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Volume 57 (2008)
- Issue 6 Pages 633-
- Issue 5 Pages 527-
- Issue 4 Pages 423-
- Issue 3 Pages 295-
- Issue 2 Pages 189-
- Issue 1 Pages 1-
Volume 57, Issue 2
Displaying 1-11 of 11 articles from this issue
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HIROYUKI TAMAKI, KENGO YOTANI, AYUMU YUKI, HIROAKI TAKEKURA2008 Volume 57 Issue 2 Pages 189-196
Published: April 01, 2008
Released on J-STAGE: August 13, 2008
JOURNAL FREE ACCESSDisused rat hindlimb caused by sciatic denervation is characterized by osteopenia accompanying alterations in trabecular bone architecture. We studied the effects of short-term denervation followed by reinnervation on the 2-dimensional architecture of trabecular bone using a unilateral sciatic nerve freezing model rat of temporary disuse. Male Fischer-344 rats aged 11-weeks underwent unilateral hind-limb denervation by either sciatic neurectomy (SN) or nerve freezing (NF) by contact with a stainless steel rod cooled in liquid nitrogen, while control rats were sham-operated. Right and left tibiae of denervated and control rats were obtained at 0, 1, 2, 3, 4 and 5 weeks after surgery. Histomorphometric analyses were performed on longitudinal sections of proximal tibial metaphyseal secondary spongiosa. Sciatic denervation by SN or NF resulted in a marked loss of trabecular bone, mostly within first 2 weeks after denervation. Trabecular bone area decreased and gradually recovered with the breaking point at 3 weeks, returning to approximately 55% of basal-control levels (at 0 weeks) by 5 weeks after NF. Both the thickness and length of trabecular bone were significantly decreased after denervation. Trabecular thickness at 5 weeks after NF was significantly greater compared to that at 3 weeks after NF and at 5 weeks after SN, while decreased trabecular length after NF did not during the experimental period. These findings suggest that 1) sciatic nerve freezing results in marked loss of trabecular bone, mostly within the first 2 weeks after surgery ; 2) temporary denervation and subsequent reinnervation reversibly affects trabecular bone architecture, particularly trabecular thickness.View full abstractDownload PDF (238K) -
YOICHI HAYASHI, RYOTA OKANO, MASAHARU HIRABAYASHI, YASUTOMI KATAYAMA, ...2008 Volume 57 Issue 2 Pages 197-206
Published: April 01, 2008
Released on J-STAGE: August 13, 2008
JOURNAL FREE ACCESSThe aim of this study was to examine a weight reduction program and residual effects, through confirming the relationship between changes in the morphological and psychological indices including personality and self-efficacy (SE) of the participants. Twenty-five middle-aged women were divided into two groups based on type of weight reduction program intervention. Thirteen women participated in a 3-month diet-only weight reduction program (DO group, 53.3±7.4 yr), and 12 women took part in a 3-month diet and aerobic exercise program (DE group, 48.3±9.6 yr). After the programs, the compatibility score of personality in the DO group was negatively correlated to SE that is indicated as confidence in ability to maintain decreased body weight at 2, 3, and 4 years after the program (r=-0.69, -0.58, and -0.60). It can be seen that personality has an effect on the results of the DO group weight reduction program. Additionally, despite a significant decrease in body-weight and %fat in both groups, only the change of %fat significantly correlated with SE. On the basis of these correlations, the changes of %fat that related to the movability perception of body movements has a greater effect on SE after the program than the information only of weight loss. The results of this study suggest that personality and SE accounted for weight maintenance, and were associated with the results of the weight reduction program.View full abstractDownload PDF (242K) -
EUNHEE KIM, SANGKAB PARK, YOOCHAN KWON2008 Volume 57 Issue 2 Pages 207-216
Published: April 01, 2008
Released on J-STAGE: August 13, 2008
