• Journal of the Korean Society of Physical Medicine
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• v.18 no.1
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• pp.15-24
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• 2023

PURPOSE: This study examined the effects of lowintensity resistance exercise combined with blood flow restriction on muscle activity and muscle fatigue to determine if such a combination may be an alternative to high-intensity resistance exercise in maintaining the muscle mass and strength and preventing degenerative loss of skeletal muscle and to provide basic data for presenting the effectiveness of exercise. METHODS: The interventions were provided for five weeks, four sessions a week, once a day, 60 minutes a session to Experimental group I (n = 13), in which low-intensity resistance exercise was applied by combining blood flow restriction with the biceps curl and experimental group II (n = 12), in which only high-intensity resistance exercise was applied. As a pre-test, the biceps brachii muscle activity and fatigue were measured by surface electromyography, and the hemodynamic variables, such as blood pressure and heart rate, were measured. The post-test was performed identically to the pre-test and compared and analyzed with the pre-test. RESULTS: A significant difference within-group was observed in the biceps brachii muscle activity and fatigue in experimental group I and only in biceps brachii activity in experimental group II. No significant differences were observed between the two groups. CONCLUSION: Since the low-intensity resistance exercise combined with blood flow restriction has similar effects to high-intensity resistance exercise, it is considered an alternative for improving muscle function in groups unable to perform high-intensity resistance exercise.

• The Korean Journal of Food & Health Convergence
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• v.7 no.6
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• pp.17-24
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• 2021

This study investigates the exercise-physiological changes in stages through the movement of the automatic stepper and to analyze the usefulness of the automatic stepper. For 18 male university students, out of 10 levels, 5 level and 10 level of automatic stepper exercise were performed. At each 10, 20, 30 minutes during exercise, 5 and 10 minutes after exercise stop the subjects were examined to analyze the changes in energy consumption after minutes, respiratory exchange rate, heart rate, oxygen consumption per body weight, METs, cumulative energy consumption, and lactic acid to verify the usefulness of the automatic stepper. The mean and standard deviation were calculated using the SPSS, and one-way ANOVA with repeated measure was performed to verify the difference in the mean between time periods. The LSD method was used for the post-hoc test, and the significance level was set to α = .05. There were no significant changes in both 5 and 10 level, but the cumulative energy consumption over time increased significantly. In addition, as a low-intensity exercise intensity is shown, a low increase in lactic acid indicated a safe exercise level. In future studies, in-depth studies of various variables through regular exercise programs are needed for those who need safe exercise.

• Physical Therapy Korea
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• v.7 no.2
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• pp.20-34
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• 2000

The purpose of this study was to establish modified physiological cost index (PCI) for predicting energy consumption by heart rate (HR) at isokinetic ergometer exercise testing. The subjects were twenty-eight healthy men in their twenties. All of them performed upper and lower extremity isokinetic ergometer exercise tests which had six loads (400, 500, 600, 700, 800, and 900 kg-m/min) and five loads (400, 500, 600, 700, and 800 kg-m/min) respectively. The exercise sessions were finished when HR was in plateau. HR and oxygen consumption were determined during the final minute. Resting heart rate and oxygen consumption were used for calculating heart rate, oxygen consumption changes and modified PCI. Regression analysis established the relationship between each variable to work load, HR and oxygen consumption. The results were as follows: 1) In the lower extremity ergometer exercise test, oxygen consumption increased continuously as work load increased, but in the upper extremity ergometer test, oxygen consumption only increased until work load was 700 kg-m/min. 2) HR increased as work load increased in both exercise tests, but in the upper extremity ergometer test, HR decreased from the 700 kg-m/min. 3) The modified PCI increased as work load mcreased until the 700 kg-m/min point in the lower extremity ergometer test and until the 500 kg-m/min point in the upper extremity ergometer test when it started to decrease in both tests. 4) In the lower extremity ergometer exercise test, regression analysis established the relation as $dVO_2$ = -.0215HR - .2141 where $dVO_2$ is given in l/min and HR in beat/min ($R^2$ = .2677, p = .000). ln the upper extremity ergometer exercise test. regression analysis established the relation as $dVO_2$ = -.0115HR + .2746 ($R^2$ = .1308, p = .000). The results of this study were similar to previous studies but were different under high work load conditions. So modified PCI should be used with only low intensity work load testing. Subjects for upper extremity ergometer exercise testing should complete a prescribed training course prior to testing, and only low intensity work load should be used for safety considerations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.140-148
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• 2017

