Frontiers in Sports and Active Living最新文献

Background: In elite youth soccer, the interplay between the development of key physical qualities, change-of-direction (COD) performance, explosive strength, and flexibility, remains poorly understood. Conventional training often assumes transfer effects, yet empirical evidence on how these qualities co-occur within elite youth cohorts across a competitive season remains limited. We tested the hypothesis that flexibility and explosive strength would be positively associated with COD performance at end-season (T2).

Methods: Forty-five elite male youth players (Serie A academy; U12-U14) were monitored across one competitive season. COD performance (T-Test completion time), flexibility (sit-and-reach), and explosive strength (standing broad jump, SBJ) were assessed at the season's start (T0; September 1, 2024) and end (T2; May 1, 2025). Primary analyses used paired t-tests with Cohen's d_z and 95% confidence intervals (CI). Pearson correlations (with 95% CI) were computed cross-sectionally at T2.

Results: Significant season-long improvements were observed in flexibility [Δsit-and-reach = + 1.83 ± 1.42 cm; 95% CI (1.40, 2.26); p = 4.87 × 10^-11; d_z = 1.29], explosive strength [SBJ Δ =  + 12.8 ± 3.8 cm; 95% CI (11.66, 13.94); p < 1 × 10^-20; d_z = 3.37], and COD performance [ΔT-Test = -1.16 ± 0.87 s; 95% CI (-1.42, -0.90); p = 1.86 × 10^-11; d_z = -1.33]. At T2, SBJ was moderately associated with COD performance [SBJ vs. T-Test: r = -0.41, p = 0.005; 95% CI (-0.63, -0.13)] and with flexibility [SBJ vs. sit-and-reach: r = 0.32, p = 0.032; 95% CI (0.03, 0.56)], whereas sit-and-reach was not significantly related to T-Test time (r = -0.15, p = 0.31).

Conclusions: Elite youth players improved COD performance, flexibility, and horizontal power across the season. Cross-sectionally, higher SBJ performance co-occurred with faster COD performance at end-season, while sit-and-reach flexibility did not. These findings support multi-domain monitoring and targeted training prescriptions, while highlighting the need for maturation-informed designs to test longitudinal coupling of individual adaptations.

Purpose: This study examined the effects of intermittent blood flow restriction (LI-BFR) compared to low- (LI) and high-intensity interval exercise (HI) on substrate utilization and energy expenditure (EE).

Methods: Exercise protocols consisted of 2-minute work intervals interspersed with 1-minute recovery intervals (20W), HI consisted of 5 intervals performed at a workload corresponding to 140% of ventilatory threshold intensity and LI and LI-BFR consisted of 10 intervals performed at 70% of ventilatory threshold. BFR cuffs were inflated to 80% of limb occlusion pressure during each work interval and deflated during each recovery. Following each exercise protocol subjects rested for three hours, during which excess EE and substrate utilization were measured. For all comparisons, statistical significance was set at p ≤ 0.05.

Results: Fat oxidation rate was significantly greater in LI-BFR (0.11 ± 0.03 g min^-1) compared to HI (0.09 ± 0.03 g min^-1) at 120 MIN (d = 1.13). Fat oxidation in LI-BFR (60 MIN = 0.14 ± 0.01 g·min^-1, 120 MIN = 0.11 ± 0.01 g min^-1) was greater than LI (60 MIN = 0.08 ± 0.02 g min^-1, 120 MIN = 0.9 ± 0.02 g min^-1). Total excess EE was greater in LI-BFR (184.0 ± 37.6 kcals) compared to HI (127.0 ± 12.0 kcals; d = 3.23) and LI (144.83 ± 35.5 kcals; d = 2.21).

Conclusion: This study suggests that the addition of BFR to low-intensity results in increased fat oxidation following exercise as well as increased EE. The observed increased fat oxidation and EE could potentially have significant long-term effects on weight management.

Aim: Sleep and physical activity are two important lifestyle factors that significantly influence overall health and wellbeing. This comprehensive review aims to provide a detailed understanding of the interplay between sleep and physical activity habits.

Methods: A narrative review was conducted through a comprehensive assessment of primary and secondary sources, incorporating scientific publications from databases such as MedLine, Cochrane, Embase, PsychINFO, and Cinahl. The inclusion criteria focused on studies published between 2000 and 2025, addressing topics such as physical activity, sleep quality, sleep disorders, energy balance, and related health outcomes. Exclusion criteria included gray literature, unpublished studies, books, conference proceedings, and dissertations.

