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Volume 48, Issue 1
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1999 Volume 48 Issue 1 Pages 1-79
Published: February 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (15703K) -
HUNKYUNG KIM, KIYOJI TANAKA, TOMOKO NAKANISHI, HITOSHI AMAGAI1999 Volume 48 Issue 1 Pages 81-90
Published: February 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe purposes of this study were to examine the loss of bone mineral density (BMD) with increasing age and to investigate the relationship between the BMD and body composition. Cross-sectional measurements of total body and regional (head, arms, legs, trunk, ribs, pelvis and spine) BMD and body composition were made in 112 Japanese healthy women, aged 20 to 87 years, by dual-energy X-ray absorptiometry (DXA) . The mean peak BMD for the trunk, ribs, and pelvis was observed at the age of 40-49 years, in the arms and spine at the age of 30-39 years, and in the head, legs, and total body at the age of 20-29 years. The loss of spine BMD appears to begin prior to BMD loss in other regions and the rate of bone loss as a function of aging was readily apparent. Appendicular bone loss did not occur until age 49 yr, accelerated from ages 50 to 69 yr, and then decelerated somewhat after age 70 yr. In this cross-sectional analysis, we found cumulative loss of BMD from peak to 80-89 yr of age was 31.2% for the spine, 25.0% for the total body, and 21.5% for the ribs. To examine the relationship between the BMD and body composition, multiple regression analysis was performed with total body and regional BMD as the dependent variable and fat-free mass (FFM) and fat mass as the independent variable. From this analysis, the results indicated that FFM was a significant predictor of total body and regional BMD but did not evaluate the effects of exercise or other potential variables that might affect BMD. In conclusion, our findings indicate that spine bone loss begins prior to the loss of compact bone, and the rate of bone loss in the spine due to aging was greater than that of other specific regions. Secondly, FFM and fat mass are related to total and regional BMD in Japanese women with the strongest relationship being FFM.View full abstractDownload PDF (1223K) -
MOTOHIKO MIYACHI, MITSUHARU OKUTSU, HIDEHIRO NAKAHARA, TAKESHI SAITOH1999 Volume 48 Issue 1 Pages 91-97
Published: February 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSA study was conducted to determine non-invasively the effects of endurance training on the size of the inferior vena cava in humans. Twelve healthy male subjects were assigned to either an exercise-trained group (ET, n=7) or a sedentary control group (S, n=5) . The ET group underwent cycle-endurance training for 8 weeks (80%Vo2max, 40 min/day, 4 days/week) . The S group led normal lives during the 8-week period. Before and after the training period, cross-sectional areas (CSA) of the inferior vena cava and the ascending and abdominal aorta were measured by echography. The CSA of the inferior vena cava after training was significantly larger than that before training in the ET group. There was no significant difference in the S group. These results indicate that the inferior versa cava can be morphologically altered as an adaptive response to endurance training. We consider that this adaptation partly contributes to the improvement in the efficiency of venous return from exercising muscles to the heart. Although the present training also increased the CSA of the aorta, the degree of change was smaller than that seen in the inferior vena cava, implying that the factors of adaptation and adaptability to endurance training in the inferior vena cava differ from those in the aorta.View full abstractDownload PDF (2518K) -
NORIKATSU KASUGA, SUSUMU YAMASHITA, HITOMI OGASAWARA, HIDEKI SUZUKI, H ...1999 Volume 48 Issue 1 Pages 99-109
Published: February 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe running behavior and muscle characteristics associated with voluntary running activity were studied in female Fischer 344 rats after 9 weeks of training in voluntary exercise wheel cages. The exercise wheel employed allowed a load to be added to the wheel axis. The running activity was recorded as the number of rotations every 10 s for 24 h, and the number of running bouts, running duration, running speed and distance run per day were varied. Addition of a load to the wheel axis allowed the running style to be changed, and reduced the running duration and speed in each bout. The voluntary running training was done with no load, 30% per body weight load, and 60% per body weight load, and as treadmill running (40 m/min, 60 min/day) .
