• 한국체육학회지인문사회과학편
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• v.55 no.6
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• pp.691-700
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• 2016

The purpose of this study was to investigate the effects of long-term endurance exercise or resistance exercise training on muscle anabolic/catabolic pathway. 50wks-old male Wistar rats(n=30) were randomly assigned for 3 groups (sedentary, endurance exercise, resistance exercise group). After 12-week of training, plantaris muscles were dissect to measure protein level. Akt/mTOR signal-related proteins were significantly increased only after resistance exercise training, but catabolic signal-related proteins, FoxO1 and MuRF1, were significantly decreased after resistance and endurance exercise training. After endurance exercise training, AMPK and PGC-1α protein levels were significantly increased. Therefore, the endurance exercise training has been shown to affect the protein balance of aging muscle through inhibition of muscle protein catabolism. The present results suggest the possibility that not only resistance exercise but also endurance exercise will be affectable to keep or increase muscle volume and capacity of middle-aged people.

• Korean Journal of Exercise Nutrition
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• v.16 no.2
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• pp.113-122
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• 2012

This study assessed the amount of energy consumed and fat deposition after endurance training in order to review the effect of 4-week endurance exercise on resting metabolic rate of a mouse during and after exercise and the effect of exercise. A total of 19 seven-week-old ICR male mice were used as the study subject. Those mice were divided into sedentary group (Sed) and trained group (Tr) after a week of environment adaption. The Tr group was trained with endurance exercise five times a week for four weeks. Weight and the amount of food intake were daily weighed and resting metabolic rate and metabolic rate after exercise were assessed before starting exercise and on the fourth week after training. Metabolic rate during exercise were measured four weeks after training. At the end of breeding period, statistically significant difference was shown in weights of trained and sedentary groups (p < 0.05). During a resting period, no significant difference was shown in oxygen intake, respiratory exchange ratio, and the amount of carbohydrate and fat oxidized. Moreover, no significant difference was shown in excess post-exercise oxygen consumption (EPOC) of an hour period after training. In contrast, the maximal oxygen uptake (VO₂ max) was approximately 11.1% higher in trained group after training compare to before. However, there was no significant difference in respiratory exchange ratio and carbohydrate and fat oxidization. During exercise, oxygen uptake, carbon dioxide production, and respiratory exchange ratio in energy metabolism during exercise showed no significant difference. However, significant difference was exhibited in the amount of fat oxidized in both groups. Summing up those results, endurance exercise could be concluded to be effective in weight control. However, weight loss is thought to be resulted from increase in fat oxidization during exercise unlike the conclusion made from previous studies where weight loss is prominently influenced by energy metabolism during a resting period and increased fat oxidation during post-exercise recovery. All experimental procedures were carried out at the Animal Experiment Research Center of Konkuk University. This study was conducted in accordance with the ethical guidelines of the Konkuk University Institutional Animal Care and Use Committee.

• Journal of Life Science
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• v.27 no.3
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• pp.361-369
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• 2017

Mitochondrial homeostasis is tightly regulated by two major processes: mitochondrial biogenesis and mitochondrial degradation by autophagy (mitophagy). Research in mitochondrial biogenesis in skeletal muscle in response to endurance exercise training has been well established, while the mechanisms regulating mitophagy and the relationship between mitochondrial biogenesis and degradation following endurance exercise training are not yet well defined. Studies have demonstrated that endurance exercise training increases the expression levels of mitochondrial biogenesis-, dynamics-, mitophagy-related genes in skeletal muscle. However, the increased levels of mitochondrial biogenesis marker proteins such as Cox IV and citrate synthase, by endurance exercise training were abolished when autophagy/mitophagy was inhibited in skeletal muscle. This suggests that both autophagy/mitophagy plays an important role in mitochondrial biogenesis/homeostasis and the coordination between the opposing processes may be important for skeletal muscle adaptation to endurance exercise training to improve metabolic function and endurance exercise performance. It is considered that endurance exercise training regulates each of these processes, mitochondrial biogenesis, fusion and fission events and autophagy/mitophagy, ensuring a relatively constant mitochondrial population. Exercise training may also have contributed to mitochondrial quality control which replaces old and/or unhealthy mitochondria with new and/or healthy ones in skeletal muscle. In this review paper, the molecular mechanisms regulating mitochondrial biogenesis and mitophagy and the coordination between the opposing processes is involved in the cellular adaptation to endurance exercise training in skeletal muscle will be discussed.

