It has well known that post-exercise hypotension (PEH) after a bout of aerobic exercise was a major mechanism to reduce blood pressure though exercise training, and that citrulline supplementation reduced blood pressure by increasing nitric oxide in vivo. However, the effects of citrulline supplementation on PEH have not been fully elucidated yet. This study was designed to examine the effects of citrulline supplementation on PEH after a bout of aerobic exercise in prehypertensive and normotensive 20s males. The effects of a four-day citrulline or placebo treatment on blood pressure, cardiovascular function, and blood lactate concentration measured at rest and during recovery phase after a bout of exercise performed for 30 min at 70% VO2max were compared and analyzed. All subjects participated in a citrulline trial and a placebo trial repeatedly according to a counter-balanced order. Main results of the present study were as follows: 1) Systolic blood pressure, diastolic blood pressure, and mean arterial pressure measured at 10-60 min of recovery phase in citrulline trial were significantly lower than placebo trial. Rate-pressure product measured at 30 min and 45 min of the recovery phase in citrulline trial was significantly lower than placebo trial. 2) No significant differences were found in heart rate (HR), cardiac output (CO), and total peripheral resistance (TPR) measured during the recovery phase between two trials. There were significant differences in HR, stroke volume, CO, and TPR among times within a trial. 3) No significant difference was found in blood lactate concentration measured at rest and during the recovery phase between two trials. The results would be summarized that the PEH was augmented by the citrulline supplementation, and that burden to cardiac muscle as well as cardiovascular function were not affected by the citrulline supplementation. It was concluded that the short-term citrulline supplementation would be very effective to augment the PEH. A research investigating the effects of citrulline supplementation on the PEH in pre-hypertensive and/or hypertensive individuals would be warranted. In addition, a study examining the effects of citrulline supplementation during long-term exercise training on the blood pressure in hypertensive patients also would be warranted in near future.
The frailty, characterized by reduced physiological function is closely related to a fall, disability, institutionalization, hospitalization, and mortality in the elderly. A reduced physical fitness is a major phenotype of the frailty. The purpose of this study was to investigate the relationship among pre-frailty, physical activity (PA) and functional fitness in the community dwelling elderly women. The study participants were elderly women (n=338, 70.6±4.2years) aged over 65 who took part in the Korean Healthy Fitness Criteria study for the National Fitness Award Project in 2015. The pre-frailty was defined using the Cardiovascular Health Study frailty criteria. PA was assessed using the International PA Questionnaire (IPAQ). The participants were classified as regular PA participants if they meet the World Health Organization (WHO) PA recommendation for the elderly. Functional fitness was assessed using the composite of the National Fitness Award fitness testing for the elderly. Quality of life was evaluated using EuroQoL visual analogue scale and WHO quality of life assessment. As the results, the pre-frail elderly women were significantly older and obese (body mass index, percent body fat, waist circumference) than the healthy elderly. The pre-frail elderly presented significant decreases in walking, moderate intensity, and total PA compared to the healthy elderly even after adjusted for age and percent body fat. However, no significant difference was found in vigorous-intensity activity between the pre-frail and healthy elderly. Also, the pre-frail elderly women showed the decrease in functional fitness and quality of life compared to the healthy elderly. Regular PA was associated with high levels of muscular endurance and coordination in healthy and pre-frail elderly. In pre-frail elderly, high levels of cardiorespiratory endurance was associated with PA. In conclusion, regular PA is inversely associated with fitness decline in healthy and pre-frail community-dwelling elderly women. Regular PA might attenuate fitness decline in pre-frail elderly women.
The purpose of this study was to describe the epidemiology of Korean collegiate injuries during 2015. Collegiate student-athletes(n=167) in six sports (badminton, baseball, basketball, rugby, taekwondo, and volleyball) participating in all practices and games during pre-season, in-season, and post-season were tracked via the injury surveillance system(rate, location, type, and cause of musculoskeletal injury). Injury rate for 1000 athlete-exposure(AE) and 1000 time-exposure(TE) were calculated with 95% confidence intervals(CI). We captured a total of 961 injuries, a rate of 19.29/1000 AE(95% CI=18.07, 20.51) and 0.16/1000 TE(95% CI=0.15, 0.17). Commonly injured body locations were knee(17.5%, n=168), thigh(16.1%, n=155), ankle(12.1%, n=116), and finger(8.4%, n=81). Injuries were mostly diagnosed as contusion(40.1%, n=385), ligament sprain(21.1%, n=203), and laceration/abrasion/skin injury(13.5%, n=130). Common causes were contact with another athlete(44.6%, n=429), contact with moving object (12.7%, n=122), overuse/atraumatic(11.9%, n=114), and contact with non-yielding object(9.4%, n=90).
