The ACTN3 R577X polymorphism has been associated with an elite athletes status. Several studies have determined that the R allele is connected with power-oriented athletic performance, whereas the nonfunctional XX genotype may give some beneficial effect for endurance performance. The main aim of the study was to determine the possible interaction between the ACTN3 R577X polymorphism and an power-oriented athlete status in Korean elite athletes(wrestling 31, judo 13, boxing 16, fencing 6, cycle 16, ≤400m athlete 18). Each athletes performed a 30-second WAPtest with a resistance equal to 7.5% for male and 5% for female body weight. Genotyping for the ACTN3 R577X (rs1815739) polymorphism was performed using the TaqMan approach. The ACTN3 R577X genotypes exhibited a HardyWeinberg equilibrium distribution in our population. The relative and absolute average power results of the 30-second Wingate test did not differ significantly among the genotypes. However, the relative peak power result of the Wingate test was significantly higher in the R-allele- dominant model groups than in the XX group in male but not female athletes. These results suggest that the ACTN3 R allele is associated with the relative peak power during the Wingate test in male Korean elite athletes.
Purpose The purpose of this study was to identify the effect of a power-specific weight training program in order to improve the muscle strength of Korean national team’s freestyle wrestlers. Methods Participants were 13 male athletes in the national freestyle wrestling team. The period of the program was 6 weeks. Muscle strength, muscular endurance, muscle power, flexibility, agility, cardiorespiratory endurance, anaerobic power and isokinetic muscle function were measured. Data were analyzed using IBM SPSS Statistics ver. 23.0 (IBM Co., Armonk, NY, USA). Paired t-test was conducted for comparison between pre-test and post-test score. Results There were significant difference and tendency in the leg isokinetic power and trunk isokinetic flexion strength. However, there was no significant difference in muscle strength, muscular endurance, muscle power, flexibility, agility and cardiorespiratory endurance. Conclusion The 6-week program focusing on the power-specific weight training indicated a significant difference not in every variable but in isokinetic muscle power, speed power and core strength. It is suggested that the training program was applied to the athletes less continuously and not in the long term because of frequent international games abroad and the need for losing weight. Consequently, a year-long training program with personalized methods should be developed to bring about more significant outcomes.
Purpose The purpose of this study was to investigate the effects of training methods on body composition, isokinetic strength and muscle endurance, cardiopulmonary function, and anaerobic power in female judo players. Methods Subjects performed weight training (n=10) and circuit weight training (n=10) consisting of 10 sports items for 12 weeks. In order to analyze the effects of training, body composition, isokinetic strength and muscle endurance, cardiopulmonary function, and anaerobic power were measured and the effect of training was verified. Results First, the comparison of body composition between WT and CWT groups showed that significant interaction effect between group and period was found in all variables (weight: F=1082.694, p=.001, body fat mass F=199.999, p=.001; skeletal muscle mass F=2481.698, p=.001, and percentage body fat: F=496.246, p=.001). Second, there was a significant interaction effect between group and duration in shoulder muscle strength and knee endurance (EPTL: F=6.598, p=.019; EAPL: F=12.860, p=.002). Conclusions The result of this study showed that the interaction effect between period and group was not significant according to the training method but the overall effect of the circuit weight training group was more positive than the weight training group. Therefore, it can be concluded that the 12 weeks circuit weight training can contribute to improve the performance of female Judo players by improving body composition, strength and muscle endurance, cardiopulmonary function and anaerobic power.
