• Korean Journal of Exercise Nutrition
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• v.25 no.1
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• pp.1-6
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• 2021

[Purpose] We determined the effect of partial sleep deprivation (PSD) after an exercise session on exercise performance on the following morning. [Methods] Eleven male athletes performed either a normal sleep trial (CON) or a PSD trial. On the first day (day 1), all subjects performed an exercise session consisting of 90 min of running (at 75% ${\dot{V}}O_{2max}$) followed by 100 drop jumps. Maximal strength (MVC) was evaluated before and after exercise. In the CON trial, the sleep duration was 23:00-7:00, while in the PSD trial, the sleep duration was shortened to 40% of the regular sleep duration. On the following morning (day 2), MVC, the metabolic responses during 20 min of running (at 75% ${\dot{V}}O_{2max}$), and time to exhaustion (TTE) at 85% ${\dot{V}}O_{2max}$ were evaluated. [Results] On day 2, neither the MVC nor ${\dot{V}}O_2$ during 20 min of running differed significantly between the two trials. However, the respiratory exchange ratio was significantly lower in the PSD trial than in the CON trial (p = 0.01). Moreover, the TTE was significantly shorter in the PSD trial than in the CON trial (p = 0.01). [Conclusion] A single night of PSD after an exercise session significantly decreased endurance performance without significantly changing muscle strength or cardiopulmonary response.

• Journal of muscle and joint health
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• v.29 no.2
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• pp.133-140
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• 2022

Purpose: This study was to examine the effects of auricular acupressure on competitive state anxiety and the accuracy of breaking in taekwondo players. Methods: This study was a quasi-experimental study with a time-series design. Twenty-two taekwondo breaking players were assigned to the control group for the first two weeks and then assigned to the experimental group for the next two weeks. Anxiety was measured by the revised Competitive State Anxiety Inventory-2 and the accuracy of breaking was measured as a percentage of breaking the wooden board. Results: Auricular acupressure for two weeks significantly increased the accuracy of breaking from 80.83±7.99% to 90.92±7.57% (t=7.74, p<.001). Auricular acupressure for two weeks significantly increased anxiety from 35.66±10.36 to 50.64±7.45 (t=4.38, p<.001). Among three subtypes of competitive state anxiety, somatic anxiety was increased from 12.48±4.97 to 22.95±4.54 (t=2.09, p=.011). Cognitive anxiety was significantly increased from 10.11±3.96 to 14.68±3.89 (t=5.37, p<.001) but self-confidence was not changed. Conclusion: The results of this study showed that auricular acupressure was effective in increasing the accuracy of breaking in taekwondo players.

• Korean Journal of Exercise Nutrition
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• v.13 no.3
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• pp.185-192
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• 2009

The aim of this study was to examine the use of such dietary supplementation practices, opinions, taking period for dietary supplement, and among elite Judoists varying in age and gender. Subjects were recruited from Korea National Team Judoists in elite athlete training centers (Taenuing in Seoul, Korea and surrounding area), a total of 223 elite Judoists (2003y n=34, 2005y n=41, 2006y n=101, 2007y n=30, 2008y n=17). Data were collected from personal interviews with Judoists who participated at the Olympic games, Asian game and World Championship game since 2003-2008. Elite Judoists representing mean age of 2003y (men: 23.5±2.7, women: 22.6±2.4), 2005y (men: 23.4±2.6, women: 22.5±2.3), 2006y (men: 20.3±3.2, women: 21.9±2.4), 2007y (men: 25.3±2.6, women: 22.5±2.8) and 2008y (men: 23.9±3.9) completed a validated questionnaire assessing dietary supplementation practices and opinions. Older Judoists were significantly more likely to report greater dietary supplementation usage; to be advised by oneself; health food store and pharmacy retailers; to decrease taking period days per week and past 6 month. Relative to gender, significant differences were observed for the types of dietary supplementation reported; supplementation practice trend; reasons for dietary supplementation use.

• Advances in nano research
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• v.15 no.4
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• pp.329-337
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• 2023

Wearing the right sportswear is one of the essential points in exercising, which is mainly neglected. Sportswear should be suitable for the ambient temperature and not cause more heat or cold in the athlete's body. On the other hand, increased sweating and blood circulation during exercise should not cause fatigue or heatstroke in the athlete. Nanotechnology has grown significantly in the field of producing more efficient equipment in the field of sports. The increase in demand in sports for complete sports equipment has revealed the necessity of using the highest quality materials in this sector. In the world of championship sports, a minor change in equipment can lead to significant changes in causing failure and victory. Since the sole is the most critical part of sports shoes, with the introduction of nanotechnology and nanocomposites, it is possible to help athletes rush and increase their sense of calm and satisfaction. Using nanocomposites in the soles of shoes can improve some of their characteristics, prevent the smell and sweat of shoes, and induce water repellency in these shoes. In this research, titanium dioxide (TiO₂) nanocomposite, along with cellulose, has been used to create antibacterial and hydrophobic properties in the soles of sports shoes. The synthesized nanocomposite has been synthesized using the least amount of chemicals, which shows this method's easy and cost-effective synthesis.

