.64, p < .001; b = 1.59, p = .01), whereas body temperature predicted performance goal (b = 0.58, p = .03). Affect mediated relationships involving blood lactate concentration and $\stackrel{.}{V{O}_2}$, an important mediating variable when applying desire-goal conflicts to exercise. The four physiological responses to exercise have different but significant motivational implications.

This study assessed the interunit reliability of Global Navigation Satellite System (GNSS) and accelerometer-derived metrics during high-intensity shuttle run protocols. Thirty-three female football players completed three shuttle run protocols (2 × 20 m, 4 × 10 m, and 8 × 5 m). Two STATSports Apex Pro units (18 Hz GPS and 10 Hz Augmented GNSS; 100 Hz accelerometer) recorded accelerometer-derived (fatigue index [FI] and dynamic stress load [DSL]) and GNSS-derived (total distance, acceleration and deceleration counts, maximum speed, speed intensity and total metabolic power) metrics. Interunit reliability and agreement were evaluated using intraclass correlation coefficients (ICC), and Bland-Altman analysis. GNSS metrics demonstrated good to excellent reliability (ICC: 0.845-0.999), whereas accelerometer-derived metrics, FI (ICC: 0.495) and DSL (ICC: 0.484), showed poor reliability. Percentage bias in accelerometer-derived metrics ranged from -1.76% (FI) to -7.72% (DSL), and in GNSS metrics ranged from -0.1% (speed intensity) to 5.83% (decelerations), limits of agreement increased in protocols with more directional changes. Overall, the interunit reliability of accelerometer-derived metrics should be considered cautiously, especially in short, high-intensity activity. ICC and Bland-Altman analysis confirmed close agreement for the GNSS metrics but highlighted variability in accelerometer-derived metrics. Practitioners are advised to avoid interchanging units between athletes and sessions to maintain reliability.

This systematic review aimed to investigate COVID-19 impacts on motor competence (MC) in children and adolescents. SportDiscus, APAPsycInfo, CINAHL, Scopus, PubMed, Web of Science, Medline were searched in November 2024. Studies were included if they were in English; from 2015; measured actual MC pre and post COVID-19; in apparently healthy 3- to 19-year olds. Risk of bias assessment used the Effective Public Health Practice Project instrument. Eligible studies were synthesised narratively due to heterogeneity, and with Vote Counting to assess pre-post COVID-19 trend. Of the 568 studies, 278,536 participants, mean ages 5-11 years, took part in 11 eligible studies (4 longitudinal, 7 cross sectional): from Europe (7), Asia (2) and South America (2). Ten studies found a reduction in MC following the pandemic (Sign Test p = 0.01) with declines in: stability (one study, effect size, ES -0.30), locomotor domain (6 studies, ES -0.10 to -0.53), object control (3 studies, ES -0.07 to -0.25), composite MC (one study ES -0.65 in boys to -0.88 in girls). Seven studies were rated weak for selection bias, 8 for attrition and 6 for data collection methods. MC declined post-pandemic but there is a need for more global evidence. Funding: Scottish Funding Council. PROSPERO CRD42023467766.

Football is the most popular sport among adolescents, yet many do not achieve the World Health Organization's recommended 60 min of moderate to vigorous physical activity (MVPA) daily. This study investigated whether regular football practice helps meet this recommendation by assessing physical activity through accelerometry in 74 female players from a Spanish football academy (Senior Team, Reserves Team, U16 and U13). A second goal was to assess coaches and players perceptions and coaches' interpersonal style. Given the variation in physical demands by playing position, MVPA data were also analysed by player role. Average MVPA minutes per training session and match, with over 60 min played, were: Senior Team: 48.72 ± 3.63 and 57.19 ± 17.51; Reserves Team: 41.87 ± 5.38 and 48.35 ± 13.18; U16: 40.62 ± 5.67 and 44.51 ± 15.98; U13: 39.31 ± 3.04 and 44.29 ± 12.21. Players consistently rated themselves as 'very well recovered' in Total Quality Recovery (TQR) before and after sessions/matches. Rate of Perceived Exertion (RPE) values for players and Rate of Intended Exertion (RIE) values for coaches were similar during training (coaches: 12.39 ± 0.27, players: 12.66 ± 0.94) but higher for coaches during matches (coaches: 15.25 ± 2.91, players: 13.62 ± 1.98). Results suggest that regular football practice may help adolescent female players meet MVPA recommendations, contributing to an active lifestyle and potential health benefits.

Although active play contributes to children's physical activity (PA) levels, the parental influences on the development of motor competence for active play are unknown. Therefore, this study analysed whether parental influences predicted their child's motor competence for active play. Data from the InFANT cohort study, collected at ages 5 and 9.5 years, included 199 parent-child pairs. Parents self-reported on their parenting efficacy (α = 0.76), facilitation (α = 0.74) and attitude (α = 0.58) towards children's PA at age 5. At 9.5 years, parents proxy-reported their child's motor competence for active play. Separate and multivariate regression models tested the three parenting constructs as predictors of motor competence for active play, adjusted for covariates (child sex, socioeconomic position, child's 5-year motor competence). Parental efficacy (β = 0.25), facilitation (β = 0.29) and attitude (β = 0.25) each served as significant predictors of motor competence for active play in the separate models. In the multivariate model, parental facilitation (β = 0.20, p < 0.01) dominated the predictive power for children's motor competence for active play; attitude (β = 0.17, p = 0.03) still had a significant effect but not efficacy (β = 0.13, p = 0.15). The findings highlight the importance of targeting parents in promoting children's development of motor competence, with a focus on effective facilitation of physically active lifestyles in unstructured activity contexts.

Coach-athlete interaction is a central component of skill learning in sports. When done well, interventions by a coach can shape an athlete's perceptual, motivational, and physical capacities and dramatically improve performance. Such interaction is not well modelled by thinking of a coach as transferring rules and directives to the individual athlete. Instead, an ecological perspective on coaching encourages attention to interactions during play, and the diverse ways it can support athlete development and performance. This paper uses microethnographic analysis of a Muay Thai developmental bout to showcase methods that track rich and dynamic real-world interactions between coach and athlete to ground better theoretical understanding of skill learning in the wild. Based on close analysis of coach-athlete interactions, including during and between rounds of a bout, we examine how skill is achieved in a complex learning environment. We suggest how specific coaching interventions scaffold a novice's capacity to perform and identify five coaching functions - diagnosis, strategy, implementation, affirmation and consolidation - that were part of the coach's approach to enhancing the fighter's performance. Intensive field-based methods like microethnography can more precisely chart the complex ecological features of authentic skill learning and coaching and move us beyond individualistic or exclusively laboratory-based understandings of skill.