Il-Young Paik

Fluid replacement following dehydration reduces oxidative stress during recovery

To investigate the effects of hydration status on oxidative DNA damage and exercise performance, 10 subjects ran on a treadmill until exhaustion at 80% VO(2max) during four different trials [control (C), 3% dehydration (D), 3% dehydration+water (W) or 3% dehydration+sports drink (S)]. Dehydration significantly decreased exercise time to exhaustion (D<C and S). Plasma MDA levels were significantly higher at pre-exercise in D than C. Plasma TAS was significantly lower at pre-exercise in C and S than in D, and was significantly lower in S than D at 60min of recovery. Dehydration significantly increased oxidative DNA damage during exercise, but fluid replacement with water or sports drink alleviated it equally. These results suggest that (1) dehydration impairs exercise performance and increases DNA damage during exercise to exhaustion; and (2) fluid replacement prolongs exercise endurance and attenuates DNA damage.

Effects of a structured exercise program on insulin resistance, inflammatory markers and physical fitness in obese Korean children.

ABSTRACT Thirty-eight obese Korean children (21 boys, 17 girls), whose ages were between 9 and 15, were divided into either the intervention group (19 obese children: BMI>95P) or the age- and sex-matched obese control group. The intervention group performed an intensive exercise program under the supervision of educated instructors for 12 weeks (90 minutes/day, two days/week) and received lifestyle modification counseling using food diaries and phone calls. The control group participated in conventional counseling at an out-patient clinic. The intervention group appeared to have more improvement of body weight, body composition, serum lipid profiles and high-sensitivity C-reactive protein (hs-CRP) levels (P < 0.05) but without changes in serum adiponectin level. HOMA-IR decreased from 2.3 to 1.3 in the intervention group. Maximal oxygen consumption (VO2 max) and other physical fitness parameters were significantly improved after the intervention program (P < 0.05).

Effects of the NADPH oxidase p22phox C242T polymorphism on endurance exercise performance and oxidative DNA damage in response to aerobic exercise training.

We examined the effects of the NADPH oxidase p22phox C242T polymorphism on endurance exercise performance and oxidative DNA damage in response to acute and chronic exercises. One hundred three subjects were recruited, among which 26 healthy subjects (CC: 12, TC: 12, and TT: 2) were studied during rest, exercise at 85% VO2max, and recovery before and after 8 weeks of tread-mill running. Lymphocyte DNA damage increased significantly in response to exercise (p < 0.05). There were no significant differences in plasma MDA, SOD concentrations and lymphocyte DNA damage between CC genotype and T allele group, but significant endurance training differences were observed. Endurance training increased exercise time to exhaustion in both the CC genotype and T allele groups (p < 0.05) but no significant difference was found between groups. The results of the current study with young, healthy, Korean men are interpreted to mean that 1) the majority had the CC genotype of the NADPH oxidase p22phox C242T polymorphism (82.5%: CC, 15.5%: TC, 1.9%: TT), 2) acute exercise increased lymphocyte DNA damage, 3) endurance training significantly increased exercise time to exhaustion, and alleviated lymphocyte DNA damage, and 4) The NADPH oxidase p22phox C242T polymorphism, however, did not alter lymphocyte DNA damage or exercise performance at rest, immediately after exercise, or during recovery.

Effects of Regular Walking Exercise on Health-Related Parameters in Persons with Chronic Diseases

The purpose of this study was to investigate the effects of regular walking exercise on health-related parameters in the elderly with chronic diseases - apoplexy, overweight, impaired fasting glucose, and overweight + impaired fasting glucose. A total of 85 subjects, 27, 17, 21 and 20 in apoplexy (A), overweight (O), impaired fasting glucose (IFG), overweight + impaired fasting glucose group (O_IFG), respectively, completed a 12-week walking exercise. The health-related parameters were measured before and at the completion of the exercise program including anthropometric measurements, functional physical fitness levels, blood pressure, fasting glucose, blood lipid profiles and chronic inflammatory markers (CRPs). Significant improvements in body weight, BMI, %body fat, blood pressure, all blood lipid measurements and all measured physical fitness items were shown in A; those in %body fat, TC, HDL-C and LDL-C in O; those in body weight, BMI, %body fat, fasting glucose, TC, TG and HDL-C in IFG; and those in body weight, HDL-C and LDL-C in O_IFG (p

Exhaustive submaximal endurance and resistance exercises induce temporary immunosuppression via physical and oxidative stress

