• Nutrition Research and Practice
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• v.9 no.4
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• pp.370-378
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• 2015

BACKGROUND/OBJECTIVES: Athletes generally desire changes in body composition in order to enhance their athletic performance. Often, athletes will practice chronic energy restrictions to attain body composition changes, altering their energy needs. Prediction of resting metabolic rates (RMR) is important in helping to determine an athlete's energy expenditure. This study compared measured RMR of athletic and non-athletic adolescents with predicted RMR from commonly used prediction equations to identify the most accurate equation applicable for adolescent athletes. SUBJECTS/METHODS: A total of 50 athletes (mean age of $16.6{\pm}1.0years$, 30 males and 20 females) and 50 non-athletes (mean age of $16.5{\pm}0.5years$, 30 males and 20 females) were enrolled in the study. The RMR of subjects was measured using indirect calorimetry. The accuracy of 11 RMR prediction equations was evaluated for bias, Pearson's correlation coefficient, and Bland-Altman analysis. RESULTS: Until more accurate prediction equations are developed, our findings recommend using the formulas by Cunningham (-29.8 kcal/day, limits of agreement -318.7 and +259.1 kcal/day) and Park (-0.842 kcal/day, limits of agreement -198.9 and +196.9 kcal/day) for prediction of RMR when studying male adolescent athletes. Among the new prediction formulas reviewed, the formula included in the fat-free mass as a variable [$RMR=730.4+15{\times}fat-free\;mass$] is paramount when examining athletes. CONCLUSIONS: The RMR prediction equation developed in this study is better in assessing the resting metabolic rate of Korean athletic adolescents.

• Korean Journal of Applied Biomechanics
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• v.28 no.2
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• pp.79-85
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• 2018

Objective: This study aimed to create a strategic training method to enhance optimal athletic ability using information from 1H to 10H rhythmic units. Method: Top three world class athletes and three national winners of 110-m hurdle finals from the 2010 Daegu International Athletics Competition and 2017 National Athletics Championship, respectively, were selected. To analyze the kinematic variables, Dartfish 9.0 was used for two-dimensional analysis. Results: Regarding the interval time from the start to the finish line, the national athletes took less time during the pure acceleration phase (start to 1H) than the foreign athletes. The horizontal velocity increase was slower after 1H; the national athletes showed a lack of ability to accelerate at the interval phases. Moreover, the hurdle clearance time between phases was longer in the national athletes than in the foreign athletes and lacked consistency. Conclusion: The national athletes lacked the ability to accelerate at the transition, maximum rhythm, rhythm maintenance, and re-acceleration phases and showed a longer hurdle clearance time. If technical improvements and strategic training methods using rhythmic units are applied for hurdling motions, the national athlete's hurdling abilities, performance, and consistency could improve.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.545-553
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• 2016

The purpose of this study is finding out the effect of self-confidence and stress on University Judo Athletes performance. For this study, 249 participants of University Judo team athletes were sampled using convenient sampling method. To process data, AMOS 23.0 and SPSS PC+23.0 Version statistical program for WINDOWS were used and frequency analysis, confirmatory factor analysis, reliability, correlations and structural equation model analysis were conducted. Through such processes and method of the study as above, the results of this study are as follows. Firstly, it was discovered that self-confidence had static influence to athletes performance. Secondly, the stress did not affect the athletes performance.

• Journal of Digital Convergence
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• v.14 no.3
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• pp.401-408
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• 2016

This study was an investigation of 379 people to analyze the relations between leadership and happiness recognized by university athletes. First, happiness of university athletes showed the highest score in smooth relationship with parents. And male athletes score higher than female athletes. Second, the sub-factors of achievement and self-acceptance of happiness have significantly correlated with all factors of leadership. In particular, self-improvement, goal-seeking, and influence are most highly correlated. And the religious influence was the lowest correlation. Third, achievement orientation of leadership factors affect all sub-factors of happiness and influence, and self-regulation has an effect to sub-factors of happiness. Fourth, flexible leadership, interpersonal understanding, teamwork and cooperation, orientation did not affect happiness.

• The Korean Journal of Physiology
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• v.24 no.2
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• pp.249-260
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• 1990