Results: The results highlight the complex bidirectional relationship between sleep and physical activity. Regular physical activity improves sleep quality and duration, while adequate sleep enhances physical activity performance and recovery. Sleep disorders negatively affect physical activity engagement, but interventions involving exercise demonstrate significant potential in mitigating these effects.

Conclusions: In conclusion, understanding the multifaceted interactions among sleep, physical activity, and nutrition is crucial for promoting overall health and wellbeing. Future research should leverage advancements in wearable technology, personalized interventions, and precision medicine approaches to optimize these interrelated behaviors and their health impacts.

Over the past 40 years, English-language scholarship has often portrayed Norwegian friluftsliv as an ideal way for people to build a simple, healthy, fulfilling, and low-impact relationship with nature. This idealized image was questioned by the first author during a conference presentation in 2024. In response, the second author addressed five critiques raised in that presentation, which led to an extended written debate between the authors in the following months. This study explores some of the supposed theoretical foundations of friluftsliv practices. Its goal is to offer the literature a richer and more nuanced understanding of what friluftsliv both is and is not. The research uses critical dialogue as its methodology: the authors' debate, structured around the five original themes, serves as the core data for interrogation. The discussion produced four main findings. First, the English language friluftsliv literature (largely authored by Scandinavians and North Americans) has depicted a certain romantic and idealized conception of friluftsliv. Second, three historical waves of friluftsliv are presented, which illustrate the changing nature of meanings associated with it over time. Third, the paper builds on the growing acceptance that friluftsliv can be difficult to define and increasingly means many things to many people. Fourth, it is highlighted how friluftsliv-just as outdoor education, leisure and tourism in other parts of the world-needs to address challenges relating to inequalities, over-consumption, and increased carbon emissions.

Monitoring high-speed displacements in team sports commonly relies on maximal values, often referred to as Peak Match Speed (PMS). These values are widely used to guide training prescription, injury-prevention strategies, and performance profiling. However, PMS metrics may be distorted by anomalous events, such as tackles or collisions, which generate implausible speed-time patterns and compromise the accuracy of player monitoring. The purpose of this commentary is to present a practical strategy to identify and resolve such abnormalities, thereby increasing the reliability of athlete-monitoring processes. Systematically plotting acceleration-time and speed-time curves together, with the acceleration axis aligned to PMS, allows practitioners to rapidly detect unrealistic patterns, such as extreme accelerations or decelerations near maximal speeds, that deviate from physiological expectations. By identifying and excluding these artefacts, practitioners ensure that derived metrics more accurately reflect players' true physical capacities. This proposed strategy is adaptable to a wide range of team sports and can also enhance the interpretation of submaximal sprint efforts. Importantly, this low-cost and widely applicable approach strengthens the reliability of athlete-tracking outputs, safeguarding both performance analysis and training decision-making.

This study proposes a novel analytical framework for categorizing Japanese professional baseball players based on comprehensive hitting performance data. Our primary goal is to identify player groupings that may inform decision-making related to substitution and trade strategies within teams. The dataset used in this analysis was provided by DELTA Corporation, a Japanese firm specializing in advanced baseball analytics. It includes 115 distinct hitting-related performance indices for 327 fielders who participated in official Nippon Professional Baseball (NPB) games during the 2020 season. To make the analysis more structured, we first organized these 115 indices into eight meaningful categories, following the classification methodology defined by DELTA. These categories represent various aspects of hitting performance, such as plate discipline, power, contact ability, and situational hitting, among others. To focus on players with a significant level of contribution, we filtered the original sample and selected 72 players who recorded a "Wins Above Replacement" (WAR) value of 1.0 or higher during the season.

Introduction: Physical activity and sedentary time, along with other health-related behaviors, are influenced by various environmental factors. This study examines the associations of family, social, and built environments with physical activity and sedentary time in adolescents.

Methods: Participants aged 10-16 years were enrolled, with data from 308 adolescents analyzed. Physical activity and sedentary time were assessed using accelerometers, while family, social, and built environments were evaluated through questionnaires completed by parents/guardians. General Linear Models were used to examine associations between environmental factors and physical activity and sedentary time, adjusting for covariates.