• Molecules and Cells
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• v.27 no.5
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• pp.557-562
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• 2009

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% $VO_2max$, and recovery before and after 8 weeks of treadmill 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.

• The Journal of Korean Physical Therapy
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• v.14 no.4
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• pp.100-118
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• 2002

This study was to investigate the effect of long-term high intensity endurance training on the activation of antioxidation enzyme activity, lipid peroxidation and lipoprotein metabolism. 15 subjects were divided into, endurance exercise + antioxidation Vitamin supplement(n=5), endurance exercise(n=5), and the control(n=5) groups. The endurance exercise groups(endurance exercise + antioxidation Vitamin supplement and endurance exercise) had 12 week of endurance exercise program. The antioxidation Vitamin supplement group was taken a Vitamin C tablet with 1000mg/day and Vitamin E tablet with 671.14mg/day right after lunch. The results obtained from this study were as follows; 1. Looking at the changes of SOD, Endurance exercise+antioxidation Vitamin supplement group and endurance exercise groups showed the significantly greater decrease in the activation of SOD after 12 weeks of all-out exercise. 2. Looking at the changes of CAT, Endurance exercise+antioxidation Vitamin supplement group revealed subjects tended to increase CAT after all-out exercise although statistically non-significant. Endurance exercise+antioxidation Vitamin supplement group showed the significantly greater increase in the activation of CAT after 12 weeks treatment for all-out exercise. 3. Looking at the changes of GPX, Endurance exercise+antioxidation Vitamin supplement group revealed subjects tended to increase GPX for the rest and after all-out exercise although statistically non-significant. Endurance exercise+antioxidation Vitamin supplement group showed the significantly greater increase in the activation of GPX after 12 weeks treatment for all-out exercise. 4. The MDA change showed the significant decrease after 6 weeks, after 12 weeks for the all-out exercise of Endurance exercise + antioxidation Vitamin supplement group. 5. There was non-significant change in lipoprotein metabolism for the rest and after all-out exercise.

• Korean Journal of Exercise Nutrition
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• v.13 no.2
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• pp.161-167
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• 2009

The purpose of this study was to investigate whether two different exercises, acute exhaustive exercise and long-term endurance exercise training could affect to the expression of Mn-SOD, HSP70, and PPAR-γ protein in myocardium. The Wistar-Kyoto rats(n=24, 4 weeks) were used and randomly divided into 3 groups; endurance exercise training group (EET, n=8), acute exhaustive exercise group (AEE, n=8) or control group (CON, n=8). EET performed treadmill exercise for 12 weeks (5 days/week, 30~60 min/day). AEE exercised treadmill running (speed increased gradually to 14-26 m/min, 60 min ±10min) until exhausted when EET finished the program. Then, all the rats were sacrificed 48 hours rest at least after the last session of their own exercise program. Hearts were isolated and then the expression of Mn-SOD, HSP70, and PPAR-γ were analyzed by western blotting. One-way repeated ANOVA was used and p value under 0.05 was considered as statistical significance. The results were followed as; the expression of Mn-SOD of AEE was decreased compared with CON. However, the expression of Mn-SOD of EET was increased compared with CON. There was significant difference between AEE and EET in the expression of Mn-SOD. The expressions of HSP70 and PPAR-γ in the both AEE and EET were significantly increased compared with CON. In conclusion, acute exhaustive exercise might induce oxidative stress wheres endurance exercise training could ameliorate the oxidative conditions by increase of Mn-SOD, HSP70, and PPAR-γ. Therefore, we suggested that endurance exercise training could enhance the complementary antioxidant system and improve to prevent apoptosis. Further, a long-term moderat aerobic exercise program might play a important role in mitochondrial biogenesis in the heart.

