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Volume 46, Issue 1
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1997 Volume 46 Issue 1 Pages 1-37
Published: February 01, 1997
Released on J-STAGE: September 30, 2010
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TOSHIYA NAGAMATSU, TAKASHI ARAO1997 Volume 46 Issue 1 Pages 39-47
Published: February 01, 1997
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSWe investigated the effects of feeding a large meal to female rats (n = 66) just before or just after voluntary wheel running on energy metabolism during a final endurance exercise test. The rats were divided into three groups ; one fed a large meal just before exercise (BE), one fed a large meal just after exercise (AE), and one fed ad libitum (AD) . The rats were allowed to run voluntarily from 20 : 00 to 07 : 00 h. The BE group were given a large meal (more than 12 g) between 19 : 00 and 20: 00 h and a small meal (3 g) between 07 : 00 and 08 : 00 h. The AE group were given a large meal (more than 12 g) between 07 : 00 and 08 : 00 h and a small meal (3 g) between 19 : 00 and 20 : 00 h. After 4 weeks, 6 rats in each group were sacrificed at 22 : 00 h, and 12 rats in each group were sacrificed after 30 min starting from 22 : 00 h at 15 m/min (n=6) or 35 m/min (n=6) on a rodent treadmill (0° grade) . Four rats in each group were sacrificed after 30 min starting from 22 : 00 h at rest on the treadmill as a control. The plasma free fatty acid (FFA) and glycerol concentrations increased significantly during low-speed exercise in the AD group, and during higher-speed exercise in all groups. The liver glycogen concentration was significantly greater in the AE group than in the other groups at rest, and decreased significantly during exercise at both speeds in the AD group, but not in the BE and AE groups. The gastrocnemius muscle glycogen concentration was decreased significantly during exercise at both speeds in the AD group, and at high speed in the BE and AE groups.
These results indicate that intake of a large meal just after exercise can store a high level of liver glycogen at the beginning of exercise than ad libitum feeding or large meal intake just before exercise, and expend plasma FFA in muscle during exercise compared with ad libitum feeding. This suggests that large meal intake just after exercise contributes to improvement of metabolic capacity in endurance exercise with enhanced liver glycogen sparing.View full abstractDownload PDF (1131K) -
HIROMI YANO, SACHIFUMI KINOSHITA, LISA YANO1997 Volume 46 Issue 1 Pages 49-54
Published: February 01, 1997
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSIn this study, we investigated the effect of acute exercise on the mitochondrial structure of hepatocytes surrounding the terminal hepatic venule (zone III) in the rat liver acinus. Male SD rats were assigned to a resting group (n=8) and to running groups ran on a motor-driven treadmill for 100 min (n = 8) or did continued running beyond 100 min until exhaustion (n = 5) . Plasma guanase activity was increased with duration time of exercise. The arterial ketone body rate (AKBR) increased during the 100 min of running, but the AKBR significantly diminished with exhaustive running as compared with that for 100 min of running. Although there was no change in the mitochondrial structure of hepatocytes in the perportal area (zone I) during exhaustion, remarkable swelling was observed in that in zone III.
These results suggest that acute running affects mitochondrial structures in zone III, and that this might be a hypoxia zone during exercise.View full abstractDownload PDF (5075K) -
TOMOHISA MIYANISHI, NORIHISA FUJII, MICHIYOSHI AE, YASUO KUNUGI, MORIH ...1997 Volume 46 Issue 1 Pages 55-67
Published: February 01, 1997
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSTwenty-four male university baseball players were each requested to throw a baseball, and filmed using the direct linear transformation method of three-dimensional (3D) videography. 3 D coordinates of landmarks were obtained. Resultant joint forces and resultant joint torques in the wrists, elbows, shoulders, neck, and upper torso joints were calculated using the inverse dynamics method. The mechanical powers caused by the resultant joint forces (joint force power) and by the resultant joint torques (joint torque power) of each segment were calculated, and the mechanical work was also obtained by integrating the joint torque powers with time. Peak values of energies of the upper torso, upper arm, forearm, hand, and ball appeared in sequence from the proximal segment to the distal segment. The joint force powers in any segment were markedly larger than the joint torque powers. Little joint torque power was produced in the wrist throughout the throwing motion. The negative joint force power and joint torque power at the proximal end of the upper torso were rapidly increased immediately after the foot contact stride. It was clarified that the appearance of the large energies in the distal throwing arm segments during the final phase of throwing motion were caused mainly by transfer of the energies produced by the motions of the torso and shoulder joints. This paper discusses the mechanical energy flows of the upper torso and upper limb segments during the motion of baseball throwing.View full abstractDownload PDF (1438K) -
KIYOSHI SANADA, TSUTOMU KUCHIKI, HIROSHI EBASHI, TAKASHI ABE, TETSUO F ...1997 Volume 46 Issue 1 Pages 69-76
Published: February 01, 1997