The purpose of this study was to examine the effects of acute aerobic exercise at different intensities on the blood pressure, blood lipids and fibrinolytic markers in pre-hypertension college-aged males. Six subjects performed an acute running exercise at three different intensities(low intensity(LI): 50-60% heart rate reserve(HRR), moderate intensity(MI): 60-70%HRR, and high intensity(HI): 70-80%HRR). The blood pressure(systolic(SBP) and diastolic blood pressure(DBP), blood lipids(total cholesterol(TC) and high-density lipoprotein cholesterol(HDL-C)) and fibrinolytic markers(tissue plasminogen activator(tPA) and plasminogen activator inhibitor-1(PAI-1)) were determined before(PRE), immediately after(POST) and 60minutes after the exercise(60 POST). Results: the SBP in the LI group was significantly increased at POST(p=0.013). The ES levels for the SBP in the MI and HI groups were reduced (-1.33 and -1.23, respectively), though the differences were not significant. The HDL in the MI(p=0.003) and HI(p=0.002) groups were significantly increased at 60 POST. Also, the tPA in the MI(p=0.021) and HI(p=0.042) groups were significantly increased at POST.

• Journal of Life Science
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• v.19 no.2
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• pp.271-276
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• 2009

The Purpose of this study was to examine the effects of boxing aerobic training on resting heart rate variability (HRV) in females. The subjects for this study were performed 16 female college students that aged 19-23. The subjects were divided into two groups; boxing aerobic exercise group (9 students) and control group (7 students). Boxing aerobic training program was performed three times a week for twelve weeks with $VO_{2max}$ 60-80% exercise intensity. The results of this study were following; 1. Mean HRT (mean heart rate) had no signigicant difference among the groups and exercise time. 2. SDNN (standard deviation of the normal to normal interval) had no significant difference among the group and exercise time. 3. RMS-SD (square root of the mean squared differences of successive normal to normal interval) had no significant difference among the groups and exercise time. 4. TP (total power) had no significant difference among the groups and exercise time. 5. LF (low frequency) had no significant difference among the groups and exercise time. 6. HF (high frequency) had no significant difference among the groups and exercise time. 7. LF/HF (low frequence/high frequency ratio) had no significant difference among the groups and exercise time. 8. VLF (very low frequency) had no significant difference among the groups and exercise time.

• The Korean Journal of Physiology
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• v.6 no.2
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• pp.31-37
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• 1972

The right cervical vagus nerve was electrically stimulated for 30 sec, and 30 minutes recording cardiac rate responses and electrocardiogram. The main purposes of the present experiment are to determine effect of stimulation frequency on the maintenance of cardiac rate responses and to determine recovery time of sinus rhythm after asystole period followed by idioventricular rhythm during prolonged electrical stimulation of the vagus, and the optimal stimulation parameters for vagal stimulation were studied as well. The results obtained are summarized as follows: 1. The maximum negative chrontropic responses were obtained with the following ranges of electrical parameters. Intensity: 3V-7V, Frequency: 20/sec-60/sec, and pulse duration: 5 msec-20 msec. 2. Compared with the responses from sympathetic effectors, cardiac rate responses to electrical stimulation of vagus nerve were well maintained with all stimulation frequencies. 3. At all stimulation frequencies except 20/sec, sinus node started to take over primary pacemaker activity when cardiac rates were restored to about 38-40/min. 4. It was indicated that upper limit of idioventricular rhythm does not exceed 38-40/min. 5. With the stimulation parameter set of 20/sec-5 msec-3 V, sinus rhythm did not appear during 30 minutes of stimulation period. Therefore, this electrical parameter set appears to be optimal for elicitation of prolonged and maximum cardiac rate responses by vagal stimulation.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.49-49
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• 2003

