• Journal of Life Science
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• v.20 no.4
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• pp.572-577
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• 2010

The purpose of this study was to find out the Bcl-2 (B-cell leukemia/lymphoma-2), Bax, and caspase-3(cysteine-aspartic proteases-3) protein expression in soleus and EDL muscle according to treadmill exercise intensity in 60 week-old SD rats. The SD rats were randomly divided into four groups (n=10 in each group): control (CON), low intensity exercise (LE), moderate intensity exercise (ME), and high intensity exercise (HE). The exercise was given to the rats for 8 wk, 5 day/wk. The animals underwent treadmill exercise at intensities of 30 min at 8 m/min for the LE group, 15 min at 16 m/min for the ME group, and 9 min at 24 m/min for the HE group. The results were as follows: the expression of Bcl-2 protein was lowest in the HE group and the expression of Bax protein was highest in the HE group. The expression of caspase-3 (cleaved form) protein was observed in the HE group. For the different types of muscle fiber, Bcl-2 protein expression in the soleus muscle was decreased in all groups. Bax protein expression in the soleus muscle was increased in the HE group only. Bcl-2 protein expression in the EDL muscle was decreased in the HE group, and Bax protein expression in the EDL muscle was increased in the ME and HE groups. Consequently, the protein expression related to the aged rats shows a difference according to the intensity of exercise. In addition, caspase-3 protein expression appeared in the HE group; however, in all amounts of intensity, DNA fragmentation was not observed. Therefore, apoptosis on skeletal muscles of aged mice can be intervened with optimal exercise. On the other hand, high intensity exercise can potentially accelerate the apoptosis of muscle fiber in aged rats.

• Journal of Biomedical Engineering Research
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• v.27 no.6
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• pp.370-375
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• 2006

The purpose of this work is to predict the systolic blood pressure (BP) during exercise from pulse transit time (PTT) for warning of possible danger. PTT was calculated as the time between R-peak of ECG and the peak of differential photoplethysmograph (PPG). For the PTT-BP model, we used regress equations from previous studies and 3 kinds of new models combining linear and nonlinear regress equation. The model parameters were estimated with the data measured under low to middle intensity exercise, and then was tested with the data measured under high intensity exercise. Predicted BP values after high intensity exercise were compared with those measured by cuff-type sphygmomanometer. The results showed that the error between measured and predicted values were acceptable for the monitoring BP. We tested PTT-BP models 1 month after the identification without further calibration. Models could predict the BP and the errors between measured and predicted BP were about 5mmHg. The suggested system is expected to be helpful in recognizing any danger during exercise.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.6 no.1
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• pp.1-15
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• 2008

This study was designed to investigate the effect of treadmill exercise of low-intensity and high-intensity on the functional recovery and histological change in spinal cord injury rats. Sprague-Dawley rats were experimented(n=15) for this research. Spinal cord injury was induced by the NYU drop impacter device after laminectomy. After operation, rats were test at modified Tarlov scale at 3 days, and divided into the control group(n=5), experimental group I(n=5, low-intensity treadmill) and experimental group II(n=5, high-intensity treadmill). The rats were disciplined from 7 day through 21 day. Functional recovery was evaluated by the BBB scales and the Grid Walk test for the progressive locomotor recovery at 3, 7, 14, 21 days. Histopathological studies for the muscle in order to observation the change of damage and size of the organized surface which is visible visually it executed hematoxylin & eosin stain. According to the result of 4 weeks of treadmill exercise, group II showed improvement than group I of motor behavior after spinal cord injury.

• Journal of the Korea Convergence Society
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• v.12 no.6
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• pp.27-32
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• 2021

The purpose of this study was to compare the immediate effect of EMS (electrical muscle stimulation) on rectus femoris thickness during resisted knee extension exercise in healthy adults. This experiment was conducted on 20 healthy adults as pretest-posttest nonequivalent one group design. The subject's 1RM of both knee extension was measured indirectly using an elastic band, and the knee extension resistance exercise using an elastic band was applied to high intensity (80% of 1RM) on the right leg and low intensity (50% of 1RM with EMS) on the left leg, which were applied with 5 sets. Muscle measurements were performed on the rectus femoris (1/2 site, 1/4 site) using ultrasonography before and after exercise. There was a statistically significant difference on the thickness of the rectus femoris in low intensity exercise of the elastic band applied with EMS between pre-test and post-test (p<.05). The results of this study showed that elastic band low intensity exercise combined with EMS had an immediate effective in increasing the thickness of rectus femoris. Based on this result, it is also necessary to verify the effectiveness of intervention methods incorporating low-intensity resistance exercises applying EMS to elderly who cannot exercise high-intensity resistance training in the future, and to develop exercise programs for various body parts.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.1
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• pp.43-49
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• 2021