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe purpose of this study was to investigate the relationships between muscle mass or muscle power and bone mineral density in 43 postmenopausal women. Single photon absorptiometry was used to measure the bone mineral density and bone width of the calcaneuse. Isotonic muscle power of knee extensions (KE), knee flexions and incline squats (ISQ) were measured, using the power processor (VINE Co., Ltd.) . Statistical analysis demonstrated a significant positive correlation (p<0.05) between bone mineral density and lean body mass or muscle thickness. Although, bone mineral density was not significantly correlated with body mass index or fat mass, it was significantly corre-lated with leg muscle power. Further, the bone mineral density was also positively correlated with muscle contraction speed in the motion of KE (p<0.01) and ISQ (p<0.05), but not with muscle strength. This data suggest that the bone mineral density is closely related to the muscle power and/or speed rather than the muscle strength in postmenopausal women.View full abstractDownload PDF (910K) -
ATSUSHI KIUCHI, SATOSHI SHIMEGI, HITOSHI AMAGAI, ATSUYA OHNO, SHIGERU ...1997 Volume 46 Issue 1 Pages 77-85
Published: February 01, 1997
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe effects of running exercise on bone histomorphometric parameters were examined in sham-treated (Sham) and ovariectomized (OVX) rats. The rats were either kept sedentary (C) or trained (T) on a rodent treadmill at 25 m/min, 30 min/day, 5 days/week for 10 weeks. Fat-free dry bone weight, bone mineral content (BMC), and histomorphometric parameters were assessed after excision of the tibiae at sacrifice. The results are summarized as follows
1) There were no significant differences in fat-free dry bone weight and BMC between OVX-C and Sham-C rats. However, BMC/body weight in OVX-C rats was significantly lower than in Sham-C animals. OVX-C rats had significantly lower trabecular bone volume at the proximal tibial metaphysis than Sham-C animals. Values of bone formation parameters were significantly higher in OVX-C rats than in Sham-C animals.
2) BMC/body weight in OVX-T rats was significantly higher than in OVX-C animals. OVX-T rats had a significantly higher trabecular bone volume at the proximal tibial metaphysis than OVX-C animals. There were no significant differences in bone formation parameters between OVX-T and OVX-C rats.
3) No significant differences were found in any parameters between sham-C and Sham-T rats.
These results suggest that (1) running exercise has a suppressive effect on bone loss after OVX, and (2) training-induced reduction of bone loss by OVX does not seam to be associated with facilitation of bone formation but with suppression of bone resorption.View full abstractDownload PDF (3093K) -
-SOCCER, RUGBY, BASKETBALL PLAYER IN JAPANESE HIGH SCHOOL-TAKEHISA YAMADA, IWAI TOHNAI, MINORU UEDA1997 Volume 46 Issue 1 Pages 87-92
Published: February 01, 1997
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe use of mouth guards in contact sports effectively prevents oral injuries and preserves oral structures. Many contact sports in which a high impact collision could easily cause oral injury do not require athletes to use mouth guards. We discuss the circumstance of oral injury and awareness concerning the use of mouth guards in Japanese high school soccer and rugby and basketball teams.
During an interview, each athlete was asked a series of questions concerning their history of oral injury while participating in sports and actual circumstances of using a mouth guard.
The incidence of oral injuries was 32.3% in soccer, and 56.5% in rugby, 46.6% in basketball while 0.8% of athletes possessed some type of mouth guard in soccer, 24.1% in rugby and 1.3% in basketball. Although 81.8% of soccer athletes and 81.2% of basketball athletes thought mouth guards were unnecessary, only 26.2% of rugby athletes shared this opinion. Many athletes playing soccer and basketball had insufficient knowledge about mouth guards, and were not interested in preventing oral injury. Due to the diversity of sports that can produce oral injury, it is recommended that mouth guards be worn by all individuals participating in rugby, soccer and basketball.View full abstractDownload PDF (517K) -
SHIGERU OBARA, MIYOKO HAYASHI, HIDEO ARAKI1997 Volume 46 Issue 1 Pages 93-100
Published: February 01, 1997
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe response of systolic blood pressure (SBP) to pedalling exercise was studied in 32 healthy young men. The subjects performed the exercise at different intensities for 3 min using an incremental loading method. The first work load was 30W and increased by 30W until the heart rate (HR) reached about 170 bpm. SBP at HR 100. 160 bpm (SBP@HR 100-160) was calculated from the cubic regression equation in each subject. Mean SBP and SEM at HR 100, 110, 120, 130, 140, 150, 160 were 143.9 (2.49), 152.9 (2.79), 161.6 (3.02), 170.0 (3.16), 177.8 (3.25), 184.5 (3.34), and 189.7 (3.45) mmHg, respectively. However, the rate of elevation of SBP was zero at HR 175 bpm, which was calculated from the cubic regression equation. This may indicate that SBP is inhibited by baroreceptors and other factors at HR above 170 bpm. There were no significant relationships between SBPs@HR 100-160 and indices of aerobic capacity such as maximal oxygen consumption or PWC 170. Double product (DP) as an index of oxygen consumption by cardiac muscle increased with HR without any reduction in its rate of elevation during exercise.View full abstractDownload PDF (1002K) -