In the voluntary training, a difference in the total running distance was observed with increased load. The total distance run under 0%, 30% and 60% load in the voluntary group was about 552, 475, and 438 km, respectively, after training for 9 weeks. As a result of training, the weights of dorsiflexor muscles tended to increase with treadmill running, whereas weights of plantar-flexor muscles increased significantly in the voluntary training groups. In the plantaris muscle, the cross-sectional area of all fiber types was not changed by treadmill training, but in voluntary training, almost every type of fiber was enlarged. Voluntary running with a 30% load increased the cross-sectional area of type I and type ha fibers in the plantaris muscle compared with no load exercise. However, no significant differences in the cross-sectional area of these fibers were observed between 30% and 60% load exercise. The fatigue tolerance of the plantaris muscle improved significantly in all training groups, and the 60% load group showed the highest value.
These results suggest that voluntary loaded running is more effective for muscle enlargement than treadmill training and/or voluntary training with no load.View full abstractDownload PDF (2341K) -
TOMOHIRO OKURA, KIYOJI TANAKA1999 Volume 48 Issue 1 Pages 111-123
Published: February 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSA study was conducted to develop prediction equations for cardiorespiratory fitness (maximal oxygen uptake : VO2max and oxygen uptake at anaerobic threshold : VO2AT) in Japanese adult men and women. Eighty-three healthy men and 86 healthy women, aged 20-64 years (41.1±13.5 and 41.5±13.5, respectively), were recruited as subjects. Mean (±SD) of VO2max and VO2AT measured during a cycling test were 37.2±6.4 and 20.5±4.7 ml/kg/min, respectively, in men and 32.7±7.3 and 17.8±4.1 ml/kg/min, respectively, in women. In this study 36 kinds of equations applicable to each sex were developed using all the subjects (n=169) . These equations consisted of independent variables such as work rate divided by body weight (W/Wt), age and body fat percentage (%Fat), which were signficantly correlated with measured VO2max and VO2AT. Multiple correlation coefficients (R) and standard errors of estimate (SEE) of the equations ranged from 0.641 to 0.830 (P<0.05) and from 3.66 to 4.98 ml/kg/min, respectively, for VO2max and from 0.661 to 0.815 (P<0.05) and from 2.77 to 3.20 ml/kg/min, respectively, for VO2AT. Reliability coefficients (r) between the first and second tests were 0.911 in men and 0.873 in women for VO2max, and 0.869 in men and 0.770 in women for VO2AT, all of which were statistically significant (P<0.05) . It is concluded that the equations developed in the present study have the merits of simplicity, economy, accuracy and reliability. Furthermore, from the viewpoint of safety and convenience, the following prediction equations are recommended.
(Male)
VO2max (ml/kg/min) =6.57 WRPE-legs 15/Wt-0.19 Age-0.36%Fat+41.29
(R=0.830, SEE=3.66 ml/kg/min)
VO2AT (ml/kg/min) =7.35 WRPE-legs 14/Wt-0.06Age-0.23%Fat+15.62
(R=0.815, SEE=2.77 ml/kg/min)
(Female)
VO2max (ml/kg/min) =7.30 WRPE-legs 15/Wt-0.12 Age-0.46%Fat+37.32
(R=0.828, SEE =4.16 ml/kg/min)
VO2AT (ml/kg/min) =5.03 WRPE-legs 14/Wt-0.01 Age-0.16%Fat+14.15
(R=0.680, SEE=3.06 ml/kg/min)View full abstractDownload PDF (1415K) -
EVALUATION OF THE MUSCLE OXYGENATION CURVE BY NEAR-INFRARED SPECTROSCOPY (NIRS) DURING RAMP EXERCISE—A NEW METHOD OF EVALUATION AND ITS RELATIONSHIP TO PHYSICAL FITNESS—TSUYOSHI WADAZUMI, YUTAKA KIMURA, YOSHITAKE OSHIMA, TADAYOSHI MIYAMOTO ...1999 Volume 48 Issue 1 Pages 125-135
Published: February 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSA study was conducted to establish a method for quantitative evaluation of both the rate and degree of muscle oxygenation during ramp exercise using Near Infrared Spectroscopy (NIRS), and to determine the relationship of the indices to body composition and physical fitness. The subjects were 13 healthy men. After a warm-up period of 3 min at 20-W, the ramp exercise test was conducted. The exercise consisted of an increasing work rate at a slope of 20 W/min on a cycle ergometer performed until volitional fatigue. The NIRS probe used in the cycling exercise was placed on the vastus lateralis muscle. After 30 min of exercise, calibration