ABSTRACT
The purpose of this study was to examine the effectiveness of the cultured <i>Cordyceps sinensis</i> (Cs, supplement) powder during exhaustive running of human comparing with the placebo (control). These supplements were given to 36 male sedentary subjects over period of 2 weeks. During the exercise, following bio-signals were measured such as the respiratory variables (VO<sub>2</sub>, VCO<sub>2</sub>, VE), the blood pressure (BP), the heart rate (HR), and the lactic acid (LA). In addition, their storing urine for one night was inspected about the catecholamine (CA, Adr, NorA, Dop) and the cortisol hormone (17-KA-S and 17-OHCS) at the pre-and the post-ingesting with those supplements. The changing ratio calculating between the pre- and the post-variables of VO<sub>2</sub>/kg (5.2±0.1 & 4.8±0.1 ml), VE (12.0±0.2 & 11.0±0.2 L), and LA (6.1±2.1 & 5.2±2.6 mmol/dl) had decreased to lower percentages at the recovery period from the exercise test than those of CON, significantly (p<0.01). Futhermore, concentration of the total CA (1.19±0.51 & 1.29±0.49 mg/L), Adr (13.5±1.2 & 17.7±1.9<i>μ</i>g/L), NorA (127.4±8.1 & 130.0±8.5<i>μ</i>g/L), Dop (1.06±0.1 & 1.14±0.4mg/L), 17-OHCS/creatinine (4.42±0.30 & 4.2±0.31), and 17-KS-G/creatinine (3.18±0.09 & 3.06±0.07) showed changes of significant difference related to the placebo (p<0.05). There have been appeared an augmentation of the energy generation and the anti-fatigue ability intaking with this supplement during the exercise test. During this prolonged exercise, ingesting with this Cs might elicit the superior efficiency and the economical function on the energy metabolism.
ABSTRACT
A study was conducted to investigate the neural connection between the afferents of the upper extremity and the motoneurons innervating the extensors of the lower extremity. Healthy young males and females were recruited. The median nerve was cutaneously stimulated, and the soleus H reflex, reflecting the excitability of motoneurons, was evoked. The C-T interval and intensity of the conditioning stimulus were modulated. A conditioning stimulus with an intensity of 1.4 xMT and a C-T interval of 69 ms inhibited the soleus H reflex pathway (I<SUB>1.4</SUB>) . Additionally, a conditioning stimulus with an intensity of 2.1 xMT and a C-T interval of 13 ms inhibited the soleus H reflex pathway (I<SUB>2.1</SUB>) . The conduction velocity of the afferents responsible for I<SUB>1.4</SUB> was 19m/s and that for I<SUB>2.1</SUB> was 39 m/s. The conduction velocity of the afferent fiber type responsible for I<SUB>1.4</SUB> was similar to that of the group III afferents, and the conduction velocity for I<SUB>2.1</SUB> was similar to that of the group II afferents. However, further investigation is needed to identify the afferents responsible, because the results conflict with those of previous studies in terms of inhibition thresholds.
ABSTRACT
The purpose of this study was to investigate the effects of cervical traction on the soleus H reflex amplitude. Young healthy men were recruited as the subjects. In experiment 1, cervical traction under three conditions, i. e. at an intensity of 3 kgf, 6 kgf or 9 kgf was applied to the subjects in the experimental group for a duration of 1 minute in the second minute of each trial. In experiment 2, cervical traction at an intensity of 3 kgf for a duration of 1 minute, 2 minutes, or 3 minutes was applied to the subjects in the experimental group. Cervical traction was not applied to the subjects in the control group. The soleus H reflex amplitude was measured before, during, and after cervical traction.<BR>The H reflex amplitudes under the 9kgf condition were largest and positive for every block, whereas those under the 3 kgf condition were smallest among the three experimental conditions employed. Significantly smaller H reflex amplitude compared to that in the control was observed under the 3 kgf condition.<BR>In experiment 2, the H reflex amplitudes under every experimental condition employed were smaller than that in the control. However, the differences in degree of depression of the soleus H reflex amplitudes among the three duration conditions were not significant.<BR>This study shows that cervical traction at an intensity of 3kgf depresses the gain of the soleus H reflex pathway. The cause of this depression may be an “after-effect” or flexor reflex afferents. A difference in the duration of cervical traction didn't result in any difference in the soleus H reflex amplitude.
