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Volume 48 (1999)
- Issue 6 Pages 671-
- Issue 5 Pages 547-
- Issue 4 Pages 447-
- Issue 3 Pages 343-
- Issue 2 Pages 245-
- Issue 1 Pages 1-
Volume 48, Issue 4
Displaying 1-12 of 12 articles from this issue
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HIROFUMI TANAKA, GREGORY A., DAVID R. BASSETT1999 Volume 48 Issue 4 Pages 447-452
Published: August 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThere has been increasing emphasis on maintaining the patients' quality of life while on antihypertensive therapy (e. g., regular physical activity as a lifestyle modification) . However, no information is available on the effects of regular swimming exercise on mental health despite the popularity and potential benefits of this life-style modification. To determine the efficacy of swim training on mood states, 19 obese subjects with stages 1 to 2 essential hypertension were randomly assigned to either a swim training (n=12) or control group (n=7) . Subjects were assessed before and after a 10 week supervised swim exercise program with the Profile of Mood State (POMS) questionnaire. The swim training group completed an average of 94% of the scheduled exercise sessions, and were able to gradually and significantly (p<0.05) increase daily swim distance. Additionally, resting heart rate was significantly reduced (p<0.05) . Swim training resulted in significantly higher (p<0.05) vigor-activity scores. In addition, anger and fatigue scores were 34 and 28% lower after the swim training period. No significant changes were observed in any of the POMS scores in the control group. The improved mood state observed after swim training may have a clinically important influence on the quality of life in these subjects with essential hypertension.View full abstractDownload PDF (584K) -
KAZUAKI SAKAI, JOHN SHEAHAN, KAORU TAKAMATSU1999 Volume 48 Issue 4 Pages 453-466
Published: August 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThis study investigated the relationship of high-power work capacity with physiological variables during supramaximal intermittent exercise and individually measured alactic (ATP-CP), lactic (LA), and oxygen (O2) energy delivery systems. Nineteen university handball players (experiment 1) and 23 university basketball players (experiment 2) performed an intermittent exercise routine consisting of a combination of high-power and low-power exercise. The exercise protocols were a laboratory test consisting of pedaling on a bicycle ergometer (experiment 1) and a field test consisting of a running protocol incorporating changes in direction (experiment 2) . The main results were as follows :
(1) The ATP-CP system was significantly related to power output during the early stage of intermittent exercise and the O2 system was significantly related to power output in the middle and late stages of intermittent exercise. As an indicator of the O2 system, blood lactate concentration during submaximal exercise correlated more closely with power output during intermittent exercise compared with VO2max/BW. The LA system was not significantly related to power output during intermittent exercise.
(2) Subjects were divided into 2 groups according to energy delivery ability and then power output ability during intermittent exercise was compared. The high ATP-CP system group had a significantly higher power output during the early stage of intermittent exercise compared with the low ATP-CP system group. The high O2 system group had a significantly higher power output in the middle and late stages of intermittent exercise compared with the low O2 system group. Compared to the low O2 system group, the high O2 system group had a higher absolute VO2 during the low intensity active recovery periods of intermittent exercise, as well as a tendency to have lower blood lactate levels. The high LA system group showed lower power output over the course of intermittent exercise compared with the low LA system group.
These results indicate that the O2 system is important for exerting higher power output during supramaximal intermittent exercise.View full abstractDownload PDF (1464K) -
JUN SUGAWARA, YUTAKA HAMADA, YOSHIHARU NABEKURA, TAKAHIKO NISHIJIMA, M ...1999 Volume 48 Issue 4 Pages 467-475
Published: August 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSIt has been shown that the time constant of heart rate decline for the first 30 sec (T30) after exercise, at an intensity lower than the ventilatory threshold (VT), can serve as a specific index to assess post-exercise vagal reactivation. The purpose of this study was to validate the use of a simpler alternative index, i. e. %Δ HR30 (the ratio of heart rate decrement for the first 30 sec after exercise) for the evaluation of parasympathetic nervous reactivation, and to examine whether it would be a useful index in the conditioning of athletes. Eighteen college students performed 4 minutes cycle ergometer exercise routines at intensities of 40%, 80%, and 120% VT to compare the %Δ HR30 and the T30. In addition, the %Δ HR30 was obtained by a field test (4 minutes jogging) in 15 college middle and long distance runners, every morning during summer camp training to assess the state of athletic conditioning. The %Δ HR30 at 80% VT was similar to the value at 40% VT, but significantly different from the value at 120% VT, as was the T30 at 80% VT.