was performed by cuff occlusion for 10 min with a pressure of 260 mmHg for quantitative determination of the NIRS curve. The oxygenation curve measured by NIRS during the exercise initially exhibited a linear decrease as the work rate increased. This rate of decrease in oxygenation was indicated by the NIRS slope (%/W) obtained from the calibration curve. In later stages of the exercise, the NIRS curve became flattened with increased work rate. The breaking point between the sloping phase and the flat phase was named the “NIRS Threshold 2, NT 2”. In addition, the rate of decrease in oxygenation at the end of exercise per maximal NIRS decrease obtained from the calibration curve was indicated as the %NIRS fall. The mean NIRS slope and %NIRS fall were 0.3±0.1%/W (range, 0.13 to 0.50%/W) and 29.9±11.8% (range, 12.0 to 50.0%), respectively. NT 2 was observed in 8 of the 13 subjects. The subjects were divided into two groups (NT 2 (+) and NT 2 (-) ) based on the appearance of NT 2. Both the NIRS slope and %NIRS fall in the NT 2 (+) group were significantly higher than those in the NT 2 (-) group. The NIRS slope was significantly correlated with VO2/wt at VT (r=0.73, p<0.05) and wattage at VT (r=0.86, p<0.0001) . The %NIRS fall was significantly correlated with VO2/wt at peak (r=0.80, P<0.001) . The NIRS slope and %NIRS fall were not significantly correlated with body mass index, %fat or thigh circumference.
These findings suggest that the NIRS slope indicates the efficiency of oxygen exchange in muscles activated during incremental exercise, and that the %NIRS fall indicates the ability to utilize Oxy-Hb+Mb against maximal oxygenation capacity in muscles. The NIRS slope and %NIRS fall can therefore be used as indices of muscular limitation during exercise, and as indices of muscular adaptation during exercise.View full abstractDownload PDF (1031K) -
KOICHI HIRAOKA, AKIRA NAGATA1999 Volume 48 Issue 1 Pages 137-145
Published: February 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSA study was conducted to investigate the neural connection between the afferents of the upper extremity and the motoneurons innervating the extensors of the lower extremity. Healthy young males and females were recruited. The median nerve was cutaneously stimulated, and the soleus H reflex, reflecting the excitability of motoneurons, was evoked. The C-T interval and intensity of the conditioning stimulus were modulated. A conditioning stimulus with an intensity of 1.4 xMT and a C-T interval of 69 ms inhibited the soleus H reflex pathway (I1.4) . Additionally, a conditioning stimulus with an intensity of 2.1 xMT and a C-T interval of 13 ms inhibited the soleus H reflex pathway (I2.1) . The conduction velocity of the afferents responsible for I1.4 was 19m/s and that for I2.1 was 39 m/s. The conduction velocity of the afferent fiber type responsible for I1.4 was similar to that of the group III afferents, and the conduction velocity for I2.1 was similar to that of the group II afferents. However, further investigation is needed to identify the afferents responsible, because the results conflict with those of previous studies in terms of inhibition thresholds.View full abstractDownload PDF (913K) -
MITSUKUNI MOCHIZUKI, KATSUHIKO SUZUKI, SHIGEYUKI NAKAJI, KAZUO SUGAWAR ...1999 Volume 48 Issue 1 Pages 147-159
Published: February 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSWe investigated both the acute effects of maximal exercise and the chronic effects of training on nonspecific immunity in 15 winter-sports athletes during different periods of training : (a) before the athletic season, in summer, when the athletes were undertaking extensive endurance training to enhance aerobic capacity, (b) during the winter sports season, in early winter, when endurance and athletic training were being undertaken, and (c) after the winter sports season, in spring, when the athletes were resting (detraining for a month) . The mean value of the maximal oxygen uptake in each training period was (a) 65.4 (SD 4.6) mL·kg-1·min-1, (b) 63.1 (SD 5.5) mL· kg-1·min-1, and (c) 58.3 (SD 5.8) mL·kg-1·min-1, respectively. Following maximal exercise, acute peripheral leukocytosis due to lymphocytosis and neutrophila was observed in every period. The capacity of isolated neutrophils to produce reactive oxygen species upon stimulation with opsonized