Journal of Sports Medicine and Physical Fitness最新文献

Introduction: Basketball, as a widely popular sport, can be associated with a high risk of injury. This study aimed to provide a comprehensive overview of basketball-related injuries in various groups through the utilization of a systematic review methodology.

Evidence acquisition: An extensive search was conducted in the four valid databases using three groups of keywords up to November 2023 based on the PRISMA guidance. Two reviewers independently performed the steps of the study, including study selection, data extraction, and quality assessment. In case of any disagreements, the opinion of a third researcher was sought to achieve agreement in each step. The agreement between the reviewers was examined by computing Cohen's kappa coefficient. The quality assessment of the articles in this study was conducted using the Joanna Briggs Institute (JBI) critical appraisal tools.

Evidence synthesis: The prevalence range of injuries in these people was between 0.38% and 92.0%. Ankle injuries in 12 out of 28 studies (42.86%), knee injuries in 7 out of 28 studies (25.00%), head and tooth injuries in 3 out of 28 studies (10.71%), and shoulder and hand injuries in three out of 28 studies (10.71%) had the highest prevalence among various injuries. Five out of six studies (83.33%) showed a higher percentage of the injuries in males. Only a study compared the prevalence of injuries between people with various ages.

Conclusions: These findings emphasize the need for injury prevention and management strategies, particularly targeting vulnerable areas like the ankle and knee.

Background: The study aimed to assess whether prior intake of metformin enhances performance in the FRAN workout, a popular Functional Fitness Training protocol.

Methods: Fourteen men (mean±SD: 24.2±3.5 years; height: 173.3±7.8 cm; weight: 78.3±14.1 kg; body mass index: 25.9±3.0 kg/m²) participated. During the first visit, anthropometric measurements were taken, and participants performed the FRAN workout. After 72-96 hours, a retest was conducted to establish test-retest reliability. In the third and fourth visits, participants completed the FRAN workout under two conditions: metformin and placebo, using a crossover, counterbalanced, and double-blind design. The FRAN workout consisted of barbell thrusters (43.2 kg) and bodyweight butterfly pull-ups, performed in 21, 15, and 9 repetitions across three rounds.

Results: Significant differences were observed in partial times between rounds (F=28.91; P<0.01), but no significant differences were found between metformin and placebo conditions (F=0.08; P=0.77) or interaction effects (F=0.87; P=0.42). Similarly, total time differed significantly between rounds (F=158.04; P<0.01), with no significant differences between conditions (F=0.02; P=0.88) or interaction effects (F=0.30; P=0.73).

Conclusions: Acute metformin intake did not enhance FRAN workout performance, nor did it affect heart rate or perceived exertion. Coaches and athletes should consider that metformin's impact on exercise performance appears nonexistent, and its use in this context might not provide the desired ergogenic effect.

Background: Joint stiffness endurance is considered essential in many sports events. We previously reported that reduced joint stiffness due to repetitive hopping was associated with reduced active muscle stiffness. However, the determinants of active muscle stiffness endurance were unknown. This study aimed to compare the effects of repeated isometric contractions (ISO), which induced metabolic muscle fatigue, and repeated eccentric contractions (ECC), which induced muscle damage, on active muscle stiffness endurance.

Methods: Fourteen males performed two kinds of fatigue tasks (ISO and ECC) using only ankle joint. Before and after the fatigue tasks, changes in estimated muscle force and fascicle length during fast stretching were used to calculate the active muscle stiffness of the medial gastrocnemius muscle. In addition, the thickness of the plantar flexor muscles was measured before and after fatigue tasks.

Results: After fatigue tasks, no difference in the relative increase of muscle thickness was found between ISO and ECC. The increase in torque during fast stretching did not change after both ISO and ECC. The increase in fascicle length during fast stretching significantly increased after ECC but not ISO. Active muscle stiffness significantly decreased after ECC but not ISO.

Conclusions: Active muscle stiffness decreased after repeated eccentric contractions damaging fascicles and did not change with repeated isometric contractions causing metabolic fatigue. These results implied that the joint stiffness reduction due to repetitive stretch-shortening cycle exercises shown in previous studies involved a reduction in active muscle stiffness due to repeated eccentric contractions.

