This study aims to suggest the guide line for weight category sports(Taekwondo, Judo, Wrestling, Weightlifting, and Boxing) who have to lose weight to pass weigh-in before games. Reference data was collected from RISS, Medline, PubMed, SciELO and effects of short term weight loss on physiological variables(body composition, physical fitness, blood components, oxidative stress and hormone, immune function) were analyzed. Also, weight loss procedures for weight category sports athletes were analyzed in details. The results of the research are as follows: weight category sports athletes prefer short term (3~5 days) weight loss methods (3~5%) with dietary control, sweating and exercise. Physical changes caused by the loss in body weight, fat-free mass, and BMI, however, do not affect body fat percentage. Different changes of physical strength element depend on weight reduction period. In short term weight loss method, anaerobic exercise capacity, muscular strength, and reaction time partially decrease and affect staying power. In contrast, long term weight loss method do not affect aerobic and anaerobic exercise capacity. Furthermore, most of previous studies show that blood component change has negative effect on body water balance, stress-related hormone, and immune function. In conclusion, short term weight loss method negatively affects athletic performance of weight class competition athletic. Therefore, careful long term weight loss methods are recommended with dietetic consideration to prevent dehydration during weight loss period. Excessive weight loss on lightweight athlete should be prevented by institutional basis as well.
PURPOSE High blood pressure and obesity pose significant health problems for older individuals. Previous studies showed that regular exercise improves physical fitness factors and decreases blood pressure and obesity. Therefore, this study investigated differences in blood pressure and obesity according to the physical fitness level of Korean older individuals using the National Fitness 100 data and used them to recognize the importance of maintaining physical fitness through regular physical activity or exercise for older individuals. METHODS From 2013 to 2019, a total of 218,848 subjects (men=74,271, women=144,577) aged ≥65 years who participated in the National Fitness 100 had their muscular strength, muscular endurance, cardiorespiratory endurance, balance, coordination, and flexibility measured, and they were ascribed a fitness level. Blood pressure, body mass index (BMI), percentage of bodyfat, and waist circumference were measured to compare the difference in fitness level. RESULTS There was a significant difference in the systolic and diastolic blood pressure in older men, and the diastolic blood pressure of older women by the fitness level (p<.001). In both older men and women, there was a significant difference in BMI, percentage of bodyfat, and waist circumference according to the fitness level (p<.001). CONCLUSIONS In conclusion, men and women showed different aspects in blood pressure, but Korean older individuals with having a high level of fitness managed their weight and body fat well. The decrease in obesity and improvement of physical fitness through regular physical activity and exercise could be a positive effect on maintaining health and extending healthy life years.
Purpose The purpose of this study is to investigate the alienation and the overcoming process of the physical activity participation of people with Adventitious Visual Impairment(AVI) Methods 21 Adults with AVI were recruited and one on one semi-structured interview was conducted. Ground theory was used to analyze the data. Member check, peer debriefing was conducted to enhance the trustworthiness of this study. Results As a result, a total of 203 concepts were derived. This consisted of 21 subcategories and the common themes of the subcategories were categorized into nine categories. Specific results are as follows. First, the physical activity of people with AVI was directly affected by the sports facilities, physical activity programs, and professional instructor. This causal condition resulted in the loss of leisure experience in the context of the busy daily life and the depressed psychological state. Second, due to the perceived need of health care and the positive involvement of others, people with AVI came to expect the effect of exercise. Third, people with AVI participated in physical activity again as a tool to achieve the purpose of health improvement. This type of physical activity has a limitation that it can not guarantee the continuity of physical activity due to the limitation that it does not contain autonomy and interest of people with AVI. Conclusions Based on these results, the following suggestions were made. First, it is necessary to improve the environment for ensuring participation in physical activity of people with AVI. Moreover education and promotion of the effects and values of the exercise should be carried out for people with AVI and their guardians. Second, it is necessary to diversify physical activity types and reconstruct existing exercise programs.
