Journal of Sports Medicine and Physical Fitness最新文献

Background: This study evaluated the effects of external focus distance for novice soccer players to determine motor skills and enhancing shooting accuracy in soccer. Soccer demands a unique combination of physicality and technical finesse, with precision, accuracy, and ball-handling skills distinguishing great players. This study aims to investigate the impact of different external focus cues on the shooting accuracy of novice male soccer players during a crossbar challenge. It aims to provide insights for coaches and players to optimize training techniques for skill development.

Methods: The study involved 45 male participants aged 18-25 who were assigned to the distal external focus, proximal external focus, and control group. Participants performed a practice trial followed by five experimental trials with specific focus instructions. Shooting accuracy was measured using the Loughborough Soccer Shooting Test. Statistical analysis was done using SPSS version 20, which included a mixed paired t-test and one-way ANOVA to compare the group performances.

Results: Participants with a distal external focus (M=2.4080) group consistently achieved the highest scores, followed by the proximal external focus group (M=1.5573), with the control group (M=1.3467) having the lowest scores.

Conclusions: The study shows that, in comparison to a proximal external focus and a control group, a distal external focus significantly increases soccer shooting accuracy. These findings provide valuable insights for optimizing motor skills and enhancing shooting accuracy in soccer.

Background: This study aimed to determine the effects of changes in muscle mass and quality on muscle function and physical performance following an 8-week resistance training (RT) intervention.

Methods: Thirty-three healthy young women (23.1±2.2 years) underwent high- or low-velocity concentric knee extension RT at 60% one-repetition maximum strength (1RM) load for 10 repetitions × 4 sets, 3 times a week for 8 weeks. Before and after the RT intervention, quadriceps femoris muscle thickness (MT) (muscle mass index) and echo intensity (EI) (muscle quality index) were measured using B-mode ultrasound. Muscle function, including maximum isokinetic muscle strength, 1RM, rate of velocity development (RVD), and peak power, was assessed. Physical performance was evaluated using the countermovement jump (CMJ). Percentage changes (%change) in all parameters before and after the intervention were calculated for subsequent analyses. Multiple regression analysis was used to examined the contributions of changes in EI and MT to various muscle functions and physical performance, with the intervention group included as the covariate.

Results: MT %change was associated with 1RM %change (std.β=0.51, P=0.003), whereas EI %change was correlated with RVD %change (std.β=-0.39, P=0.025), peak power %change (std.β=--0.39, P=0.025), and CMJ %change (std.β=-0.44, P=0.011).

Conclusions: RT-induced increases in muscle mass contributed to improvements in 1RM, whereas enhancements in muscle quality were associated with gains in peak power, RVD, and CMJ. These results suggest training programs aimed at improving dynamic explosive performance in young adults should not only target muscle hypertrophy but also incorporate strategies to enhance muscle quality.

Background: Match running performance is crucial for evaluating physical demands in elite soccer, with potential differences across age categories. Understanding these differences is essential for optimizing the physical preparation and career progression of young players. This study aimed to compare match running performance among senior, under-20 (U20), and under-17 (U17) elite soccer teams.

Methods: Data were collected from FIFA World Cup 2022, U20 World Cup, and U17 World Cup 2023 from the FIFA website. Running performance was assessed at both the team level and the individual level. Key performance variables included total distance covered (TD), distance across five running zones, sprints (SPR), high-speed runs (HSR), and maximum sprinting speed (MSS). Linear mixed model was used to compare performance across the three age groups.

Results: No significant differences between senior and U20 teams in most variables (all P>0.05) were observed, except for walking distance, which favored the senior teams in both team and individual performance (P<0.05). U20 teams covered greater distances in jogging and moderate speed running (MSR) (team performance), and jogging distance (individual performance) compared to senior teams (P<0.05). Senior and U20 teams generally outperformed U17 teams in most variables (P<0.05), except for walking distance, where U17 teams performed higher than U20 teams (P<0.001), with no significant differences between U17 and senior teams (P>0.05) for individual performance. Additionally, U17 teams showed similar performance to senior teams in jogging distance (team performance) (P>0.05).