-A STUDY IN WATER AT 25°C, 30°C AND 34°C-TAKAKO KISHINO, MITSUO MATSUDA1997 Volume 46 Issue 1 Pages 101-112
Published: February 01, 1997
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe purpose of this study was to assess an alteration of cardiac autonomic nerve activity during water immersion. Ten healthy young males (age : 21-28 yr.) were immersed in water at the temperatures of 25°C, 30°C and 34°C. Subjects sat calmly for 20 minutes in sitting position before water immersion, and then were immersed in water at subaxillary level in sitting position for 15 minutes, performing controlled breathing (15 cycle/min.) . Electrocardiograms were recorded continuously. Autonomic nerve activity was estimated with the analysis of power spectral by using the Fast Fourier Transformation (FFT) . High (HF ; 0.15-0.50 Hz) and low (LF ; 0.04-0.15 Hz) frequency areas and the ratio of LF to HF (LF/HF) were calculated as the indices of cardiac parasympathetic nerve activity, sympathetic nerve activity with parasympathetic modulation, and sympathetic nerve activity, respectively. During the water immersion at 25°C, 30°C and 34°C, HF was significantly increased, while the heart rate and LF/HF were significantly decreased. There were no statistically significant differences among both of HF and LF/HF during the immersion at 25°C, 30°C and 34°C, although the rate of change in HF at the temperature of 25°C appeared to be prominent compared to those at 30°C and 34°C and some subjects showed an exaggerated change in HF immediately after immersion. These results suggest that cardiac parasympathetic nerve activity is enhanced and cardiac sympathetic nerve activity is suppressed during a short time water immersion at the thermo-neutral temperature (34°C) and the temperatures of 25°C and 30°C, which are the usual temperatures found in indoor pools.View full abstractDownload PDF (1573K) -
YASUTAKE SATO, KEN-ICHI NIWA1997 Volume 46 Issue 1 Pages 113-121
Published: February 01, 1997
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSTo examine the effects of water replacement on sweating and body cooling during exercise, We studied the sweat rate, changes in body weight and body temperature during exercise with or with-out drinking various amounts of water. The subjects had been dehydrated or normally hydrated prior to exercise.
1. Rectal temperature increased significantly with body weight loss.
2. Sweat rate during exercise was constant (968-996 g/h) regardless of whether the subjects were dehydrated or hydrated.
3. Body weight loss was negatively correlated with the amount of water intake, but was not correlated with the total amount of sweating.
4. Total heat loss increased with increased water intake, and corresponded to 1345% of heat storage during exercise without drinking.
These results suggest that although water replacement during exercise dose not affect the sweat rate, it has physiological significance in the maintenance of body fluid, and a physical effect in terms of body cooling.View full abstractDownload PDF (925K) -
SHIHO SAWAI, NOBUHIKO YOSHIOKA, SACHIKO TSURUMI1997 Volume 46 Issue 1 Pages 123-134
Published: February 01, 1997
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSAerobic dance (AD) is a form of fitness exercise whose program is constructed by a combination of various joint movements. Therefore the exercise is expected to give enough stimulus to not only the cardiorespiratory but also the musculoskeletal system. The purpose of this study was to evaluate the activity level of the leg muscles among the major 22 AD leg movements, or steps (13 low-impact steps and high-impact steps), by electromyography (EMG) analysis. The subjects were two trained AD instructors, who were asked to perform individual steps at a pitch of 144 bpm. EMG data were recorded from the iliopsoas, gluteus maximus, vastus lateralis, biceps femoris, tibialis anterior, and gastrocnemius muscles on the right side by means of surface electrodes. The half-wave of the raw EMG was rectified and integrated over periods of 20 s during the exercise. From the raw EMG data it was observed that the pattern and amplitude of the electrical discharge of each muscle varied in response to the difference in step motion. The integrated EMGs of the iliopsoas, biceps femoris, and gastrocnemius tented to show higher values for high-impact steps in comparison with low-impact steps, but that of the tibialis anterior showed a contrary trend. The mean value and stan-dard deviation of iEMG of each muscle for the 22 steps was calculated for the same subjects, and the muscle activity level was classified into 5 degrees. Making use of this evaluation table, it may be possible to construct an AD program that can activate the leg muscles impartially.View full abstractDownload PDF (1100K) -
HIDEYUKI TOBE, SHIGEHO TANAKA, MICHIKO KODA, TAKASHI SATAKE, KOMEI HAT ...1997 Volume 46 Issue 1 Pages 135-138
Published: February 01, 1997
Released on J-STAGE: September 30, 2010
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[in Japanese]1997 Volume 46 Issue 1 Pages 139-145
Published: February 01, 1997
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (975K) -
1997 Volume 46 Issue 1 Pages 147-155
Published: February 01, 1997
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (1538K) -
1997 Volume 46 Issue 1 Pages 156-158
Published: February 01, 1997
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (510K)
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