Purpose This study was conducted to analyze the differences of physical characteristics focused on the physique, strength, and power for cycling national athletes (Sprint cyclists and Road race cyclists). Methods We measured various factors (e.g., height, weight, body fat ratio, thigh circumference, waist circumference, anaerobic power, isokinetic muscular strength, muscle power, squat jump by 1RM intensity, and so on) for a total 11 male cycling national athletes (5 Sprint cyclists and 6 Road race cyclists). Results First, the body composition showed the significant differences only in weight (p=0.31) and BMI (p=.001) for Sprint cyclists. Second, the values of the anaerobic power for the Sprint cyclists were significantly higher than those for the Road race cyclists only at peak power (p=0.28), whereas there was no significant difference in average power, isokinetic muscular strength, and muscle power between the two groups. Third, the isokinetic trunk flexion muscle (p = .016) for the Sprint cyclists were significantly higher than those for the Road race cyclists. Fourth, the significant difference in Time to Peak Torque was not found between two groups. Fifth, the values for the Sprint cyclists showed the significant difference in all 5 intensity groups (0%, 30%, 50%, 60%, and 80%) (p=.001) of the squat jump. Also, there was a statistically significant difference only in 0% velocity between the two groups, except for exercise intensity. Conclusions From the various measures between two groups, the Sprint cyclists relatively showed the high weight, BMI (muscle mass), and maximum power. Additionally, the isokinetic trunk flexion muscle and the squat jump were higher in the Sprint cyclists than the Road race cyclists. These data may be used as basic data to improve the physical fitness factors related to the athletic performance of the athletes by reflecting them in the effective training plan and evaluation of the athletes.
PURPOSE Inclusive leadership has become increasingly important in sport organizations. Accordingly, this study examines interorganizational inclusive leadership effects on organizational trust and affiliated organizations’ employees depending on power distance. METHODS A total of 250 affiliated sport organization employees participated, and latent moderated structural equation modeling with a bifactor structural model was employed to test the hypotheses. RESULTS The results indicated that macro inclusive leadership as well as its two components significantly enhance organizational trust. Interestingly, power distance positively moderated the macro effect of interorganizational inclusive leadership on organizational trust. Lastly, organizational trust enhanced job performance and well-being, and reduced turnover intention. CONCLUSIONS The results provide meaningful insight into the relationship between lead and affiliated organizations in the context of highly competitive and collaborative sport organizations.
PURPOSE The purpose of this study was to develop the estimating equations for 4 types of Wingate Anaerobic test setting. METHODS 80 male elite athletes performed 4 trials of the Wingate Anaerobic test by each type. Subjects were conducted the retest one week later. Data collected from the Wingate Anaerobic test included mean power, peak power, and power drop for 30s were measured. Coefficient of correlation was used for validity of type 1(DOS version) and the other types(ver. 2.24, 3.3.0, and 3.2.1). Pearson’s correlation coefficient was used to examine the reliability of test and retest. Simple regression analysis was used for calculating the estimating equation. RESULTS There was significant correlation for absolute value(Watt, p<.01) and relative value(Watt/kg, p<.01) of mean power, absolute value(W, p<.01), relative value(Watt/kg, p<.05), and power drop rate(%, p<.01). Test and retest reliability was excellent for all test variables(p<.01). CONCLUSIONS From the all results, the estimating equation was calculated to convert all outputs from each type to the other types of the Wingate Anaerobic test setting. These findings suggest that the estimating equations are compatiable to 4 types of Wingate Anaerobic test setting.
PURPOSE The purpose of this study was to investigate the characteristics of field and on-ice performances of ice-hockey players and the relationship of performance with subjective joint pain and dysfunction. METHODS A total of 25 male college icehockey players were evaluated for 19 items of performance. Pain and dysfunctions in the lower extremities and lower back were confirmed through the Foot and Ankle Outcome Score, Knee Injury and Osteoarthritis Outcome Score, Hip Dysfunction and Osteoarthritis Outcome Score, and Osweatry Disability Index questionnaire. Players with similar performance characteristics were classified through a cluster analysis, and differences in performance and patient-reported outcomes between clusters were analyzed with a one-way analysis of variance. RESULTS The ice-hockey players were classified into “lower muscular strength and performance (cluster 1),” “lower cardiorespiratory endurance (cluster 2),” and “high muscular strength and performance (cluster 3).” Players in cluster 1 had more frequent ankle and knee joint dysfunctions and pain compared to those in cluster 3. Several performance test items affected the subjective joint score, and the related performance items were more in the proximal joint than in the distal joint. CONCLUSIONS Ice hockey players should perform training to supplement their individual lack of on-ice and field performance. Since performance may be limited because of joint dysfunction and pain, a joint-specific intervention strategy should be applied to improve physical and athletic performances.
