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Volume 36 (1987)
- Issue 6 Pages 335-
- Issue 5 Pages 231-
- Issue 4 Pages 179-
- Issue 3 Pages 105-
- Issue 2 Pages 53-
- Issue 1 Pages 1-
Volume 36, Issue 4
Displaying 1-8 of 8 articles from this issue
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AKIHIKO ISHIHARA, YASUHARU OHISHI, NORIYUKI SHIDE, SHIGERU KATSUTA1987 Volume 36 Issue 4 Pages 179-185
Published: August 01, 1987
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe present study was undertaken in order to investigate effects of short-term, high intensity training on the total number and histochemical properties of fast tibialis anterior, slow soleus muscle fibres and their dominant motor neurons in male rats.
The animals were subjected to 4 meters of sprint-running by the operant conditioning, 12 times a day interposed with 5 minutes rest periods for 14 weeks.
This training had no effect on the total number and enzyme activities of muscle fibres and dominant neurons. However, hypertrophy of FOG and FG fibres in tibialis anterior muscle was caused by the training.
The conclusion, therefore, is that short-term but high intensity training causes selec. tive hypertrophy of fast twitch muscle fibres, but does not have an influence on the histochemical properties of motor units because the training is far a short period of time.View full abstractDownload PDF (753K) -
—TRANSIENT CHANGES AT THE START AND END OF EXERCISE DURING LBNP—TAKESHI NISHIYASU, NARIHIKO KONDO, MIYAKO INAZAWA, HARUO IKEGAMI1987 Volume 36 Issue 4 Pages 186-194
Published: August 01, 1987
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSIn order to evaluate the effect of muscle pump on blood circulation at the start and end of exercise, cardiac responses to pedaling exercise at 75 watt in the supine position were investigated under lower body negative pressure (LBNP) of -60mmHg. Six healthy male college students volunteered for subjects. Cardiac output (Q), stroke volume (SV), thoracic impedance (ZO) and heart rate (HR) were determined by using ensemble-averaged impedance cardiogram and ECG.
The results obtained were as follows.
1) By the initiation of exercise under LBNP, SV and Q promptly and more markedly increased and ZO decreased than the control experiment which were done under normal pressure. These changes were suggested to be caused by mobilization of previously pooled blood in the legs by muscle pump. Effects of muscle pump arrived to a plateau within about 30 sec after the start of exercise. And these effects were immediately disappeard by the cessation of exercise.
2) By the release of LBNP during resting condition, the same changes were observed in SV, Q and ZO as in the start of exercise under LBNP. However HR decreased in the case while it increased in the case of exercise in LBNP. This difference in HR might be the result of the chronotropic effects by the exercise.
3) In the very early phase of exercise in the control exercise, SV decreased and ZO increased. These changes were probably caused by superiority of chronotropic action by the exercise to increase in venous return in this position.
These results led us to a conclusion that the effect of muscle pump appeares immediately by the start of the exercise and it arrives at plateau within about 30 sec. This effect is immediately disappeared by the cessation of exercise.View full abstractDownload PDF (1011K) -
—RELATIONSHIP BETWEEN CONTRACTION FORCE AND BLOOD VOLUME AND PUMPING ACTION—TAKESHI NISHIYASU, SHINJI GOTO, YOSHIHARU NABEKURA, HARUO IKEGAMI1987 Volume 36 Issue 4 Pages 195-201
Published: August 01, 1987
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe purpose of this study was to investigate the effects of contraction force and the pooled blood volume in the calf on the pumping action of calf muscle contraction. Calf blood volume was controlled by lower body negative pressure (LBNP) and isometric contraction of calf extensor muscle was performed using a handmade dynamometer in recumbent position. The relative volume changes (ΔV/V%) of calf were determined using rubber straingage, when isometric contractions (5, 10, 20, 40 and 60 kg) of the calf muscle were repeated under LBNP of 0, -20, -40, and -60 mmHg.
During resting condition, Δ V/V was increased by 1.04% under -20 mmHg LBNP, 1.88% under -40 mmHg, and 2.54% under -60 mmHg. These increases of ΔV/V were due to the increased blood pooling in the calf. It was shown that the increased blood volume was almost expelled by several bouts of muscle contractions of proper force. The optimum force of contractions for expelling pooled blood was 20 kg under -20mmHg LBNP, and 40 kg under -40 and -60 mmHg LBNP. And it was apparent that the effectiveness of muscle pump was accumulated with repeating contractions, arriving to a plateau after several bouts.
It was shown that the effect of muscle pump in the given contraction force was more effective under the condition with more amount of blood contained in the calf, but the muscle pumping action by light contraction forces couldn't overcome the effect of severe LBNP.View full abstractDownload PDF (786K) -
NAOTO KIMURA, SHOJI IGAWA, TOSHINA MIYAJIMA, KOICHI HIROTA1987 Volume 36 Issue 4 Pages 202-209
Published: August 01, 1987
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe purpose of this study was to examine the effects of physical training on red blood cell properties, in particular red cell 2, 3-diphosphoglycerate (2, 3-DPG) and aerobic work capacity. The subjects were 28 healthy men and they were divided into three groups: Group 1 (12 athletes-long distance runners, cross country skiers performing daily aerobic training), Group 2 (8 athletes-sprinters (400 m), alpine skiers playing aerobic and anaerobic training every day) and Control (8 untrained persons) .
The results obtained were as follows:
1) In aerobic work capacity (VO2max/w, O2 pulse max) there was significant difference (p<0.01) among 3 groups (Group 1>Group 2>Control) .
2) Red blood cell properties (RBC, Hb, Hct) of each group showed no significant difference. However MCH, MCHC of Group 1 was significantly lower than Group 2 and Control, MCV was also a tendency to be lower. Red cell 2, 3-DPG concentration was significantly higher in Group 1, 2 as compared with Control. But there was no significant difference between Group 1 and Group 2.
3) Red cell distribution curve of Group 1 tended to shift to the left in comparison with other two groups.
4) The relationship between VO2max/w and red cell 2, 3-DPG significantly correlated for all subjects composing the three groups. In addition a significant correlation was found for Group 1.View full abstractDownload PDF (942K) -
M. MIYASHITA, B.A. KEER1987 Volume 36 Issue 4 Pages 210-216
Published: August 01, 1987
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSPrevious research has demonstrated that the VO2max is a strong predictor of performance time in distance running. Collecting data from previous studies and from their laboratory, the authors have developed a set of normative tables for predicting times for serious runners competing in the 5, 10 km and marathon races. Recognizing individual differences in psychological and biomechanical factors, as well as environmental influences, five categories ranging from“poor”to“super excellent”have been developed for each value from 55 to 85 ml·kg-1·min-1. By periodically assessing their VO2max values, runners can aspire to reach the top category and achieve his/her peak performance.View full abstractDownload PDF (634K) -
HIROYO KITAO, MITSUO MATSUDA, ICHIRO KONO, SHUKOU HAGA, HIDEO FUKUSHIM ...1987 Volume 36 Issue 4 Pages 217-220
Published: August 01, 1987
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (418K) -
1987 Volume 36 Issue 4 Pages 221-225
Published: August 01, 1987
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (663K) -
1987 Volume 36 Issue 4 Pages 225-229
Published: August 01, 1987
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (587K)
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