Conclusions: Senior and U20 teams consistently outperformed U17 teams in most variables, except for walking distance. These findings provide valuable insights into the physical demands of match play across age groups.

Background: This study examines sports-related concussions (SRC) experiences, beliefs, and behaviors among male and female teenage grassroots soccer players in the UK, focusing on how these are shaped by interpersonal and mediated relations with coaches, parents, and peers.

Methods: A cross-sectional cohort study informed by interpretivist epistemology and qualitative research design. Data collection involved focus groups, using a topic guide covering SRC knowledge, attitudes, behaviors, and reporting intentions. Focus group sessions were conducted between July 2023 and April 2024. Participants were enrolled through convenience and snowball sampling at a single grassroots soccer club in the UK. Three cohorts of male participants (N.=15) and one cohort of female participants (N.=5) participated in three focus groups each. The 12 focus groups were held at the grassroots soccer academy with the club welfare officer present. Sessions were digitally recorded, transcribed, and analyZed using a framework analysis model.

Results: Participants identified and recognized many symptoms associated with SRC, though knowledge was mainly acquired through informal channels (e.g., the media). However, this understanding did not lead to safety-related behavior changes, with significant non-compliance observed among players, parents, and coaches.

Conclusions: Effective SRC management requires tailored education programs to overcome barriers and promote safety within grassroots youth soccer. Addressing gender norms and enhancing education can foster a culture of support and accountability, safeguarding the well-being of young athletes. There is a need for better awareness and more precautionary behaviors among all stakeholders in grassroots soccer.

Background: Soccer is the most practiced sport globally, and adequate dietary intake can significantly impact athletic performance. This study aimed to assess the nutritional knowledge of semi-professional and professional Italian soccer players and evaluate whether their dietary intake aligns with international recommendation for elite soccer players.

Methods: Male players from two Italian football league teams (one in Category C, one in Category D) participated during the regular season. Demographic and anthropometric data were collected during the initial visit. Nutrition knowledge was evaluated using a simplified version of the "Nutrition for Sport Knowledge Questionnaire" (NSKQ). Participants completed a 4-day food diary and dietary data were compared against dietary references for elite athletes and soccer players.

Results: Twenty-five soccer players (11 from a Category C team and 14 from a Category D team) participated in the study. Total energy intake was consistently below recommendations but increased on match days. Category C players consumed more protein and fat but fewer carbohydrates than Category D players, with significant differences on specific days (P<0.05). The Category D team showed greater adherence to macronutrient intake guidelines: protein (60.7% vs. 38.6%, P=0.023), fat (58.9% vs. 15.9%, P<0.0001), and carbohydrates (23.2% vs. 9.1%, P=0.053). NSKQ scores indicated poor nutritional knowledge in both teams, with no significant correlation between NSKQ scores and dietary adherence.

Conclusions: The dietary composition of the Category D team more closely aligned with reference guidelines compared to the Category C team. This discrepancy might reflect differences in dietary habits or nutritional misconceptions.

Background: Physical exercise is known to modulate arterial stiffness. However, this modulation can vary according to the type of exercise or training. This study aims to compare levels of arterial stiffness among healthy young men practicing different exercise modalities, including resistance training (RT), high-intensity cross-training (HICT), and running (RUN), and comparing these results with a control group.

Methods: Eighty healthy young men were divided into three exercise groups according to the type of exercise they practiced (RT, N.=20; HICT, N.=20; RUN, N.=20), plus a sedentary control group (CON, N.=20). In this observational study, participants were evaluated for arterial stiffness with carotid-femoral Pulse Wave Velocity (c-f PWV, m/s) and pulse wave analyses (Augmentation Index [Aix] and Augmentation Index normalized to a heart rate of 75 bpm [AIx@75bpm]). Participants were also assessed for cardiorespiratory fitness (VO2max, mL/kg/min) by means of maximal graded exercise testing.