Results: On average, participants engaged in 27.7 min of moderate-to-vigorous physical activity, 232.8 min of light physical activity, took 6,800 steps, and spent 595.4 minutes in sedentary time per day, with only 10% meeting the recommended 60 min of moderate-to-vigorous physical activity. Higher family support was associated with more moderate-to-vigorous physical activity (β = 5.2), more light physical activity (β = 7.9), more steps per day (β = 688), and less sedentary time (β = -13.2) per additional unit of family support. The social environment total score was not associated with physical activity or sedentary time. However, when analyzing individual components, social cohesion was negatively associated with physical activity and positively associated with sedentary time, while social control showed no significant relationship. No associations were found between the built environment and physical activity or sedentary time.

Conclusions: This study highlights the significant role of family support in promoting physical activity and reducing sedentary time in adolescents, with the family environment showing the strongest associations. In contrast, the social and built environments had limited influence on physical activity behaviors. The findings underscore the importance of family-based strategies to encourage active lifestyles.

Clinical trials registration: # NCT02784509.

In Alberta, Canada, the provincial government has enacted legislation to ban transgender women and girls from participating in women's sport. The government invoked the notwithstanding clause in the Canadian Charter of Rights and Freedoms to shield the ban from legal challenge for violating the right to non-discrimination, among other constitutional rights. Various countermeasures are available to the Canadian sport system to oppose Alberta's ban and circumvent its use of the notwithstanding clause. These countermeasures involve constitutional and corporate laws, the federal government's spending powers, privacy law, and administrative law. Sport organizations, the federal government, and athletes can pursue these countermeasures to ensure that affected transgender women and girls are not unfairly denied the opportunity to participate in women's sport.

Public policies in sport and good governance adopted by local authorities aim to promote healthier habits and widespread participation in sport. However, little is known about the use of policy instruments by Portuguese municipalities to assess its implementation, evaluation and monitoring. At the same time, there is insufficient data available to evaluate political action and local sports development, making it difficult to assess this progress. Therefore, this research was designed to measure satisfaction with the current level of development in municipalities according to different sports development indicators. We followed an exploratory methodology using quantitative-descriptive and inferential analysis. Data was collected through a questionnaire between November 2024 and January 2025 with 937 responses obtained after validation. Results show a level of agreement between genders regarding satisfaction with the level of sports development, sports services and facilities, while transparency does not show encouraging results due to high level of non-formed opinion. There is also a high level of agreement on policy priorities and the influence of political orientation on public investment in sports. Municipalities play a key role in promoting local sports and modernizing cities and sport facilities, being essential to keep studying their action in different perspectives to measure good governance in sports development and political transparency perception.

Background: It has been shown that unilateral balance training (BT) enhances balance and neuromuscular performance in the trained and untrained leg and thus has the potential to reduce side-to-side differences. However, it is unresolved how effective unilateral single-mode BT compared to unilateral combined balance and plyometric training (BT + PT) is in reducing interlimb asymmetry. Thus, we examined the impact of both training modalities on soccer players' interlimb asymmetry in balance and neuromuscular performance.

Methods: Sixty male elite youth soccer players were randomly assigned to a unilateral single-mode BT group (n = 20), a unilateral combined BT + PT group (n = 22) or an active control group (n = 22). All groups trained for nine weeks (2 sessions/week) with their non-dominant leg. The interventions included balance exercises for the single-mode BT group, balance and plyometric exercises for the combined BT + PT group and stretching exercises for the active control group. Training progression was achieved by manipulating sensory input (balance exercises), the number of floor contacts (plyometric exercises), or the duration of the stretching exercises. Before and after the intervention period, performance in the Y Balance Test - Lower Quarter (YBT-LQ) and the single leg drop landing (SLDL) test as well as leg muscle activity were assessed. The magnitude of interlimb differences was quantified by calculating the limb symmetry index (LSI) and compared using repeated measures analysis of variance (significance level: p < .05).

Results: The analysis revealed significant main effects of test (pre vs. post) for the LSI values of the YBT-LQ (anterior reach: η _p ² = .07; posterolateral reach: η _p ² = .11) and activity of the gastrocnemius muscle (η _p ² = .33) but not for the SLDL test. Further, a significant test×group interaction was detected for the LSI value of the anterior reach (η _p ² = .10) and post-hoc analyses yielded a significant LSI reduction for the unilateral single-mode BT group (d = .79) only.

Conclusion: Nine weeks of unilateral single-mode BT and combined BT + PT proved to be effective and feasible (attendance rates of ≈ 99%-100%). In particular, unilateral single-mode BT appears to be suitable for reducing the LSI value of the YBT-LQ anterior reach, which is a predictor for time loss non-contact lower limb injuries.