Journal of Sports Medicine and Physical Fitness最新文献

Background: Multimodal training characterized by diverse, large, and novel bone strains improves bone mass, but after menopause the evidence is inconsistent. This intervention evaluated the osteogenic efficacy of multimodal high-intensity gymnastics for postmenopausal women.

Methods: Thirty-three healthy women participated in a 19-week controlled intervention followed by 11-weeks detraining: Group I (N.=21): 3x30 min fully supervised and personalized gymnastics weekly (age 57.1±4.8 yrs; weight 64.5±8.1 kg; BMI 22.9±2.9 kg/m²; VO2max 30.3±3.9 mL/kg/min [mean±SD]). Group C (N.=12): Controls (age 57.9±3.9 yrs; weight 63.9±10.6 kg; BMI 22.7±3.0 kg/m²; VO2max 30.4±4.9 mL/kg/min [mean±SD]). Primary outcomes: lumbar spine (L1-L4) and total proximal femur (TPF) bone mineral density (BMD) (g/cm²) and markers of bone formation (procollagen type-I amino-terminal propeptide [PINP] and osteocalcin [OC] µg/L) and resorption (C-terminal telopeptide of type-I collagen [CTX-I], ng/L).

Results: Post-intervention, percent ΔBMD (mean±SEM) were larger for I than C in L1-L4 (0.9±0.5% vs. -1.1±0.8%, P<0.05) and right (0.8±0.4% vs. -1.0±0.3%, P<0.005) and left (0.7±0.3% vs. -0.5±0.3%, P<0.05) TPF. Percent ΔOC (mean±SEM) were larger (P<0.005) for I than C after 3 weeks (11.7±20.5% vs. -9.3±19.4%), 12 weeks (23.7±17.6% vs. -11.5±29.0%) and post-intervention (18.0±25.9% vs. -14.8±28.6%). Percent ΔPINP and ΔCTX-I did not differ between I and C, despite consistent significant increases in PINP for I. Following detraining, percent ΔBMD between-group differences had increased further in L1-L4 (P<0.005) and right TPF (P<0.001).

Conclusions: The osteogenic impact of 19-weeks high-intensity gymnastics for postmenopausal women was significant and consistent regardless of the assessment method. Thus, gymnastics proved to be effective to counteract the postmenopausal BMD reductions.

Background: Introduced in the mid-1990s and recently recognized as an Olympic sport, kitesurfing combines surfing, windsurfing, and wakeboarding. Despite its growing popularity and high-speed maneuvers that heighten injury risks, there is a significant gap in research on the epidemiological aspects of injuries. This study aims to evaluate the prevalence, patterns, and factors related to orthopedic injuries among kitesurfers. The secondary outcomes focus on characteristics associated with injuries, treatment options, duration of absence from sports, and subsequent effects on performance. These findings underscore the urgent need for developing effective safety protocols to mitigate these risks.

Methods: This cross-sectional study utilized a convenience sample of kitesurfing athletes aged 18 years or older, each with at least one year of experience, recruited through the Brazilian Kitesurfing Association. Participants completed an online questionnaire detailing their personal details, kitesurfing specifics and injury-related data.

Results: A total of 442 kitesurfers, aged 18 to 70 (mean 41.9 years), were included. Findings show that 66.6% of athletes reported injuries, more frequently among more experienced, especially those classifying themselves as advanced. Most injuries occurred during training within 50 meters of the shore, under moderate wind speeds (11-27 knots), and mainly affected the knee, foot, or ankle.

Conclusions: The findings highlight the necessity for improved safety protocols and injury prevention measures in kitesurfing. Given the sport's rising popularity and inherent risks, these measures are crucial to reduce injury rates and mitigate their impact on performance and sport continuity. Additionally, kitesurfing's Olympic inclusion underscores the importance of global safety concerns.

Background: Running has increased in popularity as a form of exercise, and with it, the incidence of running-related injuries. Barefoot running has gained attention as a strategy to potentially reduce injury risk, though empirical evidence supporting this remains limited. The purpose of this study was to compare injury incidence between barefoot and shod runners based on self-reported history.

Methods: A total of 545 participants completed a survey assessing their running patterns and injury history. Descriptive and inferential analyses were conducted to examine associations between footwear type and injury incidence.

Results: Statistical analyses were performed showing strong association between the barefoot group and reduced reports of injury. A post-hoc matched-pair analysis of 21 barefoot runners and 21 shod runners (matched by age, gender, and BMI) indicated a significantly lower reported injury rate among barefoot runners (P=0.011).

Conclusions: These findings suggest that barefoot running was associated with a lower risk of injury in a matched subgroup, although further research is needed to confirm these results.

