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Volume 40 (1991)
- Issue 6 Pages 505-
- Issue 5 Pages 437-
- Issue 4 Pages 355-
- Issue 3 Pages 271-
- Issue 2 Pages 145-
- Issue 1 Pages 1-
Volume 40, Issue 2
Displaying 1-13 of 13 articles from this issue
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SHIGERU OBARA, HISAO YAMAGUCHI, EIZO BANDO, HIROSHI MIYAMOTO1991 Volume 40 Issue 2 Pages 145-155
Published: April 01, 1991
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe systolic time intervals (STI's) and the diastolic time (DT) as functions of the RR interval during exercise were proved to be described by cubic regression equations that converge to the origin of the coordinates. Using the equations, we compared I) the systolic time and DT of trained and untrained men, and II) examined the relations between parameters of STI's. I) Forty healthy male subjects aged 19-22 years old were divided into three groups, i, e., 8 long distance runners (group LD), 16 men with relatively high fitness (group A) and 16 men with relatively low fitness (group B) . They performed submaximal exercise test using a cycle ergometer for measuring the time of electromechanical systole (QS2) and DT. After test, maximal exercise test was conducted to determine the maximal heart rate (HRmax) in each subject. Means±SD of the minimum QS2 and the minimum DT of the 40 subjects predicted from the regression equations at the HRmax were 209.7±12.5 and 108.2±15.6 ms, their ratio being about 2: 1. The QS2 was significantly shorter, whereas DT was longer in the group LD than in the groups A and B at the HR of more than 120 bpm. II) Ten healthy male subjects aged 19-22 years old performed submaximal exercise to clarify the relations between any two of QS2, the left ventricular ejection time (LVET) and the preejection period (PEP) at the same HR: there were positive and negative significant correlations between QS2 and LVET, and between LVET and PEP, respectively, at the HR of more than 100 bpm. These results reveal that, when the HR is increased in exercise, the left ventricular systolic time (QS2) is shortened while the diastolic time is lengthened for the subjects trained as long distance runners. The shortening of the systolic time is mainly caused by shortening of LVET. The changes in the systolic and diastolic times suggest that contractility of cardiac muscle is enhanced during exercise of above moderate intensity after an extensive period of the aerobic training.View full abstractDownload PDF (1131K) -
ATSUO MARUYAMA, KOHJI HIRAKOBA, KOUJI MISAKA1991 Volume 40 Issue 2 Pages 156-163
Published: April 01, 1991
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSBlood lactate disappearance in endurance-trained men (ET) and untrained men (UT) was investigated by application of recovery exercise with high relative intensity. Blood lactate was measured in five male long-distance runners as ET and in seven male relatively active students as UT, using a cycle ergometer (60 rpm) . Two kinds of recovery exercise were performed at intensities of 70% and 40% Vo2max for 20 min followed by main exercise at 90% Vo2max for 3 min. The rate of blood lactate removal was calculated by linear regression of time (min) against blood lactate (mmol·l-1) at 5, 10, 15 and 20 min during recovery exercise. Values of blood lactate at 10, 15 and 20 min during recovery exercise at 70% Vo2max were significantly more reduced in ET than in UT (P<0.05, P<0.01) . There was, however, no significant difference between ET and UT during recovery exercise at 40% Vo2max. The rate A of blood lactate removal during 70% recovery exercise was significantly greater in ET (0.2730±0.0920mmol·l-1.min-1) than in UT (0.0520±0.1010mmol·l-1·min-1) (P<0.01), but there was no significant difference in the rate between ET and UT during 40% recovery exercise. The rate B of blood lactate removal during 70% recovery exercise was significantly higher in ET (0.3770±0.08000 mmol·l-1· min-1) than in UT (0.1163±0.14416 mmol·l-1·min-1) (P<0.01), but there was no significant difference in the rate between ET and UT during 40% recovery exercise.