ABSTRACT
Twenty biochemical components of serum were compared between normal healthy subjects and professionalwrestlers undergoing maximum training daily. Significant difference was found for 13 blood components : creatinine, uric acid, calcium, inorganic phosphorus, LDH, GOT, GPT, γ-GTP, alkaline phosphatase, direct bilirubin, cholesterol, triglyceride and glucose.<BR>Except for direct bilirubin, 12 parameters in wrestlers were higher than in healthy subjects. The higher concentrations of LDH, calcium, inorganic phosphorus, alkaline phos-phatase and creatinine were considered to be related to heavier physical exercise and special diet. The higher concentrations of alkaline phosphatase, calcium and inorganic phosphorus were thought to be mainly related to bone metabolism.
ABSTRACT
The present studies were performed to investigate changes of reaction time and increase of muscle strength by isometric training of biceps brachii muscle. The intensity of its training was the three types of maximal voluntary contraction (MVC), 70%MVC and 50%MVC. EMG reaction time (EMG-RT) as a function of motor control in center nervous system was measured by isometric contraction on fixed elbow.<BR>After training for 8 weeks period, integrated EMG (IEMG) and power spectorum (mean power frequency, MPF) were increased as a component of muscle strength. IEMG and MPF were increased 83.6% and 16.6% in MVC training group, and were increased 86.2% and 20.8% in 70%MVC training group, and were increased 69.2% and 13.2% in 50%MVC training group. Increase of muscle strength in MVC, 70%MVC and 50%MVC training group increased 36.8%, 42, 3% and 30.6%, respectively. Consequently, decrease of EMG-RT was markdly associated with increase of muscle strength. The heavy intensity of isometric training, MVC and 70%MVC groups, decreased the EMG-RT greater than 50%MVC training group. Therefore, the decrease of training-induced EMG-RT correlated to development of muscle strength due to stimulation by training intensity. These results suggest that the decreased EMG-RT might be due to stimulation on motor central system by muscle training of heavy intensity.
ABSTRACT
The present studies were performed to investigate changes of reaction time and increase of muscle strength by isometric training of biceps brachii muscle. The intensity of its training was the three types of maximal voluntary contraction (MVC), 70%MVC and 50%MVC. EMG reaction time (EMG-RT) as a function of motor control in center nervous system was measured by isometric contraction on fixed elbow.<BR>After training for 8 weeks period, integrated EMG (IEMG) and power spectorum (mean power frequency, MPF) were increased as a component of muscle strength. IEMG and MPF were increased 83.6% and 16.6% in MVC training group, and were increased 86.2% and 20.8% in 70%MVC training group, and were increased 69.2% and 13.2% in 50%MVC training group. Increase of muscle strength in MVC, 70%MVC and 50%MVC training group increased 36.8%, 42, 3% and 30.6%, respectively. Consequently, decrease of EMG-RT was markdly associated with increase of muscle strength. The heavy intensity of isometric training, MVC and 70%MVC groups, decreased the EMG-RT greater than 50%MVC training group. Therefore, the decrease of training-induced EMG-RT correlated to development of muscle strength due to stimulation by training intensity. These results suggest that the decreased EMG-RT might be due to stimulation on motor central system by muscle training of heavy intensity.
ABSTRACT
Neuromuscular fatigability of different muscle groups was studied under various physiological conditions in eight healthy male subjects by means of EMG fatigue curve analysis (E/F ratio defined as the rate of rise in IEMG/force as a function of time) which has been commonly used.<BR>Under the experimental conditions and assumptions described in the present investigation, the following conclusions could be justified on the basis of the experimental results.<BR>1. The E/F ratio for the biceps brachii muscle was significantly greater (p<0.0005) than that of the soleus muscle at 40% of MVC, suggesting that the biceps brachii with presumably greater %FT fibers were consistantly more fatigable than their own soleus muscle.<BR>2. The exponential growth of the E/F ratio as a function of either the maximal sustaining time (T<SUB>s</SUB>) or different fractions of MVC suggested a possible neurophysiological link between the fatigability of the biceps brachii muscle and their MU activities which might increase in an accelerated fashion.<BR>3. The evaluation of static work capacity (W<SUB>s</SUB>) described in the present study revealed that the differences in the critical force level and Ws during free circulation and arterial occlusion could be explained by the relative availability of muscle blood flow which might determine the rate of energy reconstitution.<BR>4. The EMG data taken during a constant torque output on an electrically braked bicycle ergometer indicated that some shift in the MU recruitment and/or MU firing frequency may occur during the application of arterial occlusion causing local muscle hypoxia.