Results: Despite the absence of statistical significance (P>0.05), the CON group showed less favorable arterial stiffness indices (AIx: 1.85±2.99; AIx@75bpm: -7.41±3.00) compared to all exercise groups ([RT AIx: -5.68±2.29; AIx@75bpm: -13.98±2.41]; [HICT AIx: -1.36±2.20; AIx@75bpm: -10.26±2.16]; [RUN AIx: -2.29±3.09; AIx@75bpm: -7.14±3.09]). The RUN group showed significantly higher VO2max than the other groups (RUN vs. CON, P<0.001; RUN vs. RT, P<0.001; and RUN vs. HICT, P<0.001).

Conclusions: The findings suggest that arterial stiffness does not differ according to different exercise modalities practiced by healthy young men.

Background: Health-related fitness (HRF) is essential for wellbeing and daily functioning. While objective fitness assessments are preferred, self-report measures are practical for large-scale or geographically diverse studies. Existing self-report HRF measures may lack sensitivity for younger or healthy adults. Additionally, many include items with no or poorly defined reference populations, potentially limiting their validity and comparability. This study examined the reliability and validity of single-item self-reported HRF measures of aerobic fitness, muscular strength and endurance, flexibility, coordination, agility, and body composition.

Methods: Between April and July 2023, University of Calgary students and staff (N.=129; mean age 28±9 years) completed the first questionnaire, with subsets completing a second questionnaire and validated fitness assessment. Nine items captured participants' self-rated HRF relative to those of the same age and gender. The nine self-reported HRF items were aggregated to obtain an estimate of overall HRF (Multidimensional Health-Related Fitness Scale, MHFS). We used intraclass correlations (ICC) to estimate test-retest reliability of the individual self-reported HRF items and MHFS. We assessed convergent validity with self-reported leisure physical activity (LPA) and concurrent validity with objective fitness measures using age- and sex-adjusted partial correlations.

Results: The single-item self-reported HRF measures (ICC=0.60-0.85) and MHFS (ICC=0.87) had acceptable test-retest reliability. The MHFS also had high internal consistency (Cronbach's α=0.87). Evidence of validity was observed with partial correlations ≥0.30 between self-reported HRF and LPA, and objective fitness measures.

Conclusions: The MHFS provides a reliable and valid HRF indicator among younger adult populations.

Background: This study aimed to investigate the relationships between well-being, recovery state, game loads, and game performance across 20 official games involving 16 highly trained collegiate basketball players. Understanding how these factors interact is essential for optimizing performance and workload management in competitive basketball.

Methods: Principal component analysis (PCA) identified six key components contributing to performance: PC1 (loads) accounted for 50% of the total variance, PC2 (well-being) explained 11%, PC3 (jump) captured 8%, PC4 (high-intensity jump) explained 6%, while PC5 (recovery) and PC6 (PlayerLoad per minute) each explained 2%. Generalized linear mixed-effects models were applied to assess the associations between these components and key performance indicators, including Performance Index Rating (PIR) and Player Total Contribution (PTC).

Results: Game loads showed a negative association with PIR (β=-1.22, 95% CI=-2.33 to -0.12, P<0.05). In contrast, high-intensity jumps were positively associated with both PIR (β=1.08, 95% CI=0.39 to 1.77, P<0.01) and PTC (β=0.99, 95% CI=0.34 to 1.64, P<0.01), explaining 43.86% of the variance in PIR and 40.17% in PTC. The effects of well-being and recovery were limited.

Conclusions: High-intensity physical activities, particularly jumps, are crucial to enhancing basketball performance, while excessive game loads can negatively impact outcomes. The limited influence of well-being and recovery suggests that their effects may be more evident over longer periods or under different contexts. Future research should focus on optimizing the balance between game loads and high-intensity actions to improve performance.