The %Δ HR30 significantly correlated with the T30 and VO2max. During the camp, the %Δ HR30 was higher on mornings following light training days than on mornings following hard training days. These results suggest that the %Δ HR30, at an exercise intensity lower than the VT, could be a simple and useful index to evaluate post-exercise parasympathetic nervous reactivation in the conditioning of athletes.View full abstractDownload PDF (1063K) -
—EXAMINATION USING EVENT-RELATED POTENTIALS (P300) —TAKESHI KANEDA, YOSHIAKI NISHIHIRA, ARIHIRO HATTA, MASAHIRO SHIMODA, M ...1999 Volume 48 Issue 4 Pages 477-483
Published: August 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe purpose of this study was to investigate the effect of the sleep deprivation for central information processing. Therefore we examined the changes in the amplitude and the latency of P300 event-related potentials (ERPs) before and after sleep deprivation in eight subjects. In addition to P300, we examined the power spectral changes of the EEG and the R-R intervals at rest before ERP measurements. The subjects performed an auditory target discrimination task and were instructed to keep mental count of each target stimulus. Then 2000 Hz tones (target) and 1000 Hz tones (nontarget) were randomly presented with probabilities of 0.2 and 0.8.
P300 latency at Fz, Cz, C3 and C4 was significantly prolonged after sleep deprivation (p<0.05) . P300 amplitude at Cz after sleep deprivation was significantly smaller than before sleep deprivation (p<0.05) . Alpha 1 power (8-10 Hz) at Cz on EEG was significantly decreased after sleep deprivation, but no other bands changed on EEG. The R-R interval was also significantly extended after sleep deprivation. We concluded that both central information processing and the autonomic nervous system may be influenced by sleep deprivation.View full abstractDownload PDF (718K) -
HIDEAKI ONISHI, RYO YAGI, MINEO OYAMA, KOUJI IHASHI, YASUNOBU HANDA1999 Volume 48 Issue 4 Pages 485-492
Published: August 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe purpose of this study is to investigate the relationship between joint angle and EMG activity concerning the human knee joint and hamstring muscles. Ten healthy males participated in this study. They performed maximum voluntary isokinetic knee flexion in the flexion angle range of 0° to 120° in a prone position on a table. The EMG activities of the semitendinosus, semimembranosus, long and short heads of the biceps femoris muscles were detected by bipolar fine wire electrode, and were integrated at knee flexion range intervals of 15° from 0° to 120°. After three months, the same examination was performed with the same subjects to confirm the reliability of this study. Results showed the mean peak isokinetic torque was attained from a 15° to 45° knee flexion angle. The EMG activities of the hamstring muscles varied with changes in the knee flexion angle. The integrated EMG of the semitendinosus, semimembranosus and short head of the biceps femoris muscles in-creased gradually as the knee flexion angle was increased from 0° to 105°. The peak integrated EMG of these three muscles was attained between 90° and 105° knee flexion in both trials. On the other hand, the peak integrated EMG of the long head of the biceps femoris muscle was largest at a knee angle ranging from 15° to 30°. Peak integrated EMG decreased when the knee flexion angle increased in both trials. These results show that the electromyographic activity of agonist muscles during maximum voluntary movement varied with the change of muscle length or joint angle. Therefore, it was considered that the relationship between joint torque and joint angle is influenced not only by the sarcomere length and the moment arm but also muscle activities of agonist muscles, even if the movement is performed with maximum effort.View full abstractDownload PDF (2509K) -
SHINICHI DEMURA, SHUNSUKE YAMAJI, MASAKI MINAMI, YOSHINORI NAGASAWA, I ...1999 Volume 48 Issue 4 Pages 493-500
Published: August 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe evaluation of muscular power function has been mainly limited to dynamic contraction, but force-time parameters in static explosive contraction may be useful. The purpose of this study was to examine the trial-to-trial differences of exertion pattern and the reliability of the force-time parameters in the development phase of static maximal explosive grip (SEG) using seventy healthy young male subjects (age 18.8±2.3yr) . In SEG measurement, subjects were instructed to exert maximal isometric force with a dominant hand as fast and forcefully as possible. Data was collected from two trials with 3 minutes rest between trials. Eleven variables (time to fixed level, average force, integrated area, maximal rate of force development, and equivalent for mechanical power parameter) were selected as force-time parameters.