• IMMUNE NETWORK
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• v.14 no.5
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• pp.255-259
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• 2014

Physical activity could be considered one of the factors that affect the immune system status and function. To find the relation between exercise and cytokines, we examined the possible effects of an 8-week endurance training program on the serum levels of cytokines, including tumour necrosis factor-alpha (TNF-${\alpha}$) and interferon-gamma (IFN-${\gamma}$) in sedentary men. A total of 30 healthy young male volunteers were randomly divided into an endurance training group and a control group. The training group followed a specific exercise protocol (running on a treadmill for 15~30 min at 50~70% maximal heart rate) for 8 weeks and the control group did not participate in any exercise program. Venous blood samples were collected from both the groups 24 h before and 24 h and 48 h after the exercise. Repeated ANOVA was used for statistical purposes. The serum levels of TNF-${\alpha}$ and IFN-${\gamma}$ were determined by ELISA. Significant (p<0.05) and non-significant (p>0.05) decreases were observed in the serum levels of IFN-${\gamma}$ and TNF-${\alpha}$, respectively, after the 8-week endurance training program. Our findings indicated that an 8-week endurance exercise may affect the serum levels of some inflammatory cytokines, suggesting the beneficial role of this training protocol in elderly population and people with certain conditions (inflammation of the vertebrae or other inflammatory diseases).

• Journal of Nutrition and Health
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• v.35 no.8
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• pp.825-833
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• 2002

The effects of dietary supplementation of Eleutherococcus senticosus, taurine and carnitine on maximal endurance exercise performance along with other related parameters were evaluated in rats that underwent aerobic exercise training for 6 weeks. Thirty-two male rats (4 weeks old) were randomly divided into 4 groups, and fed experimental diets and/or aerobic exercise trained according to the protocol: SC (sedentary control group), EC (exercise-trained control group), EE (exercise-trained Eleutherococcus senticosus-supplemented group), and EETC (exercise-trained Eleutherococcus senticosus, taurine and carnitine-supplemented group). The food efficiency ratio of EC rats was significantly lower than the value for SC rats (p < 0.01). Exercise-trained control animals (92 $\pm$ 8.8 min) could run significantly longer until exhausted on the treadmill than sedentary control rats (11 $\pm$ 0.8 min) (p < 0.001). Animals fed an Eleutherococcus senticosus-supplemented diet, and an Eleuthherococcus sonticosus, taurine and carnitine- supplemented diet while undergoing aerobic exercise training for 6 weeks exhibited, respectively, 8 and 5 minutes longer running performance until exhausted than the rats fed the control diet. The gastrocnemius muscle glycogen concentration of the rats, measured at 48 hours post maximal exercise performance test, was 43% higher in EC rats than the value for SC rats (p < 0.05), but was not different among EC, EE, and EETC rats. The mitochondrial citrate synthase activity of the soleus muscle was significantly higher in EC rats compared to the value for SC rats (p < 0.01), and showed a tendency to increase, without statistical significance, in EE or EETC rats compared to the value for EC rats. These results indicate that aerobic exercise training for 6 weeks significantly improved maximal exercise performance, muscle glycogen content along with citrate synthase activity, which are important in the energy metabolism of muscle under aerobic exercise. Dietary supplementation of Eleutherococcus senticosus in rats while undergoing aerobic exercise training improved maximal endurance exercise performance without significantly affecting muscle glycogen content and enzyme activities involved in energy metabolism during exercise. Taurine and carnitine supplementation failed to show an additive effect on maximal endurance exercise performance when consumed along with Eleutherococcus senticosus.

