Japanese Journal of Physical Fitness and Sports Medicine
Online ISSN : 1881-4751
Print ISSN : 0039-906X
ISSN-L : 0039-906X
Volume 47, Issue 5
Displaying 1-20 of 20 articles from this issue
  • MITSUGI MOTOYAMA, HIROAKI TANAKA, MUNEHIRO SHINDO, KIKUO ARAKAWA
    1998 Volume 47 Issue 5 Pages 473-488
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
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  • KUMI AKATAKI, KATSUMI MITA, YASUSHI ITOH
    1998 Volume 47 Issue 5 Pages 489-497
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    The repeatability of the mechanomyogram (MMG) must be carefully determined before the signal can be generally used as a reliable tool in the fields such as physical fitness, sports and rehabilitation. In the present investigation, both the between-trial and between-day repeatability of the MMG was examined in the time and frequency domain and was compared with that of the more established electromyogram (EMG) . Isometric contraction trials of the biceps brachii muscles at different force levels of 10% to 90% MVC were held until a force plateau lasting 5 s was completed. The testing session consisting of 9 submaximal trials was repeated 6 times on the same day for estimation of the variation between trials. The same testing session was also performed 8 times over 3 weeks with a 2-day rest interval to examine the day-to-day variation. The coefficient of variation (CV) between-trials as well as between-days of the root mean squared (rms) MMG, mean frequency and median frequency did not demonstrate any significant differences among the force levels. The combined CV of the rms MMG over all the force levels was approximately 9 % between trials and 22% between days. The mean frequency and the median frequency presented the CV between-trials and between-days of approximately 6% and 10%, respectively. The different CV between the time and frequency domain parameters of the MMG may result from different contributing factors in the motor unit activation pattern. The results of this study suggest that the repeatability of the time domain parameter of the MMG is similar to that of the more established EMG, whereas the frequency parameters are somewhat less repeatable than those of the EMG.
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  • KAZUNOBU OHMORI, ISAO MURAOKA, YOSHIO NAKAMURA, FUKIO OHTA
    1998 Volume 47 Issue 5 Pages 499-507
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    The purpose of this study was to compare the influence of prolonged continuous (CON) and intermittent (INT) exercises on metabolic and hormonal responses in 8 male college students (age ; 23.0±0.5 yr, weight; 67.7±1.5 kg, VO2max ; 2.8±0.1 L/min, mean±SE) . Both trials consisted of two 40 min cycling bouts divided by a 5-min rest period. The intensity of INT was alternated every 4 min at low intensity (25% VO2max) and high intensity (75% VO2max), whereas the intensity of CON was maintained at 50% VO2max. Blood samples were collected before, and after 40 and 80 min of exercise, to determine blood lactate, serum glucose, FFA, insulin, plasma adrenaline and noradre-naline. Perceived exertion (RPE) was assessed at 40 and 80 min of exercise using the Borg scale. Although the changes in the concentration of plasma noradrenaline and serum insulin from basal values were similar in INT and CON, the degree of increase in plasma adrenaline during INT was significantly smaller than that during CON (90.5±16.6 vs. 152.8±27.0 pg/ml, p<0.05, after 80 min of exercise) . There was no difference in the change in the serum glucose level between the two trials. However, serum FFA in INT was significantly smaller than that in CON after 40 min (0.28±0.06 vs. 0.10±0.04 mEq/l, p<0.05) and 80 min (0.54±0.08 vs. 0.33±0.07 mEq/l, p<0.05) of exercise. RPE did not differ between the trials. These data indicate that even if performed total work and exercise duration are the same, metabolic and hormonal responses during prolonged intermittent exercise differ from those during continuous exercise.
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  • HIDEKI SHIMAMOTO, KIYOJI TANAKA, YUKIO ADACHI
    1998 Volume 47 Issue 5 Pages 509-516
    Published: October 01, 1998
    Released on J-STAGE: December 10, 2010
    JOURNAL FREE ACCESS
    The purpose of this study was to determine whether body composition alterations induced by aerobic exercise training show seasonal varition. Ninety-five middle-aged Japanese obese women volunteered as subjects. All subjects participated in our “exercise+diet” program for 3 months. The subjects were categorized into two groups (Summer group : S, and Winter group : W) based on the season when they participated in the program. Body composition, cardiorespiratory variables and dietary habituation were evaluated before and after the programs. More desirable changes in body composition were observed in Group W than in Group S. Group W showed a significant decrease in body mass from 62.2±8.7 kg to 60.3±8.6 kg, and in percentage body fat from 34.0±7.0% to 30.5±6.0%, while fat-free mass increased significantly from 41.0±3.9 kg 41.9±3.6 kg. However, alterations in cardiorespiratory variables were not associated with body composition alterations. It is concluded that season may have an effect on body composition alterations, but has no effect on cardiorespiratory variables, and that body composition may be improved by an exercise+diet program more effectively in winter than in summer.