Maximal cardiac output and oxygen uptake $(VO_{2max})$ were measured during treadmill exercise for seven top-class marathoners and nine non-athletes using impedance cardiograph developed by one of the authors (DW Kim). Results of this study are summarized as belows. 1) New shoes with sponge and silicon rubber attached to the soles were developed to reduce motion artifact during treadmill exercise. Ensemble everaging techneque with the developed shoes was also used to improve the measurement of stroke volume using impedance cardiography. 2) Maximal cardiac output of the athletes, 14.98 L/min, was significantly higher than that of the non-athletes, 13.46 L/min. As maximal heart rate of the marathoners is lower than that of non-athletes, stroke volume of the former is significantly larger than that of the latter. 3) $VO_{2max}$ of the marathoners, 59.38 ml/kg/min, was higher than that of the non-athletes, 40.22 ml/kg/min. At the anaerobic threshold. $VO_{2max}$ of the former was 62.3% of $VO_{2max}$ and this was significantly higher than that of the non-athletes, 57.2%, This results indicates that the marathoners have higher aerobic capacity than the non-athletes. 4) The marathoners showed larger $VO_2$ than the non-athletes at the same cardiac output, indicating that a-v $O_2$ of the former is higher than that of the latter. 5) Maximal systolic pressure of the marathoners was higher than that of the non-athletes, and so was maximal rate-pressure products. These results indicate that heart oxygen consumption rate $(hVO_2)$ of the marathoner is higher than that of the non-athletes is mainly due to higher stroke volume. And higher oxygen consumption of the marathoners is due to higher stroke volume. And higher oxygen consumption of the marathoners is due to their larger a-v $O_2$. The marathoners show both higher threshold and $VO_{2max}$. Especially, measurement of cardiac output during treadmill exercise by improved impedance cardiography is expected to contribute in study of cardiac function of athletes.

• Clinics in Shoulder and Elbow
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• v.20 no.2
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• pp.77-83
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• 2017

Background: Although there have been multiple reports on surgical outcomes of superior labral anterior to posterior (SLAP) lesions in overhead athletes, only a few reports exist in the literature about the results of nonoperative treatment in elite (collegiate or professional) overhead athletes. To determine the clinical outcomes of nonoperative treatment of SLAP lesions in elite overhead athletes. Methods: Between January 2006 and December 2011, 69 patients were selected. Initial arthroscopic SLAP repair was performed in 19 patients and of the 50 patients who underwent nonsurgical treatment, such as range of motion gain and periscapular muscle strengthening, 14 patients were converted to surgical treatment; 5 patients were lost to follow-up. Medical records of 31 elite overhead athletes who underwent nonsurgical treatment were retrospectively reviewed. Four clinical outcome measures were used: visual analogue scale (VAS) for pain, VAS for satisfaction, American Shoulder and Elbow Surgeons (ASES) score, and subjective feeling of recovery. Results: The average follow-up period was 35.9 months (range, 24-62 months). The VAS for pain decreased from 6.5 to 2.2 (p<0.01) and VAS for satisfaction was 7.6. The ASES score increased from 54.1 to 85.9 (p<0.01). The overall average value of subjective feeling of recovery was 72%. Twenty-three out of 31 elite athletes (74.2%) returned to play after rehabilitation; these 23 athletes performed at the same or higher levels after rehabilitation. Conclusions: Nonsurgical treatment in elite overhead athletes with SLAP lesion should be considered as a treatment option.

• Korean Journal of Applied Biomechanics
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• v.22 no.1
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• pp.9-16
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• 2012

The purpose of this study was to compare and analyze muscle function and EMG of the trunk and the lower extremity in short and long distance athletes and in order to determine difference in peak torque per unit weight, muscle power per unit weight, endurance ratio, and %MVIC classified by muscle. For that purpose, isokinetic muscle function tests for waist, knee, and ankle joints and EMG measurements for the trunk and the lower extremity muscle with running motion were conducted for 7 short and long distance high school athletes respectively. The study over muscle function of waist, knee, and ankle joints indicates that peak torque per unit weight of short distance athletes is higher than that of long distance athletes in extension and flexion of waist joint, plantar flexion of right ankle joint, and dorsi flexion of left ankle joint. In case of the muscle power per unit weight of short distance athletes is also higher than long distance athletes in waist, knee, and ankle joints. No difference in endurance ratio of waist, knee, and ankle joints between the two groups was founded. The results of the test over EMG of the trunk and the lower extremity show that %MVIC of erector spinae, rectus femoris, vastus medialis, vastus lateralis, and tibialis anterior is higher than that of long distance athletes in support phase. The above results proved to be the same in flight phase except for %MVIC of medial gastrocnemius. In other words, %MVIC of medial gastrocnemius for short distance athletes turned out to be higher than that of long distance athletes in flight phase.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.1 s.160
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• pp.44-56
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• 2007