Regular running and strength training are the best ways to improve aerobic capacity and develop the size of skeletal muscles. However, uncontrolled physical activities can often lead to an undertraining or over-training syndrome. In particular, overtraining causes persistent fatigue and reduces physical performance due to changes in the various physiological and immunological factors. In this study, we gave an exhaustive submaximal endurance or resistance exercise to participants and investigated the relationship between physical stress (cortisol level in blood), oxidative stress (intracellular ROS accumulation), and adaptive immune response (CD4:CD8 ratio). Materials and Methods Ten male volunteers were recruited, and performed a submaximal endurance or resistance exercise with 85% of VO2max or 1-repetition maximum until exhaustion. Blood samples were collected at rest, and at 0 and 30 min after the exercise. Cortisol levels, oxidative stress, and immune cell phenotypes in peripheral blood were evaluated. Cortisol levels in the sera increased after the exhaustive endurance and resistance exercises and such increments were maintained through the recovery. Intra-cellular ROS levels also increased after the exhaustive endurance and resistance exercises. The ratio of CD4+ T cells to CD8+ T cells after each type of submaximal exercise decreased compared with that at the resting stage, and returned to the resting level at 30 min after the exercise. In this study, an exhaustive endurance or a resistance exercise with submaximal intensity caused excessive physical stress, intra-cellular oxidative stress, and post-exercise immunosuppression. This result suggests that excessive physical stress induced temporary immune dysfunction via physical and oxidative stress.

The Effect of Kinesio Taping on Muscle Strength Improvement, Blood Fatigue Factors, Muscle Fatigue and Damage Index

본 연구의 목적은 kinesio taping 적용이 근력 향상에 미치는 영향을 직 간접적으로 관찰함으로써 운동 수행시의 상해예방 및 수행력 향상을 위한 수단으로서의 taping 요법에 대한 기초 자료를 제공하는데 있었다. 본 연구는 남자 대학생 10명을 대상으로, 근력 향상의 정도를 직접적으로 관찰하기 위하여 1RM test와 Cybex test를 실시하였으며, 생리학적 변인으로는 CK, LDH, phosphorus, ammonia, creatinine, IGF-I의 6가지 혈중 성분을 분석함으로써 피로와 근 손상의 정도를 분석하였다. 본 연구를 통하여 kinesio taping은 근력향상의 직접적인 지표(1RM, 등속성 운동능력)에는 긍정적으로 작용했지만, 85%-1RM의 웨이트트레이닝 시의 근 피로 또는 근 손상 지표물질의 농도는 유의하게 감소시키지 못함을 알 수 있었다. 하지만 본 연구의 결과만을 가지고 taping의 적용이 피로 및 근 손상 완화 효과가 없다고 판단할 수는 없을 것으로 생각된다. 왜냐하면, 본 연구에서의 피로 및 근 손상 유발 수단인 85%-1RM 웨이트트레이닝은 고강도의 운동이며 운동에 소요된 시간도 40분 정도로 장시간이지만 다양한 근육부위에 적은 반복수와 set를 적용하였기 때문에 피로 및 근 손상 지표물질의 축적이 현저하지 않았을 수 있기 때문이다. 이는 taping 적용 후 나타난 여러 혈중성분들의 감소(Creatinine 제외) 경향으로 설명할 수 있으며, 실제로 선행 연구 중 특정 대근육에 대한 반복적인 운동에 kinesio taping을 적용하여 피로 및 근 손상 완화를 입증하기도 하였다. 본 연구가 가지는 의의는 특정 동작에 있어서의 근력 향상을 중점적으로 관찰한 연구가 아닌, 전신에 대한 taping을 적용한 후 각 근육 부위에 어떠한 영향을 미치는지 다양한 관점에서 관찰하였다는 데 있다. 이후의 연구에서는 본 연구에서 관찰한 변인들 이외에도 신경계통의 변인들과의 상관관계도 함께 관찰 하는 통합적인 연구도 의의가 있다고 하겠다. 【The purpose of this study was to examine the effect of kinesio taping on muscle strength and changes of muscle fatigue and damage. 10 male subjects participated in 1-RM and isometric cybex muscle strength tests with and without taping application. Muscle strength (bench press, leg press) and extension (knee, shoulder) strength were significantly increased after taping, but there was no significant difference in flexion (knee, shoulder) strength. The concentration of fatigue factors (ammonia, phosphorous), muscle damage index substances (CK, LDH), IGF-I and creatinine were reduced after taping, but there were no significant differences.】

The Effect of Prunus Mume Supplementation on Energy Substrate Levels and Fatigue Induction Factors

The purpose of this study is to examine the effect of Prunus mume supplementation on changes of energy substrate (glucose, FFA) and fatigue factors (lactate, ammonia, phosphorous) in the performance of exercise. The subjects of this study were 15 male university students. The exercise test was performed for 30 minutes at 75% VO₂max on the treadmill and conducted both before and after administering Prunus mume for 6 weeks. Through Prunus mume supplemntation, the accumulation of such fatigue factors as lactate, ammonia, and phosphorous along with concentration of glucuse decreased, but the concentration of FFA increased. From the study, it can be seen that Prunus mume plays a positive role for the use of energy substrates and accumulated fatigue factors.

