Journal of Sports Medicine and Physical Fitness最新文献

Background: Sports injuries often occur during landing, necessitating postural stability for injury prevention. Electrical stimulation of the plantar foot induces activities of the intrinsic foot muscles and improves somatosensory and postural stability during landing. However, this effect remains unclear. Therefore, the aim of this study was to investigate the immediate effects of electrical stimulation on the activities of the intrinsic foot muscles, plantar somatosensory system, and postural stability during landing.

Methods: Twenty-two college athletes were divided into an electrical stimulation group and a control group. Electrical stimulation was applied to the plantar foot using a commercial device. The toe function and plantar tactile sensations were evaluated. The activities of the intrinsic muscles and the parameters of the ground reaction force were measured and calculated. We compared pre- and postintervention outcomes.

Results: In the electrical stimulation group, two subjects showed improvement in toe function, and plantar tactile sensation improved significantly postintervention. The control group exhibited no significant change in plantar tactile sensation. A significant interaction was observed in anteroposterior postural stability during landing, notably improving in the electrical stimulation group.

Conclusions: Electrical stimulation of the plantar foot immediately improved toe function, plantar tactile sensation, and postural stability during landing. Such stimulation would be beneficial in preventing sports injuries.

Background: Activity trackers are becoming increasingly popular in everyday life, sport and research. Accurate measurement of step counts is essential for understanding an individual's daily activity levels and promoting healthier lifestyles. As the sensor technology has become very sophisticated, such a device can be worn on the body for several hours or days without restricting the subject's daily activities. The aim of this study was to evaluate the accuracy of a commercially available wrist-worn pedometer in accurately recording step counts.

Methods: A total of twenty-one subjects participated in this comparative study by running at various speeds in a laboratory setting while wearing a Garmin Forerunner 245 Music watch (Garmin Ltd, Schaffhausen, Switzerland) on each wrist. Simultaneously, their steps were recorded by a camera system. The step counts recorded by the pedometer were compared with the counts obtained by the camera system. Descriptive statistical analyses such as Pearson correlation and Bland-Altman plots were used to assess the accuracy and reliability of the pedometer.

Results: For most settings the results on the treadmills showed a high correlation between the pedometer and the camera system. On the step machine the results showed a low correlation between the pedometer and the camera system, the pedometer showed a systematic bias by consistently overestimating the number of steps. Bland-Altman plots showed that the results were within the limits of agreement.

Conclusions: Although pedometers provide a convenient tool for monitoring step count, this study highlights some limitations and potential inaccuracies of a commercially available pedometer. Our study indicates that the Garmin watch is sufficiently accurate to be used as a measurement tool in a treadmill running environment.

Introduction: The FIFA 11+ preventive program is designed to reduce the incidence of injury in sports. However, to gain a better understanding of its effect a systematic review and meta-analysis is needed. The current review aims to investigate the effect of the FIFA 11+ preventive program on injury incidence among male and female football players.

Evidence acquisition: This study used Scopus, PEDro, SPORTDiscus, and ProQuest as data sources. The initial selection of the studies, thorough assessment of the tile, and abstract. Extraction of the necessary study data was conducted by two independent researchers. Another two independent researchers assessed the quality of each included study against 39 used criteria. These criteria were combined from several popular quality assessment scales. The incidence of injuries measured in the lower extremities in football players after addressing the FIFA11+ was the outcome of interest.

Evidence synthesis: This review included 12 trials of variable methodological quality from which 10 trials were selected for the meta-analysis. In general, the FIFA11+ program showed a significant reduction (P<0.1) in lower limb injury incidence for male young and adults in comparison to other programs. However, evidence of its effectiveness in females is lacking and more studies are needed.

Conclusions: The FIFA 11+ program is recommended to be used and implemented as a preventive strategy in males. Although, the result showed a significant reduction in injury incidence in adult males, heterogeneity between studies is high which may reduce the generalizability of the results. More studies are needed to investigate the effect of the FIFA 11+ program on females.

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.

Background: The present study aimed to compare different pre-exercise strategies on jumping performance in female volleyball players.

Methods: Fifteen healthy female volleyball players (age=18±0.6 years; training experience = 7.3±1.4 years; height = 164.8±5.4 cm; body mass = 57.2±8.1 kg) volunteered to participate in the study. Three different pre-exercise conditions (5 repetition maximum knee extension, electromyostimulation [EMS] and ischemic preconditioning [IPC]) were applied to the subjects and compared to a control condition performing a standardized warmup. Subjects performed the squat jump and 15 sec repeated countermovement jumps following a rest period. Measures associated with jumping performance were collected and compared between conditions. Rating of perceived exertion was also collected after each performance test.

Results: No pre-exercise condition outperformed a standardized warm-up on inducing improvements in jumping performance and in fact, EMS and IPC conditions resulted in performance decrements compared to control (P<0.05).

Conclusions: We conclude that a standardized warm-up is enough to induce improvements in jumping performance in female volleyball players. Future research should examine alternative strategies alongside standardized warm-up to determine how best to prepare for jumping and related sport-specific tasks in female volleyball players.

Background: Intra-individual factors like ovarian hormone profiles and body weight variations may influence sports practice and performance in female athletes and need to be characterized. The "Answ'Her" questionnaire was designed to develop a relevant and reproducible field-based tool to assess self-reported ovarian hormone status (natural menstrual cycle and hormonal contraceptive use) and body weight variations practices among female athletes.

Methods: French females with a regular sports practice responded (once: N.=210; twice: N.=86; thrice: N.=66) to this 73-item questionnaire reporting their ovarian hormone status, associated symptoms, perceived influence on sports practice, and body weight variations. Reproducibility was evaluated, then a descriptive cross-sectional analysis was conducted on athletes.