The purpose of this study was to find out what experiences pre-service physical education teachers have before, during and after student teaching along with teacher educational meanings in the experiences. The subjects of this study were 7 senior students in department of physical education of B university located in A city. The data were collected through daily records of student teaching and in-depth interview(group and individual). The collected data were analyzed using the methods of Smith & Kinsella(2009) and Spradley(1980). The analysis showed expectation for learning(knowledge, skills, behavior) and realization(feeling, stimulation, awareness) before student teaching, fight and compromise with 'me'(body, spirit, life), 'you'(teacher, student) and 'it'(instruction, environment, episode) during student teaching, and regret of 'instruction'(plan, execution, evaluation), 'relationship'(forming, maintaining, improving) and 'role'(teacher, attitude, sense of calling) after student teaching. These characteristics were discussed in 4 aspects of educational meanings including seeking essence, seeking forms, seeking roles and seeking status. Lastly, the study suggested unification of student teaching contents, introduction of exclusive teacher system for student teaching, establishment of evaluation system for student teaching program and development of field ability strengthening program available to connect with student teaching in physical education.
The purpose of this study was to develop and validity Competitive State Anxiety Scale for Taekwondo Form athlete(CSATF). The participants were composed of the 48 Taekwondo Form athlete to explore sub-factors of Competitive State Anxiety for Taekwondo Form athlete. The data were collected by an open-ended questionnaire and interview. The participants were composed of 257 national Taekwondo Form athlete to develop Competitive State Anxiety Scale for Taekwondo Form athlete. This 157 athlete data were used for items analysis, reliability analysis and exploratory factor analysis. And 100 athlete data were utilized for confirmatory analysis. Also convergent validity, discriminant validity, predictive validity latent mean analysis of CSATF were performed The results of this study were as follows. Firstly, the results revealed that the four general dimensions were identified such as cognitive anxiety, somatic anxiety, state of confidence, environmental anxiety. Secondly, CSATF comprised cognitive anxiety(5 item), somatic anxiety(5 item), state of confidence(5 item) and environmental anxiety(6 item). Thirdly, convergent validity, discriminant validity and predictive validity, the multi-group analysis according to gender examined validity of CSATF.
The purpose of this study is to examine acculturation strategies of expatriates in Korea in relation to spectator sport involvement. Berry's(1997) bi-dimensional model of acculturation was used as a theoretical framework to categorize the type of acculturation strategies of expatriates in Korea. Acculturation strategies of expatriates were classified into four types: integration, assimilation, separation, and marginalization. To be specific, there were 79 participants using the integration strategy, 28 using the assimilation strategy, 53 using the separation strategy, and 20 using the marginalization strategy. Research hypotheses were established to analyze differences on spectator sport involvement of expatriates between Korean spectator sport and their original cultural sport. There were significant differences in spectator sport involvement among foreigners in Korea. Firstly, the spectator sport involvement of the participants using the integration strategy was higher than that of marginalization. Second, participants categorized as using assimilation strategy were found to have lower sport involvement with Korea's spectator sport and had a higher involvement with their original cultural sport. Third, participants categorized as using separation strategy were found to have higher involvement with their original cultural sport than Korea's. Fourth, participants categorized as using separation strategy did not show significant differences with assimilation participants in comparing original cultural spectator sport. In conclusion, the result of the research indicated that expatriates living in Korea showed similar characteristics of Berry's (1997) acculturation strategies. Thus, It indicated that Berry's (1997) acculturation strategies are useful theoretical tools predicting psychological preference of expatriates in Korea. However, participants showed little difference in that all expatriates of four categories showed higher involvement with their original cultural spectator sport. Therefore, unlike Berry's (1997) theory, people with high level of acculturation showed higher levels of involvement with their original cultural spectator sport. It may provide useful information for Korean sport marketers regarding s foreign sport consumers in order to develop a market.
The purpose of this study was (1) to develop a archery lesson using forced connection method-sportcasting for cultivating collaborative problem-solving competencies, and (2) to apply and to examine the responses of students after physical education(PE) lesson. A archery lesson of Understanding-Performance-Appreciation step was developed according to LfPE(Lee, 2014) using backward curriculum design. Participants were tenth grade students (N=148) in a high school. Open-ended question used to collect the data. The analysis of data indicates that students expressed features in lessons. Six features are (a) 朋友信之, (b) 君子不器, (c) 能竭其力, (d) 觀其所由, (e) 溫故知新, (f) 思而不學. In-depth interviewers were carried out for further analysis of the answers to the questionnaires. The results are as follows. First, 朋友信之 means lesson cultivating collaborative problem solving competencies. Second, 君子不器 means pleasant and funny lesson. Third, 能竭其力 means lesson cultivating self management ability. Fourth, 觀其所由 means lesson cultivating appreciativeness for archery. Fifth, 溫故知新 means lesson improving the status of PE teacher and school. This study concluded that a archery lesson generated fun and interest for students. Implication for developing lesson using LfPE, utilize and transform forced connection method-sportcasting in PE were discussed.