The aim of this study is to provide fundamental data on the development of dress shirts pattern appropriate for the body types of athletes. The research subjects are 257 athletes from wrestling, bodybuilding, weight lifting, Judo, canoe, rowing. In regards to the category used in the measurement of bust somatotype, there are 48 types directly measured, 4 types indirectly measured, 7 types calculated and 1 bodyweight of type, making it 60 categories in total. The bust somatotype of a sports athlete and general person were compared together and after examining the characteristics of the bust somatotype, the somatotype of sports athlete was divided according to drop. The results of the study are as follows: 1. Questionnaire Results of the questionnaire showed that 63.4% of the respondents chose dress shirt as the most uncomfortable upper garment for athletes. And as for the result of the most uncomfortable body part turned out to be 'the neck is tight'. 2. Somatotype Analysis Results of direct, indirect measurement and the average somatotype of 97 National standard physique were compared. The characteristics of somatotype of athletes with well-developed upper body are that they are taller and have longer upper body and arms than the general person. And also the width of the trunk is wider, the girth bigger and the waist measure relatively slimmer. Looking at sports by category, it we could see that wrestlers were the largest neck parameter and width. Bodybuilders were the largest body parts for most categories. Weight lifting and Judo athletes were the largest waist and buttock. Canoe and rowing athletes were the largest height and arm parts. Dividing the somatotype of athletes according to drop, 72.8% of the research group belonged to the body type that resembled the letter Y.

• Korean Journal of Applied Biomechanics
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• v.25 no.3
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• pp.275-281
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• 2015

Objective : In order for Taekwondo athletes to perform destructive kicking performance, they are expected to have Taekwondo-specific muscle properties such as high muscle strength and power. The purpose of this study was to investigate the joint angle-dependent force-producing property of Taekwondo athletes' knee extensor muscles, which is one of the primary muscle groups involved in kicking performance. Method : Ten Taekwondo male athletes (age: $19.9{\pm}0.7yrs$, height: $180.6{\pm}6.2cm$, body mass: $75.9{\pm}8.9kg$, career: $9.2{\pm}2.9yrs$.) and 10 healthy male non-athletes (age: $26.3{\pm}2.6yrs$, height: $174.2{\pm}4.8cm$, body mass: $72.8{\pm}7.7kg$) participated in this study. Subjects performed maximum isometric knee extension at knee joint angles of $40^{\circ}$, $60^{\circ}$, $80^{\circ}$, and $100^{\circ}$ (the full knee extension was set to $0^{\circ}$) with the hip joint angles of $0^{\circ}$ and $80^{\circ}$ (the full extension was set to $0^{\circ}$). During the contractions, knee extension torque using an isokinetic dynamometer simultaneously with muscle activities of the rectus femoris (RF), and the vastus lateralis (VL) and vastus medialis (VM) using surface electromyography were recorded. Based on the torque values at systematically different knee-hip joint angles, the joint torque-angle relationships were established and then the optimal joint angle for the knee extensor was estimated. Results : The results of this study showed that the isometric knee extension torque values were greater for the Taekwondo athletes compared with the non-athlete group at all hip-knee joint angle combinations (p<.05). When the hip joint was set at $80^{\circ}$, the peak isometric torque was greater for the Taekwondo athletes compared with the non-athlete group ($313.61{\pm}36.79Nm$ and $221.43{\pm}35.92Nm$, respectively; p<.05) but the estimated optimum knee joint angles were similar ($62.33{\pm}5.71^{\circ}$ and $62.30{\pm}4.67^{\circ}$ for the Taekwondo athletes and non-athlete group, respectively). When the hip joint was set at $0^{\circ}$, the peak isometric torque was greater for the Taekwondo athletes compared with the non-athlete group ($296.29{\pm}45.13Nm$ and $199.58{\pm}25.23Nm$, respectively; p<.05) and the estimated optimum knee joint angle was larger for the Taekwondo athletes compared with the non-athlete group ($78.47{\pm}5.14^{\circ}$ and $67.54{\pm}5.77^{\circ}$, respectively; p<.05). Conclusion : The results of this study suggests that, compared with non-athletes, Taekwondo athletes have stronger knee extensor strength at all hip-knee joint angle combinations as well as longer optimum muscle length, which might be optimized for the event-specific required performance through prolonged training period.

• Journal of Sport and Applied Science
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• v.6 no.4
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• pp.11-23
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• 2022

New insights into the aetiology of anaemia in athletes have been discovered in recent years. From hemodilution and redistribution, which are thought to commit to so-called "sports anaemia," to iron deficiency triggered by higher requirements, dietary requirements, decreased uptake, enhanced losses, hemolysis, and sequester, to genetic factors of different types of anaemia (some related to sport), anaemia in athletes necessitates a careful and multisystem methodology. Dietary factors that hinder iron absorption and enhance iron bioavailability (e.g., phytate, polyphenols) should be considered. Celiac disease, which is more common in female athletes, may be the consequence of an iron deficiency anaemia that is unidentified. Sweating, hematuria, gastrointestinal bleeding, inflammation, and intravascular and extravascular hemolysis are all ways iron is lost during strength training. In training, evaluating the iron status, particularly in athletes at risk of iron deficiency, may work on improving iron balance and possibly effectiveness. Iron status is influenced by a healthy gut microbiome. To eliminate hemolysis, athletes at risk of iron deficiency should engage in non-weight-bearing, low-intensity sporting activities.