JOURNAL FREE ACCESSThe purpose of this study was to investigate the changes in functional fitness and risk factors for metabolic syndrome after 12 weeks of combined exercise in women of advanced age. Subjects consisted of twenty women of advanced age with metabolic syndrome (Control, 10 ; Combined, 10) whose age was over 75. The combined exercise program included stretching for 20 minutes, aerobic exercise for 30 minutes, resistance training for 15 minutes, and Asana yoga for 15 minutes. Subjects exercised 4 times a week for 12 weeks. We found that LBM (lean body mass) was significantly increased and visceral fat was significantly decreased after 12 weeks. Also, self-reliance fitness and the risk factors for metabolic syndrome were significantly improved after 12 weeks in the combined exercise group. Therefore, it appears that combined exercise plays a positive role in body composition and fitness and reduces the risk factors for metabolic syndrome in women of advanced age.View full abstractDownload PDF (408K) -
TAEKO TAJIMA, CHIGAYA TADANO, RYOTA SHIMOSE, MASAE YONA, YUKO NAITO, H ...2008 Volume 57 Issue 2 Pages 217-224
Published: April 01, 2008
Released on J-STAGE: August 13, 2008
JOURNAL FREE ACCESSObject : The purpose of this study was to test the response of the decline in heart rate (HR) induced by compression on the eyeball (eyeball pressure : EP) and voluntary non breath (VNB) after pedaling exercise.
Methods : EP ; Nine male subjects performed exercise for 3 min in a supine position using a bicycle ergometer. Immediately after the exercise all subjects received EP for 10 seconds. After that, subjects undertook the same protocol without EP (CON-E). VNB ; Four male and two female subjects performed exercise for 5 minutes using a bicycle ergometer. Immediately after the exercise subjects received VNB for 7 seconds. After that subjects undertook the same protocol without VNB (CON-V).
Results : The slope of the decline in HR recovery (HRDS) after exercise in EP increased significantly more than that in CON-E (p<0.05). However, time constant (HRTC) in CON-E declined faster than that in EP. Thereby, the relationship between HRDS in EP and HRTC in CON-E correlated (r=-0.562). The HRDS of VNB was greater than that of EP and CON-V. However the relationship between HRDS in VNB and HRTC in CON-V did not correlate.
Conclusion : We suggest that EP affects vagal nervous activity and VNB affects strength of baroreflex sensitivity. Therefore HRDS of EP might evaluate vagal nervous activity.View full abstractDownload PDF (254K) -
MASASHI KAWABATA, YOSHINORI KAGAYA, NORIHIRO SHIMA, HIDETSUGU NISHIZON ...2008 Volume 57 Issue 2 Pages 225-234
Published: April 01, 2008
Released on J-STAGE: August 13, 2008
JOURNAL FREE ACCESSThis study examined changes in intra-abdominal pressure and trunk activation during drop jump and the influence of those factors on performance. Intra-abdominal pressure (IAP) and surface electromyography (EMG) activity from the rectus abdominis (RA), transversus abdominis-internal oblique (TrA-IO) and erector spinae (ES) muscles were measured in seven males (22.3±1.0 years) during double-leg drop jumps from a 0.4 m height. Development of IAP (ΔIAP) and normalized rmsEMGs were calculated in the pre-contact, impact and push-off phases, after divided by ground reaction force data. TrA-IO activation which occurred prior to ground contact were the earliest and strongest compared to other muscles activation during each phase.ΔIAP during the impact phase coincided with the peak vertical force. There were significant positive correlations between ΔIAP, TrA-IO activation and vertical force per weight. In addition, the contact time correlated negatively with ΔIAP, TrA-IO activation and vertical force per weight. These findings indicate that ΔIAP and TrA-IO activation may contribute to trunk stability and efficient landing during double-leg drop jump.View full abstractDownload PDF (261K) -
KUMIKO MINATO, TAKAHARU KONDO2008 Volume 57 Issue 2 Pages 235-240
Published: April 01, 2008
Released on J-STAGE: August 13, 2008