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  • YOUNGMI LEE, TAKEO NAKAGAWA, TAKAYUKI MIURA
    1998 Volume 47 Issue 5 Pages 517-524
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    The purpose of this study is to obtain more information about the occurrence of sports injury and through this to prevent injury in handball players.
    Aquestionnaire was delivered to Japanese and Korean company handball players totaling 244 women (8 Japanese teams, 136 women and 7 Korean teames, 108 women), during the period from December, 1996 through March, 1997. The return rate was 88.9%. Injury rate in Korean teams was 73.2% and 71.7% in Japanese teams ; no statistical differences were found among these two countries. The injury rate was high on ankle joint, knee joint and lumbar in that order. Korean teams presented higher occurrence of jumper's knee and stress fracture.
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  • TOSHIYUKI HOMMA, SACHIKO HOMMA, ATSUKO KAGAYA
    1998 Volume 47 Issue 5 Pages 525-533
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    The purpose of this study was to clarify the changes in oxygen kinetics in two different thigh muscles recruited for dynamic knee-extension exercise at varying intensities in seven female subjects. Pulmonary oxygen uptake (Vo2) was measured by the 10-s mixing chamber method. Changes in oxygenated hemoglobin (HbO2), deoxygenated hemoglobin (Hb), and total hemoglobin (HbT) contents were measured in the vastus lateralis (VL) and rectus lemons (RF) muscles using near-infrared spectroscopy, and the oxygen saturation (SO2) was calculated as the HbO2 divided by HbT in percent. The surface electromyograms (EMG) of both muscles were also recorded. The integrated EMGs (iEMG) of the VL and RF increased linearly with increasing exercise intensity up to 100%VO2peak. However, the HbO2 and Hb remained unchanged when exercise intensity was below 50%Vo2peak, above which the increase in Hb and decrease in HbO2 were observed. Thus the decline in SO2 occurred at 60%Vo2peak in the RF, and 70%Vo2peak in the VL. These results suggest that muscle deoxygenation is accelerated during exercise above a certain intensity, which is lower in the RF than in the VL, during dynamic knee-extension exercise.
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  • MITSUGI OGATA, HIROKI FUKUSHIMA, KEIGO OHYAMA, TOSHIFUMI YASUI, YASUO ...
    1998 Volume 47 Issue 5 Pages 535-542
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    The influence of aerobic and anaerobic components of muscular endurance on the lower limbs, on sprint ability while under conditions of muscular fatigue, was investigated. Fifteen track and field athletes (400 m sprinters, decathletes and middle distance runners) participated in the study in which running and sprinting movements at respective points (360 m and 50 m) along two distance conditions (400 m and 80 m, respectively), were filmed by high-speed video camera. Running speeds at each point were computed from the film analysis. The running speed at 360 m point was defined as the speed under fatigue, while the running speed at the 50m point was defined as the maximal speed. Further, the rate between speed under fatigue and maximal speed was defined as %Max. Speed. Maximal O2 intake, O2 debt and isokinetic muscular endurance were measured.
    The results were summarized as follows :
    1) Oxygen debt showed significant correlation with the average speed during 400m running (r=0.546 ; p<0.05), but not with the speed under fatigue (r=0.388 ; p>0.05) .
    2) Speed under fatigue was positively correlated with muscular endurance of hip flexion and extension (r=0.683 ; p<0.01, r=0.572 ; p<0.05) .
    3) Percent Max. Speed was negatively correlated with the maximal speed (r = -0.643 ; p <0.01) and positively correlated with the muscular endurance of hip flexion and extension, and knee flexion (r=0.640 ; p <0.05, r=0.517 ; p<0.05, r=0.646 ; p<0.01) .
    These results suggest that; raising %Max. Speed to improve the muscular endurance of lower limbs and, to improve aerobic ability by developing the number of capillaries in the muscle, is important.
