• Journal of the Korean Dietetic Association
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• v.15 no.1
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• pp.52-68
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• 2009

This study compared activity factor. predicted resting metabolic rate (RMR), and nutrient intakes between athletic and non-athletic high school students in Gangwon-do. Fifty soccer players (30 males and 20 females; mean ages 16.7${\pm}$1.0 years and 16.4${\pm}$1.1 years. respectively) and 50 non-athletic (30 males and 20 females: mean ages 17.5${\pm}$0.4 years and 16.4${\pm}$1.1 years respectively) high school students were included. Anthropometric measurements included: weight and height. triceps skinfold, mid-ann circumference, and body fat. Prediction equations consisted of those from the Harris-Benedict. FAO/WHO/VNU, IMNA, Cunningham, Mifflin et al., and Owen et al. A one-day activity diary was collected by interview, and the 24-hour recall method was used to analyze nutrient intakes of subjects. The activity factors of the male and female athletic groups (2.23 and 2.16, respectively) were significantly higher than those (1.52 and 1.46, respectively) of the non-athletic group. There was only a significant difference in RMR by use of the Cunningham's equation between two groups. For the males. almost all nutrient intakes of the athletic group (except carbohydrate, iron, vitamin $B_1$, $B_6$, and niacin) of athletic group were significantly higher than those of the non-athletic group. The female athletic group showed significantly higher nutrient intakes with the exception of most vitamins. These results suggest that assessments of energy balance between energy intake and energy expenditure by employing RMR and activity factors would be useful to prevent and treat obesity in high school athletes. In addition, the Cunningham's equation would be appropriate for predicting their energy needs.

• Korean Journal of Applied Biomechanics
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• v.29 no.4
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• pp.255-261
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• 2019

Objective: The purpose of this study was to investigate differences of shock attenuation strategies between double-leg and single-leg landing on sagittal plane using statistical parametric mapping. Method: Nine healthy female professional soccer players (age: 24.0±2.5 yrs, height: 164.9±3.3 cm, weight: 55.7±6.6 kg, career: 11.2±1.4 yrs) were participated in this study. The subjects performed 10 times of double-leg and single-leg landing from the box of 30 cm height onto force plates respectively. The ground reaction force, angle, moment, angular velocity, and power of the ankle, knee, and hip joint on sagittal plane was calculated from initial contact to maximum knee flexion during landing phase. Statistical parametric mapping was used to compare the biomechanical variables of double-leg and single-leg landing of the dominant leg throughout the landing phase. Each mean difference of variables was analyzed using a paired t-test and alpha level was set to 0.05. Results: For the biomechanical variables, significantly increased vertical ground reaction force, plantarflexion moment of the ankle joint, negative ankle joint power and extension moment of the hip joint were found in single-leg landing compared to double-leg landing (p<.05). In addition, the flexion angle and angular velocity of the knee and hip joint in double-leg landing were observed significantly greater than single-leg landing, respectively (p<.05). Conclusion: These findings suggested that negative joint power and plantarflexion moment of the ankle joint can contribute to shock absorption during single-leg landing and may be the factors for preventing the musculoskeletal injuries of the lower extremity by an external force.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.4
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• pp.71-83
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• 2021

Purpose : This study compared the differences in power and agility of athletes in each sports using visual response speed test (VRST) scores after conducting 10 weeks of body stability exercise (BSE) on elementary school athletes in handball, football, volleyball and conducted a post-hoc test on the measured values. The subjects of this study were baseball (n=27), taekwondo (n=22), and football (n=23) athletes with at least two years of athletic experience. A total of 72 elementary school athletes were measured by VRST after 10 weeks of BSE under the same conditions. Methods : For VRST measurement of the upper extremity, the right and left hands were alternately touched in the order the blazepod equipment lights were turned on. The number of touches for 15 seconds and response touch were measured. In the case of the measurement of lower extremity the left lower extremity was measured first when the Blaze pod equipment light came on. The average value was obtained by measuring 3 times using a measurement sensor with the position indicated in order to measure the upper arms and legs the same. Results : This study confirmed homogeneity among sports and that VRST improved after implementing BSE for sports. However, no statistically significant difference was identified when comparing VRST improvements between sports, and post-hoc test results showed no significant differences either. Conclusion : After applying the BSE program under the same conditions for 10 weeks to elementary school students who can improve their power and agility the most, the results of the examination using the Blaze pod showed that the power and agility of baseball, taekwondo, and soccer players were similarly improved. From the fact that there was no significant difference among sports, it could be inferred that the BES training program could improve VRST without being limited to some sports.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.827-838
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• 2017

Twenty male soccer players volunteered as the experimental subjects. The subjects were randomly assigned to the "Winter training with Cornus officinalis extract intake group"(WCI; n=10) and "Winter training group"(WT; n=10). The variables of blood fatigue substance, muscle damage and liver function where measured in all the subjects before the start of the Cornus officinalis intake after at the end of the 4 weeks winter training. Winter training program was proceeded with 6 days a week for 4 weeks. Exercise intensity was measured using the HRR(70~95%). Changes in the heart rate were also measured with the Polar. WCI group were ingested 80 mL of Cornus officinalis extract after every breakfast and dinner for 4 weeks. The test data were analyzed by paired t-test, and independent t-test(%diff), and the alpha level of p<.05 was set for all tests of significance. Lactate in WCI group had significantly decreased, and the changes between the groups were significantly lower in the WCI group than in the WT group. Ammonia in WCI group had significantly increased. CK in WCI group had significantly decreased. LDH in both group had significantly decreased. AST in WCI group had significantly decreased, and the changes between the groups were significantly lower in the WCI group than in the WT group. ALT in WCI group had significantly decreased. In conclusion, the results of this study show that Cornus officinalis extract seem to have a positive influence on blood fatigue substance, muscle damage and liver function. Therefore Cornus officinalis extract is considered to be able to contribute an ergogenic aids.

• Korean Journal of Community Nutrition
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• v.22 no.5
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• pp.413-425
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• 2017

Objectives: Accurate assessment of energy expenditure is important for estimation of energy requirements in athletic children. The objective of this study was to evaluate the accuracy of accelerometer for prediction of selected activities' energy expenditure and intensity in athletic elementary school children. Methods: The present study involved 31 soccer players (16 males and 15 females) from an elementary school (9-12 years). During the measurements, children performed eight selected activities while simultaneously wearing the accelerometer and carrying the portable indirect calorimeter. Five equations (Freedson/Trost, Treuth, Pate, Puyau, Mattocks) were assessed for the prediction of energy expenditure from accelerometer counts, while Evenson equation was added for prediction of activity intensity, making six equations in total. The accuracy of accelerometer for energy prediction was assessed by comparing measured and predicted values, using the paired t-test. The intensity classification accuracy was evaluated with kappa statistics and ROC-Curve. Results: For activities of lying down, television viewing and reading, Freedson/Trost, Treuth were accurate in predicting energy expenditure. Regarding Pate, it was accurate for vacuuming and slow treadmill walking energy prediction. Mattocks was accurate in treadmill running activities. Concerning activity intensity classification accuracy, Pate (kappa=0.72) had the best performance across the four intensities (sedentary, light, moderate, vigorous). In case of the sedentary activities, all equations had a good prediction accuracy, while with light activities and Vigorous activities, Pate had an excellent accuracy (ROC-AUC=0.91, 0.94). For Moderate activities, all equations showed a poor performance. Conclusions: In conclusion, none of the assessed equations was accurate in predicting energy expenditure across all assessed activities in athletic children. For activity intensity classification, Pate had the best prediction accuracy.