JOURNAL FREE ACCESSIn the previous studies, we found that endurance training increased pancreatic weight, protein content, and enzyme activity with hypertrophied acinar cells in rats. The purpose of the present study was to investigate the effect of endurance training on pancreatic exocrine response to CCK in rats. Female F344 rats were divided into control (C, n=6) and endurance training (T, n=6) groups. The trained rats were exercised for 60 min on a treadmill (final speed, 35 m/min), 5 days a week, for 8 weeks. Food intake in both groups was matched. On the final day of the experiment, the rats were anesthetized after an overnight fast and prepared with cannulae into the pancreatic duct. After 1-h basal collection with 0.9% NaCl (7.5 ml/kg body weight/h) injected intravenously, CCK-8 (0.06μg/kg body weight/h) was injected intravenously and pancreatic secretions were collected for the additional three 1-h periods. Final body weight in the T group was slightly, but not significantly, lower than in the C group (C : 145±6, T : 137±8 g). Pancreatic wet weight in the T group was significantly higher than in the C group (C : 4.14±0.16, T : 4.71±0.18 mg/g BW). CCK-stimulated pancreatic juice secretion was not significantly changed. There were significant increases in pancreatic protein and amylase secretions with CCK administration. CCK-stimulated pancreatic protein and amylase secretions were significant higher in the T group than in the C group. Total pancreatic protein secretion with CCK administration during 3 hours were significant higher in the T group than in the C group (C : 2.52±1.92, T : 5.11±1.50 mg/3 h). Total amylase secretion with CCK administration during 3 hours were also significant higher in the T group than in the C group (C : 0.69±0.43, T : 1.12±0.37 U/3 h). These results suggest that the endurance training increased pancreatic exocrine secretion response to CCK. CCK may play an important role in exercise-induced enhancement of the exocrine pancreas.View full abstractDownload PDF (185K) -
MARIKO SAWADA, TSUTOMU INAMIZU, SHUNSUKE TAITO, KIYOKAZU SEKIKAWA, KOT ...2008 Volume 57 Issue 2 Pages 241-248
Published: April 01, 2008
Released on J-STAGE: August 13, 2008
JOURNAL FREE ACCESSDownload PDF (208K) -
YUKO MEKATA, OSAMU KASHIMURA, YUKARI KAWANO2008 Volume 57 Issue 2 Pages 249-260
Published: April 01, 2008
Released on J-STAGE: August 13, 2008
JOURNAL FREE ACCESSThis study was undertaken to compare the effect of the pre-exercise intake of a dry egg white protein supplement (86 kcal) on the post-exercise alterations in leukocytes and the plasma interleukin-6 (IL-6) concentrations in male collegiate runners. The 43 runners who participated in this study were divided into 2 groups, namely those with (E groups) and without (C groups) a 12,000 m pace run, and then they were further divided into 4 subgroups in which the subjects were given the 86 kcal nutrient supplemented including either 0, 5, 10, or 20 g protein from egg white. Peripheral blood samples were collected before supplementation (Pre), just after running (Post 0h), and at 1 h after running (Post 1h). The concentrations of the leukocytes, neutrophils, and monocytes in both groups E and C remained unchanged at Post 0 h. Furthermore, these concentrations increased significantly at Post 1 h. The lymphocytes were not significantly different at Pre. The plasma IL-6 concentrations were significantly higher at Post 0 h than at Pre or Post 1 h. In addition, no effect of the protein supplementation on the leukocytes, leukocytes subsets, or the IL-6 concentrations was observed. These observations suggested that such isocaloric supplementation as described above may therefore be able to help control the changes in the concentrations of leukocyte and leukocyte subsets immediately after running a 12,000 m time trial.View full abstractDownload PDF (339K) -
KOHEI NAKAGAKI, TOSHITSUGU YOSHIOKA, YOSHIHARU NABEKURA2008 Volume 57 Issue 2 Pages 261-270
Published: April 01, 2008
Released on J-STAGE: August 13, 2008
