PURPOSE This study examined the biomechanical differences in running shoes with two midsole materials, ethylene-vinyl acetate (EVA) and polyether block amide (PEBA), and carbon fiber plate insertion. METHODS Ten recreational runners participated in the study and performed running trials on a 12m runway at a controlled speed of 3.89 m/s ± 5%. Biomechanical data were obtained for time-continuous variables of the metatarsophalangeal (MTP) joint (angle, moment, and power), as well as for discrete variables (push-off time, peak vertical impact force, peak anterior propulsion force, and timing of joint power transition). Data were analyzed using statistical parametric mapping for continuous data and the Wilcoxon signed-rank test for discrete variables (α = .05). RESULTS Compared with no-plate conditions, the EVA sole with plate significantly reduced push-off time, MTP joint range of motion, positive joint power, and peak anterior propulsion force, with an earlier timing of joint power transition (p < .05). In contrast, the PEBA sole with plate decreased MTP joint range of motion but increased plantar flexion moment, negative joint power, and push-off time (p < .05). Furthermore, under plate-inserted conditions, PEBA significantly increased plantar flexion moment, negative joint power, and push-off time, as well as exhibited a delayed timing of joint power transition compared with EVA (p < .05). CONCLUSIONS The interaction between midsole material and plate insertion causes complex variations in MTP joint energy management. Specifically, EVA shoes with a plate may facilitate rapid roll-off and promote swift turnover, thereby enhancing acceleration. In contrast, PEBA shoes with a plate may promote prolonged energy absorption, which could potentially reduce joint fatigue during long-distance running.
PURPOSE This study investigated the effects of 12 weeks of clubbell and stepbox training on physical fitness, badminton skills, and fatigue in male badminton, grade A (top grade) club members aged 20–30s, with over 5 years’ experience. METHODS Participants in a training group (TR: n=15) engaged in 12 weeks of clubbell and stepbox circuit training involving maximum 8–12 reps of clubbell exercises and stepbox exercises at over 77% of HRmax for 50–55 min/sessions three times a week. Participants in a control group (CON: n=15) maintained their normal lifestyle pattern during the same intervention period. Dependent variables were measured and compared using repeated measures two-way ANOVA. RESULTS The main results were as follows: 1) The groups showed no significant differences in body composition. 2) Regarding physical fitness, VO2max, relative peak power, relative average power, grip strength, push ups, repeated jump squats, SSPT (seated single-arm shot-put test), 10 m sprint, and hexagon agility increased significantly in the TR, while push ups decreased significantly in the CON. 3) As for badminton skills, forehand clear accuracy, badminton agility, badminton endurance, and smash speed increased significantly in the TR. Forehand clear accuracy decreased significantly in the CON, but badminton agility and smash speed increased significantly. 4) The groups showed no significant differences in fatigue. CONCLUSIONS In male badminton club members aged 20–30s, 12 weeks of clubbell and stepbox circuit training effectively improved physical fitness and badminton skills. However, lack of any improvement in body composition and fatigue warranted further research in these areas.
PURPOSE This study aims to investigate the effects of a 12-week equipment-based Pilates training on physical fitness, cardiovascular function, and vascular endothelial function in obese middle-aged women. METHODS Twenty-four women, aged 30-40 years with a body mass index ≥ 25 and percent body fat ≥ 30% were randomly assigned to one of two groups: the Pilates training group (TR; n=12); and control group (CON; n=12). The TR participants underwent three 50-minute equipmentbased Pilates training sessions per week for 12 weeks. Participants in the CON maintained their normal life patterns for the same intervention period. Variables regarding physical fitness, cardiovascular function, and vascular endothelial function were measured and compared pre-test and post-test u a two-way ANOVA with repeated measures. RESULTS The main results of the study were as follows: 1) Regarding physique and body composition, participants’ body weight, body mass index, fat mass, percent body fat, waist circumference, hip circumference, and waist-to-hip ratio decreased significantly in the TR. 2) Regarding physical fitness, muscle strength, muscular endurance, flexibility, and cardiorespiratory endurance increased significantly in the TR. 3) Regarding cardiovascular response, SV increased significantly in the TR. 4) Regarding vascular endothelial function, blood vessel diameter at rest and during vasodilation as well as blood flow volume during vasodilation decreased significantly in the CON, resulting in a significant interaction between group and test in FMD percentage. CONCLUSIONS It was concluded that the 12-week equipment-based Pilates program improved the physical fitness and vascular endothelial function in obese middle-aged women.