zymosan measure by luminol-dependent chemiluminescence (LDCL) was significantly enhanced after maximal exercise before and during the athletic season. However, the degree of enhancement was smaller during after-season detraining, suggesting that the conditioning state affected the exercise-induced changes in neutophil functional status. Serum opsonic activity also showed a similar pattern. As for the chronic effects of training, the resting values of the neutrophil count, especially the segmented neutrophil count, the neutrophil LDCL response and the serum IgG level, declined significantly in the pre-season training period. Since the subjects were engaged in exhaustive endurance training under heat exposure at that time, the nonspecific immune status might have been partially compromised due to chronic overload.View full abstractDownload PDF (1333K) -
TAKESHI SAITOH, HIROMI YANO, MOTOHIKO MIYACHI1999 Volume 48 Issue 1 Pages 161-169
Published: February 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe muscle fiber-capillary barrier consists of the capillary endothelium and the interstitium. Thinning of the barrier is physiologically significant for gas exchange in skeletal muscle because it shortens the diffusion distance of gases. The purpose of the present study was to examine the effect of endurance training on the ultrastructure of the muscle fiber-capillary barrier in soleus muscle of growing rats. Seventeen male Fischer 344 rats, aged 5 weeks, were assigned to either an exercisetrained group (ET, n=5), a paired-weight sedentary group (PWS, n=6), or a sedentary group (S, n=6), and matched as closely as possible with regard to body mass and Vo2max. The ET group performed a treadmill running program for 5 days/week for 10 weeks. The ET and S rats were freely fed rat chow and water. The PWS rats had their food intake restricted so that their mean body mass would be the same as that of the ET rats. After the training period, the diffusion distance in the ET group was significantly shorter than that in the PWS and S groups. There were no differ-ences in the thicknesses of the capillary endothelium among the three groups, but the interstitium was significantly thinner in the ET group than in the PWS and S groups. The degree of decrease in the interstitium thicknesses in the ET group was almost equal to that of the diffusion distance. Therefore it was identified that endurance training shortens the diffusion distance, which depends on thinning of the interstitium. These results suggest that morphological adaptation to endurance training partly contributes to the improvement of gas exchange in the muscle and aerobic work capacity.View full abstractDownload PDF (3125K) -
TETSURO SAEKI, YOSHIHARU NABEKURA, KAORU TAKAMATSU1999 Volume 48 Issue 1 Pages 171-177
Published: February 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe purpose of the present study was to investigate the relationships between the peak running velocity, and aerobic and anaerobic capacity in incremental running in pre- and post-competitive season using eight long distance runners. Measurements were peak running velocity, VO2max, running velocity and VO2 at respiratory exchange ratio (RER) 1.0, and blood lactate after exhaustion in the incremental running test. Correlation analysis revealed that pre-season velocity at RER 1.0 and post-season blood lactate were both related to peak running velocity. Furthermore, change in peak running velocity was related to change in blood lactate between pre-and post-season. These results suggest that factors that probably influenced running performance change from aerobic capacity in the pre-season to anaerobic capacity in the post-season, and that running performance during the competitive season may be highly dependent upon anaerobic capacity.View full abstractDownload PDF (809K) -
NAOKI MUKAI, TOMOO ISHII, HIROSHI KAMADA, YUTAKA MIYANAGA, KOICHIRO HA ...1999 Volume 48 Issue 1 Pages 179-185
Published: February 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSTo investigate the influence of long-distance running on bone metabolism, we measured bone metabolism markers in eight healthy young men before and 4 months after the start of training program of 10 km running. Measurements were then taken the day before a marathon race, immediately after, and 1 day, 2 days and 5 days after.