JOURNAL FREE ACCESSThe purposes of this study were to investigate the characteristics of physiological responses during flat-water kayaking events, and to quantify the contribution of aerobic and anaerobic energy systems. Eight male kayak paddlers participated in the study. The subjects performed an incremental test and five all-out tests (20, 40, 120, 240 and 600 sec) on a kayak ergometer. Peak oxygen uptake (VO2peak ; 3790 ml · min-1) in the incremental test was significantly lower than maximal oxygen uptake (VO2max ; 3944 ml · min-1) in the all-out test. In contrast, power at VO2peak (154.0 W) was significantly higher than power at VO2max (144.1 W). The contributions of energy systems were calculated by measurements of the accumulated oxygen uptake and accumulated oxygen deficit. The relative anaerobic energy system contributions for 200 m(40 sec), 500 m (120 sec), and1000 m (240 sec) averaged 71%, 43%, and 26%, respectively. These higher relative anaerobic energy system contributions, due to higher anaerobic capacity in kayak athletes, and the smaller muscle mass involved in kayak paddling limit oxygen uptake when exercise intensity is high. Furthermore, slower exercise cadence in kayak paddling leads to higher muscular tension, and thus may enhance the limiting of oxygen uptake.View full abstractDownload PDF (304K) -
MASANORI SAKAMOTO, TOSHIKI TAZOE, SHINICHIRO SHIOZAWA, TOMOYOSHI KOMIY ...2008 Volume 57 Issue 2 Pages 271-284
Published: April 01, 2008
Released on J-STAGE: August 13, 2008
JOURNAL FREE ACCESSModulation of the excitability of the corticospinal tract and spinal reflex in static upper and lower limbs was investigated during arm or leg cycling. The excitability of the corticospinal tract was examined with motor-evoked potentials (MEPs) following transcranial magnetic stimulation (TMS). H-reflexes were evoked by electrical stimulation of peripheral nerves in the upper and lower limbs. MEPs and H-reflexes were recorded from the soleus while the subject performed arm cycling and the soleus was at rest. In addition, MEPs and H-reflexes were recorded from the flexor carpi radialis (FCR) during leg cycling while the FCR was at rest. MEPs and H-reflexes were also evoked without arm or leg cycling as a control. TMS or electrical stimulation was delivered at 4 different pedal positions. The subjects performed arm or leg cycling at 30 and 60 rpm. The amplitudes of MEP in the soleus significantly increased during arm cycling compared to the control. In contrast, H-reflexes in the soleus significantly decreased during arm cycling compared to control values. The same results were obtained in FCR during leg cycling. MEPs and H-reflexes were not modulated in a phase-dependent manner during either arm or leg cycling. The degree of modulations in MEP and H-reflex amplitudes depended on the cadence of arm and leg cycling. These findings suggest that a differential regulation of spinal and supraspinal excitability in the static limb was induced by arm and leg cycling. The corticospinal tract and the reflex arc independently would be responsible for coordination between the upper and lower limbs.View full abstractDownload PDF (303K)
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YASUO SENGOKU, KAZUTERU NAKAMURA, HITOMI OGATA, TOSHITSUGU YOSHIOKA, K ...2008 Volume 57 Issue 2 Pages 285-294
Published: April 01, 2008
Released on J-STAGE: August 13, 2008
JOURNAL FREE ACCESSThe present study was conducted to obtain basic information about blood glucose fluctuation and relation with race performance during 100 km marathon. Subcutaneous glucose of one well-trained runner was measured by continuous glucose monitoring system (CGMS) at 5 min interval and blood samples for biochemical analysis were drawn at pre, middle and post of the race. Energy balance during one week prior to the 100 km race was recorded, and the whole energy and fluid intake during the race was analyzed. Blood glucose fluctuated reflecting duration of exercise and energy supply during the race. During the latter part of the race (65–70 km), abrupt declines in blood glucose level, which reflected insufficient carbohydrate intake before the race (119 g), were accompanied by decrease in running speed. The present report suggests that continuous glucose monitoring supplemented with standard nutritional and physiological measurement provides precise and valuable information on runner’s energy state during the ultra-endurance race, and that athletes need to reassess their preparation for the race and planning of energy intake during the race.View full abstractDownload PDF (262K)
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