In conclusion, the present data indicate that endurance-trained men possess more pronounced capability for blood lactate removal during recovery exercise at high relative intensity.View full abstractDownload PDF (989K) -
AKIRA CHIBA1991 Volume 40 Issue 2 Pages 164-173
Published: April 01, 1991
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSExperiments were performed on twelve young, healthy males. The subjects were asked to step in accordance with acoustic stimuli with a cyclic time of 1.2 s, while EMGs were recorded with surface bipolar electrodes from the vastus lateralis and medialis, semitendinosus, biceps femoris, tibialis anterior, and medial and lateral gastrocnemius muscles. An electrical stimulus consisting of 5 train pulses (duration : 1 ms, frequency : 300 Hz, 1.5 times perceptual threshold) was applied randomly to either the sural or posterior tibial nerve at the ankle joint during various stepping phases. In general, polyphasic reflex responses were elicited by the peripheral nerve stimulation. The reflex response of flexor muscles showed facilitation followed by inhibition, while that of extensor muscles showed inhibition followed by facilitation with either type of nerve stimulation. However in the case of sural nerve stimulation, inhibition followed by facilitation was observed during the early stance phase in the semitendinosus and biceps femoris muscles, which work as extensors during this phase. The effects of posterior tibial nerve stimulation on the femoral muscles during the stance phase were weak as than those of sural nerve stimulation. The amplitude of the reflex response changed depending on both the EMG activity of each muscle and the joint angle of the lower limb during stepping. It is suggested from these results that sensory inflow from the sole controls stepping, and that bifunctional muscles play an important role in the maintenance of equilibrium using peripheral inflow during stepping.View full abstractDownload PDF (1168K) -
OSUNG GWON, YOSHIHARU NABEKURA, HARUO IKEGAMI1991 Volume 40 Issue 2 Pages 174-186
Published: April 01, 1991
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSA study was conducted to elucidate the changes in circulatory responses to sudden strenuous exercise (SSE) using beat-by-beat analysis of heart rate (HR), stroke volume (SV) and blood pressure (BP) . The effects of warming-up on these responses were also studied.
Six healthy male students volunteered for the study. A bicycle ergometer was prepared for SSE. The intensity and duration of SSE were 100% VO2max and 1 min, respectively. Warming-up of 80% VO2max for 5 min followed by SSE. The interval between SSE and warming-up varied from 5 to 30 min. A control experiment was also performed without warming-up.
The main results obtained were as follows :
1) BP decreased in the initial stage of SSE, followed by a steep increase. This temporary drop in BP was prevented by warming-up. This might contribute to the prevention of myocardial ischemia which is occasionally observed in the initial stage of SSE without warming-up.
2) Time constants of HR and SV during SSE were shortened by warming-up with long intervals, while the time constant of BP was shortened when the interval was short.
3) The recovery response of each parameter was accelerated by warming-up, but the effect of warming-up had almost disappeared after a 30 min interval.
These results suggest the following conclusions :
Warming-up accelerates the up-stroke and recovery of circulatory responses to SSE, but these effects of warming-up are strongly influenced by interval time. In particular, the effect of recovery acceleration is almost abolished by a 30 min interval.View full abstractDownload PDF (1451K) -
NORIKI NAGAO, YURIKO TAKAI, MITSUTSUGU ONO1991 Volume 40 Issue 2 Pages 187-194
Published: April 01, 1991
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSA study was performed to investigate the effects of exercise and Spirulina platensis (SPL) intake on the hapten specific immune response of growing mice.
Male BALB/C mice aged five weeks were divided into 6 groups : Group A was a control group given a normal diet ; group B, sedentary with a normal diet ; group C, exercise with a normal diet ; group D, control with SPL diet ; group E, sedentary with a SPL diet ; group F, exercise with a SPL diet. The mice in groups C and F were trained by swimming for about 30 min 4 times a week for 5 weeks. The SPL diet was a mixture of SPL (20%) and the normal diet (80%) . At 4 weeks after the experiment, the mice belonging to groups B, C, E and F were sensitized with 1% toluene-2, 4-diisocyanate (TDI) . Five days after sensitization, TDI was painted on the ears of the mice, and delayed type hypersensitivity (DTH) was evaluated by measuring the ear thickness at 24 h later as an index. After this evaluation, the body weights of the mice, the weights of the thymus and spleen, and serum TDI-specific IgG antibody levels as an index of humoral immunity, were measured.