The reliability of maximal grip strength (MAX) was very high (ICC=0.944, p<0.05) . In the above-stated instruction condition, the trial-to-trial difference expanded from 0.1- 0.4 sec, then re-duced in the vicinity of MAX during SEG exertion. Significant differences, however, were not found at any exertion time and reproducibility of SEG exertion pattern was very high between the two trials. The trial-to-trial reliability in all force-time parameters was significant (ICC=0.346-0.878, p<0.05) .
Reliability of the parameters measuring the earlier phase (about 0.1-0.5 sec) was low or moderate (ICC<0.7), while reliability of the parameters measuring the MAX vicinity tended to be high. The MAX relationship to force-time parameters in the MAX vicinity is high, but is low or moderate for the other parameters. It was suggested that the force-time parameters in the vicinity of MAX in SEG exertion might be useful for evaluating static power function in a clinical setting.View full abstractDownload PDF (1024K) -
GANG-JIAN QU, HIROSHI KANEKO, NAOYUKI EBINE, KAYOKO KITA, SEIJI TOMITA ...1999 Volume 48 Issue 4 Pages 501-507
Published: August 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe purpose of this research was to study the effects of Tu-Chung extract (Eucommia ulmoides OLIV.) administration on serum testosterone and the possible mechanisms in hindlimb- suspended rats. 25 five-week old male Wistar rats were used. All rats were randomly divided into two groups : those treated with Tu-Chung extract (Tu-Chung G, n=suspended for 37 days in hindlimb. 1 mg/ml Tu-Chung extract was administered orally once daily at a dose of 1 ml/100 g body weight. Distilled water was administered in a similar way to the control group. The following results were observed :
1. Serum testosterone concentration in Tu-Chung G was significantly higher than in Cont. G (P<0.001) .
2. There was no significant difference between Tu-Chung G and Cont. G in serum LB concentrations.
3. The Testicular cAMP level in Tu-Chung G was significantly higher than that in Cont. G (P<0.01) .
4. 24-h urinary excretion of 17-ketosteroid in Tu-Chung G was significantly higher than that in Cont. G (P<0.001) .
5. There were no significant differences between the two groups in the weights per body weight of the kidneys, adrenal grand and testes. These results suggest that the adininstration of Tu-Chung extract inducing high serum testosterone concentrations in hindlimb-suspended rats might be due to enhanced testicular and adrenal functions, not pituitary.View full abstractDownload PDF (892K) -
SHIGERU YAMADA, YOSHINORI OGAWA1999 Volume 48 Issue 4 Pages 509-514
Published: August 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe role of exercise in skeletal muscle hypertrophy was examined using op/op mice, which have a hereditary deficiency in the differentiation of macrophages. A tenotomy was performed to produce a compensation load for the soleus and plantaris muscles in op/op mice and a control group. After one week, the weight of the soleus and plantaris muscles had increased significantly. The cross-sectional area of the muscle fiber in the soleus of the control group increased as a result of the compensation load, indicating that the tenotomy had induced muscle fiber hypertrophy. However, the cross-sectional area of the muscle fiber in the soleus of the op/op mouse group did not change significantly. Instead, the tenotomy induced an increase in the number of thin fibers. The cross-sectional area of muscle fibers in the plantaris muscle, which is a fast muscle, decreased in the op/op mouse group. In conclusion, compensation loads in macrophage-deficient op/op mice do not result in muscle fiber hypertrophy.View full abstractDownload PDF (651K) -
TETSUNDO KITAGAWA, KEIJI YAMAJI, TADAHIRO NUNOMURA1999 Volume 48 Issue 4 Pages 515-517
Published: August 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (303K) -
[in Japanese], [in Japanese], [in Japanese]1999 Volume 48 Issue 4 Pages 519-525
Published: August 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (9259K) -
1999 Volume 48 Issue 4 Pages 527-536
Published: August 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (1661K) -
1999 Volume 48 Issue 4 Pages 537-544
Published: August 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (1146K)
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