Background: Vitamin D is a nutrient necessary for conditioning athletes. This cross-sectional study aimed to determine the nutritional status of vitamin D in farm-league professional baseball players to examine vitamin D requirements.

Methods: This study included 35 players enrolled in farm team A of the Nippon Professional Baseball Organization in the spring of 2022. The survey items included anthropometric measurements, serum 25-hydroxyvitamin D [25(OH)D] levels as an indicator of vitamin D nutritional status, a simple questionnaire for predicting vitamin D deficiency in Japanese adults, mean daily sun exposure duration, and body surface area (BSA).

Results: The serum 25(OH)D level was 29.8±1.8 ng/mL, and 17 (49%) participants were vitamin D deficient (<30 ng/mL). The serum 25(OH)D levels showed positive correlations with body height (r=0.459, P<0.01), fat-free mass (r=0.347, P<0.05), muscle mass (r=0.341, P<0.05), and BSA (r=0.434, P<0.01). Furthermore, the consumption frequency of fish with high vitamin D levels in regular diets, BSA, and body fat mass were identified as predictors of the serum nutritional status of vitamin D.

Conclusions: Athletes engaged in outdoor sports, such as the study participants, had inadequate vitamin D levels. In addition, the frequency of consumption of fish with high vitamin D levels in regular diets, BSA, and body fat mass were identified as predictors of the serum nutritional status of vitamin D. Further studies of the relationship between vitamin D supplementation and performance are needed.

Background: Relative Energy Deficiency in Sport (REDs) is a serious clinical condition. However, there is little research in athletes with a clinical diagnosis and limited evidence on the recovery of REDs.

Methods: This is a cross-sectional retrospective study whereby 55 (25.62±6.33 years) female patients with a prior diagnosis of REDs by an experienced medical specialist participated in an online questionnaire designed to capture their experience of a sports dietitian consultation and subsequent implementation of a personalized energy availability (EA) plan.

Results: A 31% increase (N.=4 vs. N.=16, P=0.002) in normal menstruation, a 22% reduction (N.=39 vs. N.=27, P=0.032) in gastrointestinal symptoms, and a 94% reduction (N.=16 to N.=1) in a very poor/poor appetite were reported following the consultation and plan implementation. Required energy intake (EI) was under-estimated by 93% of participants. Intake pre-exercise was implemented most frequently (69%, N.=38), and least likely to elicit feelings of stress and anxiety (69%, N.=38). Weight gain/shape change was the most frequently reported barrier to implementation (62%, N.=34). Eating to a planned regime (35%, N.=19) and following a timing of intake (33%, N.=18) gave the most confidence.

Conclusions: Providing an athlete with an education of their current and required EA, alongside an illustrated personalized EI plan structured around exercise, may provide the "lightbulb" moment needed to overcome the associated anxiety when increasing their EI when recovering from REDs.

Background: The aim of this study was to analyze whether there are differences in performance indicators between matches played at different altitudes in professional padel.

Methods: Data were collected and analyzed based on players' sex, set number, and set score using video footage from the World Padel Tour (WPT), including open-access TV broadcasts and WPT's YouTube channel. Performance indicators - such as break points won, errors, winners, and winning smashes - were recorded across 1122 sets (485 matches) from three WPT seasons (2020-2022).

Results: In men's padel, altitude-related differences were observed in break points (P=0.005), break points won (P=0.002), and winners (P=0.002). In women's padel, altitude-related differences were found in break points won (P=0.004), smashes (P<0.001), and winning smashes (P<0.001). Set number and set result were associated with variations in several performance indicators, depending on the tournament's altitude (below or above 500 meters).

Conclusions: These results represent reference data to help players and coaches train according to altitude conditions.

Team sports players are frequently required to integrate multiple physical components, including strength and endurance capacity, to maximize their performance during both training and competitions. The combination of strength and endurance within a periodized program is known as concurrent training. Recently, concurrent training has emerged as an innovative method to enhance both muscular strength and aerobic performance, tailored to the specific requirements and diverse nature of each sport. However, concurrent training may induce excessive fatigue and compromise performance potentiation, depending on training prescription parameters. This distinction between the interference effect and performance enhancement presents a complex challenge for any team sports system. Consequently, the objective of this review was to scrutinize the efficacy, practical application, and methodological aspects of concurrent training. Additionally, it aims to elucidate strategies to mitigate the complexities associated with the interference effect, thereby optimizing the benefits of concurrent training modality for team sports, emphasizing soccer. The major findings indicate that concurrent training can improve strength and endurance qualities in athletes, but under certain conditions, it can also interfere with adaptations. Appropriate programming strategies, such as proper sequencing, scheduling, volume, intensity, and recovery, can help mitigate these negative effects. Additionally, whereas more experienced athletes display greater proficiency in executing concurrent training programs, younger players, particularly those under 14, tend to experience minimal interference effects from this training approach, making it well-suited for their development. Overall, concurrent training has been demonstrated as an effective and efficient method for improving strength and endurance performance in team sports players.