The purpose of this study was to analysis of moving distance during games, time and heart rate for hockey games using GPS (global positioning systems) by positions in Korea national female athletes. The subjects were Korea national female hockey players (n=13) including 4 forwards, 4 midfields, and 5 fullbacks that participated in five Korea vs. Japan international games. All subjects were wearing GPS throughout the games. The results were as follows: Firstly, the average total travel distance per game was approximately 5.7km and higher in the second half. Physical movement in the games was not different from positions where 70% of physical movement was performed at low intensity and 30% at moderate and/or vigorous intensity, suggesting that the subjects; physical movement was performed at the appropriate level of exercise intensity. Secondly, during the game, the subjects performed physical movement faster than 11km/h for 22 minutes, indicating that the subjects could maintain their physical movement at a relatively faster speed throughout the games. In particular, midfields showed a greater amount of physical movement at moderate speed. Thirdly, the average exercise heart rate was 145bpm, which was equivalent to 60% of HRmax. The subjects maintained their average exercise heart rate greater than 150bpm (above 60% of HRmax) for 40 minutes during the games, indicating that the players had an ability to maintain physical movement at high intensity throughout the games. In conclusion, in spite of the fact that Korea national female hockey players have an ability to maintain physical movement at a relatively faster speed and higher intensity, their physical movement and performance are often affected. Therefore, it is necessary to develop and apply the specific interval training program for national female hockey players that can facilitate the faster recovery from the repetitive physical movement requiring power and speed at high intensity.
PURPOSE Using GPS data from actual field hockey matches, this study examined the effects of position and substitution time on the physical performance of elite female players. METHODS From 25 matches played in 2023, data involving 26 players were collected. Players’ positions were classified as forwards (FW), midfielders (MF), and defenders (DF). Substitution times were segmented into 5, 10, and 15 minutes, respectively. A two-way ANOVA was employed to analyze movement patterns across different exercise intensities as influenced by player position and substitution time, followed by Bonferroni post-hoc tests for further detailed analysis. RESULTS Analysis revealed that both position and substitution time significantly affected exercise intensity. Notably, at a substitution time of 5 minutes, substantial differences were observed in high-intensity movements, including the distance covered at high-intensity and the frequency of high-intensity efforts. Furthermore, the substitution time’s impact was particularly pronounced among forwards and midfielders. CONCLUSIONS Findings suggest that shorter substitution times can enhance players’ active movement, thereby supporting maintenance of tactical adjustments and positively influencing overall performance. Implementing shorter substitution times could be particularly beneficial for optimizing team performance, especially for players in forward positions.
PURPOSE The purpose of this review was to summarize the current knowledge on the trends in athletes’ health problems (and their preventive strategies) caused by low energy availability (LEA) and relative energy deficiency in sports (RED-S). METHODS In this narrative review, we summarized previous studies by searching the literature in the PubMed, Google Scholar, and Science Direct databases. RESULTS Energy availability (EA) refers to the amount of energy from caloric intake used for exercise, and a LEA is considered as a surrogate marker of RED-S. In several previous studies, chronic low energy availability in female athletes has been reported to cause health problems such as endocrine dysfunctions, immunosuppression, and psychological disorders, and to also affect the hypothalamic-pituitary-gonadal (HPC) axis and bone health. Moreover, it has been suggested that an increase in injury risk and a decrease in exercise performance may occur. CONCLUSIONS Since it can be difficult to recover from the health deteriorations caused by RED-S, early detection (of related signs and symptoms) and prevention are very important. Therefore, athletes, coaches, and parents need to develop educational programs that ease the recognition of the problems caused by various symptoms related to RED-S and promote educational interventions.
PURPOSE This study was conducted to estimate the tendency of psychological factors influencing cycling performance by analyzing the characteristic factors of athlete reputation in the news big-data. METHODS To explore the psychological factors influencing cycling performance, an open questionnaire was conducted on 82 cyclists, and Inductive Content Analyses was performed. Overall, 89,520 news articles were collected through BIGKinds, and forming factors of athlete reputation were derived through LDA topic modeling analysis and inductive categorization. Through regression analysis, time series tendency of the factors of athlete reputation was calculated. Finally, the tendency of psychological factors to influence cycling performance was estimated based on the previously derived results in this study. RESULTS The psychological factors influencing cycling performance were found to be; emotion control, trust capital, cognitive control, motivation and communications with the coach. The forming factors of athlete reputation was found to be; reporting of the sports event, infrastructure creation, analysis to performance, moral issue, social environmental changes and sports gossip. The time series tendency of the forming factors of athlete reputation was found to include the categories of Hot, Warm, Cool and Cold. The psychological factors influencing cycling performance are estimated to expand to exercise performance and moral intelligence. CONCLUSIONS The results of this study suggest that the discussion of psychological factors influencing cycling performance extends not only to exercise performance, but also to moral intelligence, reflecting the socio-cultural context in the discussion of performance.
