• Journal of the Korea Convergence Society
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• v.9 no.9
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• pp.309-317
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• 2018

The purpose of this study was to investigate the effect of bone age on physique and physical fitness in elementary school students. For this purpose, the structural equation model test was conducted based on the three-year longitudinal study. The results were as follows. First, bone age in boys and girls (1st~3rd grade) has a direct effect on the change of body size, but it does not affect the change of physical strength. Second, the bone age of the senior male students(4~6 grade) gave a direct effect on the change of physique, 50m running, and sit-up. On the other hand, it gave an indirect effect on push-ups, sitting basketball throws, and standing long jump. Third, the bone age of the female students(grades 4~6) affected directly on body size change, sit-up, side step and indirect effect on 50m running, half squat jump, and standing long jump. These results indicated that the evaluation of the bone age of the subjects should be included in the exercise ability evaluation items for the male and female students in elementary school over the fourth grade in relation to the myofunction.

• PNF and Movement
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• v.17 no.2
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• pp.177-187
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• 2019

Purpose: The purpose of this study was to investigate the effects of combined training on the physical fitness of male short distance athletes. Methods: Combined training was applied with CLT and isokinetric training three times a week for eight weeks. For CLT, elastic bands were used in the sitting and standing positions to gradually increase sprint and skating movements. Isokinetic training was conducted at $60^{\circ}/sec$ and $180^{\circ}/sec$ to improve muscle strength and muscle power. Results: After the application of combined training, strength (hand force) improved from 42.25 kg to 47.30 kg. Muscle power for standing long jump improved from 240.00 cm to 248.80 cm, while the sergeant jump improved from 55.00 cm to 58.00 cm. Isokinetic testing showed that muscle strength ($60^{\circ}/sec$) improved from 315.65 %BW to 365.79 %BW for the left extensor and from 306.60 %BW to 325.00 %BW for the right extensor. The left flexor improved from 177.23 %BW to 189.47 %BW, but the right flexor decreased slightly from 210.87 %BW to 201.53 %BW. Muscle power ($180^{\circ}/sec$) improved from 254.00 %BW to 293.00 %BW for the left extensor and from 256.00 %BW to 272.00 %BW for the right extensor. The left flexor improved from 150.00 %BW to 162.00 %BW and the right flexor from 145.25 %BW to 182.00 %BW. Conclusion: Combined training could be used as a physical training program for male short distance athletes.

• Journal of the Korean Applied Science and Technology
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• v.39 no.4
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• pp.527-534
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• 2022

The purpose of this study was to investigate the effects of 12 weeks of muscle power and agility training on physical fitness factors and isokinetic muscle function in elementary school male soccer players. For this purpose, 6 muscle power and agility training programs were organized for 12 elementary school male soccer players and were conducted 3 times a week for 12 weeks. The results of measurement and analysis of physical fitness factors before and after the muscle strength and agility training are as follows. First, there was a significant difference in the standing long jump in place of muscle power(p<.001). Second, there was a significant difference in the standing vertical jump of muscle power(p<.05). Third, there was a significant difference in the side step of agility(p<.01). As a result, 12 weeks of muscle power and agility training can be expected to have a positive effect on the improvement of agility and agility of elementary school male soccer players, and it is judged that it can provide training basic data for injury prevention and performance improvement.

• Korean Journal of Applied Biomechanics
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• v.27 no.2
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• pp.99-108
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• 2017

Objective: The purpose of this study was to analyze the effects of skill level and width between feet on kinematic and kinetic variables during jump rope single under with both feet. Method: Fifteen subjects in the skilled group (age: $10.85{\pm}0.40yrs$, height: $142.13{\pm}5.41cm$, weight: $36.97{\pm}6.65kg$) and 15 subjects in the unskilled group (age: $10.85{\pm}0.40yrs$, height: $143.31{\pm}5.54cm$, weight: $40.81{\pm}10.39kg$) participated in this study. Results: Participants in the skilled group minimized the anteroposterior displacement of their center of mass by modifying the width between their feet and decreased the range of motion (ROM) of their trunk in the sagittal plane. The preferred width during the jump rope decreased by 5.61~6.11 cm (32~37%) in comparison to width during static standing. The induced width was increased by 16.44~16.67 cm (82~85%), regardless of skill level. The kinematic variables of the left and right legs of members of the unskilled group were significantly different from those of members in the skilled group regarding the ROM of the hip, knee, and ankle joint. Otherwise, the members of the skilled group were consistent in terms of the kinematic variables of the right and left legs. Conclusion: The preferred width between feet during the jump rope was found to be beneficial for maintaining dynamic stability. The unskilled group exhibited asymmetry in left and right motion within the ranges of motion of the ankle, knee, and hip joints, regardless of the width. Therefore, long-term accurate jump rope motions will contribute to an improvement in the left and right imbalances of the entire body.