Purpose This study aims to investigate the experience of service yips in badminton players in depth through using grounded theory method. Methods We collected data from in-depth interviews with 14 participants in total, consisting of badminton players who experienced service yips, their doubles partners and coaches. The collected raw data were analyzed base on derive transcription, coding and paradigm models through grounded theory method. Results First, as a result, 59 concepts, 31 subcategories and 15 categories in regard to badminton service yips were deduced from open coding. Second, in axial coding, it was structured in a paradigm model by categories such as service yips, service mistakes, service proficiency, service anxiety, the imprinting experiences, the importance competition, the pressure of achievement, service practice, psychological control, tactical handling, support from partners, leaders’ coaching, advice from experienced ones, overcoming yips and persistent yips. Third, selective coding resulted in ‘Badminton service yips’ as the core category of this study. ‘Badminton service yips’ is a chronic performance impairment associated with badminton players making severe errors in swing motion on a service not intended by them that it is due to physiological or psychological symptoms such as hand tremors, overall body stiffness, arms stiffness, overstress, overanxiety, and concern over service mistakes. Conclusions We expect our study can be a theoretical foundation for understanding and explanation of ‘Badminton service yips’ and a useful reference for badminton players suffering from psychological difficulties caused by their service yips. The findings in this study should be considered for the development of potential strategies for overcoming the badminton service yips.
Purpose This is to provide essential data for training necessary for sweeping through the analysis of muscle activity generated at this time and how much sweeping and what trajectory moves the stone when the movement of the stone is controlled through sweeping. Methods To check and record the distance between the stones by checking the stop position of the stone made by sweeping each section, the length (progress distance) and width (progress direction) were recorded using a reference table and a record preparation table. With the EMG attached, a total of 60 sweeps were made 20 times each from the beginning of the section to the end of the section. Sweeping subjects were asked to sweep as much as possible under the same conditions in all three sections. Results As a result of the study, the muscle mobilization patterns of the 1st and 2nd sections of the stone with the faster speed and the 3rd section with the stone's slower speed appeared differently. It was confirmed that the sweeping motion of curling is a motion that is used evenly among the muscles of the upper extremity, and it can be verified that it is a suitable item for the development of upper body muscles. Also, the right deltoid's muscle activity rate during push and the right triceps brachii during pull was high. Conclusion Each section of the stone's sweeping effect is an exercise that has many variables, such as changes in atmospheric temperature and humidity, changes in ice temperature, temperature-size-number of pebbles, and the edge state-resilience of stones, etc. It is judged that experience can cope with these variables and requires training.
Purpose This is the first study to examine whether age impacts the response of single muscle fibers to high/low frequency and high/low volume electrical pulse stimulation. We performed in vitro experiments to evaluate the effect of low-frequency high-volume electrical pulse stimulation (EPS) on mechanistic target of rapamycin (mTOR), mitogen-activated protein kinase (MAPK) signaling pathway, and satellite cell activation in singles fibers of young and aged muscles. Methods Isolated single fibers from gastocnemius in 12-wk (n=21) and 72-wk (n=21) old male C57BL/6 mice were divided into four groups: 1) control (Con) received no EPS, 2) low-frequency low-volume EPS (LL), 3) low-frequency high-volume EPS (LH), and 4) high-frequency low-volume EPS (HL) were made to contract using independent EPS protocols. Satellite cell activation and anabolic pathway (mTOR and MAPK signaling) were measured before and after EPS. Results The number of quiescent (Pax7+/Ki67-) and active (Pax7+/Ki67+) satellite cells, myonuclear content and the phosphorylation of 4E-BP1 and ERK were higher in young when compared with old. However, regardless of age, LH and HL EPS significantly increased the number of activate satellite cells (142%, both) and phosphorylation of mTOR (129% and 133%, respectively), p70S6K (133% and 136%, respectively) and 4E-BP1 (140% and 129%, respectively) compared with Con. The protein expression of ERK phosphorylation only increased by LH EPS in both the young and old groups (123% and 125%, respectively). Conclusion Low-frequency high-volume EPS stimulated satellite cell activation and the mTOR signaling pathway in older similar to young muscle.
Purpose This study tells about my life about the past time when I studied for the teacher certification examination, using autoethnography. Methods It primarily used personal memories and diaries. The collected data was analyzed by applying longitudinal coding method through technical categories. Results The finding of this study is described in a chronological order as follows. The first part is about my unstable ego formed in my puberty period just like riding a roller coaster. It mainly features the process of choosing a career path when I was in school and the important starting point that made me today. The second part describes about my life after entering the department of physical education. I joined the military only to flee from a fruitless college life where I was wearing an unbefitting mask to hide myself from the world that is completely beyond my control. In the military, I was lucky to realize how to apply my major to set up my career path by coincidence. The third part is about the process of finding a genuine meaning of being a physical education teacher through a transitional period experienced after returning to school and form a stable self. Lastly, passing teacher certification examination with undaunted struggles boosted my self-esteem and self-efficacy and solidified my self-identity in the end. In addition, it is possible to get a glimpse of the attitudes that teachers need to have for a teaching career in the last part. Conclusions What I want to say throughout my descriptive story is that preparing for the teacher certification examination itself is a great challenge as well as a courageous decision for the candidates, but it is an attainable goal if they try with all their heart.