The purpose of this study was performance improvement through analysis of movement in elite field hockey players regarding positions using real-time GPS monitoring for compared training game and 2014 Incheon Asian Games. Fifteen elite women field hockey players (Defender: 4, Mid-fielder: 6, and Forward: 5) participated in this study. There were 2014 Incheon Asian Games Korean national team. Real-time GPS system analysis was completed during 10 training game appearances 5 2014 Incheon Asian Games appearances. The results of this study showed that in training game mid-fielder>forward>defender for 3, 4, 5, and 6 zone at speed zone by moving distance, in 2014 Incheon Asian Games forward>mid-fielder>defender for 6 zone at speed zone by moving distance. And moving distance by quarter increased all position in 2014 Incheon Asian Game more than training game. Therefore, These data might be useful to analysis of movement in field hockey players. Moreover improved performance and individual exercise ability by feedback for players distance, heart rate, and exercise trajectory. Thus, Gold-medal won at the 2014 Incheon Asian Games in field hockey.
The purpose of this study was to examine the relationship between QTc interval and maximal oxygen consumption(V˙O2max) and body fat distribution in middle-aged men. Abnormal subjects (QTc interval, ≥440ms, n=10) and normal subjects(≤430ms, n=11) using QTc interval based on the Bazzet's equation were involved in the study. After overnight fasting, blood and blood pressure were measured. Abdominal fat area and regional fat compartment were measured by computed tomography(CT) and dual-energy X-ray absorptiometry(DXA), respectively. For V˙O2max, the subjects underwent a maximal graded exercise test on a cycling ergometer. Abnormal group was significantly higher in SBP, basal insulin, HOMA-IR, and leg fat compared with normal. There was a significant relationship(r=.614, p=.03) between QTc interval and V˙O2max in all subjects. Also, partial correlation analysis showed a significant relationship(r=.480, p=.032) between the QTc interval and V˙O2max. Having a QTc interval outside normal range significantly worsened risk parameters for metabolic syndrome, in particular blood pressure and insulin resistance. Moreover, QTc interval was strongly correlated with cardiorespiratory fitness in middle-aged men. This study indicates that further study will be needed to assess the exercise training effects on QTc interval.
PURPOSE The purpose of this study was to investigate the effects of an 8-week online yoga training on body composition, muscle activity, flexibility, and balance in males (n=7) and females (n=15). METHODS Twenty-two participants were recruited and divided into two groups (Exercise group, n=11 and control group, n=11). All participants had two visits. During the visits, body composition, muscle activity for forward and back-bending poses, flexibility for sitting-forward and back-bending poses, and balance for one-leg standing were determined. After 8-week yoga training, all measurements were re-performed. An independent t-test was performed to determine the difference between the exercise and control groups. A two-way repeated measures of ANOVA was used to assess the interaction effects (group*time). All values were represented as mean ± standard deviation. An α level was set at 0.05 for all analyses. RESULTS First, the height significantly increased (F=16.573, p=0.001) and body fat mass (F=7.109, p=0.015) and body fat percent (F=7.667, p=0.012) were significantly decreased after the 8-week online yoga training. Second, the muscle activity for vatus lateralis doing a back-bending pose (F=6.140, p=0.022) significantly increased after the 8-week online yoga training. Third, the flexibility on sitting-forward bending pose (F=4.661, p=0.043) and back-bending pose (F=11.650, p=0.003) were statistically increased after the 8-week online yoga training. Lastly, balance on the Center Of Pressure (COP) X (F=5.769, p=0.026) and the Center Of Pressure (COP) Y (F=4.365, p=0.05) significantly increased after the 8-week online yoga training. CONCLUSIONS This study will provide scientific evidence on improving exercise programs using online yoga training on physical activity.