In the mormal diet groups, the highest DTH reaction was shown in the exercise group, followed by the sedentary group. On the other hand, the DTH reactions in the SPL diet groups were significantly suppressed in both the sedentary and exercise groups. However, a slightly higher DTH reaction was shown in the exercise group than in the sedentary group. Body weights of mice in the exercise groups receiving both the normal and SPL diets were suppressed in comparison with the control and sedentary groups. Although increased spleen weights were shown in all the sensitized groups, thymus weights in the 6 groups were not changed. TDI-specific IgG antibody levels were also not changed in any of the TDI sensitized groups.
From these results, the SPL diet seemed to effectively suppress the DTH reaction, and might be effective for treatment of various types of contact hypersensitivity which are currently the focus of clinical attention.View full abstractDownload PDF (965K) -
TAKANAO HIGUCHI, TOSHIYO TAMURA, TATSUO TOGAWA1991 Volume 40 Issue 2 Pages 195-201
Published: April 01, 1991
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSA portable device for long-term monitoring of oxygen uptake without discomfort has been developed based on a flow-through principle. The oxygen content of the exhaust gas was kept constant by a servo-controlled blower, so that the flow rate was essentially proportional to the oxygen uptake. This system was evaluated by both a bench test and in exercising human subjects. The limiting current-type oxygen sensor used this portable device produced results which were in good agreement those obtained using a zirconia oxygen sensor (r= 0.999), and stable values were obtained for at least 15 h. The response time for a stepped oxygen change was 4 s. The air flow rate produced by the blower was proportional to the supplied voltage. The results using a time-of-flight flowmeter were highly correlated with those for a hot-wire anemometer (r=0, 999) . The oxygen uptake of exercising human subjects measured with this portable device showed good agreement with that obtained by a conventional oxygen monitor (r=0.973 for cycle ergometer, r=0, 932 for treadmill) . This portable device was able to measure oxygen uptake in subjects during daily activities, and also while driving a car, without disturbance.View full abstractDownload PDF (2416K) -
KENJI TAKAGI, KAZUTADA OKUMURA, NORIYUKI MORIKAWA, GOUICHIROU KAJIYAMA ...1991 Volume 40 Issue 2 Pages 202-207
Published: April 01, 1991
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSSerum lipid levels in female handball players were studied. A group of well trained female handball players, in comparison with a group of less active females, had a significantly lower level of triglyceride, higher levels of HDL-cholesterol and HDL2-Cholesterol subfractions, and higher apolipoprotein A-I and LCAT activities. The ratio of apolipoprotein B/apolipoprotein A-I, as an atherogenic index, was also significantly lower in the handball players. These results suggest that prolonged regular exercise such as handball training may produce favorable changes in serum lipids, thus helping to prevent and reduce the incidence of atherosclerosis.View full abstractDownload PDF (636K) -
TAKEHIKO FUJISE, SHUICHI UCHIYAMA, TAMOTSU TERAO, SHOICHI NAKANO1991 Volume 40 Issue 2 Pages 208-218
Published: April 01, 1991
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe effects of 6 weeks (5 days/week) of endurance training under hyperoxia (60% O2 plus 40% N2) on carbohydrate and fat metabolism were studied in 42 male rats. The rats were divided into four groups ; normoxia control (NC, n=8), hyperoxia control (HC, n=9), normoxia training (NT, n=12), and hyperoxia training (HT, n=13) . NT and HT groups were made to run on a treadmill in a metabolic chamber at a speed of 20 m/min for 30 min. The metabolic chamber was perfused with hyperoxic gas. VCO2 values at rest (HC) and during exercise (HT) under hyperoxia were significantly lower (p<0.01) than VCO2 values at rest (NC) and during exercise (NT) under