• Journal of Sport and Applied Science
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• v.7 no.4
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• pp.7-12
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• 2023

Purpose: The purpose of this study is to compare and analyze power and agility, which are factors that affect performance, by dividing adult fin swimmers into groups by male and female careers, and use them as basic data for improving performance during fin swimmer guidance and training. Research design, data, and methodology: Accordingly, 21 fin swimmers were selected and they were divided to four groups by gender and career to conduct experiments. Power and agility, which are factors related to performance of fin swimmers, were measured. Independent sample T-Test was conducted to verify differences between groups. Results: As a result of this study, there was no statistically significant difference in power and agility by the careers of male and female athletes. Conclusion: The results of this study can be used as basic data for organizing training programs suitable for the gen-der of fin swimmers and basic data for the guidance and training of fin swimmers. In future follow-up studies, based on the results of this study, it is expected that follow-up studies should be con-ducted to improve detailed performance according to age, fin swimming events, and gender. Further implications were discussed.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.2
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• pp.302-322
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• 1998

This study was accompolished to analyze and compare the number and area of the occlusal contact points in healthy volunteers and athletes with normal occlusion. For this study, 15 athletes(13 amles and 2 females with average age 20) and 21 healthy volunteers(14 mles and 7 females with average age 20.09) were selected. The visual display acquired by scanning of occlusal record in maximal intercuspation was converted into 16 gray value image. Then, using computer program(J & Lee Occlusal Analyser), the pixel which was in definite range of the gray value was recognized, and the numbers of recognized pixel were calculated to area. The results were as follows ; 1. The average numbers of total occlusal contact feints were 31.05 in control group, and 34.67 in athlete group. The average area of total occlusal contacts was $100.25mm^2$ in control group, and $127.78mm^2$ in athlete group. 2. In control group, the average numbers of occlusal contact points were revealed in order as follows ; the first molar(8.48), the second molar(8.24), the second premolar(4.71), the lateral incisor(2.90), the first premor(2.43), the central incisor(2.19), and the canine(2.1). The least average in canine(2.1) was similar to the average(2.19) in central incisor and (2.09) in lateral incisor. In athlete group, the average numbers of occlusal contact points were revealed in order as follows ; the first molar(8.97), the second molar(8.47), the second premolar(5.60), the canine(3.80), the lateral incisor(3.33), the first premolar(2.67), and the central incisor(1.93). 3. In control group, the average areas of occlusal contact surface were revealed in order as follows ; the first molar($39.47mm^3$), the second molar($37.54mm^3$), the second premolar($9.54mm^3$) the first premolar($6.18mm^3$), canine($3.49mm^3$), the central incisor($2.76mm^3$), and the lateral incisor($1.28mm^3$). In athlete group, the average areas of occlusal contact surface were revealed in order as follows ; the first molar($44.11mm^3$), the second molar($40.69mm^3$), the second premolar($16.50mm^3$), the first premolar($9.39mm^3$), the canine($5.08mm^3$), the lateral incisor($3.7mm^3$), and the central incisor($2.25mm^3$). 4. With aging in both control and athlete group, there was a decreasing tendancy in average number of occlusal contact point, and was an increasing tendancy in average area of occlusal contact surface. In comparison at each age, both the numbers and area of occlusal contact were greater in athlete group than in control group. It was not significant in the numbers of occlusal contact points beween athlete and control group(p>0.1), but significant in the area of occlusal contact surface(p<0.03). 5. In comparision as to the kind of sports(Gymnastics : 2, Rugby : 3, Soccor : 5, Ice hocky : 5), the numbers of occlusal contact points were the most in ice hocky, and the area of occlusal contact surface was the greatest in gymnastics. With increasing a career in athlete group, there was a decreasing tendancy in average numbers of occlusal contact points and was an increasing tendancy in average area of occlusal contact surface. 6. By T-scan analyzing, the contact numbers on the anterior teeth were greater in control group than in athlete group, and on the posterior teeth were greater in athlete group than in control group. And the results acquired by T-scan were lesser than that caquired by the silicone bite records. It was not significant in the posterior teeth, but significant in the anterior teeth. In T-scan records, the numbers of occlusal contact points on second molar were the greatest, but in the silicone records, the numbers on first molar were the greatest.