Introduction: This systematic review with meta-analysis aimed to compare the effects of traditional exercise (using low-load resistance training (LLRT) with and without blood flow restriction (BFR)) on functional outcomes, pain levels, muscle strength, and range of motion (ROM) in patients with upper extremity disorders. The primary distinction between the experimental and control interventions lies in the application of blood flow restriction during the exercise protocol.

Evidence acquisition: Searches have been performed in the PubMed, Web of Science, Embase and Cochrane databases, together with the reference lists of randomized controlled trials (RCTs) up to March 2025. The participants in the RCTs were individuals with orthopedic abnormalities of the upper extremity arising from surgical intervention, trauma, or degenerative disorders, and the intervention was LLRT-BFR, as opposed to LLRT alone. The major focus was on assessing upper limb function and pain, with secondary considerations including muscle strength and ROM. The quality and reporting standards of the studies were evaluated via the TESTEX scale. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was conducted to verify the quality of evidence. The means and standard deviations (SDs) of the pre- and post-intervention data were extracted from each study. The means and SDs of the change scores were calculated, and these values were imported into Review Manager software (The Nordic Cochrane Collaboration) to compute the standardized mean difference (SMD) as the effect size.

Evidence synthesis: A systematic search across the aforementioned four databases initially identified 466 potentially relevant articles. Through a rigorous screening process, five articles that met the predefined inclusion criteria were ultimately selected for further analysis. These studies included 85 patients who underwent LLRT-BFR and 85 patients who received only LLRT. In patients with upper extremity dysfunction, the meta-analysis revealed significantly superior outcomes with LLRT-BFR compared with LLRT without BFR across multiple measures: pain reduction (SMD, 1.19; P=0.0002 [95% CI, 0.56-1.81]), functional improvement (SMD, 1.32; P=0.005 [95% CI, 0.39-2.24]), grip strength enhancement (SMD, 0.64; P=0.004 [95% CI, 0.20-1.07]), and radial flexion improvement (SMD, 0.81; P=0.003 [95% CI, 0.28--1.34]).

Conclusions: BFR combined with LLRT produced better outcomes than LLRT alone in terms of function, discomfort, grip strength, and wrist range of motion (ulnar deviation). For people with upper limb deficits, BFR combined with LLRT may have some potential as a complementary intervention, and further research is needed to establish its efficacy and safety, particularly in different patient populations.

Introduction: This study evaluated and quantified the effects of plyometric training (PT) on soft versus rigid surfaces on jump, sprint, and agility performance.

Evidence acquisition: A literature search was conducted using PubMed, CINAHL, Embase, SportDiscuss, and Web of Science from January 1980 to April 2024. Randomized controlled trials examining PT interventions on the lower limbs with surface descriptions were included. Data extracted by two independent reviewers comprised: 1) the name of the first author and year of publication; 2) study design and participant characteristics; 3) PT program details; and 4) main outcome measures.

Evidence synthesis: The meta-analysis revealed that soft-surface PT significantly increased the vertical jump height (standardized mean difference [SMD], 0.83; [95% confidence interval [CI] 0.59, 1.07]), while rigid-surface PT also produced significant improvements in jump height (SMD, 0.98; [95% CI 0.68, 1.28]). For horizontal jump performance, soft-surface PT showed significant effects (SMD, 0.96; [95% CI 0.64, 1.27]), while rigid-surface PT demonstrated moderate effects (SMD, 0.78; [95% CI 0.5, 1.05]). Both soft- and rigid-surface PT significantly reduced sprint time (SMD, -1.03; [95% CI -1.24, -0.81] and SMD, -0.89; [95% CI -1.22, -0.57], respectively) and enhanced agility performance (SMD, -1.07; [95% CI -1.34, -0.80]).

Conclusions: PT significantly enhanced physical performance outcomes, regardless of the surface type. Practitioners may not need to prioritize the specific surface type when implementing PT programs aimed at improving jump, sprint, and agility performances.