Frontiers in Sports and Active Living最新文献

The establishment of an anti-doping rule violation extends beyond the mere detection of a prohibited substance. Current interpretation criteria rely primarily on urinary concentration estimates, which may be misleading due to high interindividual variability or pharmacokinetics characteristics of doping agents. This study investigates the potential of capillary blood collected through volumetric absorptive microsampling (VAMS) as a complementary matrix to urine for supporting results management in doping control. Comparative concentration-time profiling in urine and capillary blood was performed using isometheptene, a stimulant subject to minimum reporting limits (MRLs), and the carbonic anhydrase II inhibitors dorzolamide and brinzolamide as model compounds. For isometheptene, capillary blood detection closely mirrored urinary findings at early time points but exhibited a markedly shorter detection window, supporting improved discrimination between in-competition and out-of-competition administration in cases where urinary concentrations alone may lead to ambiguous interpretation. In contrast, for the long-lasting diuretics brinzolamide and dorzolamide, urinary concentrations showed limited interpretative value, whereas capillary blood analysis provided more consistent detectability, reflecting their strong affinity for red blood cells. However, capillary blood concentrations did not allow unequivocal discrimination between permitted ophthalmic use and prohibited administration routes. Overall, these findings demonstrate that capillary blood analysis can enhance interpretative context of anti-doping result management, particularly for substances with complex pharmacokinetics, and provide a scientific basis for the future establishment of blood-based reporting criteria.

Introduction: The Achilles tendon (AT) plays a crucial role in force transmission and movement efficiency, and greater tendon stiffness may enhance elastic energy storage and improve performance in explosive movements. Shear-wave elastography (SWE) enables reliable, non-invasive assessment of tendon stiffness, yet its associations with other ultrasound (US)-derived properties and functional outcomes remain insufficiently defined in athletes. Limited normative data exists for university-level basketball players, despite the relevance of tendon adaptations and asymmetries in this population. Therefore, this study aimed to examine AT stiffness, thickness, echo intensity (EI), and fibrillar pattern in male and female university basketball athletes, and to explore their associations with ROM, injury history, and performance measures.

Methods: Thirty-one university basketball athletes participated in this cross-sectional study. US imaging and SWE measured AT stiffness, thickness, and EI in both the dominant jumping leg (DJL) and the non-dominant jumping leg (NDJL). Functional assessments included a single-leg vertical jump, heel raise (HR) test, and ankle dorsiflexion ROM. Participants also provided demographic information and injury history data.

Results: Female players had lower AT thickness compared to males and showed a trend toward lower stiffness. No significant differences in stiffness, thickness, or EI were observed between the dominant and non-dominant jumping legs. Male players with a prior lower-body injury exhibited lower AT stiffness. Correlation analyses revealed no consistent associations between AT properties and performance or ROM, although a strong negative correlation between AT thickness and EI emerged in both sexes.

Discussion: Considering sex and injury history when interpreting tendon properties is crucial, and future larger-scale, longitudinal studies are needed to better understand how tendon characteristics evolve and inform training and injury prevention strategies.

This article interrogates the "sport-health ideology" that equates organized sport with population wellbeing, arguing that it conflates the proven benefits of routine physical activity with the distinct injury profiles, labor relations, and political functions of modern sport. Synthesizing scholarship from sociology, public health, and bioethics, we show how elite and commercialized sport institutionalizes a culture of risk linked to musculoskeletal trauma, neurodegeneration, and normalized pain; embeds corporate sponsorships that promote unhealthy consumption; and operates through biopolitical regimes that intensify bodily manipulation for performance while denying comparable care to non-athlete publics. We trace the sport economy's dependence on precarious and exploitative labor, from collegiate exploitation to mega-event construction, and examine how patriotic pageantry and media partnerships constitute a "sport-security nexus" that aestheticizes U.S. militarism and its downstream health harms, including in Iraq and Gaza. We argue that sport bioethics must move beyond doping and concussion to treat labor rights, occupational and environmental standards, sponsorship governance, and demilitarization as first-order determinants of health. Redirecting investment toward low-risk, community-based movement, enforcing transparent safety surveillance across athletes and event workers, and severing ties with harmful industries are necessary to align sport with health justice.

[This corrects the article DOI: 10.3389/fspor.2024.1463910.].

Background: Increasing evidence highlights the association between sedentary behavior and cardiovascular disease (CVD). However, the molecular mechanisms that link sedentary behavior to adverse cardiovascular outcomes, especially the metabolomics pathways, remain unclear.