ABSTRACT
The impulsive force-external loads relationships are reported experimentally on eight adult males by the method providing different actions : soft and hard motion or attached spring on the platform, four jumping down heights of the stand : 15, 33, 67 and 125cm and four additional loads to the body weight : 1, 2, 4 and 8kg. The forces are dealed with as the momentum on the landing motion and apparatus used are multi-component forces plate and 16mm camera. The impulsive force is measured using the planimeter about recorded waves of multicomponent forces exerted in the landing motion over the time of 0.8sec. The results obtained are as follows ;<BR>1) The impulssive forces are increased on the relation of the logalithmic function proportionally with the height of stand and with the weight of load.<BR>2) According to analyses of the landing motion, these angles of the ankle, the knee and the hip are flexed greater in proportion to heigher of the stand but no changes of these angles of body segments are showed with weighter of additional loads.<BR>3) Taking these results and reference into consideration, absorbable landing motion has been assumed to involve decrement oscillation in internal body segments and to maintain potential using for the next motion.
ABSTRACT
The purpose of this study is to clarify the characteristics of the short-term motor-memory and to analyze various loads effect of motor-retention in the exercise of flexion and extension of the fore-arm. As the means of analysis, correlation function between command and response waves was used efficiently and furthermore the electric computer system helped to investigate motor-retention. Many experimental conditions were decided to 0.1-0.8 Hz of one's exercise rhythm, 0-0.5 kg of loads attached to the fore-arm, and 3-6 cm of exercise displacement. Three healthy persons were employed as subjects.<BR>As the results of this study, following points were shown clearly.<BR>(1) After the fore-arm was exercised to the flexuous and extensional directions for 25 sec., response waves of motor-retention were recorded to Data-recorders for 60 sec Quantitative analysis of this motor-retention became effective by using the method of correlation function.<BR>(2) About exercise rhythm (frequency), the rapidity of fore-arm exercises in the retentive learning was 0.05 Hz slower than that of these exercises in the begining learning.<BR>(3) About the transfer gain of these exercises between command and response waves, two motor-gains of the retentive and begining learning were shown the same values only when these exercises were practised at experimental conditions of 0.8 Hz frequency and 0.5 kg load.<BR>(4) Motor-retention rate, that was calculated from error values of performance, was dropped down such as about 0.3 rate in proportion to the time elapsed of recollection and also to rhythm-slownes of the command frequency.<BR>(5) Optimal exercise displacement of the fore-arm was proved to the median of 6 and 3 cm in order to reappear the length memorized by the begining learning.<BR>(6) Discharged voltages of the integrated EMG in Flexor and Extensor C arpi Radialis were recorded lower at the time, when motor-retention was displayed rightly and exactly.<BR>(7) Sychological reminiscence and this motor-retention were shown quite opposite results in the learning points of reaction time, rhythm, strength and displacement, because the former was dependent upon the memory in the central nervous system (brain cortex), while the latter relied upon the memory in the peripheral-nervous system (receptor) .
ABSTRACT
Analytical method of correlation function and Fourier transformation has been applied for surface electromyogram. This study is to be aimed to investigate relation between motor-activities in isotonic muscular contractions and frequency in muscular electric discharge. By help of digital electrical computer, frequency characteristics in isotonic contraction of M. Biceps Brachii and M. Rectus Femoris have been calculated as Power Spectrum Density clearly and quantitatively.<BR>As the result of this study, following points were revealed.<BR>1) Fourier transformation was cleared up as the available method of physical fitness research in interpretation of surface electromyogram, on the assumption whose phenome-non was stationary in the process of statistical probability.<BR>2) Upon isotonic contraction, high and low frequency bands were divided distinctly among muscular discharge of surface electromyogram, that were about 20Hz and 75-90 Hz bands.<BR>3) In proportion to intensities of load and to alteration of movement velocity, high discharge frequency band showed changes of ranges of ±15Hz, but low discharge frequency band showed no change.<BR>4) In high discharge frequency band, density of Power Spectrum of M. Biceps Brachii was larger than that of M. Rectus Femoris, but on the other hand of low dis-charge frequency band, this Power Spectrum displayed no difference between both muscles.<BR>5) Comparing with two sorts of muscular contraction, that were isotonic and isometric, high discharge frequency band of the former was higher about 10Hz than that of the later.<BR>6) It was supposed that this low frequency band was dependent upon tonic Neuro Muscular Units and was corresponding to slow contraction of red-colored muscles.<BR>7) It was considered that this high frequency band depended on phasic N.M.U. and had connection with quick contraction of pale-colored muscles.