Effects of 12 Week Regular Aerobic Exercise on ST-segment and QTc Interval in Type 2 Diabetes Mellitus Patients

The purpose of the present study was to examine effect of 12 week regular aerobic exercise on ST-segment and QTc interval in middle age type 2 diabetes mellitus (T2DM) patients. The subjects consist of 13 type 2 diabetes mellitus (T2DM) patients in middle age men and all of them had no other complications. Subjects participated in aerobic exercise training for 12 weeks. They started to exercise for min at of , (exercise intensity has been increased gradually) per day, times a week. The results were compared before and after. Weight and BMI, % body fat, fasting glucose, HOMA-IR, were significantly decreased and , , exercisre time were significantly increased after 12 week aerobic exercise. Also, QTc interval and ST-segment were significantly decreased during at rest, peak exercise after 12 week aerobic exercise. Conclusionally, 12 week aerobic exercise may be improvement in decreased cardiovascular mortality factors (ST-segment) and abnormal autonomic dysfunction (QTc interval) and potentially increased exercise capacity.

Effects of Regular Exercise and Diet on RMR and Hormonal Changes in Obese Women.

The purpose of this study was to examine resting metabolic rate (RMR) and thyroid hormonal (TSH, , and ) changes following weight loss by diet with regular exercise in obese women. The subjects of the present study were 7 women who were above 30% body fat. The subjects arrived into the laboratory in the morning after 12 hour overnight fasting. All subjects measured RMR, % body fat, and fat free mass at weight loss program start time, after 4 weeks and after 8 weeks. All the RMR values were expressed as absolute value (kcal/day), absolute value/FFM (kcal/day/FFM), and absolute value/BSA (kcal//hr), and were calculated predicted RMR value minus actual RMR value. Also, correlation of blood thyroid hormonal (TSH, , and ) secretion and RMR were analyzed. There were significant differences in weight, % body fat, and BSA following diet with exercise (p were higher than before. But there were no significant differences. Also, the level of was lower than rather before but there was no significant difference. Among the anthropometric factors, FFM was highly correlated (r

Effects of Long-Term Aerobic Exercise on Antioxidant System and Lymphocyte DNA Damage by Triathlon Distance

Background and Objective This study aimed to investigate the effects of long-term aerobic exercise on muscle damage markers, lymphocyte DNA damage, and antioxidant system in amateur athletes. Material and Methods Eleven healthy men in their 30s and 40s without any medical illness, who did not smoke or drink, and had completed at least two amateur triathlon races (O2 and Olympic courses) were enrolled. They underwent physical examination and four blood sampling sessions: at rest, immediately after a race, during recovery (3 and 6 days after the race), and after completing an Olympic course. Blood sampling was performed using the same method one month later. Weight (kg) and saturation of peripheral oxygen (SpO2) were measured. Tail intensity, tail moment, and tail length, and levels of superoxide dismutase (SOD), creatine kinase (CK), and lactate dehydrogenase (LDH) were analyzed. Results First, the study found significant changes between the body weight at rest and immediately after the race (p<.001) and between those immediately after the race and 3 and 6 days after the race (p<.001) for both courses. Second, for both courses, SpO2 declined immediately after the race and tended to rise again during recovery, but the difference was not significant. Third, in the Olympic course, significant differences were found between lymphocyte tail moment ™ at rest and that immediately after the race (p<.01) and between those immediately after the race and 3 and 6 days after the race (p<.05, p<.01). In the O2 course, significant differences were found between lymphocyte TM at rest and that immediately after the race (p<.01), between those at rest and 3 days of recovery (p<.001), between those immediately after the race and 3 days of recovery (p<.001), between those at rest and 6 days of recovery (p<.01), and between those at 3 and 6 days after the race (p<.01). Both courses significantly differed in lymphocyte TM immediately after the race (p<.05). Fourth, significant differences were observed between serum SOD at rest and that immediately after the race (p<.05), between those at rest and 3 days after the race (p<.01) and in serum SOD between that immediately after the race and 6 days after the race (p<.05) in the Olympic course. In the O2 course, serum SOD at rest and those at 3 and 6 days after the race significantly differed (p<.05). The two courses differed in serum SOD at 3 days after the race (p<.05). Fifth, in both courses, compared with the levels at rest, serum CK concentrations immediately after the race (p<.001) and 3 and 6 days after the race significantly differed (p<.01, p<.001). In both courses, significant differences were observed between serum CK concentrations immediately after the race and those at 3 and 6 days after the race (p<.01, p<.001) and between those at 3 and 6 days after the race (p<.001). Both courses significantly differed in serum CK concentrations immediately after the race (p<.001) and those at 3 and 6 days after the race (p<.05). In the Olympic course, serum LDH concentrations between those at rest and immediately after the race (p<.001), between those at rest and 3 days of recovery (p<.01), and between those immediately after the race and 3 and 6 days after the race showed significant differences (p<.001). In the O2 course, significant differences were found between serum LDH at rest and that immediately after the race (p<.001), between those at rest and 3 and 6 days after the race (p<.01, p<.001), between those immediately after the race and 3 and 6 days after the race (p<.001), and between those at 3 and 6 days after the race (p<.001). The two courses significantly differed in serum LDH levels immediately after the race (p<.001) and those at 3 and 6 days after the race (p<.05). Conclusion Triathlon, which involves long-term high-intensity aerobic exercise, leads to temporary weight loss, DNA damage, and muscle damage after the race, and such changes are affected by exercise duration and intensity. During this change, defense mechanisms, including the antioxidant defense mechanism, are thought to protect the body from DNA and muscle damage.