• Journal of Life Science
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• v.20 no.12
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• pp.1844-1850
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• 2010

Body fat reducing and physical-activity enhancing effects, along with artherosclerosis improving effects, of conjugated linoleic acid (CLA) were elucidated on obese male middle school students with more than 30% body fat. Twenty-four volunteers were randomly divided into control (placebo, n=12) and CLA treatment (n=12) groups. Subjects were daily fed 6 g CLA (6 capsules, twice a day) or a placebo for 12 weeks. At the end of the experiment, body composition, blood lipid composition and exercise capacities of subjects were measured. CLA significantly reduced body fat content and body mass index (BMI) along with body weight, while the placebo did not have any such effects. Similarly, CLA significantly reduced low-density lipoprotein (LDL)-cholesterol, total cholesterol, and triglyceride, but elevated high-density lipoprotein (HDL)-cholesterol content in blood. Meanwhile, in terms of exercise capacity, there were significant enhancements of trunk flexion, closed-eyes foot balance, standing long jump, shuttle run, and sit-up activities in the CLA treatment group. These results indicate that CLA consumption reduced body fats, improved atherosclerosis factors in blood and improved physical activity of young male obese middle school students, and suggest that CLA could be a useful material for the heath care of obese young men.

• Exercise Science
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• v.21 no.2
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• pp.183-190
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• 2012

This study is to evaluate the availability of cardiorespiratory fitness measurement by 20 m shuttle run test based upon energy contribution rates of elite athletes in different sports type. Sixty-seven elite athletes attending K national university participated in this study. They were divided by three groups based upon sports type, composed of Anaerobic Group (sprint, jumps, weightlifting, throw; n=35), Aerobic Group (medium-long distance; n=9), and Combat Sport Group (judo; n=23). 20 m shuttle run test was conducted by Leger et al.(1982) method and calculating acceleration using measured shuttle run repetitions was conducted by Brewer et al.(1988) method. To test the usefulness of VO₂max, graded exercise treadmill test was conducted and standing long jump and 50 m run were measured as power fitness factors. Z-jump was used for measuring power, agility, and muscular endurance. Standing long jump and 50 m run of Anaerobic Group (AnG) was significantly higher than that of Aerobic Group (AeG) and Combat Sport Group (CG) (p<0.05). However, Z-jump of CG was significantly higher than that of AnG and AeG(p<.05). There was a higher correlation of 20 m shuttle run test and VO₂max in AnG(r= 0.577, p<.0001) and CG(r= 0.760, p<.0001). Otherwise, there was a low correlation of 20 m shuttle run test and VO₂max in AeG. There was no significant group difference to test the availability of 20 m shuttle run test and there was a reduced error when converting 20 m shuttle run results into VO₂max. This study examined the usefulness of 20 m shuttle run test by converting 20 m shuttle run repetition results into VO₂max calculation, which showed reduced error. Therefore, this study confirmed that it would be needed to convert 20 m shuttle run results into VO₂max for universal and practical use in the field without dividing sports type.

• Journal of Korean Society of Forest Science
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• v.109 no.4
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• pp.544-552
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• 2020

This study investigated the effectiveness of "Healing Stay in Forest," a long-term stay forest therapy program implemented by National Center for Forest Therapy in 2019 with 49 participants by measuring pre- and post-questionnaire responses and physical changes, such as blood pressure, body composition, and HRV. Results confirmed statistically significant reduction in negative emotions and enhancement of autonomic nerve balance in the participants. Regarding the changes in the evaluation of physical fitness based on medical history, some significant differences were observed in grip strength and standing high jump, in which participants with no medical history showed better results than those with medical history. These findings are important for verifying the effectiveness of long-term stay forest therapy (6 nights and 7 days).