Objective: Exercise is a risk factor for infertility in women. However, research on the effects of different intensities of exercise on folliculogenesis has not yielded clear results. This study was conducted to analyze the effects of differences in the intensity of exercise on folliculogenesis in mice. Methods: Nineteen female BALB/c mice (age, 3-4 months; weight, 13-25 g) were randomly divided into four groups: control, mild exercise, moderate exercise, and high-intensity exercise. The mice in the exercise groups engaged in swimming, with additional loads of 3%, 6%, or 9% of body weight, respectively. There were five swimming sessions per week for 4 weeks, with a gradually increasing duration every week. At the end of the treatment, ovarian extraction was carried out and hematoxylin and eosin staining was performed to identify folliculogenesis. Results: There were significant differences in the number of total follicles between the control and moderate-exercise groups (p=0.036) and between the mild- and moderate-exercise groups (p=0.005). The mean number of primary follicles was higher in the moderate-exercise group than in the mild-exercise group (p=0.006). The mean number of secondary, tertiary, and Graafian follicles did not differ significantly among groups (p≥0.05). However, the number of total follicles and follicles in each phase tended to increase after exercise, especially moderate-intensity exercise. Conclusion: Exercise of different intensities affected the total number of follicles and primary follicles. The number of follicles of each phase tended to increase after exercise. Moderate-intensity exercise had better effects than other intensities of exercise.

• Korean Journal of Exercise Nutrition
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• v.24 no.3
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• pp.1-6
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• 2020

[Purpose] While the anti-obesity effects of exercise and capsiate are well-observed individually, the effect of exercise with capsiate intake has not been systematically explored yet. Therefore, the purpose of this study is to investigate whether the anti-obesity effects of exercise training can be further enhanced by capsiate intake. [Methods] 8-week-old male mice were divided into 3 groups (n = 8 per group): sedentary group (SED; nontrained), exercise-trained group (EXE) and exercise-trained group with 10 mg/kg of capsiate intake (EXE+CAP). All mice were offered high-fat diet and water ad libitum. The mild-intensity treadmill training was conducted 5 times a week for 8 weeks. After 8 weeks, metabolism during exercise and abdominal fat weight were measured. [Results] Body weight and the rate of total abdominal fat were significantly less in EXE+CAP than in SED but not between EXE and SED. The average of respiratory exchange rate during exercise was significantly much lower in EXE+SED (p = 0.003) compared to the difference between EXE and SED (p = 0.025). Likewise, the fat oxidation during exercise was significantly much higher in EXE+SED (p = 0.016) compared to the difference between EXE and SED (p = 0.045). Then, the carbohydrate oxidation during exercise was significantly much lower in EXE+SED (p = 0.003) compared to the difference between EXE and SED (p = 0.028). [Conclusion] In conclusion, the anti-obesity functions of exercise training can be further enhanced by capsiate intake by increasing fat oxidation during exercise. Therefore, we suggest that capsiate could be a candidate supplement which can additively ameliorate obesity when combined with exercise.

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.1
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• pp.49-54
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• 2020

Cardiovascular disease is the leading cause of death worldwide and is caused by a variety of causes. The highest risk factor for cardiovascular disease is high blood pressure, which has no obvious symptoms, but if left untreated, it causes several complications. In order to treat hypertension, medication and regular exercise are required. In people with high blood pressure, excessive physical activity can put a great strain on the heart and lead to cardiovascular disease. Therefore, there is a need for an exercise intensity monitoring system through PTT measurement that can perform exercise at an appropriate intensity. In this study, we implemented a PTT change monitoring system according to exercise intensity by calculating PTT through ECG and PPG measurement. The implemented system differentiates the R-peak of the ECG and P-peak of the PPG, and calculates the PTT using the time difference between R-peak and P-peak. A running experiment was conducted to monitoring PTT change according to exercise intensity. As a result of the experiment, low intensity PTT is 0.313s, moderate is 0.220s, high is 0.188s, it was confirmed that the PTT decreased as the exercise increase increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.7
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• pp.963-971
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• 2014