PURPOSE The quiet eye (QE) is defined as the final fixation time that is a specific target prior to initiating movement. This study aimed to identify the cause of QE in golf putting and to present an efficient practice method for improving putting skills. METHODS Thirty participants were randomly assigned to one of three groups. Each group practiced golf putting in different ways for two days. RESULTS The QE group showed a significant difference in putting scores, which was higher than that of the control group. The visual-occlusion group showed no difference compared to the other groups in terms of putting scores. The QE group showed a significant difference in terms of QE in the retention and competition tests compared to the pretest. The control group tended to have a slightly longer QE in competition tests compared to the pretest. The visualocclusion group showed no statistically significant difference in QE based on the period. All three groups had significantly longer swing times over the selected period. There was no significant difference in terms of the alpha power of the occipital lobe based on group and period. CONCLUSIONS The position of the visual-occlusion group became stable. However, the QE did not lengthen. The QE group had a longer QE. Furthermore, the control group that practiced with their eyes open tended to have longer QE. Therefore, QE may be related to visual-based cognitive processing rather than posturalkinematics. Finally, this study proved that QE practice is a more efficient method for novices in golf putting.
The purpose of this study was to investigate the effect of running economy and energy return in lower extremities according to the increase of bending stiffness of the shoes, furthermore to investigate the relationship between running economy and energy return for the improvement of sports performance. Subjects employed for this study were 10 healthy male college students who have not had the experiences in lower extremities injuries. Four different kinds of shoes in bending stiffness as with 0.56 N/mm, 0.74 N/mm, 0.96 N/mm, 1.21N/mm were used respectively. 3-D cinematography and pulmonary gas analyzer were utilized for energy return and energy consumption data during running according to the increase of bending stiffness of the shoes to obtain the following results. As the bending stiffness of running shoes increased, the statistical significance were not founded, however, the tendency of decrease in max. flexion moment and power, increase in max. extension moment and power in lower extremity joint were showed. Joints energy showed no statistical significance in phase 1, however, the tendency of lesser absorbtion as the bending stiffness of running shoes increased were showed. More energy were generated as the bending stiffness of running shoes increased in phase 2 with no statistical significance. Energy economy increased according to the increase of bending stiffness of running shoes. Negative correlation were showed between flexion moment of hip joint and energy consumption(p<0.05). Slightly higher degree of correlation between max. flexion power of hip and ankle joint and energy consumption were showed without statistical significance. Negative correlation were showed between joints energy and energy consumption for ankle joint in phase 1(p<0.05).
PURPOSE The purpose of this study was to provide information for improving the performance and skills of 500 m speed skaters by analyzing the kinematic and kinetic changes in their slide board movements over time. METHODS The subjects were 10 male short-distance skaters in their 20s to 30s who were registered as professional athletes with the Korea Sports Council. The changes in joint angle, joint moment, and joint power over time in the subjects’ slide board motion were measured and analyzed. RESULTS It was found that during phase 2 of the skater’s slide board movement, there was an increase in plantar flexion and a decrease in flexion of the lower extremity joint and extension of the knee and hip joint, with decrease in positive power of the knee joint. CONCLUSIONS The results of this study are expected to provide practical information to skating coaches and athletes by quantifying the biomechanical factors observed over time during slide board movements. In addition, this study is expected to contribute to the field of speed skating by presenting scientific training methods and proposing new analysis techniques to improve performance in the future.