• Fashion & Textile Research Journal
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• v.24 no.1
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• pp.156-163
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• 2022

Loss of leg muscle and muscle weakness, which are caused by aging, affect muscle function and sense of balance. As a way of preventing seniors from falling, we developed the idea of wearing functional supporters based on graduated compression technique and in the form of a taping supporter. Their impact on power, sense of balance, overcoming fatigue, and subjective wearing sensation was investigated. The following results were obtained. After wearing functional compression supporters, body temperature increased from 24.5 ± 0.5℃ to 26.3 ± 0.6℃. Calf size, which assesses the level of edema, decreased from 26.1 ± 1.8cm to 25.7 ± 1.8cm. The result of dynamic balance test, which helps estimate the fall prevention effect, increased from 6.4 ± 0.9sec to 7.1 ± 0.6sec. Lactate level, which indicates the level of fatigue, decreased from 8.1 ± 0.6mmol/L to 7.3 ± 0.8mmol/L. Standing long jump record, which assesses power, increased from 110.1 ± 3.1cm to 112.0 ± 2.8cm. Standing on one leg with eyes closed, which assesses sense of balance, increased from 4.2 ± 1.1sec to 6.5 ± 0.8sec. Ankle angle, which assesses joint stability, increased from 75.3 ± 4.0° to 80.1 ± 1.7°. In metabolism and physical performance testing, which assesses keep, the score increased from 26.3 ± 1.7 to 28.8 ± 1.2. Muscle supporting score, which assesses joint stability, increased from 7.3 ± 0.6 to 7.8 ± 0.4. In the category of body type, which assesses wearing sensation and body shaping function, the score increased from 5.7 ± 1.4 to 6.4 ± 1.2

• Journal of the Korean Data and Information Science Society
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• v.23 no.2
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• pp.309-315
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• 2012

The purpose of this study was to examine the comparison of physique with physical fitness according to TBS (Talented-Educational in Sport) program by H University in 2009-2011. For this study, 668 elementary students (2009: 297, 2010: 194, 2011: 177 or 1st: 506, 2nd: 104, 3rd: 58) were collected who aged 7 to 13 living in Seoul and Gyeonggi area. The subjects were measured on physique variables (5) and physical fitness variables (7). Mean comparisons (ANOVA) were conducted for each gender in order to compare the mean differences among attendance number. For association analysis, Pearson correlation coefficient was used to find association between the physique and physical fitness variables. Some physical fitness variables (sit up, half squat jump, side step, standing long jump, flexibility in male children; sit up, half squat jump, side step in female children) increased significantly in the attendance number but the physique variables did not. The results show that TES program was effective on the physical fitness variables (muscle endurance & agility) in sports talent children.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.7
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• pp.966-974
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• 2010

The aim of this study was to examine characteristics between nutrient intakes, body composition and physical fitness in gifted athletic boys. The subjects were conducted in 50 boys aged 9~12 years living in Busan, Ulsan and Gyeongsangnam-do, Korea. Dietary intake information was collected from participants using 3-day food recorded and body composition was measured by bioelectrical impedance analysis, and their anthropometric parameters were measured. Swimming group's daily energy intakes were significantly higher compared to those of other groups. Athletics and swimming groups were significantly taller than gymnastics. Swimming group was significantly higher than gymnastics group in weight, fat mass, body fat percent and lean body mass. Athletics and swimming groups were significantly longer than gymnastics group in sit and ball throwing. Swimming group was significantly better than other groups in sit up, and athletics group was significantly faster than gymnastics group in 50 m run. In correlation result for nutrient intake and body composition: 1) Body weight shows positive correlation with protein, phosphorus, sodium, vitamin $B_1$, C and niacin. BMI shows positive correlation with sodium and niacin. Fat mass shows positive correlation with niacin and folate. Body fat% shows positive correlation with vitamin C, E, niacin and folate. LBM shows positive correlation with all elements except lipid, calcium, vitamin A, C, E and folate. In correlation result for nutrient intake and physical fitness: 2) Push up shows positive correlation with iron and vitamin C. Sit and throw ball shows positive correlation with the events except lipid, fiber, vitamin A, E and folate. Sit up shows positive correlation with vitamin $B_1$. Half squat shows positive correlation with iron. Standing long jump shows positive correlation with total energy, lipid, and vitamin A, B and $B_2$. Long run shows negative correlation with protein, carbohydrate, fiber, phosphorus, iron, sodium and zinc. Side step shows positive correlation with niacin. Sit and reach shows negative correlation with total energy, carbohydrate, phosphorus, sodium, zinc and vitamin $B_2$. In correlation result for body composition and physical fitness: 3) Sit and throw ball shows positive correlation with body weight, BMI, fat mass, body fat% and LBM. Standing long jump shows positive correlation with LBM. But long run and 50 m run shows negative correlation with body weight and LBM.