ABSTRACT
Analyses of correlation function and Fourier transformation are one of the important tools in the investigation of biological phenomena. Since the method of these analyses had been applied for interpretation of surface electromyogram, isometric muscular contractions had been estimated easily and accurately. Reliability and validity of measured values had been acquired by the assistance of the electro-computer and statistology. On the assumption that generated processes of surface electromyogram of arm and leg were 1) probabilistic 2) stationary and 3) Gaussian, power spectrums of probability density functions of measured values, were calculated in X-Y charts.<BR>As the results of the expeliment, following points were revealed.<BR>1. For the estimation of surface electromyogram upon muscular isometric contractions, these analytical methods should be applied for physical fitness researches with reliability and validity of the results.<BR>2. Upon the isometric muscular contraction, main discharge-frequency among surface electromyogram were existed in two bands of about 20 Hz and 90 Hz peaks.<BR>3. In proportion to intensities of load (Kg), magnitude of the agonist's discharge was increased in the frequency-band of 90 Hz, and that of the antagonist's discharge also was increased in the frequency-band of 20 Hz.<BR>4. According to these results, it was assumed that frequency-band of about 20 Hz would be corresponded with tonic muscular discharge and that of about 90 Hz would be equivalent to phasic muscular discharge.<BR>5. The longer time of muscular contractions sustained, the wider the frequency-band of about 90 Hz became on account of mixed and interfered discharges of neighboring muscle groups.
ABSTRACT
Recently, the popular usage of the sauna bath has been greatly increased but this is not necessaeily based upon scientific ground.<BR>This investigation has been made on the most ideal usage time with special emphasis on duration of time in the actual sauna room.<BR>The usage pattern, in view of the times of taking the sauna room and the cold water, has been established.<BR>And then the influences on the body function were measured.<BR>The usage pattern were as follows (Repetition were all 3 times)<BR>(1) 5 minutes stay in the sauna and 1 minute in the water<BR>(2) 7 minutes stay in the sauna and 1 minute in the water<BR>(3) 7 minutes stay in the sauna and 2 minutes in the water<BR>(4) 10 minutes stay in the sauna and 2, 5 minutes in the watar<BR>The result were as follows<BR>1. The usage pattern (1) gave the good result for the function of whole body reaction time, patellar-tendon reflex time, maximum power of vertical jump.<BR>Another usage pattern (2), (3), (4) gave the wrong result for those function.<BR>2. There were no remarkable differences blood pressure, heart rate and skin temperature among the usage pattern (1), (2), (3), (4) .<BR>3. Oxygen intake in the usage pattern (2) gave a large value than the usage pattern (1) .<BR>In the view of the energy expenditure, it was recognized that the usage pattern (2) was the best usage.
ABSTRACT
The aim of this study was to investigate quantitatively the power ability of middle and older aged men in the vertical jump.<BR>And, we would try to point out the changes with increasing ages and the influences of the environments factor to the power ability.<BR>Based on the environment point of view, we put an emphasis and consideration on those who did physical exercises and also those who drove a car in a daily life.<BR>Subjects were the health 201 men who visited the sports sauna training center of national stadium for physical exercises.<BR>The power was calcurated from the force and velocity concerning of jumper's C.G. during the take off motion. The force was measured by using a strain gage type tranceducer, and the velocity was calcurated by integrating the equation of motion about of C.G.<BR>Result:<BR>The power ability of middle and older aged men in the vertical jump decreased with increasing ages.<BR>The rate of decrease with every 5 years of age was 0.248 horse power, 2.960×10<SUP>-3</SUP> horse power in the maximum power and maximum power per body weight.<BR>In comparison with the power ability of 25 years old, the power ability, in terms of maximum power per body weight, of 35 years old, 45 years old, 55 years old were 90.8%, 81.1%, 59.0%, respectively.<BR>There were evidently differences between trained men and untrained men, and then car driver and no car driver in the power ability. The differences of maximum power per body weight were 12.190 × 10<SUP>-3</SUP> horse power, 9.231×10<SUP>-3</SUP> horse power, respectively.