Introduction: While it is understood that resistance exercise in humans induces muscle growth primarily via muscle hypertrophy, there is some debate as to whether muscle hyperplasia also occurs. The purpose of this meta-analysis was to quantitively assess whether the presence of muscle hyperplasia occurs in humans performing resistance training.

Evidence acquisition: Medline, Scopus, and Web of Science were searched on May 17, 2024. Studies that measured or reported sufficient data to estimate muscle fiber number before and after resistance training were included in a three-level random effects model. Fiber number was estimated from the ratio of muscle cross-sectional area to fiber cross-sectional area.

Evidence synthesis: A total of 11 studies met the inclusion criteria. Changes in fiber number were estimated in the biceps brachii or vastus lateralis muscles. Meta-analysis results indicated that resistance exercise did not significantly alter the estimated number of muscle fibers (ES: 4086; 95% CI: -6430, 14,604; P=0.419). Additionally, the presence of muscle hyperplasia was not moderated by prior training status, training duration, or the muscle group analyzed (all P>0.05).

Conclusions: These findings suggest that meaningful changes in muscle fiber number are unlikely to occur in humans following resistance training interventions lasting up to 6 months. While muscle hyperplasia was not evident, it may be difficult to detect due to the relatively short duration of the included training interventions and/or difficulties in estimating muscle fiber number, which resulted in a wide range of estimates across studies.

Introduction: The development of Advanced Footwear Technology (AFT) has introduced significant changes in the realm of athletic footwear, promising enhancements in running economy and reductions in energy cost compared to traditional shoes. This systematic review aims to analyze and synthesize the existing literature on AFT, focusing on its physical, physiological, biomechanical, and perceptual impacts on athletic performance. It seeks to identify key findings, variability, and implications for athletes by comparing AFT to traditional footwear.

Evidence acquisition: Following the PRISMA 2015 guidelines for systematic reviews, a comprehensive search was conducted in PubMed, Scopus, Web of Science, and Google Scholar. Titles, abstracts, and full texts were analyzed based on predefined inclusion criteria to find relevant studies. The methodological quality of the selected studies was also assessed.

Evidence synthesis: Nine studies (N.=138 participants) were included, with an average methodological quality score of 6.22 (range: 5 to 8) on a 10-point scale. AFT was found to improve biomechanical aspects, which were associated with enhanced running efficiency, and reduce metabolic energy expenditure. However, improve biomechanical aspects, which were associated with enhanced running efficiency.

Conclusions: AFT offers significant performance and biomechanical benefits, but its physiological effects vary, and potential injury risks such as altered lower-limb stiffness and increased joint load require careful management. Personalized approaches to footwear technology are crucial to maximizing AFT's benefits.

Background: The effects of caffeine mouth rinsing on cognitive performance using a field-based approach have not yet been investigated. This study aimed to examine the effects of caffeine mouth rinsing on tennis targeting performance in young male recreational tennis players.

Methods: In total, 16 recreationally active young male tennis players (mean age: 22.03±1.74 years) were enrolled in this randomized, double-blind, placebo-controlled, crossover study. Test of groundstroke depth (TGD), test of groundstroke accuracy (TGA), test of volley depth (TVD), test of serve (TS) and tennis targeting performance (TTP), was assessed using the International Tennis Number (ITN) test. Interventions included 20 seconds of caffeine mouth rinsing (CMR: 300 mg/25 mL), placebo (PLA: 25 mL water), and a no-rinse control (CON) before each section of the ITN test. Data were analyzed using repeated measures ANOVA and Bonferroni post hoc tests, with a significance level of P≤0.05.

Results: Repeated measures ANOVA revealed a significant time-dependent difference in total tennis targeting performance scores obtained from the ITN test (P<0.01). Bonferroni post-hoc tests revealed that CMR significantly increased TGA, TVD and TTP scores. TTP points were increased in CMR group in a comparison with the PLA (147.06±26.23 vs. 130.25±20.38, P<0.001) and CON (147.06±26.23 vs. 129.19±22.27, P<0.01). TTP test scores were similar between PLA and CON (130.25±20.38 vs. 129.19±22.27, P>0.05).

Conclusions: Based on the total scores obtained from the ITN tests, the CMR intervention was found to improve tennis targeting performance in recreationally active tennis players.

Background: Fireball Extreme Challenge^TM is a coeducational high-intensity intermittent-explosive sport that lacks normative performance data; this study aimed to create multidimensional athlete profiles and establish reference benchmarks to support talent identification and training prescription.