Methods: Participants with CVD at baseline from 2006 to 2010 in the UK Biobank were involved. The all-cause mortality outcome was obtained through the National Death Registry System. Cox proportional hazards model and the elastic network regression model were employed to identify metabolic signatures related to both sedentary time and the risk of all-cause mortality. Mediation analysis was conducted to examine the mediating effects of selected metabolic signatures to the association of sedentary behavior and mortality. The follow-up data was used for validationt.

Objectives: This study aims to explore the mediating role of the metabolome in the association between sedentary behavior and all-cause mortality among individuals with CVD, providing metabolic insights for CVD management.

Results: The study included 13,561 baseline CVD participants with concentrations of 249 serum metabolites and sedentary time. Thirty-five metabolites were associated with sedentary behavior. Both sedentary time [hazard ratio (HR), 1.08 (95% CI, 1.04-1.13)] and the integrated metabolic feature which was derived from the 35 identified metabolites were associated with an increased risk of all-cause mortality [HR, 1.16 (95% CI, 1.10-1.21)]. Out of the 35 metabolites selected by elastic net regression, 24 were significantly associated with all-cause mortality. These included metabolites involved in fatty acid metabolism, branched-chain amino acid metabolism and inflammatory-related glycoproteins. The integrated metabolic feature, glycoprotein acetyls, phospholipids to total lipids in very small VLDL percentage, and monounsaturated fatty acids to total fatty acids percentage played 36.3%, 35%, 22%, 20% mediating roles respectively between sedentary behavior and all-cause mortality risk.

Conclusion: Our research has revealed the metabolic effects associated with sedentary behavior and all-cause mortality in patients with CVD, highlighting possible targets for personalized intervention and management.

In this paper, we examine the transferability of the theory of the first-mover advantage to national sports associations in individual sports for the first time. The conceptual analysis examines the replicability through a comparative analysis, a theoretical modeling, and a case logic across three approaches. The comparative analysis detects a fundamental possibility of transferring the first-mover advantage, considering macroeconomic control variables and a specific athlete assignment process to reflect structural differences between business organizations and national individual sports associations. While the theoretical modeling demonstrates that the individual first-mover advantage components can generally be transferred to national individual sports associations, the case logic simulates how plausible first-mover effects could occur in individual sports and reveals highly relevant effects to the reality of national individual sports associations. The findings serve as an important basis for future studies to explore a potential first-mover effect in individual sports and derive success-focused implications for action.

The stiffness of the triceps surae (TS) muscles during passive stretch has been increasingly studied using shear wave elastography (SWE). However, the continuous behavior of the Achilles tendon (AT) and its interaction with the TS muscles remain poorly understood, limiting understanding of tissue mechanics. This study aimed to characterize the angle-specific stiffness profiles of the individual TS muscles-the medial gastrocnemius (MG), lateral gastrocnemius (LG), and soleus (SOL)-and the AT during passive ankle dorsiflexion under identical experimental conditions. In this cross-sectional study, the ankles of 24 healthy university track and field athletes (age, 20.2 ± 1.3 years) were passively moved by a dynamometer from 30° of plantar flexion (PF) to 80% of maximum dorsiflexion (DF) at 1°/s (up to 25° DF). Shear wave velocity (SWV), an index of tissue stiffness, was measured at four sites (MG, LG, SOL, and AT). The percentage change in SWV from the -30° baseline was analyzed at 5° increments up to the neutral (0°) position using two-way analysis of variance. Significant SWV increases from baseline were observed at 10° PF for the MG, 5° PF for the LG, and 25° PF for the SOL. In contrast, the AT showed significant increases from 25° PF onward, with a rate of change consistently greater than that of all TS muscles across all measured angles. These findings indicate that the AT and TS exhibit asynchronous stiffening patterns: the tendon provides immediate resistance from the earliest range of motion, while the muscles remain compliant until further stretched. Thus, the tendon, rather than the muscle, primarily governs the initial resistive behavior of the muscle-tendon unit during passive stretch. Understanding this angle-specific behavior is essential for optimizing load management in rehabilitation and injury prevention.

Background: Swiss adolescents fall short of the WHO's guideline of 60 min of moderate-to-vigorous physical activity (MVPA) per day. Developing targeted interventions or policies requires an understanding of adolescents' daily activity patterns. Since adolescents spend much time at school, it is essential to consider not only leisure but also school segments when assessing physical activity (PA). Therefore, this study investigates how Swiss adolescents' PA is distributed across different school time segments and examines to what extent they meet recommended activity levels.