• Journal of Nutrition and Health
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• v.35 no.10
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• pp.1031-1037
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• 2002

The purpose of present study was to evaluate the effect of endurance exercise training on skeletal muscle free amino acid concentrations, and differences in free amino acid concentration between soleus muscle which consists of mostly slow twitch oxidative fiber and extensor digitorum longus muscle which consists of fast twitch oxidative glycolytic fiber. Sixteen male SD rats (4 weeks old) were randomly devided into two groups, and fed a purified AIN-93M diet with or without aerobic exercise training according to the protocol (running on the treadmill at 25 m/min for 60 min, 5 days a week) for 6 weeks. Exercise-training for 6 weeks significanly reduced the commulative body weight gain (p＜0.05) and food efficiency ratio (p＜0.01) of rats. The result showing mitochondrial citrate synthase activity of soleus muscle was significantly higher in exercise-trained rats compared to the value for control animals (p＜0.01) indicates aerobic exercise-training was successfully accomplished in the trained group. No difference was found in the muscle aminogram pattern between soleus muscle and extensor digitorum longus muscle of control animals. However, free amino acid concentrations of soleus muscle were from 1.2 to 3.9 times of those found in extensor digitorum longus muscle of control rats, depending on an individual amino acid. Intermediate level of endurance exercise training for 6 weeks did not influence concentrations of most of free amino acid in soleus muscle of rats collected at an overnight fasted and rested state. In contrast, isolucine and leucine concentrations in extensor digitorum longus muscle of exercise-trained rats were significantly lower than those for control animals. These results indicate that aerobic energy metabolism had not been efficiently conducted, and thereby the utilization of BCAA for energy substrate was enhanced in fast twitch oxidative glycolytic fibers of extensor digitorum longus muscle of rats followed exercise-training protocol for 6 weeks.

• Journal of Korean Academy of Nursing
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• v.27 no.1
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• pp.96-108
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• 1997

The purpose of this study was to determine the effect of endurance training prior to occurrence of muscle atrophy on the mass, myofibrillar protein content and fiber crossectional area of atrophied hindlimb muscles of rats. Adult female Wistar rats were trained prior to occurrence of muscle atrophy induced by hindlimb suspension. Training began on the 1st day for 10min /day at 15m /min on a 0% grade, training exercise increased daily in time and intensity so that by the 4th week rats were running 60min /day, at 34m /min on a i3.5% grade. Wet weight and relative weight of soleus, plantaris and gastrocnemius muscle decreased significantly after seven days of hindlimb suspension. Wet weight and relative weight of soleus tended to increase and that of plantaris and gastrocnemius tended to decrease in the exercise group as compared to the control group. Myofibrillar protein content of soleus and gastrocnemius tended to increase and that of plantaris tended to decrease in the endurance trained group as compared to the control group. Fiber crossectional area of Type I, II fiber in soleus and plantaris muscle tended to increase in the exercise group as compared to the control group. Wet weight and relative weight of soleus. plantaris and gastrocnemius decreased significantly, myofibrillar protein content of soleus, plantaris and gastrocnemius increased in hindlimb suspended rats following endurance training as compared to the control group. There was no change in fiber type percentage and crossectional area of type I and II fiber in soleus muscle and that of type I and IIfiber in plantaris muscle decreased in the hindlimb suspended rats following endurance training as compared to the control group. Wet weight and relative weight of soleus and plantaris tended to increase, that of gastrocnemius increased significantly, myofibrillar protein content of soleus and plantaris muscle increased significantly and that of gastrocnemius tended to increase in the hindlimb suspended rats following endurance training as compared to sedentary rats following endurance training. Crossectional area of type I fiber of soleus muscle tended to increase. that of type I fiber of plantaris muscle increased significantly and that of type II fiber tended to increase in hindlimb suspended rats following endurance training as compared to sedentary rats following endurance training. The results suggest that endurance training prior to occurrence of muscle atrophy can attenuate the decrease of mass, myofibrillar protein content and fiber crossectional area induced by hindlimb suspension.