A study was performed to evaluate the physical capacity of elite female volleyball players from Kyushu Bunka Gakuen Senior High School (Kyu. B. G.) . Twenty-four players were examined for body composition (underwater weighing), cardiorespiratory function (VO₂max and O₂debtmax by treadmill exercise test) and skinfold thickness, from 1988 to 1989.
These measurements were compared with those of 16 second-class players from Nagasaki Prefecture, and also with the results of other investigations.
The results were as follows :
1. The mean parameters for the Kyu. B. G, players were : age, 17.5 yr ; height, 168.3 cm ; weight, 59.8 kg ; percentage body fat (%Fat ), 17.9% ; lean body mass ( LBM), 49.0 kg ; LBM/ Ht, 29.1 kg/m ; sum of eight skinfold thicknesses, 109.1 mm ; VO₂max, 2.71 l/min, 45.7 ml/kg· min ; O₂debtmax, 5.69l, 94.8 ml/kg.
2. The average %Fat of the Kyu. B. G, players was significantly lower than that of the second-class players from Nagasaki Prefecture.
3. The average VO₂max (ml/kg·min) and O₂debtmax (l, ml/kg) of the Kyu. B. G, players were significantly higher than those of the second-class players.
4. The average %Fat and VO₂max (ml/kg·min) of the Kyu. B. G, players were similar to those of Japan League and All Japan volleyball players.
5. When the progress of physiological function due to training for 11 months was examined in five Kyu. B. G, players, the average VO₂max (ml/kg·min) showed a significant increase of approximately 8%.
These results indicated that the Kyu. B. G, players had a superior body composition, aerobic work capacity and anaerobic work capacity, equal to those of top volleyball players in Japan.

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The tetrapolar bioelectrical impedance (BI) method has been proposed as a convenient, valid approach for estimating the body composition of normal healthy adults. However, the validity of the BI method has not yet been confirmed for Japanese junior high school boys and girls. The purpose of this study was to develop convenient and useful equations for predicting the body composition in junior high school boys and girls by the BI method. The subjects were 297 healthy boys and girls, aged 12.15 years, all of whom were Japanese. Impedance was measured using a tetrapolar bioelectrical impedance plethysmograph (800 pA, 50 kHz SIF-891) manufactured by Selco. Multiple regression analysis was used to derive prediction equations for Db that were specifically applicable to boys and girls. The effective prediction equations for Db were as follows : 1) Db=1.1860-0.1282 (Wt·Z) /Ht², and 2) Db=1.1402-0.0706 (Wt·Z) /Ht²-0.0007· (abdomen) for boys. 1) Db=1.1337-0.0778 (Wt·Z) /Ht², and 2) Db=1.1124-0.0498 (Wt·Z) /Ht²-0.0006· (subscapular) for girls, where Db=body density (g/ml), Wt=weight (kg), Z =impedance (ohms), Ht=height (cm) . Db estimated by each respective equation was highly correlated with body density measured by underwater weighing (UW-Db) : 1) r=0.881, SEE=0.00868/ml, 2) r=0.902, SEE=0.00788/nil for boys and 1) r= 0.741, SEE=0.0101 g/ml, 2) r=0.775, SEE =0.0095g/ml for girls. Furthermore, in a cross-validation analysis of prediction equations for Db, another sample consisting of 40 boys and 66 girls was used. Db estimated from each respective equation was correlated highly with UW-Db : 1) r=0.856, 2) r=0.887 for boys and 1) r=0.837, 2) r=0.860 for girls. There were no significant differences between the mean Db obtained by the BI method and that by the criterion method. We suggest that the prediction equations proposed in this study are useful for valid assessment of body composition of Japanese junior high school boys and girls aged 12 through 15 years.

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Previous studies have shown that the process of recovery after disuse muscle atrophy varies in different experimental models. We investigated the process of recovery of M, soleus atrophy after immobilization, with special reference to changes in structural and soluble proteins by means of electrophoresis and histochemical changes using myosin-ATPase staining. After rabbits had been subjected to 3 weeks of hindlimb immobilization, the changes were investigated immediately after the termination of immobilization, and at 1, 2, 3, 4 and 6 weeks of recovery. Just after the termination of immobilization, the wet weight of the M. soleus was 32.7±14.0% that of the opposite limb. The wet weight recovered rapidly and returned to the same level as that of the opposite side by 4 weeks. The amount of structural proteins decreased after immobilization, but did not return to the control level at 6 weeks after recovery. No new bands appeared in the electrophoretic patterns of the structural and soluble proteins at any of the stages of recovery. Furthermore, the special features of the bands of myosin light chains (MLCs-1, MLCs-2) also showed no change. ATPase staining showed that the area of type 2 fibers increased, and occupied 45.2±12.6% of the total area at 3 weeks after recovery, whereas that of muscle from controls occupied 17.3±5.7%. The area did not return too the control level by 6 weeks of recovery. The discrepancy between the histochemical changes and the changes in structural or soluble proteins during the recovery process appeared to be due to differences in the turnover ratio of each protein. It appears that the process of recovery of disuse muscle atrophy after immobilization is variable and compley, and differs according to the method of observation.