As a result of exercise, the levels of serum osteocalcin (OC), a bone formation marker, and urinary deoxypyridinolin (D-Pyr), a bone resorption marker, decreased significantly. After the marathon race, the OC level decreased further corresponding to an increase of hydrocortisone right after the race. However, from the day following the race, the OC level showed a slight increase. D-Pyr showed an increasing tendency immediately after the race, and the levels of OC and D-Pyr increased significantly 5 days after the race.
Bone formation and resorption decreased as a result of light, low-frequency endurance exercise. However, both of them increased after intense physical stress. From this result, it is suggested that the intensity and frequency of exercise affect bone metabolism differently, even though the type of exercise load is similar.View full abstractDownload PDF (826K) -
KAYOKO KITA, TOSHIO MIKAMI, GANG-JIAN QU, YOUSUKE TASAKI, AKIRA ITO1999 Volume 48 Issue 1 Pages 187-199
Published: February 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSAllantoin is one of the oxidation products of uric acid resulting from attack by oxygen free radicals. In this study we attempted to clarify the antioxidant effect of uric acid during exercise, and the influence of other antioxidants on urate in vitro. Seven healthy male subjects performed exhaustive (100%VO2max) and mild endurance (40%VO2max) cycling exercise, and serum uric acid and allantoin were measured before and up to 24 h after the exercise. Various radicals were added to uric acid, ascorbic acid and glutathione were mixed with phosphate buffer or fresh human serum, and changes in each of the antioxidants (protein sulfhydryl groups in serum were measured instead of glutathione in buffer) and allantoin were examined. The serum allantoin level increased immediately after exhaustive exercise and remained high for up to 2 h, while uric acid increased at 0.5 h and remained at a high level at 24 h during recovery. On the other hand, no significant changes in allantoin and uric acid were observed after mild endurance exercise. Superoxide anion radicals (O2-) generated by a hypoxanthine-xanthine oxidase (HX-XOD) system formed allantoin with decreasing levels of other antioxidants in buffer and serum, although uric acid was generated by this system. To determine the influence of uric acid newly produced by the HX-XOD system, different kind of antioxidants in buffer were used to examine allantoin generation. Allantoin was generated in the order uric acid only>no antioxidants>three kinds of antioxidants during 20 min of reaction. Hydroxyl radicals (·OH) generated by the Fenton reaction also formed allantoin as other antioxidants decreased, while hydrogen peroxide did not oxidize uric acid to allantoin despite the fact that other antioxidants were consumed in the buffer and serum. These results suggest that O2- and ·OH oxidize uric acid to allantoin during exhaustive exercise, whereas, ascorbic acid, glutathione and protein sulfhydryl groups inhibit allantoin generation. Moreover, uric acid previously present in the body may be used for radical scavenging more effectively than that newly generated by exhaustive exercise.View full abstractDownload PDF (1379K) -
FUTOSHI MATSUBARA, TERUICHI SHIMOMITSU, KOJI OKAMURA, YUKO ODAGIRI, TO ...1999 Volume 48 Issue 1 Pages 201-210
Published: February 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSTo elucidate the phenomenon of central fatigue, we investigated the changes in the plasma amino acid level and false neurotransmitter (FNT) level during ultra-endurance exercise. Twenty-one male Japanese participants of the 1993 Ironman Japan Contest, held at Lake Biwa, were examined. Blood sampling and a questionnaire on the Profile of Mood States (POMS) test were collected two days before, immediately after and one-day following the race. The POMS questionnaire showed various changes especially due to fatigue. Indeed, the fatigue score significantly increased after the race. Although the confusion score significantly increased after the race, it quickly recovered to the pre race level the following day. The plasma concentration of the branched-chain