• Journal of the Korean Applied Science and Technology
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• v.36 no.3
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• pp.942-953
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• 2019

The objective of this study was to evaluate the effects of L-arginine supplementation on muscle damage and fatigue indices and athletic performance improvement of canoe athletes after conducting a high-intensity training program. To achieve the objective, this study applied a high-intensity training program to seven high school canoe athletes. The high-intensity training program is composed of aerobic exercise sessions (twice per week; Tuesday and Thursday), anaerobic exercise sessions (three times per week; Monday, Wednesday, and Friday), and flexibility exercise sessions (five times per week). During the 6 week high-intensity training program, drug ingestion (L-arginine or placebo) was conducted in the first two weeks, wash out (two weeks) followed it, and drug ingestion (L-arginine or placebo) was carried out again in the last two weeks. The crossover design was used for the experiment so all study subjects were assigned to either the L-arginine intake group (the treatment group) or the placebo group (the control group). Each subject ingested 3g per day. This study confirmed the significant effects of L-arginine supplementation on muscle damage indices, fatigue indices, and antioxidants using blood samples. Additionally, FMD was analyzed to evaluate vascular endothelial cell functions and canoe performance was examined using the canoe ergometer. The results of this study showed that L-arginine intake did not have direct effects on the levels of ammonia, IP, and CK. The level of LDH decreased significantly more in the ARG group than in the PLA group due to L-arginine supplementation. Moreover, L-arginine supplementation did not change total NO, d-ROMs, BAP, and FMD significantly. Lastly, the results of the 500m canoe ergometer, which was conducted to evaluate the canoe performance, revealed that L-arginine did not have direct effects on total time, stroke distance, and mean velocity. However, L-arginine supplementation significantly improved muscle damage indices, fatigue indices, antioxidants, FMD, and canoe performance. Therefore, it is believed that additional studies are needed for examining the potential effects of L-arginine supplementation athletic performance enhancement.

• Journal of the Korean Applied Science and Technology
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• v.37 no.2
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• pp.224-231
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• 2020

The purpose of this study was to analyze the effect of ankle joint taping treatment on lower extremity joint and center of pressure(COP) factors during the Uchi-mata. Twenty college judo athletes (age, 20.9 ± 0.8 years; height, 168.6 ± 7.4cm; weight, 73.5 ± 11.6kg; body mass index, 25.7 ± 2.6kg/㎡) participated, and two types before and after ankle joint taping treatment when the during the Uchi-mata was exhibited under conditions, the angle and COP factors of the support leg joints were analyzed to show the following results. At the time of E2 (t = 2.411, p = .027) E4 (t = 2.388, p = .029), the ankle joint angle was statistically less after the treatment than before the taping treatment, and E2 (t = -2.343, p = .032) At E3 (t = -4.531, p = .000), the angle of the hip joint was statistically large. And after the ankle joint taping treatment, the medial/lateral COP movement after the ankle joint taping treatment was statistically large in the P3 phase of throwing the opponent (t = 2.670, p = .016), and the anterior/posterior COP movement showed a statistically small number in the P1 phase where the opponent was tilted (t = 2.846, p = .011). Therefore, it was suggested that judo athletes who use thighs as a special technique should be used considering the movement function of the support joint and the range of movement of the COP caused by tapping of the ankle joint.

• Fashion & Textile Research Journal
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• v.17 no.4
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• pp.597-603
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• 2015

This study investigates the actual domestic and overseas cyclewear wearing conditions for male high school cyclists. The study results provide factors and degree of dissatisfaction as basic data for cyclewear development. This study was conducted on 35 male high school cyclists (freshman to seniors) by a questionnaire and interview method. Study results were: Male high school cyclists considered functionality as most important when they bought cyclewear and the brand they most often bought was a cheap domestic brand. Dissatisfaction with the crotch, thigh circumference and minimum leg circumference was higher than other parts during wearing. A cyclist is more sensitive to wear because they require more lower body motion than other parts. Cyclewear should be: less transformed even by frequent laundering, made of breathable material and use a sewing technique that minimizes air resistance and increases fit the body. Functional pads ergonomically designed with high tactile materials should be developed to prevent 'saddle sore' and groin soreness region that happens because of a lower body bending posture when cycling. A follow-up study is recommended to further develop excellence in cyclewear functionality and dimension suitability for male high school cyclists through the size system.

• The Journal of Korean Physical Therapy
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• v.32 no.3
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• pp.137-145
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• 2020

Purpose: The purpose of this study is to examine the effect of various bridge exercises on walking ability. Method: The subjects were 30 stroke patients. They were divided into a bridge exercise group on a stable support surface (Group I), a bridge exercise group on an unstable support surface (Group II), and a bridge exercise group combined with whole body vibrations (Group III). 10 subjects were randomly assigned into each group. The subjects of this study had 30 minutes of nervous system physical therapy including gait training and strength training. In addition, each group underwent a 30 minutes session five times a week for eight weeks. Before intervention, LUKOtronic was used to measure step width and step length, time was measured with a 10 m walking test, and time and number of steps were measured with the figure 8 walking test. After the intervention, remeasured and analysis was performed for each group. Results: As a result of comparing and analyzing the change of walking ability between groups, there was a statistically significant difference. As a result of the post hoc analysis according to the change of walking ability among groups, the change of walking ability was larger in Group III than in Group I and Group II. Conclusion: Based on these results, it is confirmed that the bridge exercise combined with whole body vibration was more effective for walking ability. Based on these findings, this study proposes an effective program for elite athletes as well as stroke patients.