Results: Reproducibility was verified with 92% of Lin's correlation concordance coefficients above 0.7 and 100% of weighted agreements above 70%. Ultimately 185 female athletes (23.0±4.8 years) were included in the cross-sectional analysis. Whether they used hormonal contraceptive (46.5%) or not (53.5%), most of the athletes perceived a negative impact of their ovarian hormone status on sports practice (78.7%) and performance (84.7%). Overall, 77.3% of the athletes had experienced body weight variations that were significantly associated with an interruption of menses (>3 months) and menses irregularity over the last three years.

Conclusions: The Answ'Her questionnaire is a simple and effective reproducible field-based tool for the self-reported characterisation of female athlete ovarian hormone status and body weight variations. It could be used for a unique and simple overview of the athlete situation but also in a longitudinal design to assess the athlete's evolution and/or effectiveness of implanted training strategies.

Background: Patients underwent cyclists and triathletes test, train, and race both indoors and outdoors. However, the differences between indoor and outdoor performance remain understudied. This study aimed to analyze the relationship between indoor and outdoor performance in cycling. We investigated the influence of training environment history (indoor vs. outdoor) and application of e-sport platform on the aforementioned relationship.

Methods: Forty-three well-trained triathletes performed indoor and outdoor field tests to establish maximum sprint power (MSP) and functional threshold power (FTP). The main effects for FTP and MSP were assessed by repeated-measures ANOVA to analyze the differences between power output obtained indoors and outdoors. Multiple covariates, including training environment history and application of ZWIFT e-sport platform, were applied. Multiple linear regression was performed to investigate outdoor FTP prediction based on indoor testing.

Results: No significant differences were found for MSP and FTP obtained indoors and outdoors. However, the high individual variability in the disparity between indoor and outdoor power output (PO) in triathletes was observed. There was a statistically significant interaction between FTP and training environment history (P<0.001 for FTP expressed in W*kg^-1 and W) and FTP and BMI (P=0.042 and P=0.034 for FTP expressed in W*kg^-1 and W, respectively). The prediction formulas to establish outdoor FTP based on indoor testing had high accuracy (R2 0.80 and 0.68 for full and simple model, respectively).

Conclusions: The study underlines the crucial role of the appropriate testing environment, corresponding to the training environment and racing demands. A high individual variability in the disparity between indoor and outdoor PO at FTP are associated with training environment history and BMI. No such interactions were found for MSP.

Background: To compare the effects of aquatic aerobic and combined training on neuromuscular outcomes in patients with type 2 diabetes.

Methods: Patients with type 2 diabetes were randomized to an aerobic aquatic training (AERO), a combined aquatic training (COMBI) or a procedure control (CON) three weekly for 15 weeks. The sessions were 50 minutes long. Maximal strength and muscle endurance were assessed by the 1RM and maximum repetitions at 60% 1RM tests, respectively, in knee extension and elbow flexion exercises. Timed up and go test, testosterone, cortisol and testosterone:cortisol ratio also were evaluated.

Results: Participants had 59.0±8.2 years, 51% women. All groups increased (P<0.001) the maximal knee extension strength (Mean Difference: AERO: 21.1 kg; COMBI: 14.6 kg; CON: 4.4 kg), while only COMBI group increased (P<0.001) the maximal elbow flexion strength (Mean Difference: 2.6 kg). Muscle endurance in both exercises were increased in all groups. The Timed Up and Go test at the usual and maximal speed decreased in all groups. Testosterone were not modified in present study, while cortisol and testosterone:cortisol were improved in COMBI group.

Conclusions: Aquatic training, especially combined aquatic training, improve the neuromuscular fitness of patients with type 2 diabetes.

Background: The aim of this study was to investigate the effect of normal breath and apnea swimming on acid-base balance, physiological responses and performance during high-intensity interval training in swimming.

Methods: Sixteen swimmers completed 6×50 m intervals of freestyle swimming with normal breath and apnea at maximum intensity, with 1 minute rest. Capillary blood gases (pH, PCO2, PO2, HCO3, Hct, Hb) were collected at four (4) measurement time points: 1) at rest once; 2) at rest just after the 3^rd repetition; 3) at finish; and 4) at 10 min of recovery. Heart rate (HR) during swimming, lactate acid (La) concentration and swimming time (t50) were measured.

Results: Our study showed uncompensated metabolic acidosis due to increased lactic acidosis in both breathing conditions, more pronounced in apnea, and faster swimming times in apnea without different heart rate responses.

Conclusions: Apnea during repetitive high intensity long distance interval 50 m freestyle swimming causes uncompensated metabolic acidosis but improves sprint performance.

Background: Studies have shown a positive relationship between cardiorespiratory fitness (CRF) and executive functioning in older adults. Although this relationship has been well established, there seems to be a gap in the literature on the role of sex differences concerning CRF and executive functions. The current study aimed to assess the effect of sex in the relationship between CRF and cognition in older adults by stratifying the results to examine effects in males and females.

Methods: Ninety-six older adults (61 females) gave their written, informed consent to participate in this cross-sectional study. All participants underwent a maximal continuous graded exercise test on a cycle ergometer to assess their maximal oxygen uptake (VO2max) and a computerized Stroop task (naming, inhibition, and switching) to assess their executive functions. According to VO2max test results and the American College of Sports Medicine's guidelines, females and males were classified into higher-fit and lower-fit groups. A general linear model and estimated marginal means analyses were applied.

Results: Results showed no significant differences in the naming, inhibition and switching performance tests between male and female older adults (P>0.05).

Conclusions: Based on the observed positive relationship between CRF and executive functioning, the data of the current study supports the idea that aerobic exercise, which typically increases CRF, is well-situated to improve executive functioning in older adults, irrespective of sex.