amino acids (BCAA) decreased after the race, while the level of aromatic amino acids (AAA) increased, thus resulting in a significant decrease in the BCAA/AAA ratio. The plasma level of octopamine, one type of FNT, significantly increased after the race (p<0.01) . The blood ammonia level increased after the race, but recovered to the pre-race level one-day after the race. Although no change was observed in the total tryptophan (Trp) level, the level of free Trp significantly increased during the race. The significant increases in the plasma 5-hydroxyindoleacetic acid (5HIAA), homovanillic acid (HVA) and HVA/dihydroxyphenylacetic acid (DOPAC) ratios thus suggest the serotonin (5 HT) and dopamine (DA) neuron systems activated after the race. In conclusion, ultra-endurance exercise caused a disorder of both the amino acid and monoamine metabolisms. Furthermore these changes were also related with mood changes, especially fatigue, i. e. central fatigue. These results suggest that the measurement of both the plasma BCAA/AAA ratio and FNT may therefore be useful in quantifying exercise induced central fatigue.View full abstractDownload PDF (1082K) -
JIAN WU, KEIKO KUSUHARA, SAKUKO ISHIZAKI, YOKO KATO, SENSHI FUKASHIRO1999 Volume 48 Issue 1 Pages 211-218
Published: February 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSTo examine the relationship between sports activity and bone mass acquisition, we observed one-year changes in the bone mineral content and density (BMC and BMD) of weight-bearing and non-weight-bearing bone in 68 college women who had participated in various sports since the age of 18.5 years on average. Based on their sports experience, the subjects were divided into four groups: Group A: 18 students who have not had participated in any kind of sports activity since junior high school days ; Group B: 8 students who had participated in team sports at junior and senior high school, then stopped practicing after entering college ; Group C: 14 students who had participated in team sports since junior high school ; Group D: 28 rhythmic sports gymnasts. Whole-body and regional BMC in the head, trunk, arms and legs, and BMD of the lumbar spine and proximal femur were measured using an XR-26 DXA scanner. Height, weight and calcium intake were similar among the four groups, and during the experiment their values changed little. With regard to annual changes in BMC and BMD for weight-bearing regions: 1) In Group A, no signifi-cant increases were observed in any of the body regions; 2) In Groups B and C, only the lumbar spine showed a significant increase. Comparing the changes in BMD in these two groups, Group C showed a larger increase than Group B, although the value did not reach statistical significance ; 3) In Group D, significant increases in BMD for the lumbar spine and femoral neck and in BMC for the trunk and legs were found. The annual changes in BMD were significantly higher than Group A. As to annual changes in non-weight-bearing bones such as those in the head and arms, there were not significant differences among the groups. These data indicate that sports practice may affect changes in bone mass in weight-bearing regions in female college students. Furthermore, it is possible that the amount and quality of sports training may influence the peak bone mass and its timing.View full abstractDownload PDF (937K) -
MAKOTO UBE, SHUICHI KOMIYA1999 Volume 48 Issue 1 Pages 219-226
Published: February 01, 1999
Released on J-STAGE: September 30, 2010
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[in Japanese]1999 Volume 48 Issue 1 Pages 227-231
Published: February 01, 1999
Released on J-STAGE: December 10, 2010
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1999 Volume 48 Issue 1 Pages 233-238
Published: February 01, 1999
Released on J-STAGE: September 30, 2010
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1999 Volume 48 Issue 1 Pages 239-243
Published: February 01, 1999
Released on J-STAGE: September 30, 2010
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1999 Volume 48 Issue 1 Pages e1
Published: 1999
Released on J-STAGE: September 30, 2010
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