Methods: This cross-sectional study uses baseline data from the Active School project. The sample included 666 7th-grade students (mean age = 13.27 ± 0.55 years, 47.7% boys, 51.8% girls, 0.5% diverse) from 12 secondary schools. PA data, gathered over five schooldays using wrist-worn GENEActiv accelerometers, were segmented into physical education (PE), recess, classroom time, entire school time, and leisure time. Activity levels were categorized into inactivity (IN), light physical activity (LPA), and MVPA. Descriptive and inferential statistics (ANOVAs, t-tests) examined differences across segments and gender.

Results: Within school time, MVPA varied significantly by segment (PE: 30.59%, recess: 18.80%, classroom: 5.69%, p < .001) and remained below recommendations for PE (50%) and recess (40%). IN dominated all segments, especially classroom time (75.83%). Overall, only half (49.5%) of Swiss adolescents met the school-based PA recommendation of at least 30 min of MVPA per day, while girls accumulated less MVPA and more IN than boys across all school segments (all ps < .001).

Conclusion: Substantial opportunities for PA are lost across all school segments in the Swiss context, with girls consistently less active than boys. Based on these findings, segment-specific and gender-sensitive school PA policies are discussed, and a comprehensive school approach to PA promotion is recommended to support more effective and equitable PA promotion among adolescents.

Trial registration: German Clinical Trials Register (DRKS00033362). Date of registration: January 25, 2024. Retrospectively registered.

Background: Teaching effectiveness is a key determinant of student learning outcomes. Increasing evidence supports the use of physically active teaching strategies to not only enhance student learning engagement and achievement, but also health. However, existing classroom teaching observation tools often fail to assess these active pedagogical approaches, particularly among generalist teachers. This study details the development and evaluation of the Observation of Practical Teaching Skills Instrument (OPTIn), designed to assess both general teaching effectiveness and the implementation of physically active strategies.

Methods: OPTIn was developed through a four-phase process. Initially, key domains were identified via expert consensus (n = 6), then refined with feedback from education and physical activity specialists (n = 9). The instrument was piloted in authentic classroom settings by teacher educators (n = 5). Reliability was then examined through inter- and intra-rater agreement analyses with three independent raters across five lesson observations. Content validity was assessed by comparison with expert evaluations.

Results: The final instrument includes seven domains aligned with national teaching standards, evidence-based practice and physically active teaching. Feedback confirmed the tool's clarity, relevance, and feasibility, with recommendations to expand indicators for active teaching and incorporate peer/self-assessment features. Inter-rater reliability ranged from 66.7% to 94.7%, while intra-rater agreement showed minimal variation (93.3% and 86.7%). High agreement with expert ratings supported content validity.

Conclusion: OPTIn provides a novel, practice-informed tool for observing and improving active teaching strategies. Its use can support teacher professional development and contribute to advancing the measurement of physical activity integration within educational practice.

Introduction: Sport-specific performance in football is influenced not only by physical, technical, and tactical factors but also by psychological characteristics such as personality. Previous research suggests traits like extraversion and conscientiousness are positively associated with athletic outcomes. A deeper understanding of personality may allow for more individualized training and support, potentially enhancing both short-term performance and long-term development. The present study aimed firstly to describe the prevalence and distribution of personality dimensions according to Cloninger's biopsychosocial model, assessed with the Junior Temperament and Character Inventory (JTCI), in German elite youth football players, and secondly to explore potential associations of these dimensions with motor performance and injury risk.

Methods: A total of 193 players (aged 11-18 years, mean 14.6 ± 1.9) from two elite academies were assessed during the 2023/2024 pre-season. In addition to the JTCI, body composition, 30 m sprint, heading jump, and injury history were collected. Analyses included Spearman correlations, multiple linear regression and moderation analyses (with HC3 robust standard errors), as well as logistic regression for injury occurrence.

Results: The personality dimensions of Persistence (mode: 95%-100%) and Self-Directedness (mode: 85%-90%) tended to be distributed toward high percentile ranks, while Novelty Seeking (mode: 20%-25%) and Harm Avoidance (mode: 10%-15%) tended toward low ranks. Age consistently predicted sprint performance and injury frequency, while no personality dimension showed significant associations with sprinting, jumping, or injury outcomes.

Discussion: To our knowledge, this is the first study applying Cloninger's model in German elite youth football. These findings provide rare descriptive insights into adolescent athletes' personality profiles and suggest that personality may play a greater role in long-term development, resilience, and talent progression than in immediate physical performance.