The purpose of this study was to investigate basal physical fitness and smash speed of elite national badminton players. To perform this study, total forty six korea national badminton player were participated : twenty two male players(age : 20.90±2.24years, height : 179.30±5.40cm, weight : 73.80±7.12kg, career : 11.27±1.88years) and twenty four female players(age : 19.45±1.95years, height : 167.83±4.36cm, weight : 61.39±3.60kg, career : 9.50±2.47years). Each subjects performed the 6 basal physical fitness trials : agility, muscular endurance, muscular strength, flexibility, balance and cardiorespiratory endurance. And the speed of badminton smash were analysis by using radar gun when players were standing smash success. To determine the difference between two groups, independent samples test was used. As a result, we found that there was a large difference male players and female players in basal physical fitness and smash speed. First, male players were significantly strong in agility(side step 10%), muscular endurance(repetitional jump 12%), muscular strength(left grasping power 3%, right grasping power 31%) and cardiorespiratory endurance(20m suttle run 31%). On the other hand, female players were relatively strong in flexibility(sit and reach 27%) and balance(standing on one leg with eyes closed 51%). Second, maximum smash speed show that male players were about 57km/h(24%) faster than female players(male : 247.72km/h, female : 190.37km/h). Based on the findings, we shall be applicable training program to improve flexibility, balance of male athletes and agility, muscular endurance, muscular strength, and cardiorespiratory endurance of female athletes. our results will be appliable to improve the athletic performances of national badminton players by the coaches in the future.
PURPOSE The purpose of this study was to investigate the association of physical activity level with insomnia severity (Normal, Subthreshold, Moderate and Severe) in adolescents and to use it as a basis for insomnia prevention. METHODS This study was conducted on a cohort of 50 adolescents under the age of 20 (19 males, 31 females) recruited from Hospital N in Incheon, Korea. Participants were categorized into groups according to the severity of insomnia in both males and females using the Korean version of the Insomnia Severity Index-Korean (ISI-K). The Korean version of the International Physical Activity Questionnaire was also used to calculate participants’ weekly moderate and vigorous physical activity. RESULTS The participants’ characteristics did not differ by insomnia severity in males, but there were significant differences in weight (p=.008), BMI (p=.019), SBP (p=.004), and DBP (p=.019) in females by insomnia severity. In male adolescents, there was no significant difference in the amount of physical activity by insomnia severity, but there was a trend toward decreased amount of physical activity with increasing severity. Among female adolescents, there were significant differences in the amount of physical activity by insomnia severity: moderate (p<.05), high (p<.05), and moderate-high (p<.05). In the unadjusted model, adolescents who did not meet the recommended amount of physical activity (150 minutes per week) were more likely to have insomnia (OR=4.67, 95% CI=1.34–16.24) than those who met the recommended amount of physical activity. The model after adjusting for covariates (gender and body mass index) also showed an association between the recommended amount of physical activity and insomnia (OR=3.94, 95% CI=1.17–13.28). Negatice correlations was found between insomnia index and moderate-to-vigorous physical activity (r=–.357, p=.013). CONCLUSIONS Adolescents are approximately 4.67 times more likely to suffer from insomnia if they do not meet physical activity recommendations, and there was a negative correlation between the insomnia index and moderate-to-vigorous physical activity, suggesting that physical activity should be increased to reduce the insomnia index.
PURPOSE Blood pressure (BP) in hypertensive individuals is reduced by the accumulation of post-exercise hypotension (PEH) induced by a long period of training. This study aimed to investigate the effects of intensity of two different aerobic exercises with identical energy expenditure on post-exercise blood pressure and cardiovascular function in prehypertensive men. METHODS Eleven prehypertensive men in their 30s participated in two trials repeatedly. In the first trial, the exercise was moderate in intensity and continuous (MICE) with 70% of VO2max, and the exercise in the second trial was high-intensity interval exercise (HIIE) with 50% and 90% of VO2max. Each exercise was performed for 30 min, and the variables related to BP and cardiovascular function were measured at certain times for 1 hr during the recovery phase. RESULTS Our main findings are as follows: (1) Systolic blood pressure was significantly lower at 30 and 45 min of recovery time than the baseline in the HIIE trial, and systolic blood pressure was significantly lower in the HIIE trial than the MICE trial at 10, 15, and 30 min of recovery time. (2) The rate pressure product was significantly higher in the HIIE trial than the MICE trial at 15, 30, 45, and 60 min of recovery time. (3) The heart rate was significantly higher in the HIIE trial than the MICE trial at 15, 30, 45, and 60 min of recovery time. (4) Stroke volume was significantly lower in the HIIE trial than the MICE trial at 30 min of recovery time. (5) Cardiac output was significantly higher in the HIIE trial than the MICE trial at 15 min of recovery phase. (6) Total vascular conductance was significantly higher in the HIIE trial than the MICE trial at 15 and 30 min of recovery phase. (7) Total peripheral resistance was significantly lower in the HIIE trial than the MICE trial at 15 and 30 min of recovery phase. CONCLUSIONS The HIIE shows a higher cardiovascular stress than MICE; however, HIIE contributes to the augmentation of PEH and improvement of cardiovascular function. Therefore, HIIE rather than MICE should be suggested in BP control and enhancement of cardiovascular function in prehypertensive males.