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  • YOUNGMI LEE, TAKEO NAKAGAWA, TAKAYUKI MIURA
    1998 Volume 47 Issue 5 Pages 543-548
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    A study was conducted to clarify the occurrence of injuries among Japanese and Korean handball players, their present condition, and the response to prescribed treatments. It was also ascertained whether players, after receiving proper treatment, were less susceptible to injury sequelae. A questionnaire was delivered to Japanese and Korean company handball players totaling 244 women (8 Japanese teams, 136 women ; 7 Korean teams, 108 women), during the period from December 1996 through March 1997.
    The rate of injuries and the treatment situation during and after the period when the injury was sustained, and the occurrence of sequelae in the lower limbs after the player had joined the team, were examined, and a comparison between the two countries was made. The return rate was 88.9%.
    1. The emergency treatment rate after injury was similar in the twe countries. However, Japanese players usually used taping and cooling, whereas Korea players used heat treatment. 2. Both Japanese and Korean players' injuries were diagnosed at hospital, although Koreans also went to bonesetters. 3. Japanese players resumed playing upon receiving their doctors' consent, whereas some Korean players were forced to resume playing before fully recovering ; there was a significant difference between the two countries. 4. Many players in both countries, resumed playing even though they felt pain in daily life. 5. Players who had undergone cooling treatment immediately after the injury, and who resumed activities upon their doctors' consent, and only after the pain had disappeared during daily life, had a lower incidence of sequelae.
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  • NAOTO KIMURA, TOSHIHITO KATSUMURA, TAKAFUMI HAMAOKA, TERUICHI SHIMOMIT ...
    1998 Volume 47 Issue 5 Pages 549-560
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    The purpose of the present study was to investigate the relationship between endurance time and fatigue factors at varying intensities of handgrip isometric exercise. Seven subjects performed isometric contractions at 10%, 30% and 50% of maximum voluntary contraction (MVC) sustained to exhaustion. Continuous changes in high-energy phosphates and muscle oxygen content (oxy-Hb/Mb) in the forearm flexor muscle were measured by 31P magnetic resonance spectroscopy (31P-MRS) and near infrared spectroscopy (NIRS), respectively. The endurance time to exhaustion was 963±236 (mean±S. D.), 209±41.9 and 95.3±13.6s at 10%, 30% and 50%MVC, respectively, From the onset of exercise at each %MVC, both PCr and oxy-Hb/Mb fell and Pi (H2PO4-) rose linearly with time, whereas intracellular pH remained relatively constant at resting values during the early phase. Thereafter, intracellular pH showed a linear decline. The rates of pH decline were 0.03±0.02, 0.22±0.14 and 0.51±0.17 pHunit/min, while the rates of H2PO4- increase were 20.9±19.3, 118±48.9 and 434±242 (% of resting) /min at 10%, 30% and 50%MVC, respectively. There were correlations between the changes in endurance times to exhaustion and the rates of pH decline (r= -0.58--0.87) and H2PO4- increase (r=-0.37--0.74, (n=7) ) at each intensity of exercise. In particular, significant correlations (p<0.05) between endurance time and the rate of pH decline were found at both 10% and 30%MVC. These results suggest that muscle fatigue (endurance time) at each intensity in handgrip isometric exercise is closely correlated with the rate of pH decline.
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  • —EFFECTS OF INTENSITY, DURATION AND PERIOD OF TRAINING—
    KAZUMI MASUDA, YUTAKA KANO, HIROSHI NAKANO, MITSUHARU INAKI, SHIGERU K ...
    1998 Volume 47 Issue 5 Pages 561-571
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    A study was conducted to clarify the effects of running intensity and duration of endurance training on myoglobin concentration ( [Mb] ) in rat skeletal muscles, and to clarify its temporal changes during the training. One hundred five male Wistar rats were divided into a training group and an untrained group. The training was carried out at 5 times a week for 12 weeks when the animals were 4 to 16 weeks of age. The training intensities were set at 20, 30 and 40 m/min with a duration of 60 min. The training duration was varied to 30, 60, 90 and 120 min when the rats were trained at 30 m/min. The temporal changes in the [Mb] were examined after the first, third and ninth week of training, during which the rats were trained at 40 m/min for 60 min per session. Three muscles (soleus: Sol, plantaris: P1, gastrocnemius-surface/deep: Gas-S, Gas-D) were analyzed for the [Mb] and citrate synthase activity (CS activity) . With regard to the intensity of training, the [Mb] increased with exercise intensity in Sol, Gas-D and P1, but not in Gas-S. P1 showed a greater increase of the [Mb] than Sol or Gas-D. On the other hand, CS activity in red muscle (Sol and Gas-D) increased even at low intensity, whereas white muscle (fast-twitch muscle: Pl and Gas-S) showed a significant increase in CS activity at an intensity of 40m/min. As to the duration of training, the [Mb] increased with the duration of running at 30 m/min of intensity, and showed the maximal adaptation with 90-min duration in all muscles except for Gas-S. Changes in CS activity according to the duration of running were similar to those for the [Mb] in all muscles. Finally, the [Mb] increased significantly with prolongation of the training period (after the 1 st, 3 rd and 9 th weeks training) in all muscles except Gas-S. However, the adaptive response of Mb tended to be delayed as compared with CS activity. These results suggest that 1) the response of Mb to training stimuli can depend on the muscle specificity (fiber type composition or the initial [Mb] ), and level of motor unit recruitment in usual, 2) Mb synthesis can be enhanced by an increase of training intensity, 3) a training duration of 90 min can bring out the Mb adaptation maximally and 4) the adaptive response of Mb would need more time as compared with CS activity.