목적 : 심초음파는 비침습적이므로 반복적으로 정확히 심질환의 경과를 관찰하여 치료효과 및 수술시기를 정할 수 있는 검사로서 임상적으로 매우 유용하다. 실시간 심근조영심초음파에 의한 time intensity 평가는 부위별로 수행됨으로 연속적으로 위치하는 관심영역이 intensity에 있어 심장의 움직임 변화에 영향을 받는다. Time intensity 곡선의 최적의 곡선맞춤을 위해 주기적인 심장 운동 매개변수를 조합해 기존의 모델을 보정한 안정적인 측정방법을 제시한다. 방법 : 심장의 운동에 의한 특징적인 정보를 설명하기 위해 기존의 문헌에 제시된 지수 함수에 주어진 심박수로 만들어진 시간에 관한 일반적인 정형파 함수를 추가한다. C(t) = A[1 - exp($\beta$t)] + Dsine(2$\pi$ft + $\theta$) C(t): videointensity A: plateau videointensity (blood volume) $\beta$: capillary blood velocity (rate constant of rise in videointensity) t: pulsing interval (ms) D: displacement from the periodic variance of the curve (estimated motion field from the ejection point for the ratio between systole and diastole) f: heart rate $\theta$: transit time issue A $\times$ $\beta$ : myocardial blood flow 관상동맥의 관류 데이터에 대한 실험이 펄스간격에 대한 비디오 세기로 수행되었다. 그리고 이러한 결과들이 the sum of squares due to error, R square, root mean squared error로 평가되었다. 결과 : 실험결과, 주기적인 심장의 움직임과 심박출 시점으로부터의 변위를 잘 기술하고 곡선에서의 측정 점들이 예측된 심장 움직임에 따라 성공적으로 표시되었다. 뿐만 아니라 보정된 모델이 현저한 적합도의 향상을 보여주었다. 결론 : 제시된 접근방법은 각각의 측정에서 심장 운동 영역의 변화에 독립적이며 측정 시점에 의해 영향받지 않고 심근 관류의 안정적인 측정이 가능하다. 심장의 움직임에 관한 매개변수를 조합한 모델로 곡선접합을 수행함으로써 관류의 정량적 정보를 좀더 정확하게 얻을 수 있으며 임상적 이용을 가능하게 할 것으로 기대된다.

• Advances in Traditional Medicine
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• v.4 no.1
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• pp.18-21
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• 2004

Six volunteers (mean $age=25.7{\pm}1.7$, $height=173{\pm}1.9$ and $weight=63.4{\pm}2.3{\;}kg$) participated in a graded exercise test and one hour of basic form of ChunDoSunBup (CDSB) Qi-training to investigate the cardiorespiratory responses and exercise intensity of Qi-training, a Korean traditional psychosomatic training. In the maximal exercise, the trainee showed $96.2{\pm}8.89{\;}l/min$ in ventilation (VE), $46.0{\pm}4.4$ in breath frequency (BF), $1.31{\pm}0.05$ in respiratory exchange ratio (RER), $180.7{\pm}3.0$ in heart rate (HR), and $2.6{\pm}1.1{\;}l/min$ or $40.7{\pm}2.3{\;}ml/kg/ml$ in oxygen consumption $(VO_2)$. Qi-training induced significant changes in BF, RER, HR, and $VO_2$. The exercise intensity of Qi-training were 42.3%, 46.9% and 38.7% of $HR_{max}$ during the sound exercise, slow motion (haeng-gong) and meditation respectively and the average was 46.2% of $HR_{max}$. We conclude that Qi-training is an aerobic exercise of a light (mild) intensity exercise, and it leads to decrease the metabolic rate in the trainee by breathing efficiently and relaxing them. In addition, Qi-training may affect cardiorespiratory function of BF, RER, HR and $VO_{2max}$ in trainees.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.369-376
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• 2019