This study investigated the effects of exercise intensity on PGC-$1{\alpha}$, PPAR-${\gamma}$, and insulin resistance in skeletal muscle of high fat diet-fed Sprague-Dawley rats. Forty rats were randomly divided into five groups: sedentary control group (SED), high fat diet group (HF), high fat diet+low-intensity exercise group (HFLE, 22 m/min, 60 min, 6 days/week), high fat diet+moderate-intensity exercise group (HFME, 26 m/min, 51 min), and high fat diet+high-intensity exercise group (HFHE, 30 m/min, 46 min). After 4 weeks of high fat diet and endurance exercise training, the lipid profiles, insulin, and glucose concentrations were determined in plasma. PGC-$1{\alpha}$, PPAR-${\gamma}$, and GLUT-4 contents were measured in plantaris muscle. The rate of glucose transport in soleus muscle was determined under submaximal insulin concentration ($1,000{\mu}IU/mL$ insulin, 20 min) during muscle incubation. Plasma glucose during oral glucose tolerance test in HF was significantly greater than that in SED, and plasma glucose levels in the three exercise (EX) groups were significantly lower that those in SED and HF at 30 and 60 min, respectively (P<0.05). Plasma insulin levels in the EX groups were significantly reduced by 60 min compared to that in HF (P<0.05). The protein expression level of PGC-$1{\alpha}$ as well as muscle glucose uptake were significantly higher in SED and HF than those in the three EX groups (P<0.05), and HFHE showed significantly higher levels than HFLE and HFME. Expression levels of GLUT-4 and PPAR-${\gamma}$ were significantly higher in the HFLE, HFME, and HFHE groups compared to the SED and HF (P<0.05). Therefore, the results of this study indicate that 4 weeks of high fat diet significantly developed whole body insulin resistance but did not affect PGC-$1{\alpha}$, PPAR-${\gamma}$, or the glucose transport rate in skeletal muscle, and exercise training was able to attenuate deteriorated whole body insulin resistance due to high fat diet. In addition, high intensity training significantly affected PGC-$1{\alpha}$ expression and the glucose transport rate of skeletal muscle in comparison with low and middle training intensities.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.267-274
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• 2019

To investigate the effect of high-intensity interval training (HIIT) on the outcomes of cardiac rehabilitation(CR) in elderly and younger patients with myocardial infarction(MI). Of the MI patients who received hospital-based CR from 2015 to 2017, we retrospectively reviewed the medical records of the patients who continued follow-up through the outpatient clinic. A total of 39 patients (20 elderly patients (${\geq}60year$($64.1{\pm}3.6$)) and 19 younger patients (< 60 year($55.6{\pm}2.3$)) was included in this study. The HIIT program was composed of 10 minutes of warm-up, 30 minutes of interval aerobic exercise, and 10 minutes of cool down. The aerobic exercise based on their initial exercise tolerance test outcome consisted of 3-minute usual intensity phase (60-70% of heart rate/VO2 reserve) and 4-minute of high-intensity phase (70-90% of heart rate/VO2 reserve). Exercise capacity was measured by exercise tests before and after hospital- based CR. Before CR, elderly group had a significantly lower exercise capacity in Exercise time, peak VO2, METs, Anaerobic threshold, VEmax, 02pulse than younger group. Both group showed similar improvement of cardiopulmonary exercise capacity after CR. And HIIT is safe and effective in elderly patients. It is considered necessary to further expansion for the participation of high intensity interval training in elderly patients.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.778-786
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• 2018

We investigated the effect of different exercise intensities on biomarkers of oxidant-antioxidant balance, inflammation, and muscle damage. Eighteen healthy and untrained male subjects were enrolled.Subjects were randomly and equally assigned to a moderate-intensityexercise(MIE, $65%VO_2max$) group(n=9) or a high-intensity exercise(HIE, $85%VO_2max$) group(n=9).Blood samples were collectedimmediately pre-exercise, post-exercise, and 60min post-exercisetoexamine oxidant-antioxidant balance(d-ROMs; BAP), inflammation(CRP; fibrinogen), muscle damage(CK; LDH), and lactate. Serum d-ROMs and BAP levels were significantly increased post-exercise compared with pre-exercise levels in HIE group(p<0.05). Lactate levels were significantly increased post-exercise compared pre-exercise levels in both the MIE and HIE groups(p<0.05). In addition, post-exercise serum d-ROMs and plasma lactate levels were significantly higher in the HIE group than in the MIE group(p<0.05). These results suggest that although relatively high-intensity exercises may increase oxidative stress levels in the body, they do not produce inflammatory response and/or muscle damage.