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  • OSAMU KASHIMURA, AKIO SAKAI
    1998 Volume 47 Issue 5 Pages 573-579
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    Previously, we observed that hypoxic pulmonary vasoconstriction (HPV) can be reduced by endurance exercise training. This study determined whether nitric oxide (NO) plays a role in inhibition of the HPV after endurance exercise training in isolated rat lung perfused with physiological saline solution containing meclofenamate. Sprague-Dawley rats were used, and were divided into two groups: a control (Cont) group and an endurance exercise-trained (ET) group. Endurance exercise training was carried every day on a small-animal motorized treadmill. The training protocol was 30 to 40 min/day and the rats ran at a speed of 15 to 30 m/min for 2 weeks. It appeared that HPV could be reduced by short-term endurance exercise training. The NO-forming enzyme inhibitor, NG-nitro-L-arginine methyl ester (1.5×10-8M, L-NAME), administered to the ET group increased the HPV compared in that of the Cont group. These findings indicate that endothelial NO synthesis may contribute to the inhibition of HPV in ET rats. Our data suggest that endurance exercise training promotes endothelium dependent-pulmonary vasodilation through the stimulation of NO released during HPV.
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  • —FROM THE VIEWPOINT OF EXPERIENCE OF AWARENESS AND COGNITIVE APPRAISAL—
    HIDETSUGU KOBAYASHI, SHIN-ICHI DEMURA, FUMIO GOSHI, SUSUMU SATO, JINZA ...
    1998 Volume 47 Issue 5 Pages 581-591
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    A study was conducted to examine sex differences in subjective symptoms of fatigue in men and women with reference to the experience of awareness and cognitive appraisal based on symptom of fatigue content. A total of 54 questionnaire items were administered to 730 people (290 men and 440 women) . The subjects indicated whether or not they were aware of the content, and to what degree the content of the question for each item was important. Sex differences in the response to the ratio of awareness and the degree of importance were then. The mean importance scores for subjective symptoms of fatigue in men and women were 3.9-5.4 and 4.5-5.6, respectively. It was found that a majority of the men and women showed awareness of each item. A significant difference was recognized in the factor of awareness in all items as a result of two-way ANOVA of the degree of importance by which the presence of awareness and its sex difference were assumed to be factors, and those who were aware deemed the degree of importance high. On the other hand, the 28 items for which a significant sex difference was recognized showed a high value, and there was a marked content of Languor, Loss of Vigor, and A Feeling of Impatience and Physical Disintegration in women. In the same items, it was inferred that persons who were more aware than the persons who were not aware regarded subjective symptoms of fatigue as important. Most items in which a main effect of sex was recognized were content of Loss of Vigor and a Feeling of Impatience and Physical Disintegration. It was thought that women considered these symptoms more important than men. The sex difference in symptoms of fatigue was inferred to be due to the difference in the level of acknowledgment based on experienced knowledge.
