• Korean Journal of Community Nutrition
• /
• v.13 no.1
• /
• pp.134-142
• /
• 2008

The objective of the present study was to determine the prevalence and type of nutritional ergogenic aids use, and to determine the frequency, reasons for use of nutritional ergogenic aids. Thirty-four male bodybuilders (mean age = 27.0 years), twenty-four male weight lifters (mean age = 20.9 years) participated in the study. Participants completed a comprehensive survey detailing their usage patterns. In this study, 78.1% of bodybuilders and 79.2% of weight lifters reported using nutritional ergogenic aids. The most frequently taken nutritional ergogenic aids, in ranking order, were protein/amino acid powders (79.4%), multivitamin/minerals (67.7%) and creatine (67.6%) for bodybuilders, in contrast to sports drinks (100.0%), protein/amino acid powders (50.5%) and creatine (50.5%) for weight lifters. Over the half of the respondents, 79.4% of bodybuilders and 50.6% of weight lifters, used protein/amino acid powders to gain muscle mass and to stay healthy. Bodybuilders, 67.6% and weight lifters, 41.7%, used multivitamin/minerals to stay healthy and for energy. The intakes of most vitamin and minerals through diet and nutritional ergogenic aids were much greater than RDA. Vitamin $B_1$, vitamin $B_2$, niacin, vitamin $B_6$ and folate intakes were ranged at 400-900%. Vitamin C intake was 1285.4% (for bodybuilders) and 1322.6% (for weight lifters). The correct answer rate of nutritional ergogenic aids was 46.0% for bodybuilders and 52.0% for weight lifters. Both bodybuilders and weight lifters took highly nutritional ergogenic aids and it tended to be taken irrespective of scientific background. Specific sport nutrition education applicable to athletes, especially strength athletes, is recommended. The findings of this investigation could be used to enable the professionals (sports dietician and physician) to identity common misconceptions regarding nutritional ergogenic aids and to implement educational programs.

• Clinics in Shoulder and Elbow
• /
• v.5 no.2
• /
• pp.73-80
• /
• 2002

Purpose: Weight lifting is a good training to control body weight, to correct body shape and to relieve stress. How-ever if the training is continued by inadequate training method and technique, the risks of the shoulder injuries are relatively high. Main Subject: The rotator cuff injury is the most common disorder to wright lifters and often results from the train- ing program of upright row, military press and pectoral deck. The chances of subacromial impingement in these postures are high because the shoulder rotates under the acromion at 90 abduction state. Shoulder instability in weight lifters can develop due to various causes. aepeated microtrauma and excessive abduction and external rotation may result in laxity of the anterior capsular structure, ligament and muscles. Behind the neck and bench press are high risk training postures. Other than those injuries, idiopathic osteolysis of distal clavicle, acromioclavicular separation, pectoralis major muscle rupture, and triceps muscle rupture nay develop. Conclusion: The best treatment option of the shoulder injury to weight lifters is to eliminate the possible risk elements for the weight lifters in training program and to provide proper and prompt treatment as soon as possible.

• Korean Journal of Applied Biomechanics
• /
• v.13 no.3
• /
• pp.265-276
• /
• 2003

The objective of this research is to provide basic data for improving athletic performances, suggesting methods that can be utilized at games and coaching movements in the snatch, by analyzing the level of contribution of muscles to the movements of the snatch lift through three-dimensional imaging and EMG analysis between skilled and unskilled lifters. To this end, three high school students (the skilled group), three middle school student (the unskilled group) were selected; two digital video cameras and electromyography were used. The muscles measured by an EMG include gastrocnemius muscle, biceps femoris muscle, erector spinae, latissimus dorsi muscle, trapezius muscle, and brachioradialis. Based on the Ariel Performance Analysis System (APAS) program, the results of the analysis are summarized as follows. 1. In performing snatch pulls, the skilled lifters were found to simultaneously move the weight centers of the body and the barbell close to vertical, close to the shoulders in the pulling portion; in snatching and grabbing the barbell from a sited position, it was observed that the shorter the time for adjusting to change in the height of the barbell by using rotational inertia, the better it is to perform the movements. 2. The skilled lifters were observed to perform stable and efficient movements in grabbing the bar in a sited position, by moving the barbell and weight center of the body close to vertical and moving the shoulder joint under the bar fast. 3. The results of the EMG analysis of the entire movements from the snatching portion to the portion of grabbing the bar in a sited position show that when the skilled lifters lifted the barbell vertically during the pulling portion, their shoulder joints were extended to put more weight on biceps femoris muscle and brachioradialis; and in snatching and grabbing the bar from a sited position, it was found desirable to increase the myoelectrical activity of erector spinae in order to achieve a balance in the movements of the hip joint between font and rear, as the weight centers of the body and the barbell move higher. On the other hand, the unskilled lifters were found that in response to change in posture, they increase their muscular strength inefficiently in performing the movements throughout the entire lifting process.