The purpose of this study was to the effects of exercise intensities in physical activity of 8 weeks, on fitness, blood lipid for middle school students with intellectual disabilities. Participants of the research were allocated by low-intensity(n=8, 40~54%HRR), middle-intensity(n=8, 55~69%HRR), and high-intensity(n=9, 70~85%HRR) exercise groups wirelessly. For setting and maintenance of individual exercise intensity, wireless heart rate monitor(RS-400, POLAR, Finland) was used. Fitness, BDNF, and blood lipid were measured equally before participating in physical activity and 8 weeks after participation. As a result, fitness and agility of high-intensity exercise group were significantly increased than low-intensity exercise group. BDNF of high-intensity exercise group was also significantly increased than low-intensity exercise group. For blood lipid, only total cholesterol showed differences by exercise intensity group and exercise group more than middle intensity showed significant reduction. In conclusion, when giving same exercise to middle school students with intellectual disabilities, fitness and BDNF were increased the mostly in high-intensity exercise group and total cholesterol was effective from the exercise of more than middle intensity.

• Journal of Korean Biological Nursing Science
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• v.2 no.2
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• pp.1-19
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• 2000

The purpose of this study was to identify the characteristics and physiological variables of chest pain induced by exercise test in angina suspected patients. The subjects of this study consisted of 28 inpatients and outpatients aged between 40 and 75 who underwent treadmill test at exercise testing laboratory of S-University from January 2000 to June 2000. Subjects were interviewed with questionnaire regarding sociodemography, the past health history and history related to chest pain before the exercise test. Subjects were interviewed with questionnaire concerning quality, intensity, duration of chest pain induced by walking on the treadmill(Marquette, U.S.A. 1992) according to Bruce protocol following exercise test. Systolic and diastolic blood pressure were measured before, during and after the test, heart rate was determined by ECG. The results of this study were as follows ; 1) Quality of chest pain induced by exercise test were feeling stiffness 19(67.9%), heavy 10(36.0%), exploded 9(32.1%), crushing, suffocating, tight 8(28.6%), stuffy, prickly 7(25.0%), burning 6(21.4%), clasp 5(17.9%), cleaved, tensed, piercing 3(10.7%), perfectly fitting, sore 2(7.1%), tearing, tingling, ticklish, heartburn 1(3.6%). 2) Mean score of VAS(intensity of pain) following exercise test was $5.79{\pm}2.27$ and mean duration of chest pain after the test was $7.83{\pm}5.31$ minutes. 3) Sites of chest-pain induced by exercise test were middle site 11(39.3%), left-chest 10(35.6%), right-chest 6(21.5%). Radiation site of chest-pain was neck(18.0%), right flank site 1(3.6%), left shoulder & arm 2(7.1%) and back 1(3.6%). 4) Symptoms other than chest-pain induced by exercise test were dyspnea 21(75.6%), perspiration 14(50.4%), fatigue 12(43.2%), leg-pain 11(39.6%), dizziness 7(25.2%) anxiety toward chest-pain 3(10.8%), thirst 2(7.1%), and palpation, headache and tingling sensation of hand and leg 1(3.6%). 5) Mean MET(intensity of exercise) during the exercise test was $7.64{\pm}2.57$ and mean RPE(rating of perceived exertion) was $15.89{\pm}2.36$. Mean duration of exercise was $6.79{\pm}2.88$. 6) correlation coefficients between RPE and VAS was 0.500(p=0.003), those between MET and VAS was 0.287(p=0.069) and those between either depression or elevation of ST segment and VAS was 0.236(p=0.114). 7) There was a significant difference in mean systolic pressure between before and after the test as $146.29{\pm}28.18mmHg$ and $177.96{\pm}28.82mmHg$(t=-5.640, p=0.000), a significant difference in mean diastolic blood pressure between before and after the test as $84.85{\pm}15.07mmHg$ and $88.89{\pm}13.72mmHg$(t=-2.082, p=0.047), and there was a significant difference in mean heart-rate between before and after the test as $81.89{\pm}12.22/min$ and $160.68{\pm}21.77/min$(t=-21.255, p=0.000).