normoxia, respectively. These results appear to indicate that a decreased respiratory exchange ratio was induced by hyperoxia. The results showed that at 15 min after the last training there were no differences between NT and HT in the glycogen or triglyceride content of the liver, heart, m, gastrocnemius, and m. soleus. However, blood glucose at 15 min in NT (109±13 mg/dl) was significantly lower (p<0.05) than the corresponding value at 15 min in HT (133±11 mg/dl) and at 48 h after the last training in NT (149±7 mg/dl) . The glycogen content of the liver in HC (36.4±2.6 mg/g wet wt) was significantly higher (p<0.05) than the corresponding value in NC (26.1±1.9 mg/g wet wt) . In the HT group, the triglyceride content of the liver at 48 h was lower (p<0.01) than the corresponding value at 15 min. However, the triglyceride content of the heart at 48 h in HT was significantly higher (p<0.05) than the value at 15 min. Basal lipolysis in HC was significantly higher than the corresponding values in NC, NT and HT, but there were no differences among the groups in norepinephrine-induced lipolysis. These results indicate that endurance training under hyperoxia might alter the content of tissue glycogen and triglyceride as a result of decreased carbohydrate consumption and increased fat utilization during fasting and/or exercise.View full abstractDownload PDF (1514K) -
HIROKI MATSUOKA, HIROSHI FURUTA, KAORU KITAGAWA1991 Volume 40 Issue 2 Pages 219-226
Published: April 01, 1991
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe present study examined the effects of having bigger amount of protein than usual in competitive season on lean body weight (LBW), cross-sectional area of thigh and abdomen, muscle strengths, blood constituents and urinary urea nitrogen. Seventeen male varsity throwers (javelin, discus, hammer and shot put) ranging from 19 to 22 years of age, were divided into two groups ; Group A (N=9) with a more protein diet (2.1 g·kg-1·d-1), and Group B (N=8) with a usual amount diet (1.5 g·kg-1·d-1) . The experimental period was 62 days. During this period, they practiced six days a week. Three days were for throwing practice. Other three days were for weight training. All subjects lived in the same dormitory, and their life styles were similar to each other. The averaged daily diet of Group A evaluated by means of a weighing method had 3824 kcal with 175 g of protein (2.0 g·kg-1·d-1), 115 g of fat and 552 g of carbohydrate. The averaged daily diet of Group B had 3441 kcal with 130 g of protein (1.5 g·kg-1·d-1), 76 g of fat and 559 g of carbohydrate. All the intakes of vitamins (A, B1, B2, C) and minerals (calcium and iron) of the diet of each group were higher than the Japanese recommended dietary allowance. After the period, body weight, %fat, fat and LBW of both groups did not change significantly. Muscle strengths and cross-sectional areas in abdomen and thigh of both groups did not change significantly. Urinary urea nitrogen of both groups did not change significantly. Blood constituents (RBC, Hb, Ht, TP, Alb, BUN) of each group were still in normal ranges in spite of significant changes. No significant changes in body composition and muscle strengths were found in each group. These results, therefore, indicated that the more protein diet (2.0 g·kg-1·d-1) was not effective for increasing LBW and muscle strength of varsity throwers in competitive season.View full abstractDownload PDF (980K) -
[in Japanese]1991 Volume 40 Issue 2 Pages 227-232
Published: April 01, 1991
Released on J-STAGE: September 30, 2010
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1991 Volume 40 Issue 2 Pages 233-246
Published: April 01, 1991
Released on J-STAGE: September 30, 2010
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1991 Volume 40 Issue 2 Pages 246-250
Published: April 01, 1991
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (695K) -
1991 Volume 40 Issue 2 Pages 250-269
Published: April 01, 1991
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (2901K)
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