• Korean Journal of Community Nutrition
• /
• v.12 no.6
• /
• pp.864-872
• /
• 2007

The purpose of this study was to provide a descriptive assessment of the nutritional habits of resistance trained males in relation to protein and carbohydrate intakes in comparison with the recommended values. Thirty-four male bodybuilders ($27.0{\pm}2.1years,\;173.5{\pm}5.0cm,\;8.3{\pm}0.61%$ body fat), twenty-four male weight lifters ($20.9{\pm}2.1years,\;171.8{\pm}6.9cm,\;7.6{\pm}0.98%$ body fat) and twenty-five male non-athletes ($26.9{\pm}2.5years,\;175.3{\pm}5.7cm,\;8.5{\pm}0.95%$ body fat) participated in the study. Participants completed a comprehensive survey by twenty-four hour dietary recall methods. All diets were analyzed using the Computer Aided Nutritional (Pro) analyzer by a registered dietician. Body fat was measured using skin fold thickness. The average time spent in resistance training was $18.0{\pm}1.7$ hrs/week for body builders and $14.6{\pm}8.7$ hrs/week for weight lifters. Total daily calories were $2583.6{\pm}874.8kcal\;(31.9{\pm}11.9kcal/kg)$ for bodybuilders, $3565.9{\pm}1281.8kcal\;(42.7{\pm}15.0kcal/kg)$ for weight lifters and $2016.0{\pm}955.3kcal\;(28.1{\pm}13.9kcal/kg)$ for non-athletes (p=0.001). Percent of calories from carbohydrate, protein, and fat 64.2%, 27.1%, and 8.7% for bodybuilders, and 66.3%, 18.6%, and 15.1% for weight lifters. The mean protein intake was $1.9{\pm}1.2g/kg$ of BW for bodybuilders, $1.6{\pm}0.6g/kg$ of BW for male weight lifters and $1.1{\pm}0.69g/kg$ of BW for non-athletes. Although dietary calcium (78.7%) and riboflavin (86.3%) intakes for bodybuilders were below the RDA, dietary intakes of micronutrients were not deficient. More research needs to be conducted to determine the optimal amounts of protein, carbohydrates, fats, and micronutrients for the resistance trained athletes.

• Physical Therapy Korea
• /
• v.4 no.2
• /
• pp.1-9
• /
• 1997

Skeletal muscle fatigue is often associated with diminished athletic performance and inability to maintain an expected force output as a function of time. The purpose of this study was to compare the effect of duration of exercise on skeletal muscle fatigue between Weight Lifters(WL) and Non-Weight Lifters(NWL). There were twelve normal healthy adult volunteers, ranging in age from 18 to 35 years. The group consisted of six NWL and six WL. Randomized cross-over design was set up and work-rest cycle was 8 minutes work and 1 minute rest based on 15% MVC. Muscle fatigue was measured by the amount of force produced by the wrist flexor muscle and EMG amplitude over time. Repeated measures ANOVAs($2{\times}4$) were used to determine two types of subjects(WL, NWL) during four different duration of exercises(16, 32, 48, 64 minutes). The force decreased over time in NWL and WL, but there was no significant difference(F=2.83, p>0.05). However, the EMG amplitude increased in WL(0.8200) and NWL(0.6348). The WL exhibited an increase in EMG at the end of the period, especially at 48 minutes of exercises than did the NWL(F=9.58, p<.05). This suggests the WL were able to adjust to prolonged effort with adaptations in neural effect over time, resulting in higher EMG amplitude. That is, WL may be able to learn to recruit more motor units with training. It is important to the degree of neuromuscular fatigue and the time needed for recovery may differ considerably between WL and NWL, there is a need to plan proper strength training or rehabilitation protocols to match with the requirements in different characteristics of groups.

• Journal of Nutrition and Health
• /
• v.34 no.6
• /
• pp.645-655
• /
• 2001

The purpose of this study is to investigate the dietary intake and bone mineral density(BMDs) in college women(n = 10), female swimmers(n = 10), and female weight lifters(n = 10). BMDs of lumbar spine(L2-L4), femoral neck, ward's triangle, and trochanter were measured with dual-energy X-ray absorptiometry. The results are summarized as follows. In swimmers and weight lifters, mean daily intakes of energy, protein, and fat were higher than those of college women and the intake of carbohydrate was significantly high in weight lifters. Also in swimmers and weight litters, mean daily intakes of animal flood, phosphorus, vitamin A, vitamin B$_1$, vitamin B$_2$, niacin, vitamin C, and cholesterol were found higher than those of college women but there was difference among the types of exercise. According to correlation analysis between nutrient intake and BMDs, intakes of energy, protein, carbohydrate, and vitamin B$_1$ were positively associated with BMDs of lumbar spines. According to stepwise multiple recession analysis, BMDs of lumbar spines were affected by intakes of protein, Fe, phosphorus, and vitamin B$_2$, also BMDs of femur were affected by each of vegetable protein, dietary fiber, and fe. from the above explanation, the nutrient intakes can be independent factor besides exercise. In conclusion, the weight lifting, resistant exercise, resulted in increase of both BMDs of lumbar spines and femur specially in growing and adult period of female. Whereas swimming lead to increase of BMDs of lumbar spine and decrease of BMDs of femur in female.