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Biological age based on the assessment of various physiological factors measured in a resting state has been proposed as an appropriate index of aging. We have recently developed an equation for estimation of physical fitness age (PFA), which is composed of eight age-related physical fitness variables. These include oxygen uptake corresponding to lactate threshold (Vo₂@LT), maximal oxygen uptake (Vo₂max), side step, grip strength, vertical jump, foot balance with eyes closed, trunk extension, and trunk flexion. In this study, the validity of PFA as a critical index of physical health and/or aging status was investigated from a longitudinal standpoint on the assumption that exercise habituation does contribute to health promotion. The subjects were 14 Japanese middle-aged and elderly men, aged 50 to 70 years, all of whom were patients with coronary heart disease (CHD) . The subjects participated in a supervised exercise conditioning program for 90 to 120 min each session, 2 times weekly for 4 months. Analyses of the data indicated that the mean PFA of the subjects (66.0±9.0 yr) after conditioning was significantly (P<0.05) lower than the mean PFA (72.8±8.6 yr) obtained before conditioning. After the exercise program, significant increases were documented in Vo₂@LT (17%), Vo₂max (12%), side step (26%), trunk flexion (109%), trunk extension (7%), vertical jump (12%), and foot balance with eyes closed (31%) . Therefore, we conclude that our exercise conditioning program may alter the overall physical fitness of patients with CHD, and that PFA could be a valid physical health and/or aging index.

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Excess body fat has generally been considered to be an influential factor on physical fitness and motor ability in obese girls. However, little information is available on physical fitness and motor ability in this population group. The purpose of this study was to clarify selected characteristics of physical fitness and motor ability in obese girls in comparison with non-obese girls. The subjects were 302 girls aged 12-14 years. Nineteen physical fitness and motor ability items were tested, and skinfold thickness was measured at six sites. Bioelectrical impedance was measured using a tetrapolar impedance plethysmograph (Selco SIF-891) . Body density was calculated from the formula of Kim et al. The results of the comparative study clearly indicated that the obese group was significantly inferior in the 1, 000-m run, 50-m run, 5-min run, modified pull-ups, running long jump and many other variables, but superior in grip strength and back strength. To analyze the factorial structure for these girls, principal factor analysis was applied to the correlation matrix which was calculated with 19 variables, and then six factors were extracted. The obese group was significantly inferior in total body endurance, muscular strength and muscular endurance to the non-obese group. From these results, it was confirmed that excess body fat could be one of the most important factors affecting the state of many physical fitness and motor ability elements in obese girls. However, the relationships between physical fitness, motor ability and the degree of fatness seem to be rather complicated. A great deal of data should be accumulated for more detailed analysis of the influence of excess body fat in obese girls.

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In the present study, we examined whether GLUT4 concentration in rat skeletal muscle is dependent on local muscle activity level or not. In ten male Sprague-Dawley rats, one side of gastrocnemius muscle was tenotomized, and the other side contralateral muscle was treated sham operation as a control. Gastrocnemius and plantaris muscles were excised from both legs at the five weeks after surgery. After the muscles were weighed, GLUT 4 concentration and citrate synthase (CS) activity were measured. The results are summarized as follows:
In gastrocnemius muscle, tenotomy induced decreases of 25% in muscle weight, 16% in CS activity, and 25% in GLUT 4 concentration as compared with the control muscle. These data suggest that although extramuscular environment is similar, different GLUT 4 concen-tration in both muscles is induced by different muscle activity level. Therefore, it is con-cluded that muscle activity level regulates GLUT 4 concentration in skeletal muscle. In over-loaded synergistic plantaris muscle, muscle weight and GLUT 4 content per whole muscle were increased by 18% and 17%, respectively, but GLUT 4 concentration and CS activity were not changed as compared with the control muscle. These data could be interpreted that GLUT 4 concentration and mitochondrial oxidative enzyme activity in skeletal muscle are coregulated.

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A study was conducted to investigate the mechanism of bone atrophy in various strains of inbred mice under the influence of tail-up suspension. Nine inbred strains of mice (NZB/N, NZW/N, AKR/N, Balb/C, C 57 BL, C 3 H/He, A/J, DBA, CBA/N) aged six weeks were used. Each strain was divided randomly into two groups, a suspension group (SG; n=5) and a control group (CG; n=5) . The suspension group were etherized and suspended with an elastic bandage. After one week, the tibiae were removed and their bone weights were measured using an electric balance (Metler; AE 240) . Their length was also measured with a vernier caliper. In all strains, body weight in the SG was significantly lower than that in the CG. From the bone weight and length in the CG, bone growth in the NZB/N, AKR/N, NZW/N and C3H/He strains was considered to be higher than in the other strains. On the other hand bone growth in the DBA, A/J, Balb/C, and CBA/N strains were lower than in the others. The absolute value of bone weight in the SG was significantly smaller than that in the CG in six strains (NZB/N, C 57 BL, A/J, NZW/N, C 3 H/He, Balb/C) . However in the DBA strain, the absolute value of bone weight in the SG was significantly higher than that in the CG.
From the results of this investigation we suggest that the mechanism of normal bone growth is not the same as the mechanism of bone atrophy induced by tail-up suspension.

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