Methods: Twenty-one national-level athletes (13 males and 8 females; mean age 26.2±5.8 years) completed countermovement jump, one-repetition maximum strength assessment, bilateral handgrip testing, and the 30-15 intermittent fitness test under standardized indoor (21 °C, 50% relative humidity) and outdoor (37 °C, 68% relative humidity) field conditions representative of the athletes' typical training environment in coastal southern Mexico, recorded for ecological validity rather than thermal control. We calculated descriptive statistics and percentile distributions (25^th, 50^th, 75^th), performed sex-stratified analyses adjusted for age, and conducted exploratory principal component and cluster analyses to examine interdomain associations and emergent performance groupings.

Results: Across all participants, the observed performance spectrum spanned a broad range of neuromuscular and metabolic capacities, with individual variability captured through percentile reference values (25^th, 50^th, 75^th). The highest jump heights (up to 48 cm) and peak power outputs (≈2100 W) coexisted with moderate endurance and balanced heart rate responses, defining the multidimensional nature of Fireball Extreme Challenge™ performance. Sex-stratified distributions are presented descriptively but were not the primary analytical outcome. Principal component analysis identified two dominant performance domains-neuromuscular power and metabolic strain-explaining 59% of total variance. Hierarchical clustering revealed three mixed profiles that integrated both male and female athletes, illustrating overlapping phenotypes rather than categorical differences.

Conclusions: This study provides the first multidimensional performance profile of Fireball Extreme Challenge™ athletes, establishing normative reference percentiles and identifying key physical domains-neuromuscular power and metabolic capacity-that characterize success in this coeducational, high-intensity team sport. The derived phenotypic clusters highlight overlapping attributes between male and female athletes, reflecting the integrated dynamics of mixed-team performance. These findings offer a foundational framework for evidence-based training design, athlete monitoring, and future validation in larger international cohorts.

Background: Artistic gymnastics (AG) is a sport that requires high percentages of muscle strength and power for successful execution of the exercises in various apparatus. However, studies investigating their relationship with rate of force development (RFD) as well as AG performance are limited. The purpose of the present research was to investigate the relationship between muscle strength, muscle power and RFD of lower extremities in isometric and dynamic measurement condition with performance on balance beam. A partial objective was to examine the relationship of lean mass with RFD and AG performance.

Methods: Thirteen competitive level female gymnasts, with an average age of 11.6 years participated in the research and were evaluated in terms of body composition, isometric leg press strength and RFD and countermovement jump (CMJ). In addition, balance beam routines were evaluated by four international judges. Pearson's r coefficient was used to investigate the correlation of the variables under consideration.

Results: There was no statistically significant correlation between force-time characteristics during isometric and dynamic assessment with balance beam performance (P>0.05). However, a strong correlation was found between total lean body mass (TLM) and power (r=0.985), relative power (RP) (r=0.933), max strength (MS) (r=0.727), and RFD 100 ms (r=643) and RFD 150 ms (r=0.896) during the CMJ. Furthermore, there was a strong correlation of bone density (BD) with power (r=0.903), MS (r=0.74), RFD 100 ms (r=0.735) and RFD 150 ms (r=0.883) time intervals in CMJ.

Conclusions: Balance beam performance is influenced by other physical factors and technical execution of exercises rather than lower limb strength characteristics.

Background: The aim of this study was to conduct physical profiling within national talent pathway age-group and senior national male and female England basketball players.

Methods: In total 235 players (male, 124; female, 111) from squads U14, U15, U16, U18, and senior featured. The testing battery featured; anthropometrics, countermovement jump (CMJ), 10-m sprint, modified 5-0-5 change of direction test.

Results: There were no differences in CMJ (P=0.659) between female groups (29.9-33.0 cm). CMJ was significantly different across male groups (P<0.001), senior players having a greater jump height (45.3 cm) than U14, U15 and U16 (P<0.05). There were no differences in 10-m sprint time for female (1.95-2.01 s) (P=0.469) and male groups (1.74-1.83 s) (P=0.055). There were significant differences within both female and male groups for 5-0-5L and 5-0-5R (P<0.001) with U14 and U15 females being slower (+0.12 to +0.20 s) and male performance showing a linear improvement with group age, U14 being slower than all other groups (+0.07 to +0.27 s). Significant correlations existed for both sexes between CMJ and 10-m (males; -0.582, females; -0.699) and between CMJ and both 5-0-5L (males: -0.397, females: -0.375) and 5-0-5R (males: -0.454, females: -0.370) (P<0.001).

Conclusions: The study's data and findings can be used to inform practice and guide the long-term strategy regarding physical development of talented young basketball players particularly within the national talent pathway in England.