Purpose This study is to examine the historical facts about the integration of the Korean Sports Association, the Korean Olympic Committee, and the Korean School Sports Association in 1968. Methods Primary and secondary data were used to understand the integration process of the three organizations. Result First, immediately after liberation, the Korean Sports Association was reorganized and a number of new sports organizations were founded. Second, in the 1960s, the military regime exerted the government's control, making all social groups essential to register in accordance with the Act on Social Group Registration. Third, the Korea Olympic Committee and the Korean School Sports Association frequently caused friction as they operated overlapping projects with the existing Korean Sports Association. Fourth, in February 1968, the government consolidated three groups that were considered social issues based on the experience of dissolving the Korean Special Sports Association. Fifth, the integration of the three organizations is significant in that it prevented redundant projects and wasted budget, and resolved the discord in the sports world. Conclusion The first integration of the Korean Sports Association in 1968 was a historical event that absorbed the Korean Olympic Committee and the Korean School Sports Association. The integration of the three organizations is viewed as a solution for the systematic operation of the sports administration, but on the one hand, it has become the top-ranking organization in the Korean sports community since this time by well blocking the checks of the Korean Olympic Committee and Korean School Sports Association. It can be understood as maintaining absolute power.
Purpose The study was designed to investigate the effects of 12 weeks of circuit training and L-tryptophan supplementation on physical fitness and metabolic syndrome. Methods Forty-one menopausal women were randomly assigned to one of three groups. i.e., combined circuit training and L-tryptophan supplementation group (CT+T: n=14), L-tryptophan supplementation group (T: n=14), and control group (CON: n=13). The subjects in CT+T exercised three sessions per week and took 3g of L-tryptophan per day for 12 weeks. The subjects in T took 3g of L-tryptophan per day for 12 weeks. The subjects in CON were asked to maintain their life pattern for the same period of intervention. Physical fitness and metabolic syndrome-related variables were measured at pre- and post-test. The data were compared by utilizing a repeated two-way ANOVA. Results Main results of the study were as follows: 1) Standing long jump, one leg standing with eyes closed, sit-and-reach, sit-up, and maximal oxygen uptake increased significantly in CT+T. 2) Body weight, body mass index, waist circumference, waist-hip ratio, fat mass, and percent body fat decreased significantly in CT+T. 3) Total cholesterol decreased significantly in CT+T. 4) Fasting plasma glucose (FPG), fasting plasma insulin, and HOMA-IR decreased significantly in CT+T. FPG and HOMA-IR decreased significantly in T. 5) Systolic blood pressure, diastolic blood pressure (DBP), mean arterial pressure (MAP), and rate pressure product decreased significantly in CT+T. DBP and MAP decreased significantly in T. 6) Number of metabolic syndrome risk factors decreased significantly in CT+T and T. Conclusion It was concluded that the circuit training and L-tryptophan supplementation would have positive effects on physical fitness and metabolic syndrome, and that L-Tryptophan supplementation would have positive effects on metabolic syndrome by improving insulin resistance and hypertension in menopausal women.
The purpose of this study was to critically interpret a certain sports-related idea, "Integrated Korean Team," which was an issue at the PyeongChang Winter Olympics. The idea emerges as a specific political agenda under the conditions of domestic politics and the special environment of Korean national affairs and discourse. To this end, we investigated media texts on the relationship between sports, political dynamics and views on related discourse that were produced in 1990-1991 and 2018. The main findings are as follows: First, sports functions as a political socialization tool for political power as it forms public opinion. Second, sports exchanges work as a kind of international politics. Specifically, political power controls sports as certain political situations arise and political elites' needs change. Third, mega sports events have tended to become politicized in recent years as they become more effective. Fourth, North Korea’s sports under political power cannot be easily dealt with by the private sector, and it has limitations because it is not politically independent. The analysis showed that the negotiation process and realization of the Integrated North and South Korean Team seemed to be a turning point in politics and sports. Here are the conclusions drawn from discussing the two unifying events in 1991 and the situation in 2018. First, both South and North Korea pulled the Integrated Korean Team card when political needs arose. Second, when the two Koreas did not need to reconcile due to changes in the political situation between the two Koreas, they did not want to make efforts to integrate Korean Team. Third, the position of the political elite was directly represented by the position of the South-North Korean team. Fourth, the supporting public opinions of the Integrated Korean Team are gradually diminishing as the power gap between the two Koreas widens and sports players' human rights issues emerge.