Background: Cardiorespiratory fitness is linked to various health outcomes. This study aimed to establish cut-off values for estimated cardiorespiratory fitness associated with poor physical functioning in middle-aged to older adults.

Methods: A total of 2638 participants (1083 males), aged 40-69 years, performed a 6-min walking test (6MWT) to estimate cardiorespiratory fitness (VO2max) and completed a health-related questionnaire. Physical functioning was assessed using four outcomes: perceived health, perceived fitness, difficulties in 2-km walking, and difficulties in climbing several stairs. Receiver operator characteristics (ROC) curves were used to determine cut-off values for estimated VO2max and 6MWT distance linked to poor physical functioning based on the four outcomes. Analyses were done separately for males and females, and for 40- to 49-, 50- to 59-, and 60- to 69-year-old groups. Multinomial regression was used to analyze differences between fitness thirds in outcome variables.

Results: ROC analyses were significant for all outcomes (AUC 0.686-0.834, P<0.001). In the total group, cut-off values for estimated VO2max were 29.9-30.2 mL/kg/min, and for walking distance, 588.0-599.5 m. Cut-off values decreased with age, and mean differences between males and females were 3.3 mL/kg/min and 33 m. All cut-off values were within ±1.3 mL/kg/min of the lower fitness tertile. The odds ratios of having poor physical functioning in the middle and high fitness thirds were less than 0.50 compared to low fitness third.

Conclusions: VO2max of 30 mL/kg/min and 600-m walking distance seemed reasonable cut-off values for poor physical functioning. Exceeding the currently proposed thresholds is a desirable goal to avoid consequences of insufficient fitness.

Background: Soccer is an intermittent team sport that demands high aerobic capacity. On field, soccer players' aerobic capacity, assessed through the maximal oxygen uptake (VO2max), is usually determined by an intermittent recovery test. The aim of this study was to obtain a construct validity of a new intermittent recovery test (IRT) with a fixed speed and a progressive decrement of rest period.

Methods: Twenty-five male soccer players were recruited to perform an incremental continuous test (ICT) and the new IRT, to compare their physiological data. Fifteen male soccer players were involved to perform a test-retest of IRT to assess its reliability.

Results: VEpeak, absolute VO2max, relative VO2max and VCO2peak registered during ICT and IRT correlated strongly (Pearson's correlation coefficient ranges from 0.75 to 0.80, with very large as magnitude of effects and with P<0.001). IRT showed reliability from good to excellent regarding VEpeak, absolute VO2max, relative VO2max, VCO2peak and covered distance (ICC values ranged from 0.82 to 0.95).

Conclusions: These findings and its underlying physiological and muscular demands, suggest that IRT can be considered as a valid and reliable test to assess aerobic capacity in soccer players during the competitive period.

Background: In javelin throw training, although short run-up throwing is more frequently performed than full run-up throwing (throwing like a competition), it is unclear whether the throwing motion of the short run-up throwing is different from full run-up throwing. Therefore, the purpose of this study was to clarify the differences between the short and full run-up throwing in javelin throw.

Methods: Twelve male javelin throwers were included in this study. The participants performed one-cross throwing (Cross), which involved throwing from a short run-up, and full run-up throwing (Run), which was similar to a competition. The coordinates of the reflective markers attached to the participant's body and javelin was recorded using an optical motion capture system. The analysis phase was from the time of last foot contact to the time of release. We calculated the kinematic variables related to javelin throwing performance and compared the Cross and Run.

Results: The results showed significant differences in the joint angles of the left knee, trunk, and right shoulder between Cross and Run.

Conclusions: The results indicate that different throwing motions occur in short run-up throwing compared to full run-up throwing.