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  • KOJI ZUSHI, HIDETSUGU NISHIZONO, FUMIO HIRATA
    1998 Volume 47 Issue 5 Pages 593-600
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    A study was conducted to investigate the relationship between the characteristics of torque production with special reference to eccentric and concentric muscle contraction and the structural and functional properties at the lower limb joints in the human kinetic chain. Ten male college athletes were tested with a isokinetic dynamometer (biodex) for eccentric and concentric torques during extension and flexion at the hip and knee, and plantar flexion and dorsiflexion at the ankle (angular velocity ; 30, 60, 120 deg/s) . The peak eccentric and concentric torques were higher in the order hip, knee and ankle joints, as the size of each muscle acting on its joint increased. However, the rate of peak concentric to eccentric torque (CON/ECC, %) was higher at the ankle joint than at the hip and knee joints. They tended to increase in the order of angular velocity ; 30, 60, 120 deg/s. These results suggest that the ankle joint is charactered by higher eccentric torque production. This characteristic is probably due to the fact that (1) the ankle joint is located at the end of the human kinetic chain and plays a role in transmitting the power to the ground effectively, (2) the muscle tendon complex acting at the ankle joint must have increased stiffness and tolerate great stretch loads to store and reuse the amount of elastic energy, (3) the hip and knee joints located at the center are the main sources of power supply. On the other hand, no significant correlations were observed among the torques at the hip, knee and ankle. These results suggest that torque production is independent at each of the lower limb joints, and is based on the structural and functional properties of each joint. These findings seem to be useful to clarifying the methods of strength and power training that can be adapted to the characteristics of torque production and the structural and functional properties of the hip, knee and ankle joints.
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  • MASAKI MINAMI, SHINICHI DEMURA, SUSUMU SATO, KOHSHO KASUGA, JINZABURO ...
    1998 Volume 47 Issue 5 Pages 601-615
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    A study was performed to examine sex and age differences in physique and physical fitness and the sex differences in the change of these parameters with age, and to clarify the relationship between the amount of exercise and fundamental physical fitness in 326 healthy elderly individuals over 60 years of age.
    A total of 22 variables consisting of 9 items concerning body linearity, quantitative growth, circumference growth and posture, and 13 items representing 4 domains (muscular, joint, neural, and cardiorespiratory functions) were selected. The exercise performance index (EPI) was calculated as the product of frequency and duration (yr) of exercise. The sex and age differences in physique and physical fitness were examined using two-way ANOVA (sex × age group) . Post hoc tests using Ryan's procedure were carried out when the main effect of these factors proved significant. To examine the characteristics of changes in physique and physical fitness with age, Pearson's correlation coefficient was calculated, and linear regression analysis [test item was the dependent variable (X) and age was the independent variable (Y) ] was applied. Then significant differences in the regression coefficient and intercept between males and females were examined. Furthermore, curved-line regression analysis was executed for the above variables. Applying principal component analysis for 13 physical fitness items, the first principal component was interpreted as fundamental physical fitness for performance, and the above analysis was applied to the fundamental physical fitness score (FPS) . To examine the relationship between EPI and FPS, the difference in FPS among the three EPI groups was examined using analysis of co-variance (ANCOVA) with age as the co-variable.
    The main findings of this study can be summarized as follows.
    1. With regard to physique, males showed greater body linearity, and females had more skinfold. Sex differences in circumference growth were not as significant as those in body linearity and quantitative growth. Changes in physique with age were greater in females than in males, the change becoming obvious in individuals over 80 years of age.
    2. With regard to physical fitness, males had superior muscular function and vital capacity, while females outperformed males in standing-reach. However, there was little sex difference in neural function. The trend for deterioration in physical fitness with age differed between the sexes among 4 domains of physical fitness. For example, in males muscular, neural, and joint functions deterioration significantly with age, while in females, all physical fitness variable did so. In addition, the age-related trends of deterioration in muscular function (grip strength and vertical jump), cardiorespiratory function (duration of breath-holding and vital capacity), and neural function (stepping) were differed between the sexes.
    3. The FPS was higher in males than in females. However, FPS decreased significantly with age in both sexes.
    4. It was inferred that among active and healthy elderly males and females who exercised regularly, FPS was not influenced by EPI.
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  • YUKO KITAHARA, AKIRA MIURA, MITSUHARU INAKI, SHIN-YA KUNO, YOSHIYUKI F ...
    1998 Volume 47 Issue 5 Pages 617-621
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
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  • HIDEHIRO NAKAHARA, MOTOHIKO MIYACHI
    1998 Volume 47 Issue 5 Pages 623-627
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
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  • [in Japanese]
    1998 Volume 47 Issue 5 Pages 629-635
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
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  • 1998 Volume 47 Issue 5 Pages 637-643
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
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  • 1998 Volume 47 Issue 5 Pages 644-650
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
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  • 1998 Volume 47 Issue 5 Pages 651-659
    Published: October 01, 1998
    Released on J-STAGE: September 30, 2010
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