• Korean Journal of Applied Biomechanics
• /
• v.18 no.2
• /
• pp.105-114
• /
• 2008

The purpose of this study was to compare of muscles in clean and jerk techniques between 69kg class(n=3), 58kg class(n=3) in high school female weight lifters using EMG(electromyographic) system. EMG analysis were executed on 6 major muscles and dividing clean and jerk techniques into 6 phases. In that result, in the difference by weight, it was shown that EMG value increased gradually as the weight is raised of all muscles group & phases in 58kg class. In EMG signal scale by classes, it was shown that EMG signal scale didn't increase according to class & weight. In the result of this study, that EMG value was inconsistent in 69kg class is showing that the consideration of the technical factor together with muscle power has positive affect more on the performance improvement in the heavy class.

• Korean Journal of Applied Biomechanics
• /
• v.18 no.4
• /
• pp.99-107
• /
• 2008

The aim of this study was to provide fundamental data in training to improve athletes' competitiveness through the comparative analysis of kinematic variables according to the types of stance. For this study, the subjects selected 4 Junior Weight lifters. Subjects performed two type(8-type and 11-type) Dead-lift and their performance was sampled at 60frame/sec. using four high-speed digital video cameras. After digitizing images from four cameras, the two-dimensional coordinates were used to produce three-dimensional coordinates of the 15 body segments(20 joint makers and 2 bar makers). And the results were as follows. 1. As for the time required for stances, 8-type motion was faster than 11-type motion. 2. As for the body-center shift in stances, 8-type motion was bigger than 11-type motion in back and forth motion shift, and 11-type motion was bigger than 8-type motion in right and left, up and down motion shift. 3. As for the speed of a body-center and a babel, 8-type motion was faster than 11-type motion. 4. As for the motion-trace of a babel in stances, 8-type motion was bigger than 11-type in back and forth, right and left motion and 11-type motion was bigger than 8-type in up and down motion. 5. As for the body-angles in stances, 8-type motion was bigger than 11-type in the stance angle, and 11-type motion is bigger than 8-type in the angles of a coxa, a knee and an ankle. As a result of the comparative analysis between 8-type and 11-type stance of Junior Weight lifters dead-lift, both were generally similar in variables, but 8-type motion was more stable than 11-type in aspects of time, speed, center shift, angle change.

• BMB Reports
• /
• v.42 no.9
• /
• pp.605-610
• /
• 2009

Plasma high-density lipoprotein cholesterol (HDL-C) levels are inversely correlated with the risk of cardiovascular disease, and are known to increase with repetitive exercise. In the current study, HDL fractions from athletes' sera were isolated and compared as a function of the type of sport (runners [n = 10], throwers [n = 10], wrestlers [n = 10], and weight lifters [n = 8]), and as an age- and gender-matched reference group (n = 14). Among athletes, HDL from runners had the strongest antioxidant activity. Immunodetection showed that runners and wrestlers had the highest levels of apoA-I and lowest levels of apoA-II in their HDL. Electron microscopy also revealed that HDL2 of runners and wrestlers were the largest in size. In conclusion, although all athlete groups had significantly better serum lipid/lipoprotein profiles than the reference group, runners and wrestlers had the most desirable lipoprotein function and structure, including antioxidant activity, HDL-associated enzyme activities and increased particle size.

• Korean Journal of Applied Biomechanics
• /
• v.21 no.2
• /
• pp.153-159
• /
• 2011

The purpose of this study was to develop an innovative training model and method to improve the posture and motion, while pulling up during weight lifting by evaluating the problems of Korean weight lifters performing this motion. To investigate the effectiveness of the new training method substitute members of the Korean national weight lifting team performed both the original pull up technique and new pulling training technique while kinetics and kinematics were recorded. For this study, the first phase of the new training method is more appropriate than the original training with the pull up drop slow deadlift to the knee joint. For the second phase, the new training motion is deemed to be more effective than the current box deadlift motion. Also, this new motion corrects the posture as there is more anterior hip joint motion(about 10 cm) and the knee flexes to about 120 degrees. For the third phase, starting about 10cm above the knee the box snatch high pull up is identified as a more suitable training method. For the forth phase, the box top snatch method is judged to be a more effective training method than the original top snatch training method.